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5250d7d90d
langsmoke/ref_java
Kamila Szewczyk 5250d7d90d
stuff
2023-11-12 14:49:57 +01:00

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package rocks.palaiologos.cask;
import java.io.IOException;
import java.io.InputStream;
import java.util.HashMap;
import java.util.Objects;
public class CaskBootstrap {
public static void main(String[] args) {
InputStream manifest = CaskBootstrap.class.getClassLoader().getResourceAsStream("MANIFEST");
if(manifest == null) {
throw new RuntimeException("The MANIFEST file for Cask is missing.");
}
String data;
try {
data = new String(manifest.readAllBytes());
manifest.close();
} catch (IOException e) {
throw new RuntimeException("The MANIFEST file for Cask is not readable.");
}
// Primarily just future-proofing.
HashMap<String, String> manifestMap = new HashMap<>();
String[] properties = data.replace("\r", "").split("\n");
for (String property : properties) {
int index = property.indexOf(":");
if (index == -1) {
throw new RuntimeException("Invalid property in MANIFEST: " + property);
}
manifestMap.put(property.substring(0, index).trim(), property.substring(index + 1).trim());
}
String mainClass = manifestMap.get("Main-Class");
String caskFile = manifestMap.get("Cask-File");
if (mainClass == null || caskFile == null) {
throw new RuntimeException("The MANIFEST file for Cask is missing required properties.");
}
try {
CaskClassLoader caskClassLoader = new CaskClassLoader(Objects.requireNonNull(CaskBootstrap.class.getClassLoader().getResourceAsStream(caskFile)));
Class<?> mainClassObject = caskClassLoader.loadClass(mainClass);
Thread.currentThread().setContextClassLoader(caskClassLoader);
System.setProperty("java.system.class.loader", CaskClassLoader.class.getName());
mainClassObject.getMethod("main", String[].class).invoke(null, (Object) args);
} catch (Exception e) {
throw new RuntimeException("Could not start Cask application.", e);
}
}
}
package palaiologos.kamilalisp.runtime.array;
import com.google.common.collect.Lists;
import palaiologos.kamilalisp.atom.Atom;
import palaiologos.kamilalisp.atom.Environment;
import palaiologos.kamilalisp.atom.Lambda;
import palaiologos.kamilalisp.atom.PrimitiveFunction;
import java.math.BigInteger;
import java.util.ArrayList;
import java.util.List;
public class Encode extends PrimitiveFunction implements Lambda {
@Override
public Atom apply(Environment env, List<Atom> args) {
assertArity(args, 2);
BigInteger base = args.get(0).getInteger();
BigInteger n = args.get(1).getInteger();
List<Atom> encoding = new ArrayList<>();
while (n.compareTo(BigInteger.ZERO) > 0) {
encoding.add(new Atom(n.mod(base)));
n = n.divide(base);
}
if (encoding.isEmpty())
encoding.add(new Atom(BigInteger.ZERO));
return new Atom(Lists.reverse(encoding));
}
@Override
protected String name() {
return "encode";
}
}
package palaiologos.kamilalisp.runtime.net;
import palaiologos.kamilalisp.atom.Atom;
import palaiologos.kamilalisp.atom.Environment;
import palaiologos.kamilalisp.atom.Lambda;
import palaiologos.kamilalisp.atom.PrimitiveFunction;
import palaiologos.kamilalisp.runtime.dataformat.BufferAtomList;
import java.io.InputStream;
import java.net.URL;
import java.util.List;
public class Wget extends PrimitiveFunction implements Lambda {
@Override
public Atom apply(Environment env, List<Atom> args) {
assertArity(args, 1);
try {
URL url = new URL(args.get(0).getString());
InputStream data = url.openStream();
byte[] bytes = data.readAllBytes();
data.close();
return new Atom(BufferAtomList.from(bytes));
} catch (Exception e) {
throw new RuntimeException(e);
}
}
@Override
protected String name() {
return "net:wget";
}
}
package mindustry.net;
import arc.*;
import arc.func.*;
import arc.math.*;
import arc.net.*;
import arc.net.FrameworkMessage.*;
import arc.net.dns.*;
import arc.struct.*;
import arc.util.*;
import arc.util.Log.*;
import arc.util.io.*;
import mindustry.*;
import mindustry.game.EventType.*;
import mindustry.net.Administration.*;
import mindustry.net.Net.*;
import mindustry.net.Packets.*;
import net.jpountz.lz4.*;
import java.io.*;
import java.net.*;
import java.nio.*;
import java.nio.channels.*;
import java.util.concurrent.*;
import static mindustry.Vars.*;
public class ArcNetProvider implements NetProvider{
final Client client;
final Prov<DatagramPacket> packetSupplier = () -> new DatagramPacket(new byte[512], 512);
final Server server;
final CopyOnWriteArrayList<ArcConnection> connections = new CopyOnWriteArrayList<>();
Thread serverThread;
private static final LZ4FastDecompressor decompressor = LZ4Factory.fastestInstance().fastDecompressor();
private static final LZ4Compressor compressor = LZ4Factory.fastestInstance().fastCompressor();
private volatile int playerLimitCache, packetSpamLimit;
public ArcNetProvider(){
ArcNet.errorHandler = e -> {
if(Log.level == LogLevel.debug){
Log.debug(Strings.getStackTrace(e));
}
};
//fetch this in the main thread to prevent threading issues
Events.run(Trigger.update, () -> {
playerLimitCache = netServer.admins.getPlayerLimit();
packetSpamLimit = Config.packetSpamLimit.num();
});
client = new Client(8192, 16384, new PacketSerializer());
client.setDiscoveryPacket(packetSupplier);
client.addListener(new NetListener(){
@Override
public void connected(Connection connection){
Connect c = new Connect();
c.addressTCP = connection.getRemoteAddressTCP().getAddress().getHostAddress();
if(connection.getRemoteAddressTCP() != null) c.addressTCP = connection.getRemoteAddressTCP().toString();
Core.app.post(() -> net.handleClientReceived(c));
}
@Override
public void disconnected(Connection connection, DcReason reason){
if(connection.getLastProtocolError() != null){
netClient.setQuiet();
}
Disconnect c = new Disconnect();
c.reason = reason.toString();
Core.app.post(() -> net.handleClientReceived(c));
}
@Override
public void received(Connection connection, Object object){
if(!(object instanceof Packet p)) return;
Core.app.post(() -> {
try{
net.handleClientReceived(p);
}catch(Throwable e){
net.handleException(e);
}
});
}
});
server = new Server(32768, 16384, new PacketSerializer());
server.setMulticast(multicastGroup, multicastPort);
server.setDiscoveryHandler((address, handler) -> {
ByteBuffer buffer = NetworkIO.writeServerData();
buffer.position(0);
handler.respond(buffer);
});
server.addListener(new NetListener(){
@Override
public void connected(Connection connection){
String ip = connection.getRemoteAddressTCP().getAddress().getHostAddress();
//kill connections above the limit to prevent spam
if((playerLimitCache > 0 && server.getConnections().length > playerLimitCache) || netServer.admins.isDosBlacklisted(ip)){
connection.close(DcReason.closed);
return;
}
ArcConnection kn = new ArcConnection(ip, connection);
Connect c = new Connect();
c.addressTCP = ip;
Log.debug("&bReceived connection: @", c.addressTCP);
connection.setArbitraryData(kn);
connections.add(kn);
Core.app.post(() -> net.handleServerReceived(kn, c));
}
@Override
public void disconnected(Connection connection, DcReason reason){
if(!(connection.getArbitraryData() instanceof ArcConnection k)) return;
Disconnect c = new Disconnect();
c.reason = reason.toString();
Core.app.post(() -> {
net.handleServerReceived(k, c);
connections.remove(k);
});
}
@Override
public void received(Connection connection, Object object){
if(!(connection.getArbitraryData() instanceof ArcConnection k) || !(object instanceof Packet pack)) return;
if(packetSpamLimit > 0 && !k.packetRate.allow(3000, packetSpamLimit)){
Log.warn("Blacklisting IP '@' as potential DOS attack - packet spam.", k.address);
connection.close(DcReason.closed);
netServer.admins.blacklistDos(k.address);
return;
}
Core.app.post(() -> {
try{
net.handleServerReceived(k, pack);
}catch(Throwable e){
Log.err(e);
}
});
}
});
}
@Override
public void setConnectFilter(Server.ServerConnectFilter connectFilter){
server.setConnectFilter(connectFilter);
}
private static boolean isLocal(InetAddress addr){
if(addr.isAnyLocalAddress() || addr.isLoopbackAddress()) return true;
try{
return NetworkInterface.getByInetAddress(addr) != null;
}catch(Exception e){
return false;
}
}
@Override
public void connectClient(String ip, int port, Runnable success){
Threads.daemon(() -> {
try{
//just in case
client.stop();
Threads.daemon("Net Client", () -> {
try{
client.run();
}catch(Exception e){
if(!(e instanceof ClosedSelectorException)) net.handleException(e);
}
});
client.connect(5000, ip, port, port);
success.run();
}catch(Exception e){
if(netClient.isConnecting()){
net.handleException(e);
}
}
});
}
@Override
public void disconnectClient(){
client.close();
}
@Override
public void sendClient(Object object, boolean reliable){
try{
if(reliable){
client.sendTCP(object);
}else{
client.sendUDP(object);
}
//sending things can cause an under/overflow, catch it and disconnect instead of crashing
}catch(BufferOverflowException | BufferUnderflowException e){
net.showError(e);
}
}
@Override
public void pingHost(String address, int port, Cons<Host> valid, Cons<Exception> invalid){
try{
var host = pingHostImpl(address, port);
Core.app.post(() -> valid.get(host));
}catch(IOException e){
if(port == Vars.port){
for(var record : ArcDns.getSrvRecords("_mindustry._tcp." + address)){
try{
var host = pingHostImpl(record.target, record.port);
Core.app.post(() -> valid.get(host));
return;
}catch(IOException ignored){
}
}
}
Core.app.post(() -> invalid.get(e));
}
}
private Host pingHostImpl(String address, int port) throws IOException{
try(DatagramSocket socket = new DatagramSocket()){
long time = Time.millis();
socket.send(new DatagramPacket(new byte[]{-2, 1}, 2, InetAddress.getByName(address), port));
socket.setSoTimeout(2000);
DatagramPacket packet = packetSupplier.get();
socket.receive(packet);
ByteBuffer buffer = ByteBuffer.wrap(packet.getData());
Host host = NetworkIO.readServerData((int)Time.timeSinceMillis(time), packet.getAddress().getHostAddress(), buffer);
host.port = port;
return host;
}
}
@Override
public void discoverServers(Cons<Host> callback, Runnable done){
Seq<InetAddress> foundAddresses = new Seq<>();
long time = Time.millis();
client.discoverHosts(port, multicastGroup, multicastPort, 3000, packet -> {
synchronized(foundAddresses){
try{
if(foundAddresses.contains(address -> address.equals(packet.getAddress()) || (isLocal(address) && isLocal(packet.getAddress())))){
return;
}
ByteBuffer buffer = ByteBuffer.wrap(packet.getData());
Host host = NetworkIO.readServerData((int)Time.timeSinceMillis(time), packet.getAddress().getHostAddress(), buffer);
Core.app.post(() -> callback.get(host));
foundAddresses.add(packet.getAddress());
}catch(Exception e){
//don't crash when there's an error pinging a server or parsing data
e.printStackTrace();
}
}
}, () -> Core.app.post(done));
}
@Override
public void dispose(){
disconnectClient();
closeServer();
try{
client.dispose();
}catch(IOException ignored){
}
}
@Override
public Iterable<ArcConnection> getConnections(){
return connections;
}
@Override
public void hostServer(int port) throws IOException{
connections.clear();
server.bind(port, port);
serverThread = new Thread(() -> {
try{
server.run();
}catch(Throwable e){
if(!(e instanceof ClosedSelectorException)) Threads.throwAppException(e);
}
}, "Net Server");
serverThread.setDaemon(true);
serverThread.start();
}
@Override
public void closeServer(){
connections.clear();
mainExecutor.submit(server::stop);
}
class ArcConnection extends NetConnection{
public final Connection connection;
public ArcConnection(String address, Connection connection){
super(address);
this.connection = connection;
}
@Override
public boolean isConnected(){
return connection.isConnected();
}
@Override
public void sendStream(Streamable stream){
connection.addListener(new InputStreamSender(stream.stream, 512){
int id;
@Override
protected void start(){
//send an object so the receiving side knows how to handle the following chunks
StreamBegin begin = new StreamBegin();
begin.total = stream.stream.available();
begin.type = Net.getPacketId(stream);
connection.sendTCP(begin);
id = begin.id;
}
@Override
protected Object next(byte[] bytes){
StreamChunk chunk = new StreamChunk();
chunk.id = id;
chunk.data = bytes;
return chunk; //wrap the byte[] with an object so the receiving side knows how to handle it.
}
});
}
@Override
public void send(Object object, boolean reliable){
try{
if(reliable){
connection.sendTCP(object);
}else{
connection.sendUDP(object);
}
}catch(Exception e){
Log.err(e);
Log.info("Error sending packet. Disconnecting invalid client!");
connection.close(DcReason.error);
if(connection.getArbitraryData() instanceof ArcConnection k){
connections.remove(k);
}
}
}
@Override
public void close(){
if(connection.isConnected()) connection.close(DcReason.closed);
}
}
public static class PacketSerializer implements NetSerializer{
//for debugging total read/write speeds
private static final boolean debug = false;
ThreadLocal<ByteBuffer> decompressBuffer = Threads.local(() -> ByteBuffer.allocate(32768));
ThreadLocal<Reads> reads = Threads.local(() -> new Reads(new ByteBufferInput(decompressBuffer.get())));
ThreadLocal<Writes> writes = Threads.local(() -> new Writes(new ByteBufferOutput(decompressBuffer.get())));
//for debugging network write counts
static WindowedMean upload = new WindowedMean(5), download = new WindowedMean(5);
static long lastUpload, lastDownload, uploadAccum, downloadAccum;
static int lastPos;
@Override
public Object read(ByteBuffer byteBuffer){
if(debug){
if(Time.timeSinceMillis(lastDownload) >= 1000){
lastDownload = Time.millis();
download.add(downloadAccum);
downloadAccum = 0;
Log.info("Download: @ b/s", download.mean());
}
downloadAccum += byteBuffer.remaining();
}
byte id = byteBuffer.get();
if(id == -2){
return readFramework(byteBuffer);
}else{
//read length int, followed by compressed lz4 data
Packet packet = Net.newPacket(id);
var buffer = decompressBuffer.get();
int length = byteBuffer.getShort() & 0xffff;
byte compression = byteBuffer.get();
//no compression, copy over buffer
if(compression == 0){
buffer.position(0).limit(length);
buffer.put(byteBuffer.array(), byteBuffer.position(), length);
buffer.position(0);
packet.read(reads.get(), length);
//move read packets forward
byteBuffer.position(byteBuffer.position() + buffer.position());
}else{
//decompress otherwise
int read = decompressor.decompress(byteBuffer, byteBuffer.position(), buffer, 0, length);
buffer.position(0);
buffer.limit(length);
packet.read(reads.get(), length);
//move buffer forward based on bytes read by decompressor
byteBuffer.position(byteBuffer.position() + read);
}
return packet;
}
}
@Override
public void write(ByteBuffer byteBuffer, Object o){
if(debug){
lastPos = byteBuffer.position();
}
//write raw buffer
if(o instanceof ByteBuffer raw){
byteBuffer.put(raw);
}else if(o instanceof FrameworkMessage msg){
byteBuffer.put((byte)-2); //code for framework message
writeFramework(byteBuffer, msg);
}else{
if(!(o instanceof Packet pack)) throw new RuntimeException("All sent objects must implement be Packets! Class: " + o.getClass());
byte id = Net.getPacketId(pack);
byteBuffer.put(id);
var temp = decompressBuffer.get();
temp.position(0);
temp.limit(temp.capacity());
pack.write(writes.get());
short length = (short)temp.position();
//write length, uncompressed
byteBuffer.putShort(length);
//don't bother with small packets
if(length < 36 || pack instanceof StreamChunk){
//write direct contents...
byteBuffer.put((byte)0); //0 = no compression
byteBuffer.put(temp.array(), 0, length);
}else{
byteBuffer.put((byte)1); //1 = compression
//write compressed data; this does not modify position!
int written = compressor.compress(temp, 0, temp.position(), byteBuffer, byteBuffer.position(), byteBuffer.remaining());
//skip to indicate the written, compressed data
byteBuffer.position(byteBuffer.position() + written);
}
}
if(debug){
if(Time.timeSinceMillis(lastUpload) >= 1000){
lastUpload = Time.millis();
upload.add(uploadAccum);
uploadAccum = 0;
Log.info("Upload: @ b/s", upload.mean());
}
uploadAccum += byteBuffer.position() - lastPos;
}
}
public void writeFramework(ByteBuffer buffer, FrameworkMessage message){
if(message instanceof Ping p){
buffer.put((byte)0);
buffer.putInt(p.id);
buffer.put(p.isReply ? 1 : (byte)0);
}else if(message instanceof DiscoverHost){
buffer.put((byte)1);
}else if(message instanceof KeepAlive){
buffer.put((byte)2);
}else if(message instanceof RegisterUDP p){
buffer.put((byte)3);
buffer.putInt(p.connectionID);
}else if(message instanceof RegisterTCP p){
buffer.put((byte)4);
buffer.putInt(p.connectionID);
}
}
public FrameworkMessage readFramework(ByteBuffer buffer){
byte id = buffer.get();
if(id == 0){
Ping p = new Ping();
p.id = buffer.getInt();
p.isReply = buffer.get() == 1;
return p;
}else if(id == 1){
return FrameworkMessage.discoverHost;
}else if(id == 2){
return FrameworkMessage.keepAlive;
}else if(id == 3){
RegisterUDP p = new RegisterUDP();
p.connectionID = buffer.getInt();
return p;
}else if(id == 4){
RegisterTCP p = new RegisterTCP();
p.connectionID = buffer.getInt();
return p;
}else{
throw new RuntimeException("Unknown framework message!");
}
}
}
}
package mindustry.net;
import mindustry.net.Packets.*;
import java.io.*;
public class Streamable extends Packet{
public transient ByteArrayInputStream stream;
@Override
public int getPriority(){
return priorityHigh;
}
public static class StreamBuilder{
public final int id;
public final byte type;
public final int total;
public final ByteArrayOutputStream stream = new ByteArrayOutputStream();
public StreamBuilder(StreamBegin begin){
id = begin.id;
type = begin.type;
total = begin.total;
}
public float progress(){
return (float)stream.size() / total;
}
public void add(byte[] bytes){
try{
stream.write(bytes);
}catch(IOException e){
throw new RuntimeException(e);
}
}
public Streamable build(){
Streamable s = Net.newPacket(type);
s.stream = new ByteArrayInputStream(stream.toByteArray());
return s;
}
public boolean isDone(){
return stream.size() >= total;
}
}
}
/*
* Copyright (c) 1996, 2023, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
/*
* Portions Copyright (c) 1995 Colin Plumb. All rights reserved.
*/
package java.math;
import java.io.IOException;
import java.io.InvalidObjectException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.ObjectStreamField;
import java.io.ObjectStreamException;
import java.util.Arrays;
import java.util.Objects;
import java.util.Random;
import java.util.concurrent.ForkJoinPool;
import java.util.concurrent.ForkJoinWorkerThread;
import java.util.concurrent.RecursiveTask;
import java.util.concurrent.ThreadLocalRandom;
import jdk.internal.math.DoubleConsts;
import jdk.internal.math.FloatConsts;
import jdk.internal.vm.annotation.ForceInline;
import jdk.internal.vm.annotation.IntrinsicCandidate;
import jdk.internal.vm.annotation.Stable;
/**
* Immutable arbitrary-precision integers. All operations behave as if
* BigIntegers were represented in two's-complement notation (like Java's
* primitive integer types). BigInteger provides analogues to all of Java's
* primitive integer operators, and all relevant methods from java.lang.Math.
* Additionally, BigInteger provides operations for modular arithmetic, GCD
* calculation, primality testing, prime generation, bit manipulation,
* and a few other miscellaneous operations.
*
* <p>Semantics of arithmetic operations exactly mimic those of Java's integer
* arithmetic operators, as defined in <i>The Java Language Specification</i>.
* For example, division by zero throws an {@code ArithmeticException}, and
* division of a negative by a positive yields a negative (or zero) remainder.
*
* <p>Semantics of shift operations extend those of Java's shift operators
* to allow for negative shift distances. A right-shift with a negative
* shift distance results in a left shift, and vice-versa. The unsigned
* right shift operator ({@code >>>}) is omitted since this operation
* only makes sense for a fixed sized word and not for a
* representation conceptually having an infinite number of leading
* virtual sign bits.
*
* <p>Semantics of bitwise logical operations exactly mimic those of Java's
* bitwise integer operators. The binary operators ({@code and},
* {@code or}, {@code xor}) implicitly perform sign extension on the shorter
* of the two operands prior to performing the operation.
*
* <p>Comparison operations perform signed integer comparisons, analogous to
* those performed by Java's relational and equality operators.
*
* <p>Modular arithmetic operations are provided to compute residues, perform
* exponentiation, and compute multiplicative inverses. These methods always
* return a non-negative result, between {@code 0} and {@code (modulus - 1)},
* inclusive.
*
* <p>Bit operations operate on a single bit of the two's-complement
* representation of their operand. If necessary, the operand is sign-extended
* so that it contains the designated bit. None of the single-bit
* operations can produce a BigInteger with a different sign from the
* BigInteger being operated on, as they affect only a single bit, and the
* arbitrarily large abstraction provided by this class ensures that conceptually
* there are infinitely many "virtual sign bits" preceding each BigInteger.
*
* <p>For the sake of brevity and clarity, pseudo-code is used throughout the
* descriptions of BigInteger methods. The pseudo-code expression
* {@code (i + j)} is shorthand for "a BigInteger whose value is
* that of the BigInteger {@code i} plus that of the BigInteger {@code j}."
* The pseudo-code expression {@code (i == j)} is shorthand for
* "{@code true} if and only if the BigInteger {@code i} represents the same
* value as the BigInteger {@code j}." Other pseudo-code expressions are
* interpreted similarly.
*
* <p>All methods and constructors in this class throw
* {@code NullPointerException} when passed
* a null object reference for any input parameter.
*
* BigInteger must support values in the range
* -2<sup>{@code Integer.MAX_VALUE}</sup> (exclusive) to
* +2<sup>{@code Integer.MAX_VALUE}</sup> (exclusive)
* and may support values outside of that range.
*
* An {@code ArithmeticException} is thrown when a BigInteger
* constructor or method would generate a value outside of the
* supported range.
*
* The range of probable prime values is limited and may be less than
* the full supported positive range of {@code BigInteger}.
* The range must be at least 1 to 2<sup>500000000</sup>.
*
* @apiNote
* <a id=algorithmicComplexity>As {@code BigInteger} values are
* arbitrary precision integers, the algorithmic complexity of the
* methods of this class varies and may be superlinear in the size of
* the input. For example, a method like {@link intValue()} would be
* expected to run in <i>O</i>(1), that is constant time, since with
* the current internal representation only a fixed-size component of
* the {@code BigInteger} needs to be accessed to perform the
* conversion to {@code int}. In contrast, a method like {@link not()}
* would be expected to run in <i>O</i>(<i>n</i>) time where <i>n</i>
* is the size of the {@code BigInteger} in bits, that is, to run in
* time proportional to the size of the input. For multiplying two
* {@code BigInteger} values of size <i>n</i>, a naive multiplication
* algorithm would run in time <i>O</i>(<i>n<sup>2</sup></i>) and
* theoretical results indicate a multiplication algorithm for numbers
* using this category of representation must run in <em>at least</em>
* <i>O</i>(<i>n</i>&nbsp;log&nbsp;<i>n</i>). Common multiplication
* algorithms between the bounds of the naive and theoretical cases
* include the Karatsuba multiplication
* (<i>O</i>(<i>n<sup>1.585</sup></i>)) and 3-way Toom-Cook
* multiplication (<i>O</i>(<i>n<sup>1.465</sup></i>)).</a>
*
* <p>A particular implementation of {@link multiply(BigInteger)
* multiply} is free to switch between different algorithms for
* different inputs, such as to improve actual running time to produce
* the product by using simpler algorithms for smaller inputs even if
* the simpler algorithm has a larger asymptotic complexity.
*
* <p>Operations may also allocate and compute on intermediate
* results, potentially those allocations may be as large as in
* proportion to the running time of the algorithm.
*
* <p>Users of {@code BigInteger} concerned with bounding the running
* time or space of operations can screen out {@code BigInteger}
* values above a chosen magnitude.
*
* @implNote
* In the reference implementation, BigInteger constructors and
* operations throw {@code ArithmeticException} when the result is out
* of the supported range of
* -2<sup>{@code Integer.MAX_VALUE}</sup> (exclusive) to
* +2<sup>{@code Integer.MAX_VALUE}</sup> (exclusive).
*
* @see BigDecimal
* @jls 4.2.2 Integer Operations
* @author Josh Bloch
* @author Michael McCloskey
* @author Alan Eliasen
* @author Timothy Buktu
* @since 1.1
*/
public class BigInteger extends Number implements Comparable<BigInteger> {
/**
* The signum of this BigInteger: -1 for negative, 0 for zero, or
* 1 for positive. Note that the BigInteger zero <em>must</em> have
* a signum of 0. This is necessary to ensures that there is exactly one
* representation for each BigInteger value.
*/
final int signum;
/**
* The magnitude of this BigInteger, in <i>big-endian</i> order: the
* zeroth element of this array is the most-significant int of the
* magnitude. The magnitude must be "minimal" in that the most-significant
* int ({@code mag[0]}) must be non-zero. This is necessary to
* ensure that there is exactly one representation for each BigInteger
* value. Note that this implies that the BigInteger zero has a
* zero-length mag array.
*/
final int[] mag;
// The following fields are stable variables. A stable variable's value
// changes at most once from the default zero value to a non-zero stable
// value. A stable value is calculated lazily on demand.
/**
* One plus the bitCount of this BigInteger. This is a stable variable.
*
* @see #bitCount
*/
private int bitCountPlusOne;
/**
* One plus the bitLength of this BigInteger. This is a stable variable.
* (either value is acceptable).
*
* @see #bitLength()
*/
private int bitLengthPlusOne;
/**
* Two plus the lowest set bit of this BigInteger. This is a stable variable.
*
* @see #getLowestSetBit
*/
private int lowestSetBitPlusTwo;
/**
* Two plus the index of the lowest-order int in the magnitude of this
* BigInteger that contains a nonzero int. This is a stable variable. The
* least significant int has int-number 0, the next int in order of
* increasing significance has int-number 1, and so forth.
*
* <p>Note: never used for a BigInteger with a magnitude of zero.
*
* @see #firstNonzeroIntNum()
*/
private int firstNonzeroIntNumPlusTwo;
/**
* This mask is used to obtain the value of an int as if it were unsigned.
*/
static final long LONG_MASK = 0xffffffffL;
/**
* This constant limits {@code mag.length} of BigIntegers to the supported
* range.
*/
private static final int MAX_MAG_LENGTH = Integer.MAX_VALUE / Integer.SIZE + 1; // (1 << 26)
/**
* Bit lengths larger than this constant can cause overflow in searchLen
* calculation and in BitSieve.singleSearch method.
*/
private static final int PRIME_SEARCH_BIT_LENGTH_LIMIT = 500000000;
/**
* The threshold value for using Karatsuba multiplication. If the number
* of ints in both mag arrays are greater than this number, then
* Karatsuba multiplication will be used. This value is found
* experimentally to work well.
*/
private static final int KARATSUBA_THRESHOLD = 80;
/**
* The threshold value for using 3-way Toom-Cook multiplication.
* If the number of ints in each mag array is greater than the
* Karatsuba threshold, and the number of ints in at least one of
* the mag arrays is greater than this threshold, then Toom-Cook
* multiplication will be used.
*/
private static final int TOOM_COOK_THRESHOLD = 240;
/**
* The threshold value for using Karatsuba squaring. If the number
* of ints in the number are larger than this value,
* Karatsuba squaring will be used. This value is found
* experimentally to work well.
*/
private static final int KARATSUBA_SQUARE_THRESHOLD = 128;
/**
* The threshold value for using Toom-Cook squaring. If the number
* of ints in the number are larger than this value,
* Toom-Cook squaring will be used. This value is found
* experimentally to work well.
*/
private static final int TOOM_COOK_SQUARE_THRESHOLD = 216;
/**
* The threshold value for using Burnikel-Ziegler division. If the number
* of ints in the divisor are larger than this value, Burnikel-Ziegler
* division may be used. This value is found experimentally to work well.
*/
static final int BURNIKEL_ZIEGLER_THRESHOLD = 80;
/**
* The offset value for using Burnikel-Ziegler division. If the number
* of ints in the divisor exceeds the Burnikel-Ziegler threshold, and the
* number of ints in the dividend is greater than the number of ints in the
* divisor plus this value, Burnikel-Ziegler division will be used. This
* value is found experimentally to work well.
*/
static final int BURNIKEL_ZIEGLER_OFFSET = 40;
/**
* The threshold value for using Schoenhage recursive base conversion. If
* the number of ints in the number are larger than this value,
* the Schoenhage algorithm will be used. In practice, it appears that the
* Schoenhage routine is faster for any threshold down to 2, and is
* relatively flat for thresholds between 2-25, so this choice may be
* varied within this range for very small effect.
*/
private static final int SCHOENHAGE_BASE_CONVERSION_THRESHOLD = 20;
/**
* The threshold value for using squaring code to perform multiplication
* of a {@code BigInteger} instance by itself. If the number of ints in
* the number are larger than this value, {@code multiply(this)} will
* return {@code square()}.
*/
private static final int MULTIPLY_SQUARE_THRESHOLD = 20;
/**
* The threshold for using an intrinsic version of
* implMontgomeryXXX to perform Montgomery multiplication. If the
* number of ints in the number is more than this value we do not
* use the intrinsic.
*/
private static final int MONTGOMERY_INTRINSIC_THRESHOLD = 512;
// Constructors
/**
* Translates a byte sub-array containing the two's-complement binary
* representation of a BigInteger into a BigInteger. The sub-array is
* specified via an offset into the array and a length. The sub-array is
* assumed to be in <i>big-endian</i> byte-order: the most significant
* byte is the element at index {@code off}. The {@code val} array is
* assumed to be unchanged for the duration of the constructor call.
*
* An {@code IndexOutOfBoundsException} is thrown if the length of the array
* {@code val} is non-zero and either {@code off} is negative, {@code len}
* is negative, or {@code off+len} is greater than the length of
* {@code val}.
*
* @param val byte array containing a sub-array which is the big-endian
* two's-complement binary representation of a BigInteger.
* @param off the start offset of the binary representation.
* @param len the number of bytes to use.
* @throws NumberFormatException {@code val} is zero bytes long.
* @throws IndexOutOfBoundsException if the provided array offset and
* length would cause an index into the byte array to be
* negative or greater than or equal to the array length.
* @since 9
*/
public BigInteger(byte[] val, int off, int len) {
if (val.length == 0) {
throw new NumberFormatException("Zero length BigInteger");
}
Objects.checkFromIndexSize(off, len, val.length);
if (len == 0) {
mag = ZERO.mag;
signum = ZERO.signum;
return;
}
int b = val[off];
if (b < 0) {
mag = makePositive(b, val, off, len);
signum = -1;
} else {
mag = stripLeadingZeroBytes(b, val, off, len);
signum = (mag.length == 0 ? 0 : 1);
}
if (mag.length >= MAX_MAG_LENGTH) {
checkRange();
}
}
/**
* Translates a byte array containing the two's-complement binary
* representation of a BigInteger into a BigInteger. The input array is
* assumed to be in <i>big-endian</i> byte-order: the most significant
* byte is in the zeroth element. The {@code val} array is assumed to be
* unchanged for the duration of the constructor call.
*
* @param val big-endian two's-complement binary representation of a
* BigInteger.
* @throws NumberFormatException {@code val} is zero bytes long.
*/
public BigInteger(byte[] val) {
this(val, 0, val.length);
}
/**
* This private constructor translates an int array containing the
* two's-complement binary representation of a BigInteger into a
* BigInteger. The input array is assumed to be in <i>big-endian</i>
* int-order: the most significant int is in the zeroth element. The
* {@code val} array is assumed to be unchanged for the duration of
* the constructor call.
*/
private BigInteger(int[] val) {
if (val.length == 0)
throw new NumberFormatException("Zero length BigInteger");
if (val[0] < 0) {
mag = makePositive(val);
signum = -1;
} else {
mag = trustedStripLeadingZeroInts(val);
signum = (mag.length == 0 ? 0 : 1);
}
if (mag.length >= MAX_MAG_LENGTH) {
checkRange();
}
}
/**
* Translates the sign-magnitude representation of a BigInteger into a
* BigInteger. The sign is represented as an integer signum value: -1 for
* negative, 0 for zero, or 1 for positive. The magnitude is a sub-array of
* a byte array in <i>big-endian</i> byte-order: the most significant byte
* is the element at index {@code off}. A zero value of the length
* {@code len} is permissible, and will result in a BigInteger value of 0,
* whether signum is -1, 0 or 1. The {@code magnitude} array is assumed to
* be unchanged for the duration of the constructor call.
*
* An {@code IndexOutOfBoundsException} is thrown if the length of the array
* {@code magnitude} is non-zero and either {@code off} is negative,
* {@code len} is negative, or {@code off+len} is greater than the length of
* {@code magnitude}.
*
* @param signum signum of the number (-1 for negative, 0 for zero, 1
* for positive).
* @param magnitude big-endian binary representation of the magnitude of
* the number.
* @param off the start offset of the binary representation.
* @param len the number of bytes to use.
* @throws NumberFormatException {@code signum} is not one of the three
* legal values (-1, 0, and 1), or {@code signum} is 0 and
* {@code magnitude} contains one or more non-zero bytes.
* @throws IndexOutOfBoundsException if the provided array offset and
* length would cause an index into the byte array to be
* negative or greater than or equal to the array length.
* @since 9
*/
public BigInteger(int signum, byte[] magnitude, int off, int len) {
if (signum < -1 || signum > 1) {
throw(new NumberFormatException("Invalid signum value"));
}
Objects.checkFromIndexSize(off, len, magnitude.length);
// stripLeadingZeroBytes() returns a zero length array if len == 0
this.mag = stripLeadingZeroBytes(magnitude, off, len);
if (this.mag.length == 0) {
this.signum = 0;
} else {
if (signum == 0)
throw(new NumberFormatException("signum-magnitude mismatch"));
this.signum = signum;
}
if (mag.length >= MAX_MAG_LENGTH) {
checkRange();
}
}
/**
* Translates the sign-magnitude representation of a BigInteger into a
* BigInteger. The sign is represented as an integer signum value: -1 for
* negative, 0 for zero, or 1 for positive. The magnitude is a byte array
* in <i>big-endian</i> byte-order: the most significant byte is the
* zeroth element. A zero-length magnitude array is permissible, and will
* result in a BigInteger value of 0, whether signum is -1, 0 or 1. The
* {@code magnitude} array is assumed to be unchanged for the duration of
* the constructor call.
*
* @param signum signum of the number (-1 for negative, 0 for zero, 1
* for positive).
* @param magnitude big-endian binary representation of the magnitude of
* the number.
* @throws NumberFormatException {@code signum} is not one of the three
* legal values (-1, 0, and 1), or {@code signum} is 0 and
* {@code magnitude} contains one or more non-zero bytes.
*/
public BigInteger(int signum, byte[] magnitude) {
this(signum, magnitude, 0, magnitude.length);
}
/**
* A constructor for internal use that translates the sign-magnitude
* representation of a BigInteger into a BigInteger. It checks the
* arguments and copies the magnitude so this constructor would be
* safe for external use. The {@code magnitude} array is assumed to be
* unchanged for the duration of the constructor call.
*/
private BigInteger(int signum, int[] magnitude) {
this.mag = stripLeadingZeroInts(magnitude);
if (signum < -1 || signum > 1)
throw(new NumberFormatException("Invalid signum value"));
if (this.mag.length == 0) {
this.signum = 0;
} else {
if (signum == 0)
throw(new NumberFormatException("signum-magnitude mismatch"));
this.signum = signum;
}
if (mag.length >= MAX_MAG_LENGTH) {
checkRange();
}
}
/**
* Translates the String representation of a BigInteger in the
* specified radix into a BigInteger. The String representation
* consists of an optional minus or plus sign followed by a
* sequence of one or more digits in the specified radix. The
* character-to-digit mapping is provided by {@link
* Character#digit(char, int) Character.digit}. The String may
* not contain any extraneous characters (whitespace, for
* example).
*
* @param val String representation of BigInteger.
* @param radix radix to be used in interpreting {@code val}.
* @throws NumberFormatException {@code val} is not a valid representation
* of a BigInteger in the specified radix, or {@code radix} is
* outside the range from {@link Character#MIN_RADIX} to
* {@link Character#MAX_RADIX}, inclusive.
*/
public BigInteger(String val, int radix) {
int cursor = 0, numDigits;
final int len = val.length();
if (radix < Character.MIN_RADIX || radix > Character.MAX_RADIX)
throw new NumberFormatException("Radix out of range");
if (len == 0)
throw new NumberFormatException("Zero length BigInteger");
// Check for at most one leading sign
int sign = 1;
int index1 = val.lastIndexOf('-');
int index2 = val.lastIndexOf('+');
if (index1 >= 0) {
if (index1 != 0 || index2 >= 0) {
throw new NumberFormatException("Illegal embedded sign character");
}
sign = -1;
cursor = 1;
} else if (index2 >= 0) {
if (index2 != 0) {
throw new NumberFormatException("Illegal embedded sign character");
}
cursor = 1;
}
if (cursor == len)
throw new NumberFormatException("Zero length BigInteger");
// Skip leading zeros and compute number of digits in magnitude
while (cursor < len &&
Character.digit(val.charAt(cursor), radix) == 0) {
cursor++;
}
if (cursor == len) {
signum = 0;
mag = ZERO.mag;
return;
}
numDigits = len - cursor;
signum = sign;
// Pre-allocate array of expected size. May be too large but can
// never be too small. Typically exact.
long numBits = ((numDigits * bitsPerDigit[radix]) >>> 10) + 1;
if (numBits + 31 >= (1L << 32)) {
reportOverflow();
}
int numWords = (int) (numBits + 31) >>> 5;
int[] magnitude = new int[numWords];
// Process first (potentially short) digit group
int firstGroupLen = numDigits % digitsPerInt[radix];
if (firstGroupLen == 0)
firstGroupLen = digitsPerInt[radix];
String group = val.substring(cursor, cursor += firstGroupLen);
magnitude[numWords - 1] = Integer.parseInt(group, radix);
if (magnitude[numWords - 1] < 0)
throw new NumberFormatException("Illegal digit");
// Process remaining digit groups
int superRadix = intRadix[radix];
int groupVal = 0;
while (cursor < len) {
group = val.substring(cursor, cursor += digitsPerInt[radix]);
groupVal = Integer.parseInt(group, radix);
if (groupVal < 0)
throw new NumberFormatException("Illegal digit");
destructiveMulAdd(magnitude, superRadix, groupVal);
}
// Required for cases where the array was overallocated.
mag = trustedStripLeadingZeroInts(magnitude);
if (mag.length >= MAX_MAG_LENGTH) {
checkRange();
}
}
/*
* Constructs a new BigInteger using a char array with radix=10.
* Sign is precalculated outside and not allowed in the val. The {@code val}
* array is assumed to be unchanged for the duration of the constructor
* call.
*/
BigInteger(char[] val, int sign, int len) {
int cursor = 0, numDigits;
// Skip leading zeros and compute number of digits in magnitude
while (cursor < len && Character.digit(val[cursor], 10) == 0) {
cursor++;
}
if (cursor == len) {
signum = 0;
mag = ZERO.mag;
return;
}
numDigits = len - cursor;
signum = sign;
// Pre-allocate array of expected size
int numWords;
if (len < 10) {
numWords = 1;
} else {
long numBits = ((numDigits * bitsPerDigit[10]) >>> 10) + 1;
if (numBits + 31 >= (1L << 32)) {
reportOverflow();
}
numWords = (int) (numBits + 31) >>> 5;
}
int[] magnitude = new int[numWords];
// Process first (potentially short) digit group
int firstGroupLen = numDigits % digitsPerInt[10];
if (firstGroupLen == 0)
firstGroupLen = digitsPerInt[10];
magnitude[numWords - 1] = parseInt(val, cursor, cursor += firstGroupLen);
// Process remaining digit groups
while (cursor < len) {
int groupVal = parseInt(val, cursor, cursor += digitsPerInt[10]);
destructiveMulAdd(magnitude, intRadix[10], groupVal);
}
mag = trustedStripLeadingZeroInts(magnitude);
if (mag.length >= MAX_MAG_LENGTH) {
checkRange();
}
}
// Create an integer with the digits between the two indexes
// Assumes start < end. The result may be negative, but it
// is to be treated as an unsigned value.
private int parseInt(char[] source, int start, int end) {
int result = Character.digit(source[start++], 10);
if (result == -1)
throw new NumberFormatException(new String(source));
for (int index = start; index < end; index++) {
int nextVal = Character.digit(source[index], 10);
if (nextVal == -1)
throw new NumberFormatException(new String(source));
result = 10*result + nextVal;
}
return result;
}
// bitsPerDigit in the given radix times 1024
// Rounded up to avoid underallocation.
private static long bitsPerDigit[] = { 0, 0,
1024, 1624, 2048, 2378, 2648, 2875, 3072, 3247, 3402, 3543, 3672,
3790, 3899, 4001, 4096, 4186, 4271, 4350, 4426, 4498, 4567, 4633,
4696, 4756, 4814, 4870, 4923, 4975, 5025, 5074, 5120, 5166, 5210,
5253, 5295};
// Multiply x array times word y in place, and add word z
private static void destructiveMulAdd(int[] x, int y, int z) {
// Perform the multiplication word by word
long ylong = y & LONG_MASK;
long zlong = z & LONG_MASK;
int len = x.length;
long product = 0;
long carry = 0;
for (int i = len-1; i >= 0; i--) {
product = ylong * (x[i] & LONG_MASK) + carry;
x[i] = (int)product;
carry = product >>> 32;
}
// Perform the addition
long sum = (x[len-1] & LONG_MASK) + zlong;
x[len-1] = (int)sum;
carry = sum >>> 32;
for (int i = len-2; i >= 0; i--) {
sum = (x[i] & LONG_MASK) + carry;
x[i] = (int)sum;
carry = sum >>> 32;
}
}
/**
* Translates the decimal String representation of a BigInteger
* into a BigInteger. The String representation consists of an
* optional minus or plus sign followed by a sequence of one or
* more decimal digits. The character-to-digit mapping is
* provided by {@link Character#digit(char, int)
* Character.digit}. The String may not contain any extraneous
* characters (whitespace, for example).
*
* @param val decimal String representation of BigInteger.
* @throws NumberFormatException {@code val} is not a valid representation
* of a BigInteger.
*/
public BigInteger(String val) {
this(val, 10);
}
/**
* Constructs a randomly generated BigInteger, uniformly distributed over
* the range 0 to (2<sup>{@code numBits}</sup> - 1), inclusive.
* The uniformity of the distribution assumes that a fair source of random
* bits is provided in {@code rnd}. Note that this constructor always
* constructs a non-negative BigInteger.
*
* @param numBits maximum bitLength of the new BigInteger.
* @param rnd source of randomness to be used in computing the new
* BigInteger.
* @throws IllegalArgumentException {@code numBits} is negative.
* @see #bitLength()
*/
public BigInteger(int numBits, Random rnd) {
byte[] magnitude = randomBits(numBits, rnd);
try {
// stripLeadingZeroBytes() returns a zero length array if len == 0
this.mag = stripLeadingZeroBytes(magnitude, 0, magnitude.length);
if (this.mag.length == 0) {
this.signum = 0;
} else {
this.signum = 1;
}
if (mag.length >= MAX_MAG_LENGTH) {
checkRange();
}
} finally {
Arrays.fill(magnitude, (byte)0);
}
}
private static byte[] randomBits(int numBits, Random rnd) {
if (numBits < 0)
throw new IllegalArgumentException("numBits must be non-negative");
int numBytes = (int)(((long)numBits+7)/8); // avoid overflow
byte[] randomBits = new byte[numBytes];
// Generate random bytes and mask out any excess bits
if (numBytes > 0) {
rnd.nextBytes(randomBits);
int excessBits = 8*numBytes - numBits;
randomBits[0] &= (byte)((1 << (8-excessBits)) - 1);
}
return randomBits;
}
/**
* Constructs a randomly generated positive BigInteger that is probably
* prime, with the specified bitLength.
*
* @apiNote It is recommended that the {@link #probablePrime probablePrime}
* method be used in preference to this constructor unless there
* is a compelling need to specify a certainty.
*
* @param bitLength bitLength of the returned BigInteger.
* @param certainty a measure of the uncertainty that the caller is
* willing to tolerate. The probability that the new BigInteger
* represents a prime number will exceed
* (1 - 1/2<sup>{@code certainty}</sup>). The execution time of
* this constructor is proportional to the value of this parameter.
* @param rnd source of random bits used to select candidates to be
* tested for primality.
* @throws ArithmeticException {@code bitLength < 2} or {@code bitLength} is too large.
* @see #bitLength()
*/
public BigInteger(int bitLength, int certainty, Random rnd) {
BigInteger prime;
if (bitLength < 2)
throw new ArithmeticException("bitLength < 2");
prime = (bitLength < SMALL_PRIME_THRESHOLD
? smallPrime(bitLength, certainty, rnd)
: largePrime(bitLength, certainty, rnd));
signum = 1;
mag = prime.mag;
}
// Minimum size in bits that the requested prime number has
// before we use the large prime number generating algorithms.
// The cutoff of 95 was chosen empirically for best performance.
private static final int SMALL_PRIME_THRESHOLD = 95;
// Certainty required to meet the spec of probablePrime
private static final int DEFAULT_PRIME_CERTAINTY = 100;
/**
* Returns a positive BigInteger that is probably prime, with the
* specified bitLength. The probability that a BigInteger returned
* by this method is composite does not exceed 2<sup>-100</sup>.
*
* @param bitLength bitLength of the returned BigInteger.
* @param rnd source of random bits used to select candidates to be
* tested for primality.
* @return a BigInteger of {@code bitLength} bits that is probably prime
* @throws ArithmeticException {@code bitLength < 2} or {@code bitLength} is too large.
* @see #bitLength()
* @since 1.4
*/
public static BigInteger probablePrime(int bitLength, Random rnd) {
if (bitLength < 2)
throw new ArithmeticException("bitLength < 2");
return (bitLength < SMALL_PRIME_THRESHOLD ?
smallPrime(bitLength, DEFAULT_PRIME_CERTAINTY, rnd) :
largePrime(bitLength, DEFAULT_PRIME_CERTAINTY, rnd));
}
/**
* Find a random number of the specified bitLength that is probably prime.
* This method is used for smaller primes, its performance degrades on
* larger bitlengths.
*
* This method assumes bitLength > 1.
*/
private static BigInteger smallPrime(int bitLength, int certainty, Random rnd) {
int magLen = (bitLength + 31) >>> 5;
int temp[] = new int[magLen];
int highBit = 1 << ((bitLength+31) & 0x1f); // High bit of high int
int highMask = (highBit << 1) - 1; // Bits to keep in high int
while (true) {
// Construct a candidate
for (int i=0; i < magLen; i++)
temp[i] = rnd.nextInt();
temp[0] = (temp[0] & highMask) | highBit; // Ensure exact length
if (bitLength > 2)
temp[magLen-1] |= 1; // Make odd if bitlen > 2
BigInteger p = new BigInteger(temp, 1);
// Do cheap "pre-test" if applicable
if (bitLength > 6) {
long r = p.remainder(SMALL_PRIME_PRODUCT).longValue();
if ((r%3==0) || (r%5==0) || (r%7==0) || (r%11==0) ||
(r%13==0) || (r%17==0) || (r%19==0) || (r%23==0) ||
(r%29==0) || (r%31==0) || (r%37==0) || (r%41==0))
continue; // Candidate is composite; try another
}
// All candidates of bitLength 2 and 3 are prime by this point
if (bitLength < 4)
return p;
// Do expensive test if we survive pre-test (or it's inapplicable)
if (p.primeToCertainty(certainty, rnd))
return p;
}
}
private static final BigInteger SMALL_PRIME_PRODUCT
= valueOf(3L*5*7*11*13*17*19*23*29*31*37*41);
/**
* Find a random number of the specified bitLength that is probably prime.
* This method is more appropriate for larger bitlengths since it uses
* a sieve to eliminate most composites before using a more expensive
* test.
*/
private static BigInteger largePrime(int bitLength, int certainty, Random rnd) {
BigInteger p;
p = new BigInteger(bitLength, rnd).setBit(bitLength-1);
p.mag[p.mag.length-1] &= 0xfffffffe;
// Use a sieve length likely to contain the next prime number
int searchLen = getPrimeSearchLen(bitLength);
BitSieve searchSieve = new BitSieve(p, searchLen);
BigInteger candidate = searchSieve.retrieve(p, certainty, rnd);
while ((candidate == null) || (candidate.bitLength() != bitLength)) {
p = p.add(BigInteger.valueOf(2*searchLen));
if (p.bitLength() != bitLength)
p = new BigInteger(bitLength, rnd).setBit(bitLength-1);
p.mag[p.mag.length-1] &= 0xfffffffe;
searchSieve = new BitSieve(p, searchLen);
candidate = searchSieve.retrieve(p, certainty, rnd);
}
return candidate;
}
/**
* Returns the first integer greater than this {@code BigInteger} that
* is probably prime. The probability that the number returned by this
* method is composite does not exceed 2<sup>-100</sup>. This method will
* never skip over a prime when searching: if it returns {@code p}, there
* is no prime {@code q} such that {@code this < q < p}.
*
* @return the first integer greater than this {@code BigInteger} that
* is probably prime.
* @throws ArithmeticException {@code this < 0} or {@code this} is too large.
* @implNote Due to the nature of the underlying algorithm,
* and depending on the size of {@code this},
* this method could consume a large amount of memory, up to
* exhaustion of available heap space, or could run for a long time.
* @since 1.5
*/
public BigInteger nextProbablePrime() {
if (this.signum < 0)
throw new ArithmeticException("start < 0: " + this);
// Handle trivial cases
if ((this.signum == 0) || this.equals(ONE))
return TWO;
BigInteger result = this.add(ONE);
// Fastpath for small numbers
if (result.bitLength() < SMALL_PRIME_THRESHOLD) {
// Ensure an odd number
if (!result.testBit(0))
result = result.add(ONE);
while (true) {
// Do cheap "pre-test" if applicable
if (result.bitLength() > 6) {
long r = result.remainder(SMALL_PRIME_PRODUCT).longValue();
if ((r%3==0) || (r%5==0) || (r%7==0) || (r%11==0) ||
(r%13==0) || (r%17==0) || (r%19==0) || (r%23==0) ||
(r%29==0) || (r%31==0) || (r%37==0) || (r%41==0)) {
result = result.add(TWO);
continue; // Candidate is composite; try another
}
}
// All candidates of bitLength 2 and 3 are prime by this point
if (result.bitLength() < 4)
return result;
// The expensive test
if (result.primeToCertainty(DEFAULT_PRIME_CERTAINTY, null))
return result;
result = result.add(TWO);
}
}
// Start at previous even number
if (result.testBit(0))
result = result.subtract(ONE);
// Looking for the next large prime
int searchLen = getPrimeSearchLen(result.bitLength());
while (true) {
BitSieve searchSieve = new BitSieve(result, searchLen);
BigInteger candidate = searchSieve.retrieve(result,
DEFAULT_PRIME_CERTAINTY, null);
if (candidate != null)
return candidate;
result = result.add(BigInteger.valueOf(2 * searchLen));
}
}
private static int getPrimeSearchLen(int bitLength) {
if (bitLength > PRIME_SEARCH_BIT_LENGTH_LIMIT + 1) {
throw new ArithmeticException("Prime search implementation restriction on bitLength");
}
return bitLength / 20 * 64;
}
/**
* Returns {@code true} if this BigInteger is probably prime,
* {@code false} if it's definitely composite.
*
* This method assumes bitLength > 2.
*
* @param certainty a measure of the uncertainty that the caller is
* willing to tolerate: if the call returns {@code true}
* the probability that this BigInteger is prime exceeds
* <code>(1 - 1/2<sup>certainty</sup>)</code>. The execution time of
* this method is proportional to the value of this parameter.
* @return {@code true} if this BigInteger is probably prime,
* {@code false} if it's definitely composite.
*/
boolean primeToCertainty(int certainty, Random random) {
int rounds = 0;
int n = (Math.min(certainty, Integer.MAX_VALUE-1)+1)/2;
// The relationship between the certainty and the number of rounds
// we perform is given in the draft standard ANSI X9.80, "PRIME
// NUMBER GENERATION, PRIMALITY TESTING, AND PRIMALITY CERTIFICATES".
int sizeInBits = this.bitLength();
if (sizeInBits < 100) {
rounds = 50;
rounds = n < rounds ? n : rounds;
return passesMillerRabin(rounds, random);
}
if (sizeInBits < 256) {
rounds = 27;
} else if (sizeInBits < 512) {
rounds = 15;
} else if (sizeInBits < 768) {
rounds = 8;
} else if (sizeInBits < 1024) {
rounds = 4;
} else {
rounds = 2;
}
rounds = n < rounds ? n : rounds;
return passesMillerRabin(rounds, random) && passesLucasLehmer();
}
/**
* Returns true iff this BigInteger is a Lucas-Lehmer probable prime.
*
* The following assumptions are made:
* This BigInteger is a positive, odd number.
*/
private boolean passesLucasLehmer() {
BigInteger thisPlusOne = this.add(ONE);
// Step 1
int d = 5;
while (jacobiSymbol(d, this) != -1) {
// 5, -7, 9, -11, ...
d = (d < 0) ? Math.abs(d)+2 : -(d+2);
}
// Step 2
BigInteger u = lucasLehmerSequence(d, thisPlusOne, this);
// Step 3
return u.mod(this).equals(ZERO);
}
/**
* Computes Jacobi(p,n).
* Assumes n positive, odd, n>=3.
*/
private static int jacobiSymbol(int p, BigInteger n) {
if (p == 0)
return 0;
// Algorithm and comments adapted from Colin Plumb's C library.
int j = 1;
int u = n.mag[n.mag.length-1];
// Make p positive
if (p < 0) {
p = -p;
int n8 = u & 7;
if ((n8 == 3) || (n8 == 7))
j = -j; // 3 (011) or 7 (111) mod 8
}
// Get rid of factors of 2 in p
while ((p & 3) == 0)
p >>= 2;
if ((p & 1) == 0) {
p >>= 1;
if (((u ^ (u>>1)) & 2) != 0)
j = -j; // 3 (011) or 5 (101) mod 8
}
if (p == 1)
return j;
// Then, apply quadratic reciprocity
if ((p & u & 2) != 0) // p = u = 3 (mod 4)?
j = -j;
// And reduce u mod p
u = n.mod(BigInteger.valueOf(p)).intValue();
// Now compute Jacobi(u,p), u < p
while (u != 0) {
while ((u & 3) == 0)
u >>= 2;
if ((u & 1) == 0) {
u >>= 1;
if (((p ^ (p>>1)) & 2) != 0)
j = -j; // 3 (011) or 5 (101) mod 8
}
if (u == 1)
return j;
// Now both u and p are odd, so use quadratic reciprocity
assert (u < p);
int t = u; u = p; p = t;
if ((u & p & 2) != 0) // u = p = 3 (mod 4)?
j = -j;
// Now u >= p, so it can be reduced
u %= p;
}
return 0;
}
private static BigInteger lucasLehmerSequence(int z, BigInteger k, BigInteger n) {
BigInteger d = BigInteger.valueOf(z);
BigInteger u = ONE; BigInteger u2;
BigInteger v = ONE; BigInteger v2;
for (int i=k.bitLength()-2; i >= 0; i--) {
u2 = u.multiply(v).mod(n);
v2 = v.square().add(d.multiply(u.square())).mod(n);
if (v2.testBit(0))
v2 = v2.subtract(n);
v2 = v2.shiftRight(1);
u = u2; v = v2;
if (k.testBit(i)) {
u2 = u.add(v).mod(n);
if (u2.testBit(0))
u2 = u2.subtract(n);
u2 = u2.shiftRight(1);
v2 = v.add(d.multiply(u)).mod(n);
if (v2.testBit(0))
v2 = v2.subtract(n);
v2 = v2.shiftRight(1);
u = u2; v = v2;
}
}
return u;
}
/**
* Returns true iff this BigInteger passes the specified number of
* Miller-Rabin tests. This test is taken from the DSA spec (NIST FIPS
* 186-2).
*
* The following assumptions are made:
* This BigInteger is a positive, odd number greater than 2.
* iterations<=50.
*/
private boolean passesMillerRabin(int iterations, Random rnd) {
// Find a and m such that m is odd and this == 1 + 2**a * m
BigInteger thisMinusOne = this.subtract(ONE);
BigInteger m = thisMinusOne;
int a = m.getLowestSetBit();
m = m.shiftRight(a);
// Do the tests
if (rnd == null) {
rnd = ThreadLocalRandom.current();
}
for (int i=0; i < iterations; i++) {
// Generate a uniform random on (1, this)
BigInteger b;
do {
b = new BigInteger(this.bitLength(), rnd);
} while (b.compareTo(ONE) <= 0 || b.compareTo(this) >= 0);
int j = 0;
BigInteger z = b.modPow(m, this);
while (!((j == 0 && z.equals(ONE)) || z.equals(thisMinusOne))) {
if (j > 0 && z.equals(ONE) || ++j == a)
return false;
z = z.modPow(TWO, this);
}
}
return true;
}
/**
* This internal constructor differs from its public cousin
* with the arguments reversed in two ways: it assumes that its
* arguments are correct, and it doesn't copy the magnitude array.
*/
BigInteger(int[] magnitude, int signum) {
this.signum = (magnitude.length == 0 ? 0 : signum);
this.mag = magnitude;
if (mag.length >= MAX_MAG_LENGTH) {
checkRange();
}
}
/**
* This private constructor is for internal use and assumes that its
* arguments are correct. The {@code magnitude} array is assumed to be
* unchanged for the duration of the constructor call.
*/
private BigInteger(byte[] magnitude, int signum) {
this.signum = (magnitude.length == 0 ? 0 : signum);
this.mag = stripLeadingZeroBytes(magnitude, 0, magnitude.length);
if (mag.length >= MAX_MAG_LENGTH) {
checkRange();
}
}
/**
* Throws an {@code ArithmeticException} if the {@code BigInteger} would be
* out of the supported range.
*
* @throws ArithmeticException if {@code this} exceeds the supported range.
*/
private void checkRange() {
if (mag.length > MAX_MAG_LENGTH || mag.length == MAX_MAG_LENGTH && mag[0] < 0) {
reportOverflow();
}
}
private static void reportOverflow() {
throw new ArithmeticException("BigInteger would overflow supported range");
}
//Static Factory Methods
/**
* Returns a BigInteger whose value is equal to that of the
* specified {@code long}.
*
* @apiNote This static factory method is provided in preference
* to a ({@code long}) constructor because it allows for reuse of
* frequently used BigIntegers.
*
* @param val value of the BigInteger to return.
* @return a BigInteger with the specified value.
*/
public static BigInteger valueOf(long val) {
// If -MAX_CONSTANT < val < MAX_CONSTANT, return stashed constant
if (val == 0)
return ZERO;
if (val > 0 && val <= MAX_CONSTANT)
return posConst[(int) val];
else if (val < 0 && val >= -MAX_CONSTANT)
return negConst[(int) -val];
return new BigInteger(val);
}
/**
* Constructs a BigInteger with the specified value, which may not be zero.
*/
private BigInteger(long val) {
if (val < 0) {
val = -val;
signum = -1;
} else {
signum = 1;
}
int highWord = (int)(val >>> 32);
if (highWord == 0) {
mag = new int[1];
mag[0] = (int)val;
} else {
mag = new int[2];
mag[0] = highWord;
mag[1] = (int)val;
}
}
/**
* Returns a BigInteger with the given two's complement representation.
* Assumes that the input array will not be modified (the returned
* BigInteger will reference the input array if feasible).
*/
private static BigInteger valueOf(int[] val) {
return (val[0] > 0 ? new BigInteger(val, 1) : new BigInteger(val));
}
// Constants
/**
* Initialize static constant array when class is loaded.
*/
private static final int MAX_CONSTANT = 16;
@Stable
private static final BigInteger[] posConst = new BigInteger[MAX_CONSTANT+1];
@Stable
private static final BigInteger[] negConst = new BigInteger[MAX_CONSTANT+1];
/**
* The cache of powers of each radix. This allows us to not have to
* recalculate powers of radix^(2^n) more than once. This speeds
* Schoenhage recursive base conversion significantly.
*/
private static volatile BigInteger[][] powerCache;
/** The cache of logarithms of radices for base conversion. */
private static final double[] logCache;
/** The natural log of 2. This is used in computing cache indices. */
private static final double LOG_TWO = Math.log(2.0);
static {
assert 0 < KARATSUBA_THRESHOLD
&& KARATSUBA_THRESHOLD < TOOM_COOK_THRESHOLD
&& TOOM_COOK_THRESHOLD < Integer.MAX_VALUE
&& 0 < KARATSUBA_SQUARE_THRESHOLD
&& KARATSUBA_SQUARE_THRESHOLD < TOOM_COOK_SQUARE_THRESHOLD
&& TOOM_COOK_SQUARE_THRESHOLD < Integer.MAX_VALUE :
"Algorithm thresholds are inconsistent";
for (int i = 1; i <= MAX_CONSTANT; i++) {
int[] magnitude = new int[1];
magnitude[0] = i;
posConst[i] = new BigInteger(magnitude, 1);
negConst[i] = new BigInteger(magnitude, -1);
}
/*
* Initialize the cache of radix^(2^x) values used for base conversion
* with just the very first value. Additional values will be created
* on demand.
*/
BigInteger[][] cache = new BigInteger[Character.MAX_RADIX+1][];
logCache = new double[Character.MAX_RADIX+1];
for (int i=Character.MIN_RADIX; i <= Character.MAX_RADIX; i++) {
cache[i] = new BigInteger[] { BigInteger.valueOf(i) };
logCache[i] = Math.log(i);
}
BigInteger.powerCache = cache;
}
/**
* The BigInteger constant zero.
*
* @since 1.2
*/
public static final BigInteger ZERO = new BigInteger(new int[0], 0);
/**
* The BigInteger constant one.
*
* @since 1.2
*/
public static final BigInteger ONE = valueOf(1);
/**
* The BigInteger constant two.
*
* @since 9
*/
public static final BigInteger TWO = valueOf(2);
/**
* The BigInteger constant -1. (Not exported.)
*/
private static final BigInteger NEGATIVE_ONE = valueOf(-1);
/**
* The BigInteger constant ten.
*
* @since 1.5
*/
public static final BigInteger TEN = valueOf(10);
// Arithmetic Operations
/**
* Returns a BigInteger whose value is {@code (this + val)}.
*
* @param val value to be added to this BigInteger.
* @return {@code this + val}
*/
public BigInteger add(BigInteger val) {
if (val.signum == 0)
return this;
if (signum == 0)
return val;
if (val.signum == signum)
return new BigInteger(add(mag, val.mag), signum);
int cmp = compareMagnitude(val);
if (cmp == 0)
return ZERO;
int[] resultMag = (cmp > 0 ? subtract(mag, val.mag)
: subtract(val.mag, mag));
resultMag = trustedStripLeadingZeroInts(resultMag);
return new BigInteger(resultMag, cmp == signum ? 1 : -1);
}
/**
* Package private methods used by BigDecimal code to add a BigInteger
* with a long. Assumes val is not equal to INFLATED.
*/
BigInteger add(long val) {
if (val == 0)
return this;
if (signum == 0)
return valueOf(val);
if (Long.signum(val) == signum)
return new BigInteger(add(mag, Math.abs(val)), signum);
int cmp = compareMagnitude(val);
if (cmp == 0)
return ZERO;
int[] resultMag = (cmp > 0 ? subtract(mag, Math.abs(val)) : subtract(Math.abs(val), mag));
resultMag = trustedStripLeadingZeroInts(resultMag);
return new BigInteger(resultMag, cmp == signum ? 1 : -1);
}
/**
* Adds the contents of the int array x and long value val. This
* method allocates a new int array to hold the answer and returns
* a reference to that array. Assumes x.length &gt; 0 and val is
* non-negative
*/
private static int[] add(int[] x, long val) {
int[] y;
long sum = 0;
int xIndex = x.length;
int[] result;
int highWord = (int)(val >>> 32);
if (highWord == 0) {
result = new int[xIndex];
sum = (x[--xIndex] & LONG_MASK) + val;
result[xIndex] = (int)sum;
} else {
if (xIndex == 1) {
result = new int[2];
sum = val + (x[0] & LONG_MASK);
result[1] = (int)sum;
result[0] = (int)(sum >>> 32);
return result;
} else {
result = new int[xIndex];
sum = (x[--xIndex] & LONG_MASK) + (val & LONG_MASK);
result[xIndex] = (int)sum;
sum = (x[--xIndex] & LONG_MASK) + (highWord & LONG_MASK) + (sum >>> 32);
result[xIndex] = (int)sum;
}
}
// Copy remainder of longer number while carry propagation is required
boolean carry = (sum >>> 32 != 0);
while (xIndex > 0 && carry)
carry = ((result[--xIndex] = x[xIndex] + 1) == 0);
// Copy remainder of longer number
while (xIndex > 0)
result[--xIndex] = x[xIndex];
// Grow result if necessary
if (carry) {
int bigger[] = new int[result.length + 1];
System.arraycopy(result, 0, bigger, 1, result.length);
bigger[0] = 0x01;
return bigger;
}
return result;
}
/**
* Adds the contents of the int arrays x and y. This method allocates
* a new int array to hold the answer and returns a reference to that
* array.
*/
private static int[] add(int[] x, int[] y) {
// If x is shorter, swap the two arrays
if (x.length < y.length) {
int[] tmp = x;
x = y;
y = tmp;
}
int xIndex = x.length;
int yIndex = y.length;
int result[] = new int[xIndex];
long sum = 0;
if (yIndex == 1) {
sum = (x[--xIndex] & LONG_MASK) + (y[0] & LONG_MASK) ;
result[xIndex] = (int)sum;
} else {
// Add common parts of both numbers
while (yIndex > 0) {
sum = (x[--xIndex] & LONG_MASK) +
(y[--yIndex] & LONG_MASK) + (sum >>> 32);
result[xIndex] = (int)sum;
}
}
// Copy remainder of longer number while carry propagation is required
boolean carry = (sum >>> 32 != 0);
while (xIndex > 0 && carry)
carry = ((result[--xIndex] = x[xIndex] + 1) == 0);
// Copy remainder of longer number
while (xIndex > 0)
result[--xIndex] = x[xIndex];
// Grow result if necessary
if (carry) {
int bigger[] = new int[result.length + 1];
System.arraycopy(result, 0, bigger, 1, result.length);
bigger[0] = 0x01;
return bigger;
}
return result;
}
private static int[] subtract(long val, int[] little) {
int highWord = (int)(val >>> 32);
if (highWord == 0) {
int result[] = new int[1];
result[0] = (int)(val - (little[0] & LONG_MASK));
return result;
} else {
int result[] = new int[2];
if (little.length == 1) {
long difference = ((int)val & LONG_MASK) - (little[0] & LONG_MASK);
result[1] = (int)difference;
// Subtract remainder of longer number while borrow propagates
boolean borrow = (difference >> 32 != 0);
if (borrow) {
result[0] = highWord - 1;
} else { // Copy remainder of longer number
result[0] = highWord;
}
return result;
} else { // little.length == 2
long difference = ((int)val & LONG_MASK) - (little[1] & LONG_MASK);
result[1] = (int)difference;
difference = (highWord & LONG_MASK) - (little[0] & LONG_MASK) + (difference >> 32);
result[0] = (int)difference;
return result;
}
}
}
/**
* Subtracts the contents of the second argument (val) from the
* first (big). The first int array (big) must represent a larger number
* than the second. This method allocates the space necessary to hold the
* answer.
* assumes val &gt;= 0
*/
private static int[] subtract(int[] big, long val) {
int highWord = (int)(val >>> 32);
int bigIndex = big.length;
int result[] = new int[bigIndex];
long difference = 0;
if (highWord == 0) {
difference = (big[--bigIndex] & LONG_MASK) - val;
result[bigIndex] = (int)difference;
} else {
difference = (big[--bigIndex] & LONG_MASK) - (val & LONG_MASK);
result[bigIndex] = (int)difference;
difference = (big[--bigIndex] & LONG_MASK) - (highWord & LONG_MASK) + (difference >> 32);
result[bigIndex] = (int)difference;
}
// Subtract remainder of longer number while borrow propagates
boolean borrow = (difference >> 32 != 0);
while (bigIndex > 0 && borrow)
borrow = ((result[--bigIndex] = big[bigIndex] - 1) == -1);
// Copy remainder of longer number
while (bigIndex > 0)
result[--bigIndex] = big[bigIndex];
return result;
}
/**
* Returns a BigInteger whose value is {@code (this - val)}.
*
* @param val value to be subtracted from this BigInteger.
* @return {@code this - val}
*/
public BigInteger subtract(BigInteger val) {
if (val.signum == 0)
return this;
if (signum == 0)
return val.negate();
if (val.signum != signum)
return new BigInteger(add(mag, val.mag), signum);
int cmp = compareMagnitude(val);
if (cmp == 0)
return ZERO;
int[] resultMag = (cmp > 0 ? subtract(mag, val.mag)
: subtract(val.mag, mag));
resultMag = trustedStripLeadingZeroInts(resultMag);
return new BigInteger(resultMag, cmp == signum ? 1 : -1);
}
/**
* Subtracts the contents of the second int arrays (little) from the
* first (big). The first int array (big) must represent a larger number
* than the second. This method allocates the space necessary to hold the
* answer.
*/
private static int[] subtract(int[] big, int[] little) {
int bigIndex = big.length;
int result[] = new int[bigIndex];
int littleIndex = little.length;
long difference = 0;
// Subtract common parts of both numbers
while (littleIndex > 0) {
difference = (big[--bigIndex] & LONG_MASK) -
(little[--littleIndex] & LONG_MASK) +
(difference >> 32);
result[bigIndex] = (int)difference;
}
// Subtract remainder of longer number while borrow propagates
boolean borrow = (difference >> 32 != 0);
while (bigIndex > 0 && borrow)
borrow = ((result[--bigIndex] = big[bigIndex] - 1) == -1);
// Copy remainder of longer number
while (bigIndex > 0)
result[--bigIndex] = big[bigIndex];
return result;
}
/**
* Returns a BigInteger whose value is {@code (this * val)}.
*
* @implNote An implementation may offer better algorithmic
* performance when {@code val == this}.
*
* @param val value to be multiplied by this BigInteger.
* @return {@code this * val}
*/
public BigInteger multiply(BigInteger val) {
return multiply(val, false, false, 0);
}
/**
* Returns a BigInteger whose value is {@code (this * val)}.
* When both {@code this} and {@code val} are large, typically
* in the thousands of bits, parallel multiply might be used.
* This method returns the exact same mathematical result as
* {@link #multiply}.
*
* @implNote This implementation may offer better algorithmic
* performance when {@code val == this}.
*
* @implNote Compared to {@link #multiply}, an implementation's
* parallel multiplication algorithm would typically use more
* CPU resources to compute the result faster, and may do so
* with a slight increase in memory consumption.
*
* @param val value to be multiplied by this BigInteger.
* @return {@code this * val}
* @see #multiply
* @since 19
*/
public BigInteger parallelMultiply(BigInteger val) {
return multiply(val, false, true, 0);
}
/**
* Returns a BigInteger whose value is {@code (this * val)}. If
* the invocation is recursive certain overflow checks are skipped.
*
* @param val value to be multiplied by this BigInteger.
* @param isRecursion whether this is a recursive invocation
* @param parallel whether the multiply should be done in parallel
* @return {@code this * val}
*/
private BigInteger multiply(BigInteger val, boolean isRecursion, boolean parallel, int depth) {
if (val.signum == 0 || signum == 0)
return ZERO;
int xlen = mag.length;
if (val == this && xlen > MULTIPLY_SQUARE_THRESHOLD) {
return square(true, parallel, depth);
}
int ylen = val.mag.length;
if ((xlen < KARATSUBA_THRESHOLD) || (ylen < KARATSUBA_THRESHOLD)) {
int resultSign = signum == val.signum ? 1 : -1;
if (val.mag.length == 1) {
return multiplyByInt(mag,val.mag[0], resultSign);
}
if (mag.length == 1) {
return multiplyByInt(val.mag,mag[0], resultSign);
}
int[] result = multiplyToLen(mag, xlen,
val.mag, ylen, null);
result = trustedStripLeadingZeroInts(result);
return new BigInteger(result, resultSign);
} else {
if ((xlen < TOOM_COOK_THRESHOLD) && (ylen < TOOM_COOK_THRESHOLD)) {
return multiplyKaratsuba(this, val);
} else {
//
// In "Hacker's Delight" section 2-13, p.33, it is explained
// that if x and y are unsigned 32-bit quantities and m and n
// are their respective numbers of leading zeros within 32 bits,
// then the number of leading zeros within their product as a
// 64-bit unsigned quantity is either m + n or m + n + 1. If
// their product is not to overflow, it cannot exceed 32 bits,
// and so the number of leading zeros of the product within 64
// bits must be at least 32, i.e., the leftmost set bit is at
// zero-relative position 31 or less.
//
// From the above there are three cases:
//
// m + n leftmost set bit condition
// ----- ---------------- ---------
// >= 32 x <= 64 - 32 = 32 no overflow
// == 31 x >= 64 - 32 = 32 possible overflow
// <= 30 x >= 64 - 31 = 33 definite overflow
//
// The "possible overflow" condition cannot be detected by
// examning data lengths alone and requires further calculation.
//
// By analogy, if 'this' and 'val' have m and n as their
// respective numbers of leading zeros within 32*MAX_MAG_LENGTH
// bits, then:
//
// m + n >= 32*MAX_MAG_LENGTH no overflow
// m + n == 32*MAX_MAG_LENGTH - 1 possible overflow
// m + n <= 32*MAX_MAG_LENGTH - 2 definite overflow
//
// Note however that if the number of ints in the result
// were to be MAX_MAG_LENGTH and mag[0] < 0, then there would
// be overflow. As a result the leftmost bit (of mag[0]) cannot
// be used and the constraints must be adjusted by one bit to:
//
// m + n > 32*MAX_MAG_LENGTH no overflow
// m + n == 32*MAX_MAG_LENGTH possible overflow
// m + n < 32*MAX_MAG_LENGTH definite overflow
//
// The foregoing leading zero-based discussion is for clarity
// only. The actual calculations use the estimated bit length
// of the product as this is more natural to the internal
// array representation of the magnitude which has no leading
// zero elements.
//
if (!isRecursion) {
// The bitLength() instance method is not used here as we
// are only considering the magnitudes as non-negative. The
// Toom-Cook multiplication algorithm determines the sign
// at its end from the two signum values.
if ((long)bitLength(mag, mag.length) +
(long)bitLength(val.mag, val.mag.length) >
32L*MAX_MAG_LENGTH) {
reportOverflow();
}
}
return multiplyToomCook3(this, val, parallel, depth);
}
}
}
private static BigInteger multiplyByInt(int[] x, int y, int sign) {
if (Integer.bitCount(y) == 1) {
return new BigInteger(shiftLeft(x,Integer.numberOfTrailingZeros(y)), sign);
}
int xlen = x.length;
int[] rmag = new int[xlen + 1];
long carry = 0;
long yl = y & LONG_MASK;
int rstart = rmag.length - 1;
for (int i = xlen - 1; i >= 0; i--) {
long product = (x[i] & LONG_MASK) * yl + carry;
rmag[rstart--] = (int)product;
carry = product >>> 32;
}
if (carry == 0L) {
rmag = java.util.Arrays.copyOfRange(rmag, 1, rmag.length);
} else {
rmag[rstart] = (int)carry;
}
return new BigInteger(rmag, sign);
}
/**
* Package private methods used by BigDecimal code to multiply a BigInteger
* with a long. Assumes v is not equal to INFLATED.
*/
BigInteger multiply(long v) {
if (v == 0 || signum == 0)
return ZERO;
if (v == BigDecimal.INFLATED)
return multiply(BigInteger.valueOf(v));
int rsign = (v > 0 ? signum : -signum);
if (v < 0)
v = -v;
long dh = v >>> 32; // higher order bits
long dl = v & LONG_MASK; // lower order bits
int xlen = mag.length;
int[] value = mag;
int[] rmag = (dh == 0L) ? (new int[xlen + 1]) : (new int[xlen + 2]);
long carry = 0;
int rstart = rmag.length - 1;
for (int i = xlen - 1; i >= 0; i--) {
long product = (value[i] & LONG_MASK) * dl + carry;
rmag[rstart--] = (int)product;
carry = product >>> 32;
}
rmag[rstart] = (int)carry;
if (dh != 0L) {
carry = 0;
rstart = rmag.length - 2;
for (int i = xlen - 1; i >= 0; i--) {
long product = (value[i] & LONG_MASK) * dh +
(rmag[rstart] & LONG_MASK) + carry;
rmag[rstart--] = (int)product;
carry = product >>> 32;
}
rmag[0] = (int)carry;
}
if (carry == 0L)
rmag = java.util.Arrays.copyOfRange(rmag, 1, rmag.length);
return new BigInteger(rmag, rsign);
}
/**
* Multiplies int arrays x and y to the specified lengths and places
* the result into z. There will be no leading zeros in the resultant array.
*/
private static int[] multiplyToLen(int[] x, int xlen, int[] y, int ylen, int[] z) {
multiplyToLenCheck(x, xlen);
multiplyToLenCheck(y, ylen);
return implMultiplyToLen(x, xlen, y, ylen, z);
}
@IntrinsicCandidate
private static int[] implMultiplyToLen(int[] x, int xlen, int[] y, int ylen, int[] z) {
int xstart = xlen - 1;
int ystart = ylen - 1;
if (z == null || z.length < (xlen+ ylen))
z = new int[xlen+ylen];
long carry = 0;
for (int j=ystart, k=ystart+1+xstart; j >= 0; j--, k--) {
long product = (y[j] & LONG_MASK) *
(x[xstart] & LONG_MASK) + carry;
z[k] = (int)product;
carry = product >>> 32;
}
z[xstart] = (int)carry;
for (int i = xstart-1; i >= 0; i--) {
carry = 0;
for (int j=ystart, k=ystart+1+i; j >= 0; j--, k--) {
long product = (y[j] & LONG_MASK) *
(x[i] & LONG_MASK) +
(z[k] & LONG_MASK) + carry;
z[k] = (int)product;
carry = product >>> 32;
}
z[i] = (int)carry;
}
return z;
}
private static void multiplyToLenCheck(int[] array, int length) {
if (length <= 0) {
return; // not an error because multiplyToLen won't execute if len <= 0
}
Objects.requireNonNull(array);
if (length > array.length) {
throw new ArrayIndexOutOfBoundsException(length - 1);
}
}
/**
* Multiplies two BigIntegers using the Karatsuba multiplication
* algorithm. This is a recursive divide-and-conquer algorithm which is
* more efficient for large numbers than what is commonly called the
* "grade-school" algorithm used in multiplyToLen. If the numbers to be
* multiplied have length n, the "grade-school" algorithm has an
* asymptotic complexity of O(n^2). In contrast, the Karatsuba algorithm
* has complexity of O(n^(log2(3))), or O(n^1.585). It achieves this
* increased performance by doing 3 multiplies instead of 4 when
* evaluating the product. As it has some overhead, should be used when
* both numbers are larger than a certain threshold (found
* experimentally).
*
* See: http://en.wikipedia.org/wiki/Karatsuba_algorithm
*/
private static BigInteger multiplyKaratsuba(BigInteger x, BigInteger y) {
int xlen = x.mag.length;
int ylen = y.mag.length;
// The number of ints in each half of the number.
int half = (Math.max(xlen, ylen)+1) / 2;
// xl and yl are the lower halves of x and y respectively,
// xh and yh are the upper halves.
BigInteger xl = x.getLower(half);
BigInteger xh = x.getUpper(half);
BigInteger yl = y.getLower(half);
BigInteger yh = y.getUpper(half);
BigInteger p1 = xh.multiply(yh); // p1 = xh*yh
BigInteger p2 = xl.multiply(yl); // p2 = xl*yl
// p3=(xh+xl)*(yh+yl)
BigInteger p3 = xh.add(xl).multiply(yh.add(yl));
// result = p1 * 2^(32*2*half) + (p3 - p1 - p2) * 2^(32*half) + p2
BigInteger result = p1.shiftLeft(32*half).add(p3.subtract(p1).subtract(p2)).shiftLeft(32*half).add(p2);
if (x.signum != y.signum) {
return result.negate();
} else {
return result;
}
}
@SuppressWarnings("serial")
private abstract static sealed class RecursiveOp extends RecursiveTask<BigInteger> {
/**
* The threshold until when we should continue forking recursive ops
* if parallel is true. This threshold is only relevant for Toom Cook 3
* multiply and square.
*/
private static final int PARALLEL_FORK_DEPTH_THRESHOLD =
calculateMaximumDepth(ForkJoinPool.getCommonPoolParallelism());
private static final int calculateMaximumDepth(int parallelism) {
return 32 - Integer.numberOfLeadingZeros(parallelism);
}
final boolean parallel;
/**
* The current recursing depth. Since it is a logarithmic algorithm,
* we do not need an int to hold the number.
*/
final byte depth;
private RecursiveOp(boolean parallel, int depth) {
this.parallel = parallel;
this.depth = (byte) depth;
}
private static int getParallelForkDepthThreshold() {
if (Thread.currentThread() instanceof ForkJoinWorkerThread fjwt) {
return calculateMaximumDepth(fjwt.getPool().getParallelism());
}
else {
return PARALLEL_FORK_DEPTH_THRESHOLD;
}
}
protected RecursiveTask<BigInteger> forkOrInvoke() {
if (parallel && depth <= getParallelForkDepthThreshold()) fork();
else invoke();
return this;
}
@SuppressWarnings("serial")
private static final class RecursiveMultiply extends RecursiveOp {
private final BigInteger a;
private final BigInteger b;
public RecursiveMultiply(BigInteger a, BigInteger b, boolean parallel, int depth) {
super(parallel, depth);
this.a = a;
this.b = b;
}
@Override
public BigInteger compute() {
return a.multiply(b, true, parallel, depth);
}
}
@SuppressWarnings("serial")
private static final class RecursiveSquare extends RecursiveOp {
private final BigInteger a;
public RecursiveSquare(BigInteger a, boolean parallel, int depth) {
super(parallel, depth);
this.a = a;
}
@Override
public BigInteger compute() {
return a.square(true, parallel, depth);
}
}
private static RecursiveTask<BigInteger> multiply(BigInteger a, BigInteger b, boolean parallel, int depth) {
return new RecursiveMultiply(a, b, parallel, depth).forkOrInvoke();
}
private static RecursiveTask<BigInteger> square(BigInteger a, boolean parallel, int depth) {
return new RecursiveSquare(a, parallel, depth).forkOrInvoke();
}
}
/**
* Multiplies two BigIntegers using a 3-way Toom-Cook multiplication
* algorithm. This is a recursive divide-and-conquer algorithm which is
* more efficient for large numbers than what is commonly called the
* "grade-school" algorithm used in multiplyToLen. If the numbers to be
* multiplied have length n, the "grade-school" algorithm has an
* asymptotic complexity of O(n^2). In contrast, 3-way Toom-Cook has a
* complexity of about O(n^1.465). It achieves this increased asymptotic
* performance by breaking each number into three parts and by doing 5
* multiplies instead of 9 when evaluating the product. Due to overhead
* (additions, shifts, and one division) in the Toom-Cook algorithm, it
* should only be used when both numbers are larger than a certain
* threshold (found experimentally). This threshold is generally larger
* than that for Karatsuba multiplication, so this algorithm is generally
* only used when numbers become significantly larger.
*
* The algorithm used is the "optimal" 3-way Toom-Cook algorithm outlined
* by Marco Bodrato.
*
* See: http://bodrato.it/toom-cook/
* http://bodrato.it/papers/#WAIFI2007
*
* "Towards Optimal Toom-Cook Multiplication for Univariate and
* Multivariate Polynomials in Characteristic 2 and 0." by Marco BODRATO;
* In C.Carlet and B.Sunar, Eds., "WAIFI'07 proceedings", p. 116-133,
* LNCS #4547. Springer, Madrid, Spain, June 21-22, 2007.
*
*/
private static BigInteger multiplyToomCook3(BigInteger a, BigInteger b, boolean parallel, int depth) {
int alen = a.mag.length;
int blen = b.mag.length;
int largest = Math.max(alen, blen);
// k is the size (in ints) of the lower-order slices.
int k = (largest+2)/3; // Equal to ceil(largest/3)
// r is the size (in ints) of the highest-order slice.
int r = largest - 2*k;
// Obtain slices of the numbers. a2 and b2 are the most significant
// bits of the numbers a and b, and a0 and b0 the least significant.
BigInteger a0, a1, a2, b0, b1, b2;
a2 = a.getToomSlice(k, r, 0, largest);
a1 = a.getToomSlice(k, r, 1, largest);
a0 = a.getToomSlice(k, r, 2, largest);
b2 = b.getToomSlice(k, r, 0, largest);
b1 = b.getToomSlice(k, r, 1, largest);
b0 = b.getToomSlice(k, r, 2, largest);
BigInteger v0, v1, v2, vm1, vinf, t1, t2, tm1, da1, db1;
depth++;
var v0_task = RecursiveOp.multiply(a0, b0, parallel, depth);
da1 = a2.add(a0);
db1 = b2.add(b0);
var vm1_task = RecursiveOp.multiply(da1.subtract(a1), db1.subtract(b1), parallel, depth);
da1 = da1.add(a1);
db1 = db1.add(b1);
var v1_task = RecursiveOp.multiply(da1, db1, parallel, depth);
v2 = da1.add(a2).shiftLeft(1).subtract(a0).multiply(
db1.add(b2).shiftLeft(1).subtract(b0), true, parallel, depth);
vinf = a2.multiply(b2, true, parallel, depth);
v0 = v0_task.join();
vm1 = vm1_task.join();
v1 = v1_task.join();
// The algorithm requires two divisions by 2 and one by 3.
// All divisions are known to be exact, that is, they do not produce
// remainders, and all results are positive. The divisions by 2 are
// implemented as right shifts which are relatively efficient, leaving
// only an exact division by 3, which is done by a specialized
// linear-time algorithm.
t2 = v2.subtract(vm1).exactDivideBy3();
tm1 = v1.subtract(vm1).shiftRight(1);
t1 = v1.subtract(v0);
t2 = t2.subtract(t1).shiftRight(1);
t1 = t1.subtract(tm1).subtract(vinf);
t2 = t2.subtract(vinf.shiftLeft(1));
tm1 = tm1.subtract(t2);
// Number of bits to shift left.
int ss = k*32;
BigInteger result = vinf.shiftLeft(ss).add(t2).shiftLeft(ss).add(t1).shiftLeft(ss).add(tm1).shiftLeft(ss).add(v0);
if (a.signum != b.signum) {
return result.negate();
} else {
return result;
}
}
/**
* Returns a slice of a BigInteger for use in Toom-Cook multiplication.
*
* @param lowerSize The size of the lower-order bit slices.
* @param upperSize The size of the higher-order bit slices.
* @param slice The index of which slice is requested, which must be a
* number from 0 to size-1. Slice 0 is the highest-order bits, and slice
* size-1 are the lowest-order bits. Slice 0 may be of different size than
* the other slices.
* @param fullsize The size of the larger integer array, used to align
* slices to the appropriate position when multiplying different-sized
* numbers.
*/
private BigInteger getToomSlice(int lowerSize, int upperSize, int slice,
int fullsize) {
int start, end, sliceSize, len, offset;
len = mag.length;
offset = fullsize - len;
if (slice == 0) {
start = 0 - offset;
end = upperSize - 1 - offset;
} else {
start = upperSize + (slice-1)*lowerSize - offset;
end = start + lowerSize - 1;
}
if (start < 0) {
start = 0;
}
if (end < 0) {
return ZERO;
}
sliceSize = (end-start) + 1;
if (sliceSize <= 0) {
return ZERO;
}
// While performing Toom-Cook, all slices are positive and
// the sign is adjusted when the final number is composed.
if (start == 0 && sliceSize >= len) {
return this.abs();
}
int intSlice[] = new int[sliceSize];
System.arraycopy(mag, start, intSlice, 0, sliceSize);
return new BigInteger(trustedStripLeadingZeroInts(intSlice), 1);
}
/**
* Does an exact division (that is, the remainder is known to be zero)
* of the specified number by 3. This is used in Toom-Cook
* multiplication. This is an efficient algorithm that runs in linear
* time. If the argument is not exactly divisible by 3, results are
* undefined. Note that this is expected to be called with positive
* arguments only.
*/
private BigInteger exactDivideBy3() {
int len = mag.length;
int[] result = new int[len];
long x, w, q, borrow;
borrow = 0L;
for (int i=len-1; i >= 0; i--) {
x = (mag[i] & LONG_MASK);
w = x - borrow;
if (borrow > x) { // Did we make the number go negative?
borrow = 1L;
} else {
borrow = 0L;
}
// 0xAAAAAAAB is the modular inverse of 3 (mod 2^32). Thus,
// the effect of this is to divide by 3 (mod 2^32).
// This is much faster than division on most architectures.
q = (w * 0xAAAAAAABL) & LONG_MASK;
result[i] = (int) q;
// Now check the borrow. The second check can of course be
// eliminated if the first fails.
if (q >= 0x55555556L) {
borrow++;
if (q >= 0xAAAAAAABL)
borrow++;
}
}
result = trustedStripLeadingZeroInts(result);
return new BigInteger(result, signum);
}
/**
* Returns a new BigInteger representing n lower ints of the number.
* This is used by Karatsuba multiplication and Karatsuba squaring.
*/
private BigInteger getLower(int n) {
int len = mag.length;
if (len <= n) {
return abs();
}
int lowerInts[] = new int[n];
System.arraycopy(mag, len-n, lowerInts, 0, n);
return new BigInteger(trustedStripLeadingZeroInts(lowerInts), 1);
}
/**
* Returns a new BigInteger representing mag.length-n upper
* ints of the number. This is used by Karatsuba multiplication and
* Karatsuba squaring.
*/
private BigInteger getUpper(int n) {
int len = mag.length;
if (len <= n) {
return ZERO;
}
int upperLen = len - n;
int upperInts[] = new int[upperLen];
System.arraycopy(mag, 0, upperInts, 0, upperLen);
return new BigInteger(trustedStripLeadingZeroInts(upperInts), 1);
}
// Squaring
/**
* Returns a BigInteger whose value is <code>(this<sup>2</sup>)</code>.
*
* @return <code>this<sup>2</sup></code>
*/
private BigInteger square() {
return square(false, false, 0);
}
/**
* Returns a BigInteger whose value is <code>(this<sup>2</sup>)</code>. If
* the invocation is recursive certain overflow checks are skipped.
*
* @param isRecursion whether this is a recursive invocation
* @return <code>this<sup>2</sup></code>
*/
private BigInteger square(boolean isRecursion, boolean parallel, int depth) {
if (signum == 0) {
return ZERO;
}
int len = mag.length;
if (len < KARATSUBA_SQUARE_THRESHOLD) {
int[] z = squareToLen(mag, len, null);
return new BigInteger(trustedStripLeadingZeroInts(z), 1);
} else {
if (len < TOOM_COOK_SQUARE_THRESHOLD) {
return squareKaratsuba();
} else {
//
// For a discussion of overflow detection see multiply()
//
if (!isRecursion) {
if (bitLength(mag, mag.length) > 16L*MAX_MAG_LENGTH) {
reportOverflow();
}
}
return squareToomCook3(parallel, depth);
}
}
}
/**
* Squares the contents of the int array x. The result is placed into the
* int array z. The contents of x are not changed.
*/
private static final int[] squareToLen(int[] x, int len, int[] z) {
int zlen = len << 1;
if (z == null || z.length < zlen)
z = new int[zlen];
// Execute checks before calling intrinsified method.
implSquareToLenChecks(x, len, z, zlen);
return implSquareToLen(x, len, z, zlen);
}
/**
* Parameters validation.
*/
private static void implSquareToLenChecks(int[] x, int len, int[] z, int zlen) throws RuntimeException {
if (len < 1) {
throw new IllegalArgumentException("invalid input length: " + len);
}
if (len > x.length) {
throw new IllegalArgumentException("input length out of bound: " +
len + " > " + x.length);
}
if (len * 2 > z.length) {
throw new IllegalArgumentException("input length out of bound: " +
(len * 2) + " > " + z.length);
}
if (zlen < 1) {
throw new IllegalArgumentException("invalid input length: " + zlen);
}
if (zlen > z.length) {
throw new IllegalArgumentException("input length out of bound: " +
len + " > " + z.length);
}
}
/**
* Java Runtime may use intrinsic for this method.
*/
@IntrinsicCandidate
private static final int[] implSquareToLen(int[] x, int len, int[] z, int zlen) {
/*
* The algorithm used here is adapted from Colin Plumb's C library.
* Technique: Consider the partial products in the multiplication
* of "abcde" by itself:
*
* a b c d e
* * a b c d e
* ==================
* ae be ce de ee
* ad bd cd dd de
* ac bc cc cd ce
* ab bb bc bd be
* aa ab ac ad ae
*
* Note that everything above the main diagonal:
* ae be ce de = (abcd) * e
* ad bd cd = (abc) * d
* ac bc = (ab) * c
* ab = (a) * b
*
* is a copy of everything below the main diagonal:
* de
* cd ce
* bc bd be
* ab ac ad ae
*
* Thus, the sum is 2 * (off the diagonal) + diagonal.
*
* This is accumulated beginning with the diagonal (which
* consist of the squares of the digits of the input), which is then
* divided by two, the off-diagonal added, and multiplied by two
* again. The low bit is simply a copy of the low bit of the
* input, so it doesn't need special care.
*/
// Store the squares, right shifted one bit (i.e., divided by 2)
int lastProductLowWord = 0;
for (int j=0, i=0; j < len; j++) {
long piece = (x[j] & LONG_MASK);
long product = piece * piece;
z[i++] = (lastProductLowWord << 31) | (int)(product >>> 33);
z[i++] = (int)(product >>> 1);
lastProductLowWord = (int)product;
}
// Add in off-diagonal sums
for (int i=len, offset=1; i > 0; i--, offset+=2) {
int t = x[i-1];
t = mulAdd(z, x, offset, i-1, t);
addOne(z, offset-1, i, t);
}
// Shift back up and set low bit
primitiveLeftShift(z, zlen, 1);
z[zlen-1] |= x[len-1] & 1;
return z;
}
/**
* Squares a BigInteger using the Karatsuba squaring algorithm. It should
* be used when both numbers are larger than a certain threshold (found
* experimentally). It is a recursive divide-and-conquer algorithm that
* has better asymptotic performance than the algorithm used in
* squareToLen.
*/
private BigInteger squareKaratsuba() {
int half = (mag.length+1) / 2;
BigInteger xl = getLower(half);
BigInteger xh = getUpper(half);
BigInteger xhs = xh.square(); // xhs = xh^2
BigInteger xls = xl.square(); // xls = xl^2
// xh^2 << 64 + (((xl+xh)^2 - (xh^2 + xl^2)) << 32) + xl^2
return xhs.shiftLeft(half*32).add(xl.add(xh).square().subtract(xhs.add(xls))).shiftLeft(half*32).add(xls);
}
/**
* Squares a BigInteger using the 3-way Toom-Cook squaring algorithm. It
* should be used when both numbers are larger than a certain threshold
* (found experimentally). It is a recursive divide-and-conquer algorithm
* that has better asymptotic performance than the algorithm used in
* squareToLen or squareKaratsuba.
*/
private BigInteger squareToomCook3(boolean parallel, int depth) {
int len = mag.length;
// k is the size (in ints) of the lower-order slices.
int k = (len+2)/3; // Equal to ceil(largest/3)
// r is the size (in ints) of the highest-order slice.
int r = len - 2*k;
// Obtain slices of the numbers. a2 is the most significant
// bits of the number, and a0 the least significant.
BigInteger a0, a1, a2;
a2 = getToomSlice(k, r, 0, len);
a1 = getToomSlice(k, r, 1, len);
a0 = getToomSlice(k, r, 2, len);
BigInteger v0, v1, v2, vm1, vinf, t1, t2, tm1, da1;
depth++;
var v0_fork = RecursiveOp.square(a0, parallel, depth);
da1 = a2.add(a0);
var vm1_fork = RecursiveOp.square(da1.subtract(a1), parallel, depth);
da1 = da1.add(a1);
var v1_fork = RecursiveOp.square(da1, parallel, depth);
vinf = a2.square(true, parallel, depth);
v2 = da1.add(a2).shiftLeft(1).subtract(a0).square(true, parallel, depth);
v0 = v0_fork.join();
vm1 = vm1_fork.join();
v1 = v1_fork.join();
// The algorithm requires two divisions by 2 and one by 3.
// All divisions are known to be exact, that is, they do not produce
// remainders, and all results are positive. The divisions by 2 are
// implemented as right shifts which are relatively efficient, leaving
// only a division by 3.
// The division by 3 is done by an optimized algorithm for this case.
t2 = v2.subtract(vm1).exactDivideBy3();
tm1 = v1.subtract(vm1).shiftRight(1);
t1 = v1.subtract(v0);
t2 = t2.subtract(t1).shiftRight(1);
t1 = t1.subtract(tm1).subtract(vinf);
t2 = t2.subtract(vinf.shiftLeft(1));
tm1 = tm1.subtract(t2);
// Number of bits to shift left.
int ss = k*32;
return vinf.shiftLeft(ss).add(t2).shiftLeft(ss).add(t1).shiftLeft(ss).add(tm1).shiftLeft(ss).add(v0);
}
// Division
/**
* Returns a BigInteger whose value is {@code (this / val)}.
*
* @param val value by which this BigInteger is to be divided.
* @return {@code this / val}
* @throws ArithmeticException if {@code val} is zero.
*/
public BigInteger divide(BigInteger val) {
if (val.mag.length < BURNIKEL_ZIEGLER_THRESHOLD ||
mag.length - val.mag.length < BURNIKEL_ZIEGLER_OFFSET) {
return divideKnuth(val);
} else {
return divideBurnikelZiegler(val);
}
}
/**
* Returns a BigInteger whose value is {@code (this / val)} using an O(n^2) algorithm from Knuth.
*
* @param val value by which this BigInteger is to be divided.
* @return {@code this / val}
* @throws ArithmeticException if {@code val} is zero.
* @see MutableBigInteger#divideKnuth(MutableBigInteger, MutableBigInteger, boolean)
*/
private BigInteger divideKnuth(BigInteger val) {
MutableBigInteger q = new MutableBigInteger(),
a = new MutableBigInteger(this.mag),
b = new MutableBigInteger(val.mag);
a.divideKnuth(b, q, false);
return q.toBigInteger(this.signum * val.signum);
}
/**
* Returns an array of two BigIntegers containing {@code (this / val)}
* followed by {@code (this % val)}.
*
* @param val value by which this BigInteger is to be divided, and the
* remainder computed.
* @return an array of two BigIntegers: the quotient {@code (this / val)}
* is the initial element, and the remainder {@code (this % val)}
* is the final element.
* @throws ArithmeticException if {@code val} is zero.
*/
public BigInteger[] divideAndRemainder(BigInteger val) {
if (val.mag.length < BURNIKEL_ZIEGLER_THRESHOLD ||
mag.length - val.mag.length < BURNIKEL_ZIEGLER_OFFSET) {
return divideAndRemainderKnuth(val);
} else {
return divideAndRemainderBurnikelZiegler(val);
}
}
/** Long division */
private BigInteger[] divideAndRemainderKnuth(BigInteger val) {
BigInteger[] result = new BigInteger[2];
MutableBigInteger q = new MutableBigInteger(),
a = new MutableBigInteger(this.mag),
b = new MutableBigInteger(val.mag);
MutableBigInteger r = a.divideKnuth(b, q);
result[0] = q.toBigInteger(this.signum == val.signum ? 1 : -1);
result[1] = r.toBigInteger(this.signum);
return result;
}
/**
* Returns a BigInteger whose value is {@code (this % val)}.
*
* @param val value by which this BigInteger is to be divided, and the
* remainder computed.
* @return {@code this % val}
* @throws ArithmeticException if {@code val} is zero.
*/
public BigInteger remainder(BigInteger val) {
if (val.mag.length < BURNIKEL_ZIEGLER_THRESHOLD ||
mag.length - val.mag.length < BURNIKEL_ZIEGLER_OFFSET) {
return remainderKnuth(val);
} else {
return remainderBurnikelZiegler(val);
}
}
/** Long division */
private BigInteger remainderKnuth(BigInteger val) {
MutableBigInteger q = new MutableBigInteger(),
a = new MutableBigInteger(this.mag),
b = new MutableBigInteger(val.mag);
return a.divideKnuth(b, q).toBigInteger(this.signum);
}
/**
* Calculates {@code this / val} using the Burnikel-Ziegler algorithm.
* @param val the divisor
* @return {@code this / val}
*/
private BigInteger divideBurnikelZiegler(BigInteger val) {
return divideAndRemainderBurnikelZiegler(val)[0];
}
/**
* Calculates {@code this % val} using the Burnikel-Ziegler algorithm.
* @param val the divisor
* @return {@code this % val}
*/
private BigInteger remainderBurnikelZiegler(BigInteger val) {
return divideAndRemainderBurnikelZiegler(val)[1];
}
/**
* Computes {@code this / val} and {@code this % val} using the
* Burnikel-Ziegler algorithm.
* @param val the divisor
* @return an array containing the quotient and remainder
*/
private BigInteger[] divideAndRemainderBurnikelZiegler(BigInteger val) {
MutableBigInteger q = new MutableBigInteger();
MutableBigInteger r = new MutableBigInteger(this).divideAndRemainderBurnikelZiegler(new MutableBigInteger(val), q);
BigInteger qBigInt = q.isZero() ? ZERO : q.toBigInteger(signum*val.signum);
BigInteger rBigInt = r.isZero() ? ZERO : r.toBigInteger(signum);
return new BigInteger[] {qBigInt, rBigInt};
}
/**
* Returns a BigInteger whose value is <code>(this<sup>exponent</sup>)</code>.
* Note that {@code exponent} is an integer rather than a BigInteger.
*
* @param exponent exponent to which this BigInteger is to be raised.
* @return <code>this<sup>exponent</sup></code>
* @throws ArithmeticException {@code exponent} is negative. (This would
* cause the operation to yield a non-integer value.)
*/
public BigInteger pow(int exponent) {
if (exponent < 0) {
throw new ArithmeticException("Negative exponent");
}
if (signum == 0) {
return (exponent == 0 ? ONE : this);
}
BigInteger partToSquare = this.abs();
// Factor out powers of two from the base, as the exponentiation of
// these can be done by left shifts only.
// The remaining part can then be exponentiated faster. The
// powers of two will be multiplied back at the end.
int powersOfTwo = partToSquare.getLowestSetBit();
long bitsToShiftLong = (long)powersOfTwo * exponent;
if (bitsToShiftLong > Integer.MAX_VALUE) {
reportOverflow();
}
int bitsToShift = (int)bitsToShiftLong;
int remainingBits;
// Factor the powers of two out quickly by shifting right, if needed.
if (powersOfTwo > 0) {
partToSquare = partToSquare.shiftRight(powersOfTwo);
remainingBits = partToSquare.bitLength();
if (remainingBits == 1) { // Nothing left but +/- 1?
if (signum < 0 && (exponent&1) == 1) {
return NEGATIVE_ONE.shiftLeft(bitsToShift);
} else {
return ONE.shiftLeft(bitsToShift);
}
}
} else {
remainingBits = partToSquare.bitLength();
if (remainingBits == 1) { // Nothing left but +/- 1?
if (signum < 0 && (exponent&1) == 1) {
return NEGATIVE_ONE;
} else {
return ONE;
}
}
}
// This is a quick way to approximate the size of the result,
// similar to doing log2[n] * exponent. This will give an upper bound
// of how big the result can be, and which algorithm to use.
long scaleFactor = (long)remainingBits * exponent;
// Use slightly different algorithms for small and large operands.
// See if the result will safely fit into a long. (Largest 2^63-1)
if (partToSquare.mag.length == 1 && scaleFactor <= 62) {
// Small number algorithm. Everything fits into a long.
int newSign = (signum <0 && (exponent&1) == 1 ? -1 : 1);
long result = 1;
long baseToPow2 = partToSquare.mag[0] & LONG_MASK;
int workingExponent = exponent;
// Perform exponentiation using repeated squaring trick
while (workingExponent != 0) {
if ((workingExponent & 1) == 1) {
result = result * baseToPow2;
}
if ((workingExponent >>>= 1) != 0) {
baseToPow2 = baseToPow2 * baseToPow2;
}
}
// Multiply back the powers of two (quickly, by shifting left)
if (powersOfTwo > 0) {
if (bitsToShift + scaleFactor <= 62) { // Fits in long?
return valueOf((result << bitsToShift) * newSign);
} else {
return valueOf(result*newSign).shiftLeft(bitsToShift);
}
} else {
return valueOf(result*newSign);
}
} else {
if ((long)bitLength() * exponent / Integer.SIZE > MAX_MAG_LENGTH) {
reportOverflow();
}
// Large number algorithm. This is basically identical to
// the algorithm above, but calls multiply() and square()
// which may use more efficient algorithms for large numbers.
BigInteger answer = ONE;
int workingExponent = exponent;
// Perform exponentiation using repeated squaring trick
while (workingExponent != 0) {
if ((workingExponent & 1) == 1) {
answer = answer.multiply(partToSquare);
}
if ((workingExponent >>>= 1) != 0) {
partToSquare = partToSquare.square();
}
}
// Multiply back the (exponentiated) powers of two (quickly,
// by shifting left)
if (powersOfTwo > 0) {
answer = answer.shiftLeft(bitsToShift);
}
if (signum < 0 && (exponent&1) == 1) {
return answer.negate();
} else {
return answer;
}
}
}
/**
* Returns the integer square root of this BigInteger. The integer square
* root of the corresponding mathematical integer {@code n} is the largest
* mathematical integer {@code s} such that {@code s*s <= n}. It is equal
* to the value of {@code floor(sqrt(n))}, where {@code sqrt(n)} denotes the
* real square root of {@code n} treated as a real. Note that the integer
* square root will be less than the real square root if the latter is not
* representable as an integral value.
*
* @return the integer square root of {@code this}
* @throws ArithmeticException if {@code this} is negative. (The square
* root of a negative integer {@code val} is
* {@code (i * sqrt(-val))} where <i>i</i> is the
* <i>imaginary unit</i> and is equal to
* {@code sqrt(-1)}.)
* @since 9
*/
public BigInteger sqrt() {
if (this.signum < 0) {
throw new ArithmeticException("Negative BigInteger");
}
return new MutableBigInteger(this.mag).sqrt().toBigInteger();
}
/**
* Returns an array of two BigIntegers containing the integer square root
* {@code s} of {@code this} and its remainder {@code this - s*s},
* respectively.
*
* @return an array of two BigIntegers with the integer square root at
* offset 0 and the remainder at offset 1
* @throws ArithmeticException if {@code this} is negative. (The square
* root of a negative integer {@code val} is
* {@code (i * sqrt(-val))} where <i>i</i> is the
* <i>imaginary unit</i> and is equal to
* {@code sqrt(-1)}.)
* @see #sqrt()
* @since 9
*/
public BigInteger[] sqrtAndRemainder() {
BigInteger s = sqrt();
BigInteger r = this.subtract(s.square());
assert r.compareTo(BigInteger.ZERO) >= 0;
return new BigInteger[] {s, r};
}
/**
* Returns a BigInteger whose value is the greatest common divisor of
* {@code abs(this)} and {@code abs(val)}. Returns 0 if
* {@code this == 0 && val == 0}.
*
* @param val value with which the GCD is to be computed.
* @return {@code GCD(abs(this), abs(val))}
*/
public BigInteger gcd(BigInteger val) {
if (val.signum == 0)
return this.abs();
else if (this.signum == 0)
return val.abs();
MutableBigInteger a = new MutableBigInteger(this);
MutableBigInteger b = new MutableBigInteger(val);
MutableBigInteger result = a.hybridGCD(b);
return result.toBigInteger(1);
}
/**
* Package private method to return bit length for an integer.
*/
static int bitLengthForInt(int n) {
return 32 - Integer.numberOfLeadingZeros(n);
}
/**
* Left shift int array a up to len by n bits. Returns the array that
* results from the shift since space may have to be reallocated.
*/
private static int[] leftShift(int[] a, int len, int n) {
int nInts = n >>> 5;
int nBits = n&0x1F;
int bitsInHighWord = bitLengthForInt(a[0]);
// If shift can be done without recopy, do so
if (n <= (32-bitsInHighWord)) {
primitiveLeftShift(a, len, nBits);
return a;
} else { // Array must be resized
if (nBits <= (32-bitsInHighWord)) {
int result[] = new int[nInts+len];
System.arraycopy(a, 0, result, 0, len);
primitiveLeftShift(result, result.length, nBits);
return result;
} else {
int result[] = new int[nInts+len+1];
System.arraycopy(a, 0, result, 0, len);
primitiveRightShift(result, result.length, 32 - nBits);
return result;
}
}
}
// shifts a up to len right n bits assumes no leading zeros, 0<n<32
static void primitiveRightShift(int[] a, int len, int n) {
Objects.checkFromToIndex(0, len, a.length);
shiftRightImplWorker(a, a, 1, n, len-1);
a[0] >>>= n;
}
// shifts a up to len left n bits assumes no leading zeros, 0<=n<32
static void primitiveLeftShift(int[] a, int len, int n) {
if (len == 0 || n == 0)
return;
Objects.checkFromToIndex(0, len, a.length);
shiftLeftImplWorker(a, a, 0, n, len-1);
a[len-1] <<= n;
}
/**
* Calculate bitlength of contents of the first len elements an int array,
* assuming there are no leading zero ints.
*/
private static int bitLength(int[] val, int len) {
if (len == 0)
return 0;
return ((len - 1) << 5) + bitLengthForInt(val[0]);
}
/**
* Returns a BigInteger whose value is the absolute value of this
* BigInteger.
*
* @return {@code abs(this)}
*/
public BigInteger abs() {
return (signum >= 0 ? this : this.negate());
}
/**
* Returns a BigInteger whose value is {@code (-this)}.
*
* @return {@code -this}
*/
public BigInteger negate() {
return new BigInteger(this.mag, -this.signum);
}
/**
* Returns the signum function of this BigInteger.
*
* @return -1, 0 or 1 as the value of this BigInteger is negative, zero or
* positive.
*/
public int signum() {
return this.signum;
}
// Modular Arithmetic Operations
/**
* Returns a BigInteger whose value is {@code (this mod m}). This method
* differs from {@code remainder} in that it always returns a
* <i>non-negative</i> BigInteger.
*
* @param m the modulus.
* @return {@code this mod m}
* @throws ArithmeticException {@code m} &le; 0
* @see #remainder
*/
public BigInteger mod(BigInteger m) {
if (m.signum <= 0)
throw new ArithmeticException("BigInteger: modulus not positive");
BigInteger result = this.remainder(m);
return (result.signum >= 0 ? result : result.add(m));
}
/**
* Returns a BigInteger whose value is
* <code>(this<sup>exponent</sup> mod m)</code>. (Unlike {@code pow}, this
* method permits negative exponents.)
*
* @param exponent the exponent.
* @param m the modulus.
* @return <code>this<sup>exponent</sup> mod m</code>
* @throws ArithmeticException {@code m} &le; 0 or the exponent is
* negative and this BigInteger is not <i>relatively
* prime</i> to {@code m}.
* @see #modInverse
*/
public BigInteger modPow(BigInteger exponent, BigInteger m) {
if (m.signum <= 0)
throw new ArithmeticException("BigInteger: modulus not positive");
// Trivial cases
if (exponent.signum == 0)
return (m.equals(ONE) ? ZERO : ONE);
if (this.equals(ONE))
return (m.equals(ONE) ? ZERO : ONE);
if (this.equals(ZERO) && exponent.signum >= 0)
return ZERO;
if (this.equals(negConst[1]) && (!exponent.testBit(0)))
return (m.equals(ONE) ? ZERO : ONE);
boolean invertResult;
if ((invertResult = (exponent.signum < 0)))
exponent = exponent.negate();
BigInteger base = (this.signum < 0 || this.compareTo(m) >= 0
? this.mod(m) : this);
BigInteger result;
if (m.testBit(0)) { // odd modulus
result = base.oddModPow(exponent, m);
} else {
/*
* Even modulus. Tear it into an "odd part" (m1) and power of two
* (m2), exponentiate mod m1, manually exponentiate mod m2, and
* use Chinese Remainder Theorem to combine results.
*/
// Tear m apart into odd part (m1) and power of 2 (m2)
int p = m.getLowestSetBit(); // Max pow of 2 that divides m
BigInteger m1 = m.shiftRight(p); // m/2**p
BigInteger m2 = ONE.shiftLeft(p); // 2**p
// Calculate new base from m1
BigInteger base2 = (this.signum < 0 || this.compareTo(m1) >= 0
? this.mod(m1) : this);
// Calculate (base ** exponent) mod m1.
BigInteger a1 = (m1.equals(ONE) ? ZERO :
base2.oddModPow(exponent, m1));
// Calculate (this ** exponent) mod m2
BigInteger a2 = base.modPow2(exponent, p);
// Combine results using Chinese Remainder Theorem
BigInteger y1 = m2.modInverse(m1);
BigInteger y2 = m1.modInverse(m2);
if (m.mag.length < MAX_MAG_LENGTH / 2) {
result = a1.multiply(m2).multiply(y1).add(a2.multiply(m1).multiply(y2)).mod(m);
} else {
MutableBigInteger t1 = new MutableBigInteger();
new MutableBigInteger(a1.multiply(m2)).multiply(new MutableBigInteger(y1), t1);
MutableBigInteger t2 = new MutableBigInteger();
new MutableBigInteger(a2.multiply(m1)).multiply(new MutableBigInteger(y2), t2);
t1.add(t2);
MutableBigInteger q = new MutableBigInteger();
result = t1.divide(new MutableBigInteger(m), q).toBigInteger();
}
}
return (invertResult ? result.modInverse(m) : result);
}
// Montgomery multiplication. These are wrappers for
// implMontgomeryXX routines which are expected to be replaced by
// virtual machine intrinsics. We don't use the intrinsics for
// very large operands: MONTGOMERY_INTRINSIC_THRESHOLD should be
// larger than any reasonable crypto key.
private static int[] montgomeryMultiply(int[] a, int[] b, int[] n, int len, long inv,
int[] product) {
implMontgomeryMultiplyChecks(a, b, n, len, product);
if (len > MONTGOMERY_INTRINSIC_THRESHOLD) {
// Very long argument: do not use an intrinsic
product = multiplyToLen(a, len, b, len, product);
return montReduce(product, n, len, (int)inv);
} else {
return implMontgomeryMultiply(a, b, n, len, inv, materialize(product, len));
}
}
private static int[] montgomerySquare(int[] a, int[] n, int len, long inv,
int[] product) {
implMontgomeryMultiplyChecks(a, a, n, len, product);
if (len > MONTGOMERY_INTRINSIC_THRESHOLD) {
// Very long argument: do not use an intrinsic
product = squareToLen(a, len, product);
return montReduce(product, n, len, (int)inv);
} else {
return implMontgomerySquare(a, n, len, inv, materialize(product, len));
}
}
// Range-check everything.
private static void implMontgomeryMultiplyChecks
(int[] a, int[] b, int[] n, int len, int[] product) throws RuntimeException {
if (len % 2 != 0) {
throw new IllegalArgumentException("input array length must be even: " + len);
}
if (len < 1) {
throw new IllegalArgumentException("invalid input length: " + len);
}
if (len > a.length ||
len > b.length ||
len > n.length ||
(product != null && len > product.length)) {
throw new IllegalArgumentException("input array length out of bound: " + len);
}
}
// Make sure that the int array z (which is expected to contain
// the result of a Montgomery multiplication) is present and
// sufficiently large.
private static int[] materialize(int[] z, int len) {
if (z == null || z.length < len)
z = new int[len];
return z;
}
// These methods are intended to be replaced by virtual machine
// intrinsics.
@IntrinsicCandidate
private static int[] implMontgomeryMultiply(int[] a, int[] b, int[] n, int len,
long inv, int[] product) {
product = multiplyToLen(a, len, b, len, product);
return montReduce(product, n, len, (int)inv);
}
@IntrinsicCandidate
private static int[] implMontgomerySquare(int[] a, int[] n, int len,
long inv, int[] product) {
product = squareToLen(a, len, product);
return montReduce(product, n, len, (int)inv);
}
static int[] bnExpModThreshTable = {7, 25, 81, 241, 673, 1793,
Integer.MAX_VALUE}; // Sentinel
/**
* Returns a BigInteger whose value is x to the power of y mod z.
* Assumes: z is odd && x < z.
*/
private BigInteger oddModPow(BigInteger y, BigInteger z) {
/*
* The algorithm is adapted from Colin Plumb's C library.
*
* The window algorithm:
* The idea is to keep a running product of b1 = n^(high-order bits of exp)
* and then keep appending exponent bits to it. The following patterns
* apply to a 3-bit window (k = 3):
* To append 0: square
* To append 1: square, multiply by n^1
* To append 10: square, multiply by n^1, square
* To append 11: square, square, multiply by n^3
* To append 100: square, multiply by n^1, square, square
* To append 101: square, square, square, multiply by n^5
* To append 110: square, square, multiply by n^3, square
* To append 111: square, square, square, multiply by n^7
*
* Since each pattern involves only one multiply, the longer the pattern
* the better, except that a 0 (no multiplies) can be appended directly.
* We precompute a table of odd powers of n, up to 2^k, and can then
* multiply k bits of exponent at a time. Actually, assuming random
* exponents, there is on average one zero bit between needs to
* multiply (1/2 of the time there's none, 1/4 of the time there's 1,
* 1/8 of the time, there's 2, 1/32 of the time, there's 3, etc.), so
* you have to do one multiply per k+1 bits of exponent.
*
* The loop walks down the exponent, squaring the result buffer as
* it goes. There is a wbits+1 bit lookahead buffer, buf, that is
* filled with the upcoming exponent bits. (What is read after the
* end of the exponent is unimportant, but it is filled with zero here.)
* When the most-significant bit of this buffer becomes set, i.e.
* (buf & tblmask) != 0, we have to decide what pattern to multiply
* by, and when to do it. We decide, remember to do it in future
* after a suitable number of squarings have passed (e.g. a pattern
* of "100" in the buffer requires that we multiply by n^1 immediately;
* a pattern of "110" calls for multiplying by n^3 after one more
* squaring), clear the buffer, and continue.
*
* When we start, there is one more optimization: the result buffer
* is implcitly one, so squaring it or multiplying by it can be
* optimized away. Further, if we start with a pattern like "100"
* in the lookahead window, rather than placing n into the buffer
* and then starting to square it, we have already computed n^2
* to compute the odd-powers table, so we can place that into
* the buffer and save a squaring.
*
* This means that if you have a k-bit window, to compute n^z,
* where z is the high k bits of the exponent, 1/2 of the time
* it requires no squarings. 1/4 of the time, it requires 1
* squaring, ... 1/2^(k-1) of the time, it requires k-2 squarings.
* And the remaining 1/2^(k-1) of the time, the top k bits are a
* 1 followed by k-1 0 bits, so it again only requires k-2
* squarings, not k-1. The average of these is 1. Add that
* to the one squaring we have to do to compute the table,
* and you'll see that a k-bit window saves k-2 squarings
* as well as reducing the multiplies. (It actually doesn't
* hurt in the case k = 1, either.)
*/
// Special case for exponent of one
if (y.equals(ONE))
return this;
// Special case for base of zero
if (signum == 0)
return ZERO;
int[] base = mag.clone();
int[] exp = y.mag;
int[] mod = z.mag;
int modLen = mod.length;
// Make modLen even. It is conventional to use a cryptographic
// modulus that is 512, 768, 1024, or 2048 bits, so this code
// will not normally be executed. However, it is necessary for
// the correct functioning of the HotSpot intrinsics.
if ((modLen & 1) != 0) {
int[] x = new int[modLen + 1];
System.arraycopy(mod, 0, x, 1, modLen);
mod = x;
modLen++;
}
// Select an appropriate window size
int wbits = 0;
int ebits = bitLength(exp, exp.length);
// if exponent is 65537 (0x10001), use minimum window size
if ((ebits != 17) || (exp[0] != 65537)) {
while (ebits > bnExpModThreshTable[wbits]) {
wbits++;
}
}
// Calculate appropriate table size
int tblmask = 1 << wbits;
// Allocate table for precomputed odd powers of base in Montgomery form
int[][] table = new int[tblmask][];
for (int i=0; i < tblmask; i++)
table[i] = new int[modLen];
// Compute the modular inverse of the least significant 64-bit
// digit of the modulus
long n0 = (mod[modLen-1] & LONG_MASK) + ((mod[modLen-2] & LONG_MASK) << 32);
long inv = -MutableBigInteger.inverseMod64(n0);
// Convert base to Montgomery form
int[] a = leftShift(base, base.length, modLen << 5);
MutableBigInteger q = new MutableBigInteger(),
a2 = new MutableBigInteger(a),
b2 = new MutableBigInteger(mod);
b2.normalize(); // MutableBigInteger.divide() assumes that its
// divisor is in normal form.
MutableBigInteger r= a2.divide(b2, q);
table[0] = r.toIntArray();
// Pad table[0] with leading zeros so its length is at least modLen
if (table[0].length < modLen) {
int offset = modLen - table[0].length;
int[] t2 = new int[modLen];
System.arraycopy(table[0], 0, t2, offset, table[0].length);
table[0] = t2;
}
// Set b to the square of the base
int[] b = montgomerySquare(table[0], mod, modLen, inv, null);
// Set t to high half of b
int[] t = Arrays.copyOf(b, modLen);
// Fill in the table with odd powers of the base
for (int i=1; i < tblmask; i++) {
table[i] = montgomeryMultiply(t, table[i-1], mod, modLen, inv, null);
}
// Pre load the window that slides over the exponent
int bitpos = 1 << ((ebits-1) & (32-1));
int buf = 0;
int elen = exp.length;
int eIndex = 0;
for (int i = 0; i <= wbits; i++) {
buf = (buf << 1) | (((exp[eIndex] & bitpos) != 0)?1:0);
bitpos >>>= 1;
if (bitpos == 0) {
eIndex++;
bitpos = 1 << (32-1);
elen--;
}
}
int multpos = ebits;
// The first iteration, which is hoisted out of the main loop
ebits--;
boolean isone = true;
multpos = ebits - wbits;
while ((buf & 1) == 0) {
buf >>>= 1;
multpos++;
}
int[] mult = table[buf >>> 1];
buf = 0;
if (multpos == ebits)
isone = false;
// The main loop
while (true) {
ebits--;
// Advance the window
buf <<= 1;
if (elen != 0) {
buf |= ((exp[eIndex] & bitpos) != 0) ? 1 : 0;
bitpos >>>= 1;
if (bitpos == 0) {
eIndex++;
bitpos = 1 << (32-1);
elen--;
}
}
// Examine the window for pending multiplies
if ((buf & tblmask) != 0) {
multpos = ebits - wbits;
while ((buf & 1) == 0) {
buf >>>= 1;
multpos++;
}
mult = table[buf >>> 1];
buf = 0;
}
// Perform multiply
if (ebits == multpos) {
if (isone) {
b = mult.clone();
isone = false;
} else {
t = b;
a = montgomeryMultiply(t, mult, mod, modLen, inv, a);
t = a; a = b; b = t;
}
}
// Check if done
if (ebits == 0)
break;
// Square the input
if (!isone) {
t = b;
a = montgomerySquare(t, mod, modLen, inv, a);
t = a; a = b; b = t;
}
}
// Convert result out of Montgomery form and return
int[] t2 = new int[2*modLen];
System.arraycopy(b, 0, t2, modLen, modLen);
b = montReduce(t2, mod, modLen, (int)inv);
t2 = Arrays.copyOf(b, modLen);
return new BigInteger(1, t2);
}
/**
* Montgomery reduce n, modulo mod. This reduces modulo mod and divides
* by 2^(32*mlen). Adapted from Colin Plumb's C library.
*/
private static int[] montReduce(int[] n, int[] mod, int mlen, int inv) {
int c=0;
int len = mlen;
int offset=0;
do {
int nEnd = n[n.length-1-offset];
int carry = mulAdd(n, mod, offset, mlen, inv * nEnd);
c += addOne(n, offset, mlen, carry);
offset++;
} while (--len > 0);
while (c > 0)
c += subN(n, mod, mlen);
while (intArrayCmpToLen(n, mod, mlen) >= 0)
subN(n, mod, mlen);
return n;
}
/*
* Returns -1, 0 or +1 as big-endian unsigned int array arg1 is less than,
* equal to, or greater than arg2 up to length len.
*/
private static int intArrayCmpToLen(int[] arg1, int[] arg2, int len) {
for (int i=0; i < len; i++) {
long b1 = arg1[i] & LONG_MASK;
long b2 = arg2[i] & LONG_MASK;
if (b1 < b2)
return -1;
if (b1 > b2)
return 1;
}
return 0;
}
/**
* Subtracts two numbers of same length, returning borrow.
*/
private static int subN(int[] a, int[] b, int len) {
long sum = 0;
while (--len >= 0) {
sum = (a[len] & LONG_MASK) -
(b[len] & LONG_MASK) + (sum >> 32);
a[len] = (int)sum;
}
return (int)(sum >> 32);
}
/**
* Multiply an array by one word k and add to result, return the carry
*/
static int mulAdd(int[] out, int[] in, int offset, int len, int k) {
implMulAddCheck(out, in, offset, len, k);
return implMulAdd(out, in, offset, len, k);
}
/**
* Parameters validation.
*/
private static void implMulAddCheck(int[] out, int[] in, int offset, int len, int k) {
if (len > in.length) {
throw new IllegalArgumentException("input length is out of bound: " + len + " > " + in.length);
}
if (offset < 0) {
throw new IllegalArgumentException("input offset is invalid: " + offset);
}
if (offset > (out.length - 1)) {
throw new IllegalArgumentException("input offset is out of bound: " + offset + " > " + (out.length - 1));
}
if (len > (out.length - offset)) {
throw new IllegalArgumentException("input len is out of bound: " + len + " > " + (out.length - offset));
}
}
/**
* Java Runtime may use intrinsic for this method.
*/
@IntrinsicCandidate
private static int implMulAdd(int[] out, int[] in, int offset, int len, int k) {
long kLong = k & LONG_MASK;
long carry = 0;
offset = out.length-offset - 1;
for (int j=len-1; j >= 0; j--) {
long product = (in[j] & LONG_MASK) * kLong +
(out[offset] & LONG_MASK) + carry;
out[offset--] = (int)product;
carry = product >>> 32;
}
return (int)carry;
}
/**
* Add one word to the number a mlen words into a. Return the resulting
* carry.
*/
static int addOne(int[] a, int offset, int mlen, int carry) {
offset = a.length-1-mlen-offset;
long t = (a[offset] & LONG_MASK) + (carry & LONG_MASK);
a[offset] = (int)t;
if ((t >>> 32) == 0)
return 0;
while (--mlen >= 0) {
if (--offset < 0) { // Carry out of number
return 1;
} else {
a[offset]++;
if (a[offset] != 0)
return 0;
}
}
return 1;
}
/**
* Returns a BigInteger whose value is (this ** exponent) mod (2**p)
*/
private BigInteger modPow2(BigInteger exponent, int p) {
/*
* Perform exponentiation using repeated squaring trick, chopping off
* high order bits as indicated by modulus.
*/
BigInteger result = ONE;
BigInteger baseToPow2 = this.mod2(p);
int expOffset = 0;
int limit = exponent.bitLength();
if (this.testBit(0))
limit = (p-1) < limit ? (p-1) : limit;
while (expOffset < limit) {
if (exponent.testBit(expOffset))
result = result.multiply(baseToPow2).mod2(p);
expOffset++;
if (expOffset < limit)
baseToPow2 = baseToPow2.square().mod2(p);
}
return result;
}
/**
* Returns a BigInteger whose value is this mod(2**p).
* Assumes that this {@code BigInteger >= 0} and {@code p > 0}.
*/
private BigInteger mod2(int p) {
if (bitLength() <= p)
return this;
// Copy remaining ints of mag
int numInts = (p + 31) >>> 5;
int[] mag = new int[numInts];
System.arraycopy(this.mag, (this.mag.length - numInts), mag, 0, numInts);
// Mask out any excess bits
int excessBits = (numInts << 5) - p;
mag[0] &= (int)((1L << (32-excessBits)) - 1);
return (mag[0] == 0 ? new BigInteger(1, mag) : new BigInteger(mag, 1));
}
/**
* Returns a BigInteger whose value is {@code (this}<sup>-1</sup> {@code mod m)}.
*
* @param m the modulus.
* @return {@code this}<sup>-1</sup> {@code mod m}.
* @throws ArithmeticException {@code m} &le; 0, or this BigInteger
* has no multiplicative inverse mod m (that is, this BigInteger
* is not <i>relatively prime</i> to m).
*/
public BigInteger modInverse(BigInteger m) {
if (m.signum != 1)
throw new ArithmeticException("BigInteger: modulus not positive");
if (m.equals(ONE))
return ZERO;
// Calculate (this mod m)
BigInteger modVal = this;
if (signum < 0 || (this.compareMagnitude(m) >= 0))
modVal = this.mod(m);
if (modVal.equals(ONE))
return ONE;
MutableBigInteger a = new MutableBigInteger(modVal);
MutableBigInteger b = new MutableBigInteger(m);
MutableBigInteger result = a.mutableModInverse(b);
return result.toBigInteger(1);
}
// Shift Operations
/**
* Returns a BigInteger whose value is {@code (this << n)}.
* The shift distance, {@code n}, may be negative, in which case
* this method performs a right shift.
* (Computes <code>floor(this * 2<sup>n</sup>)</code>.)
*
* @param n shift distance, in bits.
* @return {@code this << n}
* @see #shiftRight
*/
public BigInteger shiftLeft(int n) {
if (signum == 0)
return ZERO;
if (n > 0) {
return new BigInteger(shiftLeft(mag, n), signum);
} else if (n == 0) {
return this;
} else {
// Possible int overflow in (-n) is not a trouble,
// because shiftRightImpl considers its argument unsigned
return shiftRightImpl(-n);
}
}
/**
* Returns a magnitude array whose value is {@code (mag << n)}.
* The shift distance, {@code n}, is considered unnsigned.
* (Computes <code>this * 2<sup>n</sup></code>.)
*
* @param mag magnitude, the most-significant int ({@code mag[0]}) must be non-zero.
* @param n unsigned shift distance, in bits.
* @return {@code mag << n}
*/
private static int[] shiftLeft(int[] mag, int n) {
int nInts = n >>> 5;
int nBits = n & 0x1f;
int magLen = mag.length;
int newMag[] = null;
if (nBits == 0) {
newMag = new int[magLen + nInts];
System.arraycopy(mag, 0, newMag, 0, magLen);
} else {
int i = 0;
int nBits2 = 32 - nBits;
int highBits = mag[0] >>> nBits2;
if (highBits != 0) {
newMag = new int[magLen + nInts + 1];
newMag[i++] = highBits;
} else {
newMag = new int[magLen + nInts];
}
int numIter = magLen - 1;
Objects.checkFromToIndex(0, numIter + 1, mag.length);
Objects.checkFromToIndex(i, numIter + i + 1, newMag.length);
shiftLeftImplWorker(newMag, mag, i, nBits, numIter);
newMag[numIter + i] = mag[numIter] << nBits;
}
return newMag;
}
@ForceInline
@IntrinsicCandidate
private static void shiftLeftImplWorker(int[] newArr, int[] oldArr, int newIdx, int shiftCount, int numIter) {
int shiftCountRight = 32 - shiftCount;
int oldIdx = 0;
while (oldIdx < numIter) {
newArr[newIdx++] = (oldArr[oldIdx++] << shiftCount) | (oldArr[oldIdx] >>> shiftCountRight);
}
}
/**
* Returns a BigInteger whose value is {@code (this >> n)}. Sign
* extension is performed. The shift distance, {@code n}, may be
* negative, in which case this method performs a left shift.
* (Computes <code>floor(this / 2<sup>n</sup>)</code>.)
*
* @param n shift distance, in bits.
* @return {@code this >> n}
* @see #shiftLeft
*/
public BigInteger shiftRight(int n) {
if (signum == 0)
return ZERO;
if (n > 0) {
return shiftRightImpl(n);
} else if (n == 0) {
return this;
} else {
// Possible int overflow in {@code -n} is not a trouble,
// because shiftLeft considers its argument unsigned
return new BigInteger(shiftLeft(mag, -n), signum);
}
}
/**
* Returns a BigInteger whose value is {@code (this >> n)}. The shift
* distance, {@code n}, is considered unsigned.
* (Computes <code>floor(this * 2<sup>-n</sup>)</code>.)
*
* @param n unsigned shift distance, in bits.
* @return {@code this >> n}
*/
private BigInteger shiftRightImpl(int n) {
int nInts = n >>> 5;
int nBits = n & 0x1f;
int magLen = mag.length;
int newMag[] = null;
// Special case: entire contents shifted off the end
if (nInts >= magLen)
return (signum >= 0 ? ZERO : negConst[1]);
if (nBits == 0) {
int newMagLen = magLen - nInts;
newMag = Arrays.copyOf(mag, newMagLen);
} else {
int i = 0;
int highBits = mag[0] >>> nBits;
if (highBits != 0) {
newMag = new int[magLen - nInts];
newMag[i++] = highBits;
} else {
newMag = new int[magLen - nInts -1];
}
int numIter = magLen - nInts - 1;
Objects.checkFromToIndex(0, numIter + 1, mag.length);
Objects.checkFromToIndex(i, numIter + i, newMag.length);
shiftRightImplWorker(newMag, mag, i, nBits, numIter);
}
if (signum < 0) {
// Find out whether any one-bits were shifted off the end.
boolean onesLost = false;
for (int i=magLen-1, j=magLen-nInts; i >= j && !onesLost; i--)
onesLost = (mag[i] != 0);
if (!onesLost && nBits != 0)
onesLost = (mag[magLen - nInts - 1] << (32 - nBits) != 0);
if (onesLost)
newMag = javaIncrement(newMag);
}
return new BigInteger(newMag, signum);
}
@ForceInline
@IntrinsicCandidate
private static void shiftRightImplWorker(int[] newArr, int[] oldArr, int newIdx, int shiftCount, int numIter) {
int shiftCountLeft = 32 - shiftCount;
int idx = numIter;
int nidx = (newIdx == 0) ? numIter - 1 : numIter;
while (nidx >= newIdx) {
newArr[nidx--] = (oldArr[idx--] >>> shiftCount) | (oldArr[idx] << shiftCountLeft);
}
}
int[] javaIncrement(int[] val) {
int lastSum = 0;
for (int i=val.length-1; i >= 0 && lastSum == 0; i--)
lastSum = (val[i] += 1);
if (lastSum == 0) {
val = new int[val.length+1];
val[0] = 1;
}
return val;
}
// Bitwise Operations
/**
* Returns a BigInteger whose value is {@code (this & val)}. (This
* method returns a negative BigInteger if and only if this and val are
* both negative.)
*
* @param val value to be AND'ed with this BigInteger.
* @return {@code this & val}
*/
public BigInteger and(BigInteger val) {
int[] result = new int[Math.max(intLength(), val.intLength())];
for (int i=0; i < result.length; i++)
result[i] = (getInt(result.length-i-1)
& val.getInt(result.length-i-1));
return valueOf(result);
}
/**
* Returns a BigInteger whose value is {@code (this | val)}. (This method
* returns a negative BigInteger if and only if either this or val is
* negative.)
*
* @param val value to be OR'ed with this BigInteger.
* @return {@code this | val}
*/
public BigInteger or(BigInteger val) {
int[] result = new int[Math.max(intLength(), val.intLength())];
for (int i=0; i < result.length; i++)
result[i] = (getInt(result.length-i-1)
| val.getInt(result.length-i-1));
return valueOf(result);
}
/**
* Returns a BigInteger whose value is {@code (this ^ val)}. (This method
* returns a negative BigInteger if and only if exactly one of this and
* val are negative.)
*
* @param val value to be XOR'ed with this BigInteger.
* @return {@code this ^ val}
*/
public BigInteger xor(BigInteger val) {
int[] result = new int[Math.max(intLength(), val.intLength())];
for (int i=0; i < result.length; i++)
result[i] = (getInt(result.length-i-1)
^ val.getInt(result.length-i-1));
return valueOf(result);
}
/**
* Returns a BigInteger whose value is {@code (~this)}. (This method
* returns a negative value if and only if this BigInteger is
* non-negative.)
*
* @return {@code ~this}
*/
public BigInteger not() {
int[] result = new int[intLength()];
for (int i=0; i < result.length; i++)
result[i] = ~getInt(result.length-i-1);
return valueOf(result);
}
/**
* Returns a BigInteger whose value is {@code (this & ~val)}. This
* method, which is equivalent to {@code and(val.not())}, is provided as
* a convenience for masking operations. (This method returns a negative
* BigInteger if and only if {@code this} is negative and {@code val} is
* positive.)
*
* @param val value to be complemented and AND'ed with this BigInteger.
* @return {@code this & ~val}
*/
public BigInteger andNot(BigInteger val) {
int[] result = new int[Math.max(intLength(), val.intLength())];
for (int i=0; i < result.length; i++)
result[i] = (getInt(result.length-i-1)
& ~val.getInt(result.length-i-1));
return valueOf(result);
}
// Single Bit Operations
/**
* Returns {@code true} if and only if the designated bit is set.
* (Computes {@code ((this & (1<<n)) != 0)}.)
*
* @param n index of bit to test.
* @return {@code true} if and only if the designated bit is set.
* @throws ArithmeticException {@code n} is negative.
*/
public boolean testBit(int n) {
if (n < 0)
throw new ArithmeticException("Negative bit address");
return (getInt(n >>> 5) & (1 << (n & 31))) != 0;
}
/**
* Returns a BigInteger whose value is equivalent to this BigInteger
* with the designated bit set. (Computes {@code (this | (1<<n))}.)
*
* @param n index of bit to set.
* @return {@code this | (1<<n)}
* @throws ArithmeticException {@code n} is negative.
*/
public BigInteger setBit(int n) {
if (n < 0)
throw new ArithmeticException("Negative bit address");
int intNum = n >>> 5;
int[] result = new int[Math.max(intLength(), intNum+2)];
for (int i=0; i < result.length; i++)
result[result.length-i-1] = getInt(i);
result[result.length-intNum-1] |= (1 << (n & 31));
return valueOf(result);
}
/**
* Returns a BigInteger whose value is equivalent to this BigInteger
* with the designated bit cleared.
* (Computes {@code (this & ~(1<<n))}.)
*
* @param n index of bit to clear.
* @return {@code this & ~(1<<n)}
* @throws ArithmeticException {@code n} is negative.
*/
public BigInteger clearBit(int n) {
if (n < 0)
throw new ArithmeticException("Negative bit address");
int intNum = n >>> 5;
int[] result = new int[Math.max(intLength(), ((n + 1) >>> 5) + 1)];
for (int i=0; i < result.length; i++)
result[result.length-i-1] = getInt(i);
result[result.length-intNum-1] &= ~(1 << (n & 31));
return valueOf(result);
}
/**
* Returns a BigInteger whose value is equivalent to this BigInteger
* with the designated bit flipped.
* (Computes {@code (this ^ (1<<n))}.)
*
* @param n index of bit to flip.
* @return {@code this ^ (1<<n)}
* @throws ArithmeticException {@code n} is negative.
*/
public BigInteger flipBit(int n) {
if (n < 0)
throw new ArithmeticException("Negative bit address");
int intNum = n >>> 5;
int[] result = new int[Math.max(intLength(), intNum+2)];
for (int i=0; i < result.length; i++)
result[result.length-i-1] = getInt(i);
result[result.length-intNum-1] ^= (1 << (n & 31));
return valueOf(result);
}
/**
* Returns the index of the rightmost (lowest-order) one bit in this
* BigInteger (the number of zero bits to the right of the rightmost
* one bit). Returns -1 if this BigInteger contains no one bits.
* (Computes {@code (this == 0? -1 : log2(this & -this))}.)
*
* @return index of the rightmost one bit in this BigInteger.
*/
public int getLowestSetBit() {
int lsb = lowestSetBitPlusTwo - 2;
if (lsb == -2) { // lowestSetBit not initialized yet
lsb = 0;
if (signum == 0) {
lsb -= 1;
} else {
// Search for lowest order nonzero int
int i,b;
for (i=0; (b = getInt(i)) == 0; i++)
;
lsb += (i << 5) + Integer.numberOfTrailingZeros(b);
}
lowestSetBitPlusTwo = lsb + 2;
}
return lsb;
}
// Miscellaneous Bit Operations
/**
* Returns the number of bits in the minimal two's-complement
* representation of this BigInteger, <em>excluding</em> a sign bit.
* For positive BigIntegers, this is equivalent to the number of bits in
* the ordinary binary representation. For zero this method returns
* {@code 0}. (Computes {@code (ceil(log2(this < 0 ? -this : this+1)))}.)
*
* @return number of bits in the minimal two's-complement
* representation of this BigInteger, <em>excluding</em> a sign bit.
*/
public int bitLength() {
int n = bitLengthPlusOne - 1;
if (n == -1) { // bitLength not initialized yet
int[] m = mag;
int len = m.length;
if (len == 0) {
n = 0; // offset by one to initialize
} else {
// Calculate the bit length of the magnitude
int magBitLength = ((len - 1) << 5) + bitLengthForInt(mag[0]);
if (signum < 0) {
// Check if magnitude is a power of two
boolean pow2 = (Integer.bitCount(mag[0]) == 1);
for (int i=1; i< len && pow2; i++)
pow2 = (mag[i] == 0);
n = (pow2 ? magBitLength - 1 : magBitLength);
} else {
n = magBitLength;
}
}
bitLengthPlusOne = n + 1;
}
return n;
}
/**
* Returns the number of bits in the two's complement representation
* of this BigInteger that differ from its sign bit. This method is
* useful when implementing bit-vector style sets atop BigIntegers.
*
* @return number of bits in the two's complement representation
* of this BigInteger that differ from its sign bit.
*/
public int bitCount() {
int bc = bitCountPlusOne - 1;
if (bc == -1) { // bitCount not initialized yet
bc = 0; // offset by one to initialize
// Count the bits in the magnitude
for (int i=0; i < mag.length; i++)
bc += Integer.bitCount(mag[i]);
if (signum < 0) {
// Count the trailing zeros in the magnitude
int magTrailingZeroCount = 0, j;
for (j=mag.length-1; mag[j] == 0; j--)
magTrailingZeroCount += 32;
magTrailingZeroCount += Integer.numberOfTrailingZeros(mag[j]);
bc += magTrailingZeroCount - 1;
}
bitCountPlusOne = bc + 1;
}
return bc;
}
// Primality Testing
/**
* Returns {@code true} if this BigInteger is probably prime,
* {@code false} if it's definitely composite. If
* {@code certainty} is &le; 0, {@code true} is
* returned.
*
* @param certainty a measure of the uncertainty that the caller is
* willing to tolerate: if the call returns {@code true}
* the probability that this BigInteger is prime exceeds
* (1 - 1/2<sup>{@code certainty}</sup>). The execution time of
* this method is proportional to the value of this parameter.
* @return {@code true} if this BigInteger is probably prime,
* {@code false} if it's definitely composite.
* @throws ArithmeticException {@code this} is too large.
* @implNote Due to the nature of the underlying primality test algorithm,
* and depending on the size of {@code this} and {@code certainty},
* this method could consume a large amount of memory, up to
* exhaustion of available heap space, or could run for a long time.
*/
public boolean isProbablePrime(int certainty) {
if (certainty <= 0)
return true;
BigInteger w = this.abs();
if (w.equals(TWO))
return true;
if (!w.testBit(0) || w.equals(ONE))
return false;
if (w.bitLength() > PRIME_SEARCH_BIT_LENGTH_LIMIT + 1) {
throw new ArithmeticException("Primality test implementation restriction on bitLength");
}
return w.primeToCertainty(certainty, null);
}
// Comparison Operations
/**
* Compares this BigInteger with the specified BigInteger. This
* method is provided in preference to individual methods for each
* of the six boolean comparison operators ({@literal <}, ==,
* {@literal >}, {@literal >=}, !=, {@literal <=}). The suggested
* idiom for performing these comparisons is: {@code
* (x.compareTo(y)} &lt;<i>op</i>&gt; {@code 0)}, where
* &lt;<i>op</i>&gt; is one of the six comparison operators.
*
* @param val BigInteger to which this BigInteger is to be compared.
* @return -1, 0 or 1 as this BigInteger is numerically less than, equal
* to, or greater than {@code val}.
*/
public int compareTo(BigInteger val) {
if (signum == val.signum) {
return switch (signum) {
case 1 -> compareMagnitude(val);
case -1 -> val.compareMagnitude(this);
default -> 0;
};
}
return signum > val.signum ? 1 : -1;
}
/**
* Compares the magnitude array of this BigInteger with the specified
* BigInteger's. This is the version of compareTo ignoring sign.
*
* @param val BigInteger whose magnitude array to be compared.
* @return -1, 0 or 1 as this magnitude array is less than, equal to or
* greater than the magnitude array for the specified BigInteger's.
*/
final int compareMagnitude(BigInteger val) {
int[] m1 = mag;
int len1 = m1.length;
int[] m2 = val.mag;
int len2 = m2.length;
if (len1 < len2)
return -1;
if (len1 > len2)
return 1;
for (int i = 0; i < len1; i++) {
int a = m1[i];
int b = m2[i];
if (a != b)
return ((a & LONG_MASK) < (b & LONG_MASK)) ? -1 : 1;
}
return 0;
}
/**
* Version of compareMagnitude that compares magnitude with long value.
* val can't be Long.MIN_VALUE.
*/
final int compareMagnitude(long val) {
assert val != Long.MIN_VALUE;
int[] m1 = mag;
int len = m1.length;
if (len > 2) {
return 1;
}
if (val < 0) {
val = -val;
}
int highWord = (int)(val >>> 32);
if (highWord == 0) {
if (len < 1)
return -1;
if (len > 1)
return 1;
int a = m1[0];
int b = (int)val;
if (a != b) {
return ((a & LONG_MASK) < (b & LONG_MASK))? -1 : 1;
}
return 0;
} else {
if (len < 2)
return -1;
int a = m1[0];
int b = highWord;
if (a != b) {
return ((a & LONG_MASK) < (b & LONG_MASK))? -1 : 1;
}
a = m1[1];
b = (int)val;
if (a != b) {
return ((a & LONG_MASK) < (b & LONG_MASK))? -1 : 1;
}
return 0;
}
}
/**
* Compares this BigInteger with the specified Object for equality.
*
* @param x Object to which this BigInteger is to be compared.
* @return {@code true} if and only if the specified Object is a
* BigInteger whose value is numerically equal to this BigInteger.
*/
public boolean equals(Object x) {
// This test is just an optimization, which may or may not help
if (x == this)
return true;
if (!(x instanceof BigInteger xInt))
return false;
if (xInt.signum != signum)
return false;
int[] m = mag;
int len = m.length;
int[] xm = xInt.mag;
if (len != xm.length)
return false;
for (int i = 0; i < len; i++)
if (xm[i] != m[i])
return false;
return true;
}
/**
* Returns the minimum of this BigInteger and {@code val}.
*
* @param val value with which the minimum is to be computed.
* @return the BigInteger whose value is the lesser of this BigInteger and
* {@code val}. If they are equal, either may be returned.
*/
public BigInteger min(BigInteger val) {
return (compareTo(val) < 0 ? this : val);
}
/**
* Returns the maximum of this BigInteger and {@code val}.
*
* @param val value with which the maximum is to be computed.
* @return the BigInteger whose value is the greater of this and
* {@code val}. If they are equal, either may be returned.
*/
public BigInteger max(BigInteger val) {
return (compareTo(val) > 0 ? this : val);
}
// Hash Function
/**
* Returns the hash code for this BigInteger.
*
* @return hash code for this BigInteger.
*/
public int hashCode() {
int hashCode = 0;
for (int i=0; i < mag.length; i++)
hashCode = (int)(31*hashCode + (mag[i] & LONG_MASK));
return hashCode * signum;
}
/**
* Returns the String representation of this BigInteger in the
* given radix. If the radix is outside the range from {@link
* Character#MIN_RADIX} to {@link Character#MAX_RADIX} inclusive,
* it will default to 10 (as is the case for
* {@code Integer.toString}). The digit-to-character mapping
* provided by {@code Character.forDigit} is used, and a minus
* sign is prepended if appropriate. (This representation is
* compatible with the {@link #BigInteger(String, int) (String,
* int)} constructor.)
*
* @param radix radix of the String representation.
* @return String representation of this BigInteger in the given radix.
* @see Integer#toString
* @see Character#forDigit
* @see #BigInteger(java.lang.String, int)
*/
public String toString(int radix) {
if (signum == 0)
return "0";
if (radix < Character.MIN_RADIX || radix > Character.MAX_RADIX)
radix = 10;
BigInteger abs = this.abs();
// Ensure buffer capacity sufficient to contain string representation
// floor(bitLength*log(2)/log(radix)) + 1
// plus an additional character for the sign if negative.
int b = abs.bitLength();
int numChars = (int)(Math.floor(b*LOG_TWO/logCache[radix]) + 1) +
(signum < 0 ? 1 : 0);
StringBuilder sb = new StringBuilder(numChars);
if (signum < 0) {
sb.append('-');
}
// Use recursive toString.
toString(abs, sb, radix, 0);
return sb.toString();
}
/**
* If {@code numZeros > 0}, appends that many zeros to the
* specified StringBuilder; otherwise, does nothing.
*
* @param buf The StringBuilder that will be appended to.
* @param numZeros The number of zeros to append.
*/
private static void padWithZeros(StringBuilder buf, int numZeros) {
while (numZeros >= NUM_ZEROS) {
buf.append(ZEROS);
numZeros -= NUM_ZEROS;
}
if (numZeros > 0) {
buf.append(ZEROS, 0, numZeros);
}
}
/**
* This method is used to perform toString when arguments are small.
* The value must be non-negative. If {@code digits <= 0} no padding
* (pre-pending with zeros) will be effected.
*
* @param radix The base to convert to.
* @param buf The StringBuilder that will be appended to in place.
* @param digits The minimum number of digits to pad to.
*/
private void smallToString(int radix, StringBuilder buf, int digits) {
assert signum >= 0;
if (signum == 0) {
padWithZeros(buf, digits);
return;
}
// Compute upper bound on number of digit groups and allocate space
int maxNumDigitGroups = (4*mag.length + 6)/7;
long[] digitGroups = new long[maxNumDigitGroups];
// Translate number to string, a digit group at a time
BigInteger tmp = this;
int numGroups = 0;
while (tmp.signum != 0) {
BigInteger d = longRadix[radix];
MutableBigInteger q = new MutableBigInteger(),
a = new MutableBigInteger(tmp.mag),
b = new MutableBigInteger(d.mag);
MutableBigInteger r = a.divide(b, q);
BigInteger q2 = q.toBigInteger(tmp.signum * d.signum);
BigInteger r2 = r.toBigInteger(tmp.signum * d.signum);
digitGroups[numGroups++] = r2.longValue();
tmp = q2;
}
// Get string version of first digit group
String s = Long.toString(digitGroups[numGroups-1], radix);
// Pad with internal zeros if necessary.
padWithZeros(buf, digits - (s.length() +
(numGroups - 1)*digitsPerLong[radix]));
// Put first digit group into result buffer
buf.append(s);
// Append remaining digit groups each padded with leading zeros
for (int i=numGroups-2; i >= 0; i--) {
// Prepend (any) leading zeros for this digit group
s = Long.toString(digitGroups[i], radix);
int numLeadingZeros = digitsPerLong[radix] - s.length();
if (numLeadingZeros != 0) {
buf.append(ZEROS, 0, numLeadingZeros);
}
buf.append(s);
}
}
/**
* Converts the specified BigInteger to a string and appends to
* {@code sb}. This implements the recursive Schoenhage algorithm
* for base conversions. This method can only be called for non-negative
* numbers.
* <p>
* See Knuth, Donald, _The Art of Computer Programming_, Vol. 2,
* Answers to Exercises (4.4) Question 14.
*
* @param u The number to convert to a string.
* @param sb The StringBuilder that will be appended to in place.
* @param radix The base to convert to.
* @param digits The minimum number of digits to pad to.
*/
private static void toString(BigInteger u, StringBuilder sb,
int radix, int digits) {
assert u.signum() >= 0;
// If we're smaller than a certain threshold, use the smallToString
// method, padding with leading zeroes when necessary unless we're
// at the beginning of the string or digits <= 0. As u.signum() >= 0,
// smallToString() will not prepend a negative sign.
if (u.mag.length <= SCHOENHAGE_BASE_CONVERSION_THRESHOLD) {
u.smallToString(radix, sb, digits);
return;
}
// Calculate a value for n in the equation radix^(2^n) = u
// and subtract 1 from that value. This is used to find the
// cache index that contains the best value to divide u.
int b = u.bitLength();
int n = (int) Math.round(Math.log(b * LOG_TWO / logCache[radix]) /
LOG_TWO - 1.0);
BigInteger v = getRadixConversionCache(radix, n);
BigInteger[] results;
results = u.divideAndRemainder(v);
int expectedDigits = 1 << n;
// Now recursively build the two halves of each number.
toString(results[0], sb, radix, digits - expectedDigits);
toString(results[1], sb, radix, expectedDigits);
}
/**
* Returns the value radix^(2^exponent) from the cache.
* If this value doesn't already exist in the cache, it is added.
* <p>
* This could be changed to a more complicated caching method using
* {@code Future}.
*/
private static BigInteger getRadixConversionCache(int radix, int exponent) {
BigInteger[] cacheLine = powerCache[radix]; // volatile read
if (exponent < cacheLine.length) {
return cacheLine[exponent];
}
int oldLength = cacheLine.length;
cacheLine = Arrays.copyOf(cacheLine, exponent + 1);
for (int i = oldLength; i <= exponent; i++) {
cacheLine[i] = cacheLine[i - 1].pow(2);
}
BigInteger[][] pc = powerCache; // volatile read again
if (exponent >= pc[radix].length) {
pc = pc.clone();
pc[radix] = cacheLine;
powerCache = pc; // volatile write, publish
}
return cacheLine[exponent];
}
/* Size of ZEROS string. */
private static int NUM_ZEROS = 63;
/* ZEROS is a string of NUM_ZEROS consecutive zeros. */
private static final String ZEROS = "0".repeat(NUM_ZEROS);
/**
* Returns the decimal String representation of this BigInteger.
* The digit-to-character mapping provided by
* {@code Character.forDigit} is used, and a minus sign is
* prepended if appropriate. (This representation is compatible
* with the {@link #BigInteger(String) (String)} constructor, and
* allows for String concatenation with Java's + operator.)
*
* @return decimal String representation of this BigInteger.
* @see Character#forDigit
* @see #BigInteger(java.lang.String)
*/
public String toString() {
return toString(10);
}
/**
* Returns a byte array containing the two's-complement
* representation of this BigInteger. The byte array will be in
* <i>big-endian</i> byte-order: the most significant byte is in
* the zeroth element. The array will contain the minimum number
* of bytes required to represent this BigInteger, including at
* least one sign bit, which is {@code (ceil((this.bitLength() +
* 1)/8))}. (This representation is compatible with the
* {@link #BigInteger(byte[]) (byte[])} constructor.)
*
* @return a byte array containing the two's-complement representation of
* this BigInteger.
* @see #BigInteger(byte[])
*/
public byte[] toByteArray() {
int byteLen = bitLength()/8 + 1;
byte[] byteArray = new byte[byteLen];
for (int i=byteLen-1, bytesCopied=4, nextInt=0, intIndex=0; i >= 0; i--) {
if (bytesCopied == 4) {
nextInt = getInt(intIndex++);
bytesCopied = 1;
} else {
nextInt >>>= 8;
bytesCopied++;
}
byteArray[i] = (byte)nextInt;
}
return byteArray;
}
/**
* Converts this BigInteger to an {@code int}. This
* conversion is analogous to a
* <i>narrowing primitive conversion</i> from {@code long} to
* {@code int} as defined in
* <cite>The Java Language Specification</cite>:
* if this BigInteger is too big to fit in an
* {@code int}, only the low-order 32 bits are returned.
* Note that this conversion can lose information about the
* overall magnitude of the BigInteger value as well as return a
* result with the opposite sign.
*
* @return this BigInteger converted to an {@code int}.
* @see #intValueExact()
* @jls 5.1.3 Narrowing Primitive Conversion
*/
public int intValue() {
int result = 0;
result = getInt(0);
return result;
}
/**
* Converts this BigInteger to a {@code long}. This
* conversion is analogous to a
* <i>narrowing primitive conversion</i> from {@code long} to
* {@code int} as defined in
* <cite>The Java Language Specification</cite>:
* if this BigInteger is too big to fit in a
* {@code long}, only the low-order 64 bits are returned.
* Note that this conversion can lose information about the
* overall magnitude of the BigInteger value as well as return a
* result with the opposite sign.
*
* @return this BigInteger converted to a {@code long}.
* @see #longValueExact()
* @jls 5.1.3 Narrowing Primitive Conversion
*/
public long longValue() {
long result = 0;
for (int i=1; i >= 0; i--)
result = (result << 32) + (getInt(i) & LONG_MASK);
return result;
}
/**
* Converts this BigInteger to a {@code float}. This
* conversion is similar to the
* <i>narrowing primitive conversion</i> from {@code double} to
* {@code float} as defined in
* <cite>The Java Language Specification</cite>:
* if this BigInteger has too great a magnitude
* to represent as a {@code float}, it will be converted to
* {@link Float#NEGATIVE_INFINITY} or {@link
* Float#POSITIVE_INFINITY} as appropriate. Note that even when
* the return value is finite, this conversion can lose
* information about the precision of the BigInteger value.
*
* @return this BigInteger converted to a {@code float}.
* @jls 5.1.3 Narrowing Primitive Conversion
*/
public float floatValue() {
if (signum == 0) {
return 0.0f;
}
int exponent = ((mag.length - 1) << 5) + bitLengthForInt(mag[0]) - 1;
// exponent == floor(log2(abs(this)))
if (exponent < Long.SIZE - 1) {
return longValue();
} else if (exponent > Float.MAX_EXPONENT) {
return signum > 0 ? Float.POSITIVE_INFINITY : Float.NEGATIVE_INFINITY;
}
/*
* We need the top SIGNIFICAND_WIDTH bits, including the "implicit"
* one bit. To make rounding easier, we pick out the top
* SIGNIFICAND_WIDTH + 1 bits, so we have one to help us round up or
* down. twiceSignifFloor will contain the top SIGNIFICAND_WIDTH + 1
* bits, and signifFloor the top SIGNIFICAND_WIDTH.
*
* It helps to consider the real number signif = abs(this) *
* 2^(SIGNIFICAND_WIDTH - 1 - exponent).
*/
int shift = exponent - FloatConsts.SIGNIFICAND_WIDTH;
int twiceSignifFloor;
// twiceSignifFloor will be == abs().shiftRight(shift).intValue()
// We do the shift into an int directly to improve performance.
int nBits = shift & 0x1f;
int nBits2 = 32 - nBits;
if (nBits == 0) {
twiceSignifFloor = mag[0];
} else {
twiceSignifFloor = mag[0] >>> nBits;
if (twiceSignifFloor == 0) {
twiceSignifFloor = (mag[0] << nBits2) | (mag[1] >>> nBits);
}
}
int signifFloor = twiceSignifFloor >> 1;
signifFloor &= FloatConsts.SIGNIF_BIT_MASK; // remove the implied bit
/*
* We round up if either the fractional part of signif is strictly
* greater than 0.5 (which is true if the 0.5 bit is set and any lower
* bit is set), or if the fractional part of signif is >= 0.5 and
* signifFloor is odd (which is true if both the 0.5 bit and the 1 bit
* are set). This is equivalent to the desired HALF_EVEN rounding.
*/
boolean increment = (twiceSignifFloor & 1) != 0
&& ((signifFloor & 1) != 0 || abs().getLowestSetBit() < shift);
int signifRounded = increment ? signifFloor + 1 : signifFloor;
int bits = ((exponent + FloatConsts.EXP_BIAS))
<< (FloatConsts.SIGNIFICAND_WIDTH - 1);
bits += signifRounded;
/*
* If signifRounded == 2^24, we'd need to set all of the significand
* bits to zero and add 1 to the exponent. This is exactly the behavior
* we get from just adding signifRounded to bits directly. If the
* exponent is Float.MAX_EXPONENT, we round up (correctly) to
* Float.POSITIVE_INFINITY.
*/
bits |= signum & FloatConsts.SIGN_BIT_MASK;
return Float.intBitsToFloat(bits);
}
/**
* Converts this BigInteger to a {@code double}. This
* conversion is similar to the
* <i>narrowing primitive conversion</i> from {@code double} to
* {@code float} as defined in
* <cite>The Java Language Specification</cite>:
* if this BigInteger has too great a magnitude
* to represent as a {@code double}, it will be converted to
* {@link Double#NEGATIVE_INFINITY} or {@link
* Double#POSITIVE_INFINITY} as appropriate. Note that even when
* the return value is finite, this conversion can lose
* information about the precision of the BigInteger value.
*
* @return this BigInteger converted to a {@code double}.
* @jls 5.1.3 Narrowing Primitive Conversion
*/
public double doubleValue() {
if (signum == 0) {
return 0.0;
}
int exponent = ((mag.length - 1) << 5) + bitLengthForInt(mag[0]) - 1;
// exponent == floor(log2(abs(this))Double)
if (exponent < Long.SIZE - 1) {
return longValue();
} else if (exponent > Double.MAX_EXPONENT) {
return signum > 0 ? Double.POSITIVE_INFINITY : Double.NEGATIVE_INFINITY;
}
/*
* We need the top SIGNIFICAND_WIDTH bits, including the "implicit"
* one bit. To make rounding easier, we pick out the top
* SIGNIFICAND_WIDTH + 1 bits, so we have one to help us round up or
* down. twiceSignifFloor will contain the top SIGNIFICAND_WIDTH + 1
* bits, and signifFloor the top SIGNIFICAND_WIDTH.
*
* It helps to consider the real number signif = abs(this) *
* 2^(SIGNIFICAND_WIDTH - 1 - exponent).
*/
int shift = exponent - DoubleConsts.SIGNIFICAND_WIDTH;
long twiceSignifFloor;
// twiceSignifFloor will be == abs().shiftRight(shift).longValue()
// We do the shift into a long directly to improve performance.
int nBits = shift & 0x1f;
int nBits2 = 32 - nBits;
int highBits;
int lowBits;
if (nBits == 0) {
highBits = mag[0];
lowBits = mag[1];
} else {
highBits = mag[0] >>> nBits;
lowBits = (mag[0] << nBits2) | (mag[1] >>> nBits);
if (highBits == 0) {
highBits = lowBits;
lowBits = (mag[1] << nBits2) | (mag[2] >>> nBits);
}
}
twiceSignifFloor = ((highBits & LONG_MASK) << 32)
| (lowBits & LONG_MASK);
long signifFloor = twiceSignifFloor >> 1;
signifFloor &= DoubleConsts.SIGNIF_BIT_MASK; // remove the implied bit
/*
* We round up if either the fractional part of signif is strictly
* greater than 0.5 (which is true if the 0.5 bit is set and any lower
* bit is set), or if the fractional part of signif is >= 0.5 and
* signifFloor is odd (which is true if both the 0.5 bit and the 1 bit
* are set). This is equivalent to the desired HALF_EVEN rounding.
*/
boolean increment = (twiceSignifFloor & 1) != 0
&& ((signifFloor & 1) != 0 || abs().getLowestSetBit() < shift);
long signifRounded = increment ? signifFloor + 1 : signifFloor;
long bits = (long) ((exponent + DoubleConsts.EXP_BIAS))
<< (DoubleConsts.SIGNIFICAND_WIDTH - 1);
bits += signifRounded;
/*
* If signifRounded == 2^53, we'd need to set all of the significand
* bits to zero and add 1 to the exponent. This is exactly the behavior
* we get from just adding signifRounded to bits directly. If the
* exponent is Double.MAX_EXPONENT, we round up (correctly) to
* Double.POSITIVE_INFINITY.
*/
bits |= signum & DoubleConsts.SIGN_BIT_MASK;
return Double.longBitsToDouble(bits);
}
/**
* Returns a copy of the input array stripped of any leading zero bytes.
*/
private static int[] stripLeadingZeroInts(int[] val) {
int vlen = val.length;
int keep;
// Find first nonzero byte
for (keep = 0; keep < vlen && val[keep] == 0; keep++)
;
return java.util.Arrays.copyOfRange(val, keep, vlen);
}
/**
* Returns the input array stripped of any leading zero bytes.
* Since the source is trusted the copying may be skipped.
*/
private static int[] trustedStripLeadingZeroInts(int[] val) {
int vlen = val.length;
int keep;
// Find first nonzero byte
for (keep = 0; keep < vlen && val[keep] == 0; keep++)
;
return keep == 0 ? val : java.util.Arrays.copyOfRange(val, keep, vlen);
}
private static int[] stripLeadingZeroBytes(byte[] a, int from, int len) {
return stripLeadingZeroBytes(Integer.MIN_VALUE, a, from, len);
}
/*
* Returns a copy of the input array stripped of any leading zero bytes.
* The returned array is either empty, or its 0-th element is non-zero,
* meeting the "minimal" requirement for field mag (see comment on mag).
*
* The range [from, from + len) must be well-formed w.r.t. array a.
*
* b < -128 means that a[from] has not yet been read.
* Otherwise, b must be a[from], have been read only once before invoking
* this method, and len > 0 must hold.
*/
private static int[] stripLeadingZeroBytes(int b, byte[] a, int from, int len) {
/*
* Except for the first byte, each read access to the input array a
* is of the form a[from++].
* The index from is never otherwise altered, except right below,
* and only increases in steps of 1, always up to index to.
* Hence, each byte in the array is read exactly once, from lower to
* higher indices (from most to least significant byte).
*/
if (len == 0) {
return ZERO.mag;
}
int to = from + len;
if (b < -128) {
b = a[from];
}
/* Either way, a[from] has now been read exactly once, skip to next. */
++from;
/*
* Set up the shortest int[] for the sequence of the bytes
* b, a[from+1], ..., a[to-1] (len > 0)
* Shortest means first skipping leading zeros.
*/
for (; b == 0 && from < to; b = a[from++])
; //empty body
if (b == 0) {
/* Here, from == to as well. All bytes are zeros. */
return ZERO.mag;
}
/*
* Allocate just enough ints to hold (to - from + 1) bytes, that is
* ((to - from + 1) + 3) / 4 = (to - from) / 4 + 1
*/
int[] res = new int[((to - from) >> 2) + 1];
/*
* A "digit" is a group of 4 adjacent bytes aligned w.r.t. index to.
* (Implied 0 bytes are prepended as needed.)
* b is the most significant byte not 0.
* Digit d0 spans the range of indices that includes current (from - 1).
*/
int d0 = b & 0xFF;
while (((to - from) & 0x3) != 0) {
d0 = d0 << 8 | a[from++] & 0xFF;
}
res[0] = d0;
/*
* Prepare the remaining digits.
* (to - from) is a multiple of 4, so prepare an int for every 4 bytes.
* This is a candidate for Unsafe.copy[Swap]Memory().
*/
int i = 1;
while (from < to) {
res[i++] = a[from++] << 24 | (a[from++] & 0xFF) << 16
| (a[from++] & 0xFF) << 8 | (a[from++] & 0xFF);
}
return res;
}
/*
* Takes an array a representing a negative 2's-complement number and
* returns the minimal (no leading zero bytes) unsigned whose value is -a.
*
* len > 0 must hold.
* The range [from, from + len) must be well-formed w.r.t. array a.
* b is assumed to be the result of reading a[from] and to meet b < 0.
*/
private static int[] makePositive(int b, byte[] a, int from, int len) {
/*
* By assumption, b == a[from] < 0 and len > 0.
*
* First collect the bytes into the resulting array res.
* Then convert res to two's complement.
*
* Except for b == a[from], each read access to the input array a
* is of the form a[from++].
* The index from is never otherwise altered, except right below,
* and only increases in steps of 1, always up to index to.
* Hence, each byte in the array is read exactly once, from lower to
* higher indices (from most to least significant byte).
*/
int to = from + len;
/* b == a[from] has been read exactly once, skip to next index. */
++from;
/* Skip leading -1 bytes. */
for (; b == -1 && from < to; b = a[from++])
; //empty body
/*
* A "digit" is a group of 4 adjacent bytes aligned w.r.t. index to.
* b is the most significant byte not -1, or -1 only if from == to.
* Digit d0 spans the range of indices that includes current (from - 1).
* (Implied -1 bytes are prepended to array a as needed.)
* It usually corresponds to res[0], except for the special case below.
*/
int d0 = -1 << 8 | b & 0xFF;
while (((to - from) & 0x3) != 0) {
d0 = d0 << 8 | (b = a[from++]) & 0xFF;
}
int f = from; // keeps the current from for sizing purposes later
/* Skip zeros adjacent to d0, if at all. */
for (; b == 0 && from < to; b = a[from++])
; //empty body
/*
* b is the most significant non-zero byte at or after (f - 1),
* or 0 only if from == to.
* Digit d spans the range of indices that includes (f - 1).
*/
int d = b & 0xFF;
while (((to - from) & 0x3) != 0) {
d = d << 8 | a[from++] & 0xFF;
}
/*
* If the situation here is like this:
* index: f to == from
* ..., -1,-1, 0,0,0,0, 0,0,0,0, ..., 0,0,0,0
* digit: d0 d
* then, as shown, the number of zeros is a positive multiple of 4.
* The array res needs a minimal length of (1 + 1 + (to - f) / 4)
* to accommodate the two's complement, including a leading 1.
* In any other case, there is at least one byte that is non-zero.
* The array for the two's complement has length (0 + 1 + (to - f) / 4).
* c is 1, resp., 0 for the two situations.
*/
int c = (to - from | d0 | d) == 0 ? 1 : 0;
int[] res = new int[c + 1 + ((to - f) >> 2)];
res[0] = c == 0 ? d0 : -1;
int i = res.length - ((to - from) >> 2);
if (i > 1) {
res[i - 1] = d;
}
/*
* Prepare the remaining digits.
* (to - from) is a multiple of 4, so prepare an int for every 4 bytes.
* This is a candidate for Unsafe.copy[Swap]Memory().
*/
while (from < to) {
res[i++] = a[from++] << 24 | (a[from++] & 0xFF) << 16
| (a[from++] & 0xFF) << 8 | (a[from++] & 0xFF);
}
/* Convert to two's complement. Here, i == res.length */
while (--i >= 0 && res[i] == 0)
; // empty body
res[i] = -res[i];
while (--i >= 0) {
res[i] = ~res[i];
}
return res;
}
/**
* Takes an array a representing a negative 2's-complement number and
* returns the minimal (no leading zero ints) unsigned whose value is -a.
*/
private static int[] makePositive(int[] a) {
int keep, j;
// Find first non-sign (0xffffffff) int of input
for (keep=0; keep < a.length && a[keep] == -1; keep++)
;
/* Allocate output array. If all non-sign ints are 0x00, we must
* allocate space for one extra output int. */
for (j=keep; j < a.length && a[j] == 0; j++)
;
int extraInt = (j == a.length ? 1 : 0);
int result[] = new int[a.length - keep + extraInt];
/* Copy one's complement of input into output, leaving extra
* int (if it exists) == 0x00 */
for (int i = keep; i < a.length; i++)
result[i - keep + extraInt] = ~a[i];
// Add one to one's complement to generate two's complement
for (int i=result.length-1; ++result[i] == 0; i--)
;
return result;
}
/*
* The following two arrays are used for fast String conversions. Both
* are indexed by radix. The first is the number of digits of the given
* radix that can fit in a Java long without "going negative", i.e., the
* highest integer n such that radix**n < 2**63. The second is the
* "long radix" that tears each number into "long digits", each of which
* consists of the number of digits in the corresponding element in
* digitsPerLong (longRadix[i] = i**digitPerLong[i]). Both arrays have
* nonsense values in their 0 and 1 elements, as radixes 0 and 1 are not
* used.
*/
private static int digitsPerLong[] = {0, 0,
62, 39, 31, 27, 24, 22, 20, 19, 18, 18, 17, 17, 16, 16, 15, 15, 15, 14,
14, 14, 14, 13, 13, 13, 13, 13, 13, 12, 12, 12, 12, 12, 12, 12, 12};
private static BigInteger longRadix[] = {null, null,
valueOf(0x4000000000000000L), valueOf(0x383d9170b85ff80bL),
valueOf(0x4000000000000000L), valueOf(0x6765c793fa10079dL),
valueOf(0x41c21cb8e1000000L), valueOf(0x3642798750226111L),
valueOf(0x1000000000000000L), valueOf(0x12bf307ae81ffd59L),
valueOf( 0xde0b6b3a7640000L), valueOf(0x4d28cb56c33fa539L),
valueOf(0x1eca170c00000000L), valueOf(0x780c7372621bd74dL),
valueOf(0x1e39a5057d810000L), valueOf(0x5b27ac993df97701L),
valueOf(0x1000000000000000L), valueOf(0x27b95e997e21d9f1L),
valueOf(0x5da0e1e53c5c8000L), valueOf( 0xb16a458ef403f19L),
valueOf(0x16bcc41e90000000L), valueOf(0x2d04b7fdd9c0ef49L),
valueOf(0x5658597bcaa24000L), valueOf( 0x6feb266931a75b7L),
valueOf( 0xc29e98000000000L), valueOf(0x14adf4b7320334b9L),
valueOf(0x226ed36478bfa000L), valueOf(0x383d9170b85ff80bL),
valueOf(0x5a3c23e39c000000L), valueOf( 0x4e900abb53e6b71L),
valueOf( 0x7600ec618141000L), valueOf( 0xaee5720ee830681L),
valueOf(0x1000000000000000L), valueOf(0x172588ad4f5f0981L),
valueOf(0x211e44f7d02c1000L), valueOf(0x2ee56725f06e5c71L),
valueOf(0x41c21cb8e1000000L)};
/*
* These two arrays are the integer analogue of above.
*/
private static int digitsPerInt[] = {0, 0, 30, 19, 15, 13, 11,
11, 10, 9, 9, 8, 8, 8, 8, 7, 7, 7, 7, 7, 7, 7, 6, 6, 6, 6,
6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 5};
private static int intRadix[] = {0, 0,
0x40000000, 0x4546b3db, 0x40000000, 0x48c27395, 0x159fd800,
0x75db9c97, 0x40000000, 0x17179149, 0x3b9aca00, 0xcc6db61,
0x19a10000, 0x309f1021, 0x57f6c100, 0xa2f1b6f, 0x10000000,
0x18754571, 0x247dbc80, 0x3547667b, 0x4c4b4000, 0x6b5a6e1d,
0x6c20a40, 0x8d2d931, 0xb640000, 0xe8d4a51, 0x1269ae40,
0x17179149, 0x1cb91000, 0x23744899, 0x2b73a840, 0x34e63b41,
0x40000000, 0x4cfa3cc1, 0x5c13d840, 0x6d91b519, 0x39aa400
};
/**
* These routines provide access to the two's complement representation
* of BigIntegers.
*/
/**
* Returns the length of the two's complement representation in ints,
* including space for at least one sign bit.
*/
private int intLength() {
return (bitLength() >>> 5) + 1;
}
/* Returns sign bit */
private int signBit() {
return signum < 0 ? 1 : 0;
}
/* Returns an int of sign bits */
private int signInt() {
return signum < 0 ? -1 : 0;
}
/**
* Returns the specified int of the little-endian two's complement
* representation (int 0 is the least significant). The int number can
* be arbitrarily high (values are logically preceded by infinitely many
* sign ints).
*/
private int getInt(int n) {
if (n < 0)
return 0;
if (n >= mag.length)
return signInt();
int magInt = mag[mag.length-n-1];
return (signum >= 0 ? magInt :
(n <= firstNonzeroIntNum() ? -magInt : ~magInt));
}
/**
* Returns the index of the int that contains the first nonzero int in the
* little-endian binary representation of the magnitude (int 0 is the
* least significant). If the magnitude is zero, return value is undefined.
*
* <p>Note: never used for a BigInteger with a magnitude of zero.
* @see #getInt
*/
private int firstNonzeroIntNum() {
int fn = firstNonzeroIntNumPlusTwo - 2;
if (fn == -2) { // firstNonzeroIntNum not initialized yet
// Search for the first nonzero int
int i;
int mlen = mag.length;
for (i = mlen - 1; i >= 0 && mag[i] == 0; i--)
;
fn = mlen - i - 1;
firstNonzeroIntNumPlusTwo = fn + 2; // offset by two to initialize
}
return fn;
}
/** use serialVersionUID from JDK 1.1. for interoperability */
@java.io.Serial
private static final long serialVersionUID = -8287574255936472291L;
/**
* Serializable fields for BigInteger.
*
* @serialField signum int
* signum of this BigInteger
* @serialField magnitude byte[]
* magnitude array of this BigInteger
* @serialField bitCount int
* appears in the serialized form for backward compatibility
* @serialField bitLength int
* appears in the serialized form for backward compatibility
* @serialField firstNonzeroByteNum int
* appears in the serialized form for backward compatibility
* @serialField lowestSetBit int
* appears in the serialized form for backward compatibility
*/
@java.io.Serial
private static final ObjectStreamField[] serialPersistentFields = {
new ObjectStreamField("signum", Integer.TYPE),
new ObjectStreamField("magnitude", byte[].class),
new ObjectStreamField("bitCount", Integer.TYPE),
new ObjectStreamField("bitLength", Integer.TYPE),
new ObjectStreamField("firstNonzeroByteNum", Integer.TYPE),
new ObjectStreamField("lowestSetBit", Integer.TYPE)
};
/**
* Reconstitute the {@code BigInteger} instance from a stream (that is,
* deserialize it). The magnitude is read in as an array of bytes
* for historical reasons, but it is converted to an array of ints
* and the byte array is discarded.
* Note:
* The current convention is to initialize the cache fields, bitCountPlusOne,
* bitLengthPlusOne and lowestSetBitPlusTwo, to 0 rather than some other
* marker value. Therefore, no explicit action to set these fields needs to
* be taken in readObject because those fields already have a 0 value by
* default since defaultReadObject is not being used.
*
* @param s the stream being read.
* @throws IOException if an I/O error occurs
* @throws ClassNotFoundException if a serialized class cannot be loaded
*/
@java.io.Serial
private void readObject(java.io.ObjectInputStream s)
throws java.io.IOException, ClassNotFoundException {
// prepare to read the alternate persistent fields
ObjectInputStream.GetField fields = s.readFields();
// Read and validate the alternate persistent fields that we
// care about, signum and magnitude
// Read and validate signum
int sign = fields.get("signum", -2);
if (sign < -1 || sign > 1) {
String message = "BigInteger: Invalid signum value";
if (fields.defaulted("signum"))
message = "BigInteger: Signum not present in stream";
throw new java.io.StreamCorruptedException(message);
}
// Read and validate magnitude
byte[] magnitude = (byte[])fields.get("magnitude", null);
magnitude = magnitude.clone(); // defensive copy
int[] mag = stripLeadingZeroBytes(magnitude, 0, magnitude.length);
if ((mag.length == 0) != (sign == 0)) {
String message = "BigInteger: signum-magnitude mismatch";
if (fields.defaulted("magnitude"))
message = "BigInteger: Magnitude not present in stream";
throw new java.io.StreamCorruptedException(message);
}
// Equivalent to checkRange() on mag local without assigning
// this.mag field
if (mag.length > MAX_MAG_LENGTH ||
(mag.length == MAX_MAG_LENGTH && mag[0] < 0)) {
throw new java.io.StreamCorruptedException("BigInteger: Out of the supported range");
}
// Commit final fields via Unsafe
UnsafeHolder.putSignAndMag(this, sign, mag);
}
/**
* Serialization without data not supported for this class.
*/
@java.io.Serial
private void readObjectNoData()
throws ObjectStreamException {
throw new InvalidObjectException("Deserialized BigInteger objects need data");
}
// Support for resetting final fields while deserializing
private static class UnsafeHolder {
private static final jdk.internal.misc.Unsafe unsafe
= jdk.internal.misc.Unsafe.getUnsafe();
private static final long signumOffset
= unsafe.objectFieldOffset(BigInteger.class, "signum");
private static final long magOffset
= unsafe.objectFieldOffset(BigInteger.class, "mag");
static void putSignAndMag(BigInteger bi, int sign, int[] magnitude) {
unsafe.putInt(bi, signumOffset, sign);
unsafe.putReference(bi, magOffset, magnitude);
}
}
/**
* Save the {@code BigInteger} instance to a stream. The magnitude of a
* {@code BigInteger} is serialized as a byte array for historical reasons.
* To maintain compatibility with older implementations, the integers
* -1, -1, -2, and -2 are written as the values of the obsolete fields
* {@code bitCount}, {@code bitLength}, {@code lowestSetBit}, and
* {@code firstNonzeroByteNum}, respectively. These values are compatible
* with older implementations, but will be ignored by current
* implementations.
*
* @param s the stream to serialize to.
* @throws IOException if an I/O error occurs
*/
@java.io.Serial
private void writeObject(ObjectOutputStream s) throws IOException {
// set the values of the Serializable fields
ObjectOutputStream.PutField fields = s.putFields();
fields.put("signum", signum);
fields.put("magnitude", magSerializedForm());
// The values written for cached fields are compatible with older
// versions, but are ignored in readObject so don't otherwise matter.
fields.put("bitCount", -1);
fields.put("bitLength", -1);
fields.put("lowestSetBit", -2);
fields.put("firstNonzeroByteNum", -2);
// save them
s.writeFields();
}
/**
* Returns the mag array as an array of bytes.
*/
private byte[] magSerializedForm() {
int len = mag.length;
int bitLen = (len == 0 ? 0 : ((len - 1) << 5) + bitLengthForInt(mag[0]));
int byteLen = (bitLen + 7) >>> 3;
byte[] result = new byte[byteLen];
for (int i = byteLen - 1, bytesCopied = 4, intIndex = len - 1, nextInt = 0;
i >= 0; i--) {
if (bytesCopied == 4) {
nextInt = mag[intIndex--];
bytesCopied = 1;
} else {
nextInt >>>= 8;
bytesCopied++;
}
result[i] = (byte)nextInt;
}
return result;
}
/**
* Converts this {@code BigInteger} to a {@code long}, checking
* for lost information. If the value of this {@code BigInteger}
* is out of the range of the {@code long} type, then an
* {@code ArithmeticException} is thrown.
*
* @return this {@code BigInteger} converted to a {@code long}.
* @throws ArithmeticException if the value of {@code this} will
* not exactly fit in a {@code long}.
* @see BigInteger#longValue
* @since 1.8
*/
public long longValueExact() {
if (mag.length <= 2 && bitLength() <= 63)
return longValue();
else
throw new ArithmeticException("BigInteger out of long range");
}
/**
* Converts this {@code BigInteger} to an {@code int}, checking
* for lost information. If the value of this {@code BigInteger}
* is out of the range of the {@code int} type, then an
* {@code ArithmeticException} is thrown.
*
* @return this {@code BigInteger} converted to an {@code int}.
* @throws ArithmeticException if the value of {@code this} will
* not exactly fit in an {@code int}.
* @see BigInteger#intValue
* @since 1.8
*/
public int intValueExact() {
if (mag.length <= 1 && bitLength() <= 31)
return intValue();
else
throw new ArithmeticException("BigInteger out of int range");
}
/**
* Converts this {@code BigInteger} to a {@code short}, checking
* for lost information. If the value of this {@code BigInteger}
* is out of the range of the {@code short} type, then an
* {@code ArithmeticException} is thrown.
*
* @return this {@code BigInteger} converted to a {@code short}.
* @throws ArithmeticException if the value of {@code this} will
* not exactly fit in a {@code short}.
* @see BigInteger#shortValue
* @since 1.8
*/
public short shortValueExact() {
if (mag.length <= 1 && bitLength() <= 31) {
int value = intValue();
if (value >= Short.MIN_VALUE && value <= Short.MAX_VALUE)
return shortValue();
}
throw new ArithmeticException("BigInteger out of short range");
}
/**
* Converts this {@code BigInteger} to a {@code byte}, checking
* for lost information. If the value of this {@code BigInteger}
* is out of the range of the {@code byte} type, then an
* {@code ArithmeticException} is thrown.
*
* @return this {@code BigInteger} converted to a {@code byte}.
* @throws ArithmeticException if the value of {@code this} will
* not exactly fit in a {@code byte}.
* @see BigInteger#byteValue
* @since 1.8
*/
public byte byteValueExact() {
if (mag.length <= 1 && bitLength() <= 31) {
int value = intValue();
if (value >= Byte.MIN_VALUE && value <= Byte.MAX_VALUE)
return byteValue();
}
throw new ArithmeticException("BigInteger out of byte range");
}
}
/*
* Copyright (c) 1996, 2023, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
package java.io;
import java.lang.invoke.MethodHandle;
import java.lang.invoke.MethodHandles;
import java.lang.invoke.MethodType;
import java.lang.reflect.Constructor;
import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.RecordComponent;
import java.lang.reflect.UndeclaredThrowableException;
import java.lang.reflect.Member;
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
import java.lang.reflect.Proxy;
import java.security.AccessControlContext;
import java.security.AccessController;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.security.PermissionCollection;
import java.security.Permissions;
import java.security.PrivilegedAction;
import java.security.PrivilegedActionException;
import java.security.PrivilegedExceptionAction;
import java.security.ProtectionDomain;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.Comparator;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;
import java.util.concurrent.ConcurrentHashMap;
import jdk.internal.misc.Unsafe;
import jdk.internal.reflect.CallerSensitive;
import jdk.internal.reflect.Reflection;
import jdk.internal.reflect.ReflectionFactory;
import jdk.internal.access.SharedSecrets;
import jdk.internal.access.JavaSecurityAccess;
import jdk.internal.util.ByteArray;
import sun.reflect.misc.ReflectUtil;
/**
* Serialization's descriptor for classes. It contains the name and
* serialVersionUID of the class. The ObjectStreamClass for a specific class
* loaded in this Java VM can be found/created using the lookup method.
*
* <p>The algorithm to compute the SerialVersionUID is described in
* <a href="{@docRoot}/../specs/serialization/class.html#stream-unique-identifiers">
* <cite>Java Object Serialization Specification,</cite> Section 4.6, "Stream Unique Identifiers"</a>.
*
* @spec serialization/index.html Java Object Serialization Specification
* @author Mike Warres
* @author Roger Riggs
* @see ObjectStreamField
* @see <a href="{@docRoot}/../specs/serialization/class.html">
* <cite>Java Object Serialization Specification,</cite> Section 4, "Class Descriptors"</a>
* @since 1.1
*/
public final class ObjectStreamClass implements Serializable {
/** serialPersistentFields value indicating no serializable fields */
public static final ObjectStreamField[] NO_FIELDS =
new ObjectStreamField[0];
@java.io.Serial
private static final long serialVersionUID = -6120832682080437368L;
/**
* {@code ObjectStreamClass} has no fields for default serialization.
*/
@java.io.Serial
private static final ObjectStreamField[] serialPersistentFields =
NO_FIELDS;
/** reflection factory for obtaining serialization constructors */
@SuppressWarnings("removal")
private static final ReflectionFactory reflFactory =
AccessController.doPrivileged(
new ReflectionFactory.GetReflectionFactoryAction());
private static class Caches {
/** cache mapping local classes -> descriptors */
static final ClassCache<ObjectStreamClass> localDescs =
new ClassCache<>() {
@Override
protected ObjectStreamClass computeValue(Class<?> type) {
return new ObjectStreamClass(type);
}
};
/** cache mapping field group/local desc pairs -> field reflectors */
static final ClassCache<Map<FieldReflectorKey, FieldReflector>> reflectors =
new ClassCache<>() {
@Override
protected Map<FieldReflectorKey, FieldReflector> computeValue(Class<?> type) {
return new ConcurrentHashMap<>();
}
};
}
/** class associated with this descriptor (if any) */
private Class<?> cl;
/** name of class represented by this descriptor */
private String name;
/** serialVersionUID of represented class (null if not computed yet) */
private volatile Long suid;
/** true if represents dynamic proxy class */
private boolean isProxy;
/** true if represents enum type */
private boolean isEnum;
/** true if represents record type */
private boolean isRecord;
/** true if represented class implements Serializable */
private boolean serializable;
/** true if represented class implements Externalizable */
private boolean externalizable;
/** true if desc has data written by class-defined writeObject method */
private boolean hasWriteObjectData;
/**
* true if desc has externalizable data written in block data format; this
* must be true by default to accommodate ObjectInputStream subclasses which
* override readClassDescriptor() to return class descriptors obtained from
* ObjectStreamClass.lookup() (see 4461737)
*/
private boolean hasBlockExternalData = true;
/**
* Contains information about InvalidClassException instances to be thrown
* when attempting operations on an invalid class. Note that instances of
* this class are immutable and are potentially shared among
* ObjectStreamClass instances.
*/
private static class ExceptionInfo {
private final String className;
private final String message;
ExceptionInfo(String cn, String msg) {
className = cn;
message = msg;
}
/**
* Returns (does not throw) an InvalidClassException instance created
* from the information in this object, suitable for being thrown by
* the caller.
*/
InvalidClassException newInvalidClassException() {
return new InvalidClassException(className, message);
}
}
/** exception (if any) thrown while attempting to resolve class */
private ClassNotFoundException resolveEx;
/** exception (if any) to throw if non-enum deserialization attempted */
private ExceptionInfo deserializeEx;
/** exception (if any) to throw if non-enum serialization attempted */
private ExceptionInfo serializeEx;
/** exception (if any) to throw if default serialization attempted */
private ExceptionInfo defaultSerializeEx;
/** serializable fields */
private ObjectStreamField[] fields;
/** aggregate marshalled size of primitive fields */
private int primDataSize;
/** number of non-primitive fields */
private int numObjFields;
/** reflector for setting/getting serializable field values */
private FieldReflector fieldRefl;
/** data layout of serialized objects described by this class desc */
private volatile ClassDataSlot[] dataLayout;
/** serialization-appropriate constructor, or null if none */
private Constructor<?> cons;
/** record canonical constructor (shared among OSCs for same class), or null */
private MethodHandle canonicalCtr;
/** cache of record deserialization constructors per unique set of stream fields
* (shared among OSCs for same class), or null */
private DeserializationConstructorsCache deserializationCtrs;
/** session-cache of record deserialization constructor
* (in de-serialized OSC only), or null */
private MethodHandle deserializationCtr;
/** protection domains that need to be checked when calling the constructor */
private ProtectionDomain[] domains;
/** class-defined writeObject method, or null if none */
private Method writeObjectMethod;
/** class-defined readObject method, or null if none */
private Method readObjectMethod;
/** class-defined readObjectNoData method, or null if none */
private Method readObjectNoDataMethod;
/** class-defined writeReplace method, or null if none */
private Method writeReplaceMethod;
/** class-defined readResolve method, or null if none */
private Method readResolveMethod;
/** local class descriptor for represented class (may point to self) */
private ObjectStreamClass localDesc;
/** superclass descriptor appearing in stream */
private ObjectStreamClass superDesc;
/** true if, and only if, the object has been correctly initialized */
private boolean initialized;
/**
* Initializes native code.
*/
private static native void initNative();
static {
initNative();
}
/**
* Find the descriptor for a class that can be serialized. Creates an
* ObjectStreamClass instance if one does not exist yet for class. Null is
* returned if the specified class does not implement java.io.Serializable
* or java.io.Externalizable.
*
* @param cl class for which to get the descriptor
* @return the class descriptor for the specified class
*/
public static ObjectStreamClass lookup(Class<?> cl) {
return lookup(cl, false);
}
/**
* Returns the descriptor for any class, regardless of whether it
* implements {@link Serializable}.
*
* @param cl class for which to get the descriptor
* @return the class descriptor for the specified class
* @since 1.6
*/
public static ObjectStreamClass lookupAny(Class<?> cl) {
return lookup(cl, true);
}
/**
* Returns the name of the class described by this descriptor.
* This method returns the name of the class in the format that
* is used by the {@link Class#getName} method.
*
* @return a string representing the name of the class
*/
public String getName() {
return name;
}
/**
* Return the serialVersionUID for this class. The serialVersionUID
* defines a set of classes all with the same name that have evolved from a
* common root class and agree to be serialized and deserialized using a
* common format. NonSerializable classes have a serialVersionUID of 0L.
*
* @return the SUID of the class described by this descriptor
*/
@SuppressWarnings("removal")
public long getSerialVersionUID() {
// REMIND: synchronize instead of relying on volatile?
if (suid == null) {
if (isRecord)
return 0L;
suid = AccessController.doPrivileged(
new PrivilegedAction<Long>() {
public Long run() {
return computeDefaultSUID(cl);
}
}
);
}
return suid.longValue();
}
/**
* Return the class in the local VM that this version is mapped to. Null
* is returned if there is no corresponding local class.
*
* @return the {@code Class} instance that this descriptor represents
*/
@SuppressWarnings("removal")
@CallerSensitive
public Class<?> forClass() {
if (cl == null) {
return null;
}
requireInitialized();
if (System.getSecurityManager() != null) {
Class<?> caller = Reflection.getCallerClass();
if (ReflectUtil.needsPackageAccessCheck(caller.getClassLoader(), cl.getClassLoader())) {
ReflectUtil.checkPackageAccess(cl);
}
}
return cl;
}
/**
* Return an array of the fields of this serializable class.
*
* @return an array containing an element for each persistent field of
* this class. Returns an array of length zero if there are no
* fields.
* @since 1.2
*/
public ObjectStreamField[] getFields() {
return getFields(true);
}
/**
* Get the field of this class by name.
*
* @param name the name of the data field to look for
* @return The ObjectStreamField object of the named field or null if
* there is no such named field.
*/
public ObjectStreamField getField(String name) {
return getField(name, null);
}
/**
* Return a string describing this ObjectStreamClass.
*/
public String toString() {
return name + ": static final long serialVersionUID = " +
getSerialVersionUID() + "L;";
}
/**
* Looks up and returns class descriptor for given class, or null if class
* is non-serializable and "all" is set to false.
*
* @param cl class to look up
* @param all if true, return descriptors for all classes; if false, only
* return descriptors for serializable classes
*/
static ObjectStreamClass lookup(Class<?> cl, boolean all) {
if (!(all || Serializable.class.isAssignableFrom(cl))) {
return null;
}
return Caches.localDescs.get(cl);
}
/**
* Creates local class descriptor representing given class.
*/
@SuppressWarnings("removal")
private ObjectStreamClass(final Class<?> cl) {
this.cl = cl;
name = cl.getName();
isProxy = Proxy.isProxyClass(cl);
isEnum = Enum.class.isAssignableFrom(cl);
isRecord = cl.isRecord();
serializable = Serializable.class.isAssignableFrom(cl);
externalizable = Externalizable.class.isAssignableFrom(cl);
Class<?> superCl = cl.getSuperclass();
superDesc = (superCl != null) ? lookup(superCl, false) : null;
localDesc = this;
if (serializable) {
AccessController.doPrivileged(new PrivilegedAction<>() {
public Void run() {
if (isEnum) {
suid = 0L;
fields = NO_FIELDS;
return null;
}
if (cl.isArray()) {
fields = NO_FIELDS;
return null;
}
suid = getDeclaredSUID(cl);
try {
fields = getSerialFields(cl);
computeFieldOffsets();
} catch (InvalidClassException e) {
serializeEx = deserializeEx =
new ExceptionInfo(e.classname, e.getMessage());
fields = NO_FIELDS;
}
if (isRecord) {
canonicalCtr = canonicalRecordCtr(cl);
deserializationCtrs = new DeserializationConstructorsCache();
} else if (externalizable) {
cons = getExternalizableConstructor(cl);
} else {
cons = getSerializableConstructor(cl);
writeObjectMethod = getPrivateMethod(cl, "writeObject",
new Class<?>[] { ObjectOutputStream.class },
Void.TYPE);
readObjectMethod = getPrivateMethod(cl, "readObject",
new Class<?>[] { ObjectInputStream.class },
Void.TYPE);
readObjectNoDataMethod = getPrivateMethod(
cl, "readObjectNoData", null, Void.TYPE);
hasWriteObjectData = (writeObjectMethod != null);
}
domains = getProtectionDomains(cons, cl);
writeReplaceMethod = getInheritableMethod(
cl, "writeReplace", null, Object.class);
readResolveMethod = getInheritableMethod(
cl, "readResolve", null, Object.class);
return null;
}
});
} else {
suid = 0L;
fields = NO_FIELDS;
}
try {
fieldRefl = getReflector(fields, this);
} catch (InvalidClassException ex) {
// field mismatches impossible when matching local fields vs. self
throw new InternalError(ex);
}
if (deserializeEx == null) {
if (isEnum) {
deserializeEx = new ExceptionInfo(name, "enum type");
} else if (cons == null && !isRecord) {
deserializeEx = new ExceptionInfo(name, "no valid constructor");
}
}
if (isRecord && canonicalCtr == null) {
deserializeEx = new ExceptionInfo(name, "record canonical constructor not found");
} else {
for (int i = 0; i < fields.length; i++) {
if (fields[i].getField() == null) {
defaultSerializeEx = new ExceptionInfo(
name, "unmatched serializable field(s) declared");
}
}
}
initialized = true;
}
/**
* Creates blank class descriptor which should be initialized via a
* subsequent call to initProxy(), initNonProxy() or readNonProxy().
*/
ObjectStreamClass() {
}
/**
* Creates a PermissionDomain that grants no permission.
*/
private ProtectionDomain noPermissionsDomain() {
PermissionCollection perms = new Permissions();
perms.setReadOnly();
return new ProtectionDomain(null, perms);
}
/**
* Aggregate the ProtectionDomains of all the classes that separate
* a concrete class {@code cl} from its ancestor's class declaring
* a constructor {@code cons}.
*
* If {@code cl} is defined by the boot loader, or the constructor
* {@code cons} is declared by {@code cl}, or if there is no security
* manager, then this method does nothing and {@code null} is returned.
*
* @param cons A constructor declared by {@code cl} or one of its
* ancestors.
* @param cl A concrete class, which is either the class declaring
* the constructor {@code cons}, or a serializable subclass
* of that class.
* @return An array of ProtectionDomain representing the set of
* ProtectionDomain that separate the concrete class {@code cl}
* from its ancestor's declaring {@code cons}, or {@code null}.
*/
@SuppressWarnings("removal")
private ProtectionDomain[] getProtectionDomains(Constructor<?> cons,
Class<?> cl) {
ProtectionDomain[] domains = null;
if (cons != null && cl.getClassLoader() != null
&& System.getSecurityManager() != null) {
Class<?> cls = cl;
Class<?> fnscl = cons.getDeclaringClass();
Set<ProtectionDomain> pds = null;
while (cls != fnscl) {
ProtectionDomain pd = cls.getProtectionDomain();
if (pd != null) {
if (pds == null) pds = new HashSet<>();
pds.add(pd);
}
cls = cls.getSuperclass();
if (cls == null) {
// that's not supposed to happen
// make a ProtectionDomain with no permission.
// should we throw instead?
if (pds == null) pds = new HashSet<>();
else pds.clear();
pds.add(noPermissionsDomain());
break;
}
}
if (pds != null) {
domains = pds.toArray(new ProtectionDomain[0]);
}
}
return domains;
}
/**
* Initializes class descriptor representing a proxy class.
*/
void initProxy(Class<?> cl,
ClassNotFoundException resolveEx,
ObjectStreamClass superDesc)
throws InvalidClassException
{
ObjectStreamClass osc = null;
if (cl != null) {
osc = lookup(cl, true);
if (!osc.isProxy) {
throw new InvalidClassException(
"cannot bind proxy descriptor to a non-proxy class");
}
}
this.cl = cl;
this.resolveEx = resolveEx;
this.superDesc = superDesc;
isProxy = true;
serializable = true;
suid = 0L;
fields = NO_FIELDS;
if (osc != null) {
localDesc = osc;
name = localDesc.name;
externalizable = localDesc.externalizable;
writeReplaceMethod = localDesc.writeReplaceMethod;
readResolveMethod = localDesc.readResolveMethod;
deserializeEx = localDesc.deserializeEx;
domains = localDesc.domains;
cons = localDesc.cons;
}
fieldRefl = getReflector(fields, localDesc);
initialized = true;
}
/**
* Initializes class descriptor representing a non-proxy class.
*/
void initNonProxy(ObjectStreamClass model,
Class<?> cl,
ClassNotFoundException resolveEx,
ObjectStreamClass superDesc)
throws InvalidClassException
{
long suid = model.getSerialVersionUID();
ObjectStreamClass osc = null;
if (cl != null) {
osc = lookup(cl, true);
if (osc.isProxy) {
throw new InvalidClassException(
"cannot bind non-proxy descriptor to a proxy class");
}
if (model.isEnum != osc.isEnum) {
throw new InvalidClassException(model.isEnum ?
"cannot bind enum descriptor to a non-enum class" :
"cannot bind non-enum descriptor to an enum class");
}
if (model.serializable == osc.serializable &&
!cl.isArray() && !cl.isRecord() &&
suid != osc.getSerialVersionUID()) {
throw new InvalidClassException(osc.name,
"local class incompatible: " +
"stream classdesc serialVersionUID = " + suid +
", local class serialVersionUID = " +
osc.getSerialVersionUID());
}
if (!classNamesEqual(model.name, osc.name)) {
throw new InvalidClassException(osc.name,
"local class name incompatible with stream class " +
"name \"" + model.name + "\"");
}
if (!model.isEnum) {
if ((model.serializable == osc.serializable) &&
(model.externalizable != osc.externalizable)) {
throw new InvalidClassException(osc.name,
"Serializable incompatible with Externalizable");
}
if ((model.serializable != osc.serializable) ||
(model.externalizable != osc.externalizable) ||
!(model.serializable || model.externalizable)) {
deserializeEx = new ExceptionInfo(
osc.name, "class invalid for deserialization");
}
}
}
this.cl = cl;
this.resolveEx = resolveEx;
this.superDesc = superDesc;
name = model.name;
this.suid = suid;
isProxy = false;
isEnum = model.isEnum;
serializable = model.serializable;
externalizable = model.externalizable;
hasBlockExternalData = model.hasBlockExternalData;
hasWriteObjectData = model.hasWriteObjectData;
fields = model.fields;
primDataSize = model.primDataSize;
numObjFields = model.numObjFields;
if (osc != null) {
localDesc = osc;
isRecord = localDesc.isRecord;
// canonical record constructor is shared
canonicalCtr = localDesc.canonicalCtr;
// cache of deserialization constructors is shared
deserializationCtrs = localDesc.deserializationCtrs;
writeObjectMethod = localDesc.writeObjectMethod;
readObjectMethod = localDesc.readObjectMethod;
readObjectNoDataMethod = localDesc.readObjectNoDataMethod;
writeReplaceMethod = localDesc.writeReplaceMethod;
readResolveMethod = localDesc.readResolveMethod;
if (deserializeEx == null) {
deserializeEx = localDesc.deserializeEx;
}
domains = localDesc.domains;
assert cl.isRecord() ? localDesc.cons == null : true;
cons = localDesc.cons;
}
fieldRefl = getReflector(fields, localDesc);
// reassign to matched fields so as to reflect local unshared settings
fields = fieldRefl.getFields();
initialized = true;
}
/**
* Reads non-proxy class descriptor information from given input stream.
* The resulting class descriptor is not fully functional; it can only be
* used as input to the ObjectInputStream.resolveClass() and
* ObjectStreamClass.initNonProxy() methods.
*/
void readNonProxy(ObjectInputStream in)
throws IOException, ClassNotFoundException
{
name = in.readUTF();
suid = in.readLong();
isProxy = false;
byte flags = in.readByte();
hasWriteObjectData =
((flags & ObjectStreamConstants.SC_WRITE_METHOD) != 0);
hasBlockExternalData =
((flags & ObjectStreamConstants.SC_BLOCK_DATA) != 0);
externalizable =
((flags & ObjectStreamConstants.SC_EXTERNALIZABLE) != 0);
boolean sflag =
((flags & ObjectStreamConstants.SC_SERIALIZABLE) != 0);
if (externalizable && sflag) {
throw new InvalidClassException(
name, "serializable and externalizable flags conflict");
}
serializable = externalizable || sflag;
isEnum = ((flags & ObjectStreamConstants.SC_ENUM) != 0);
if (isEnum && suid.longValue() != 0L) {
throw new InvalidClassException(name,
"enum descriptor has non-zero serialVersionUID: " + suid);
}
int numFields = in.readShort();
if (isEnum && numFields != 0) {
throw new InvalidClassException(name,
"enum descriptor has non-zero field count: " + numFields);
}
fields = (numFields > 0) ?
new ObjectStreamField[numFields] : NO_FIELDS;
for (int i = 0; i < numFields; i++) {
char tcode = (char) in.readByte();
String fname = in.readUTF();
String signature = ((tcode == 'L') || (tcode == '[')) ?
in.readTypeString() : String.valueOf(tcode);
try {
fields[i] = new ObjectStreamField(fname, signature, false);
} catch (RuntimeException e) {
throw new InvalidClassException(name,
"invalid descriptor for field " +
fname, e);
}
}
computeFieldOffsets();
}
/**
* Writes non-proxy class descriptor information to given output stream.
*/
void writeNonProxy(ObjectOutputStream out) throws IOException {
out.writeUTF(name);
out.writeLong(getSerialVersionUID());
byte flags = 0;
if (externalizable) {
flags |= ObjectStreamConstants.SC_EXTERNALIZABLE;
int protocol = out.getProtocolVersion();
if (protocol != ObjectStreamConstants.PROTOCOL_VERSION_1) {
flags |= ObjectStreamConstants.SC_BLOCK_DATA;
}
} else if (serializable) {
flags |= ObjectStreamConstants.SC_SERIALIZABLE;
}
if (hasWriteObjectData) {
flags |= ObjectStreamConstants.SC_WRITE_METHOD;
}
if (isEnum) {
flags |= ObjectStreamConstants.SC_ENUM;
}
out.writeByte(flags);
out.writeShort(fields.length);
for (int i = 0; i < fields.length; i++) {
ObjectStreamField f = fields[i];
out.writeByte(f.getTypeCode());
out.writeUTF(f.getName());
if (!f.isPrimitive()) {
out.writeTypeString(f.getTypeString());
}
}
}
/**
* Returns ClassNotFoundException (if any) thrown while attempting to
* resolve local class corresponding to this class descriptor.
*/
ClassNotFoundException getResolveException() {
return resolveEx;
}
/**
* Throws InternalError if not initialized.
*/
private final void requireInitialized() {
if (!initialized)
throw new InternalError("Unexpected call when not initialized");
}
/**
* Throws InvalidClassException if not initialized.
* To be called in cases where an uninitialized class descriptor indicates
* a problem in the serialization stream.
*/
final void checkInitialized() throws InvalidClassException {
if (!initialized) {
throw new InvalidClassException("Class descriptor should be initialized");
}
}
/**
* Throws an InvalidClassException if object instances referencing this
* class descriptor should not be allowed to deserialize. This method does
* not apply to deserialization of enum constants.
*/
void checkDeserialize() throws InvalidClassException {
requireInitialized();
if (deserializeEx != null) {
throw deserializeEx.newInvalidClassException();
}
}
/**
* Throws an InvalidClassException if objects whose class is represented by
* this descriptor should not be allowed to serialize. This method does
* not apply to serialization of enum constants.
*/
void checkSerialize() throws InvalidClassException {
requireInitialized();
if (serializeEx != null) {
throw serializeEx.newInvalidClassException();
}
}
/**
* Throws an InvalidClassException if objects whose class is represented by
* this descriptor should not be permitted to use default serialization
* (e.g., if the class declares serializable fields that do not correspond
* to actual fields, and hence must use the GetField API). This method
* does not apply to deserialization of enum constants.
*/
void checkDefaultSerialize() throws InvalidClassException {
requireInitialized();
if (defaultSerializeEx != null) {
throw defaultSerializeEx.newInvalidClassException();
}
}
/**
* Returns superclass descriptor. Note that on the receiving side, the
* superclass descriptor may be bound to a class that is not a superclass
* of the subclass descriptor's bound class.
*/
ObjectStreamClass getSuperDesc() {
requireInitialized();
return superDesc;
}
/**
* Returns the "local" class descriptor for the class associated with this
* class descriptor (i.e., the result of
* ObjectStreamClass.lookup(this.forClass())) or null if there is no class
* associated with this descriptor.
*/
ObjectStreamClass getLocalDesc() {
requireInitialized();
return localDesc;
}
/**
* Returns arrays of ObjectStreamFields representing the serializable
* fields of the represented class. If copy is true, a clone of this class
* descriptor's field array is returned, otherwise the array itself is
* returned.
*/
ObjectStreamField[] getFields(boolean copy) {
return copy ? fields.clone() : fields;
}
/**
* Looks up a serializable field of the represented class by name and type.
* A specified type of null matches all types, Object.class matches all
* non-primitive types, and any other non-null type matches assignable
* types only. Returns matching field, or null if no match found.
*/
ObjectStreamField getField(String name, Class<?> type) {
for (int i = 0; i < fields.length; i++) {
ObjectStreamField f = fields[i];
if (f.getName().equals(name)) {
if (type == null ||
(type == Object.class && !f.isPrimitive()))
{
return f;
}
Class<?> ftype = f.getType();
if (ftype != null && type.isAssignableFrom(ftype)) {
return f;
}
}
}
return null;
}
/**
* Returns true if class descriptor represents a dynamic proxy class, false
* otherwise.
*/
boolean isProxy() {
requireInitialized();
return isProxy;
}
/**
* Returns true if class descriptor represents an enum type, false
* otherwise.
*/
boolean isEnum() {
requireInitialized();
return isEnum;
}
/**
* Returns true if class descriptor represents a record type, false
* otherwise.
*/
boolean isRecord() {
requireInitialized();
return isRecord;
}
/**
* Returns true if represented class implements Externalizable, false
* otherwise.
*/
boolean isExternalizable() {
requireInitialized();
return externalizable;
}
/**
* Returns true if represented class implements Serializable, false
* otherwise.
*/
boolean isSerializable() {
requireInitialized();
return serializable;
}
/**
* Returns true if class descriptor represents externalizable class that
* has written its data in 1.2 (block data) format, false otherwise.
*/
boolean hasBlockExternalData() {
requireInitialized();
return hasBlockExternalData;
}
/**
* Returns true if class descriptor represents serializable (but not
* externalizable) class which has written its data via a custom
* writeObject() method, false otherwise.
*/
boolean hasWriteObjectData() {
requireInitialized();
return hasWriteObjectData;
}
/**
* Returns true if represented class is serializable/externalizable and can
* be instantiated by the serialization runtime--i.e., if it is
* externalizable and defines a public no-arg constructor, or if it is
* non-externalizable and its first non-serializable superclass defines an
* accessible no-arg constructor. Otherwise, returns false.
*/
boolean isInstantiable() {
requireInitialized();
return (cons != null);
}
/**
* Returns true if represented class is serializable (but not
* externalizable) and defines a conformant writeObject method. Otherwise,
* returns false.
*/
boolean hasWriteObjectMethod() {
requireInitialized();
return (writeObjectMethod != null);
}
/**
* Returns true if represented class is serializable (but not
* externalizable) and defines a conformant readObject method. Otherwise,
* returns false.
*/
boolean hasReadObjectMethod() {
requireInitialized();
return (readObjectMethod != null);
}
/**
* Returns true if represented class is serializable (but not
* externalizable) and defines a conformant readObjectNoData method.
* Otherwise, returns false.
*/
boolean hasReadObjectNoDataMethod() {
requireInitialized();
return (readObjectNoDataMethod != null);
}
/**
* Returns true if represented class is serializable or externalizable and
* defines a conformant writeReplace method. Otherwise, returns false.
*/
boolean hasWriteReplaceMethod() {
requireInitialized();
return (writeReplaceMethod != null);
}
/**
* Returns true if represented class is serializable or externalizable and
* defines a conformant readResolve method. Otherwise, returns false.
*/
boolean hasReadResolveMethod() {
requireInitialized();
return (readResolveMethod != null);
}
/**
* Creates a new instance of the represented class. If the class is
* externalizable, invokes its public no-arg constructor; otherwise, if the
* class is serializable, invokes the no-arg constructor of the first
* non-serializable superclass. Throws UnsupportedOperationException if
* this class descriptor is not associated with a class, if the associated
* class is non-serializable or if the appropriate no-arg constructor is
* inaccessible/unavailable.
*/
@SuppressWarnings("removal")
Object newInstance()
throws InstantiationException, InvocationTargetException,
UnsupportedOperationException
{
requireInitialized();
if (cons != null) {
try {
if (domains == null || domains.length == 0) {
return cons.newInstance();
} else {
JavaSecurityAccess jsa = SharedSecrets.getJavaSecurityAccess();
PrivilegedAction<?> pea = () -> {
try {
return cons.newInstance();
} catch (InstantiationException
| InvocationTargetException
| IllegalAccessException x) {
throw new UndeclaredThrowableException(x);
}
}; // Can't use PrivilegedExceptionAction with jsa
try {
return jsa.doIntersectionPrivilege(pea,
AccessController.getContext(),
new AccessControlContext(domains));
} catch (UndeclaredThrowableException x) {
Throwable cause = x.getCause();
if (cause instanceof InstantiationException ie)
throw ie;
if (cause instanceof InvocationTargetException ite)
throw ite;
if (cause instanceof IllegalAccessException iae)
throw iae;
// not supposed to happen
throw x;
}
}
} catch (IllegalAccessException ex) {
// should not occur, as access checks have been suppressed
throw new InternalError(ex);
} catch (InvocationTargetException ex) {
Throwable cause = ex.getCause();
if (cause instanceof Error err)
throw err;
else
throw ex;
} catch (InstantiationError err) {
var ex = new InstantiationException();
ex.initCause(err);
throw ex;
}
} else {
throw new UnsupportedOperationException();
}
}
/**
* Invokes the writeObject method of the represented serializable class.
* Throws UnsupportedOperationException if this class descriptor is not
* associated with a class, or if the class is externalizable,
* non-serializable or does not define writeObject.
*/
void invokeWriteObject(Object obj, ObjectOutputStream out)
throws IOException, UnsupportedOperationException
{
requireInitialized();
if (writeObjectMethod != null) {
try {
writeObjectMethod.invoke(obj, new Object[]{ out });
} catch (InvocationTargetException ex) {
Throwable th = ex.getCause();
if (th instanceof IOException) {
throw (IOException) th;
} else {
throwMiscException(th);
}
} catch (IllegalAccessException ex) {
// should not occur, as access checks have been suppressed
throw new InternalError(ex);
}
} else {
throw new UnsupportedOperationException();
}
}
/**
* Invokes the readObject method of the represented serializable class.
* Throws UnsupportedOperationException if this class descriptor is not
* associated with a class, or if the class is externalizable,
* non-serializable or does not define readObject.
*/
void invokeReadObject(Object obj, ObjectInputStream in)
throws ClassNotFoundException, IOException,
UnsupportedOperationException
{
requireInitialized();
if (readObjectMethod != null) {
try {
readObjectMethod.invoke(obj, new Object[]{ in });
} catch (InvocationTargetException ex) {
Throwable th = ex.getCause();
if (th instanceof ClassNotFoundException) {
throw (ClassNotFoundException) th;
} else if (th instanceof IOException) {
throw (IOException) th;
} else {
throwMiscException(th);
}
} catch (IllegalAccessException ex) {
// should not occur, as access checks have been suppressed
throw new InternalError(ex);
}
} else {
throw new UnsupportedOperationException();
}
}
/**
* Invokes the readObjectNoData method of the represented serializable
* class. Throws UnsupportedOperationException if this class descriptor is
* not associated with a class, or if the class is externalizable,
* non-serializable or does not define readObjectNoData.
*/
void invokeReadObjectNoData(Object obj)
throws IOException, UnsupportedOperationException
{
requireInitialized();
if (readObjectNoDataMethod != null) {
try {
readObjectNoDataMethod.invoke(obj, (Object[]) null);
} catch (InvocationTargetException ex) {
Throwable th = ex.getCause();
if (th instanceof ObjectStreamException) {
throw (ObjectStreamException) th;
} else {
throwMiscException(th);
}
} catch (IllegalAccessException ex) {
// should not occur, as access checks have been suppressed
throw new InternalError(ex);
}
} else {
throw new UnsupportedOperationException();
}
}
/**
* Invokes the writeReplace method of the represented serializable class and
* returns the result. Throws UnsupportedOperationException if this class
* descriptor is not associated with a class, or if the class is
* non-serializable or does not define writeReplace.
*/
Object invokeWriteReplace(Object obj)
throws IOException, UnsupportedOperationException
{
requireInitialized();
if (writeReplaceMethod != null) {
try {
return writeReplaceMethod.invoke(obj, (Object[]) null);
} catch (InvocationTargetException ex) {
Throwable th = ex.getCause();
if (th instanceof ObjectStreamException) {
throw (ObjectStreamException) th;
} else {
throwMiscException(th);
throw new InternalError(th); // never reached
}
} catch (IllegalAccessException ex) {
// should not occur, as access checks have been suppressed
throw new InternalError(ex);
}
} else {
throw new UnsupportedOperationException();
}
}
/**
* Invokes the readResolve method of the represented serializable class and
* returns the result. Throws UnsupportedOperationException if this class
* descriptor is not associated with a class, or if the class is
* non-serializable or does not define readResolve.
*/
Object invokeReadResolve(Object obj)
throws IOException, UnsupportedOperationException
{
requireInitialized();
if (readResolveMethod != null) {
try {
return readResolveMethod.invoke(obj, (Object[]) null);
} catch (InvocationTargetException ex) {
Throwable th = ex.getCause();
if (th instanceof ObjectStreamException) {
throw (ObjectStreamException) th;
} else {
throwMiscException(th);
throw new InternalError(th); // never reached
}
} catch (IllegalAccessException ex) {
// should not occur, as access checks have been suppressed
throw new InternalError(ex);
}
} else {
throw new UnsupportedOperationException();
}
}
/**
* Class representing the portion of an object's serialized form allotted
* to data described by a given class descriptor. If "hasData" is false,
* the object's serialized form does not contain data associated with the
* class descriptor.
*/
static class ClassDataSlot {
/** class descriptor "occupying" this slot */
final ObjectStreamClass desc;
/** true if serialized form includes data for this slot's descriptor */
final boolean hasData;
ClassDataSlot(ObjectStreamClass desc, boolean hasData) {
this.desc = desc;
this.hasData = hasData;
}
}
/**
* Returns array of ClassDataSlot instances representing the data layout
* (including superclass data) for serialized objects described by this
* class descriptor. ClassDataSlots are ordered by inheritance with those
* containing "higher" superclasses appearing first. The final
* ClassDataSlot contains a reference to this descriptor.
*/
ClassDataSlot[] getClassDataLayout() throws InvalidClassException {
// REMIND: synchronize instead of relying on volatile?
if (dataLayout == null) {
dataLayout = getClassDataLayout0();
}
return dataLayout;
}
private ClassDataSlot[] getClassDataLayout0()
throws InvalidClassException
{
ArrayList<ClassDataSlot> slots = new ArrayList<>();
Class<?> start = cl, end = cl;
// locate closest non-serializable superclass
while (end != null && Serializable.class.isAssignableFrom(end)) {
end = end.getSuperclass();
}
HashSet<String> oscNames = new HashSet<>(3);
for (ObjectStreamClass d = this; d != null; d = d.superDesc) {
if (oscNames.contains(d.name)) {
throw new InvalidClassException("Circular reference.");
} else {
oscNames.add(d.name);
}
// search up inheritance hierarchy for class with matching name
String searchName = (d.cl != null) ? d.cl.getName() : d.name;
Class<?> match = null;
for (Class<?> c = start; c != end; c = c.getSuperclass()) {
if (searchName.equals(c.getName())) {
match = c;
break;
}
}
// add "no data" slot for each unmatched class below match
if (match != null) {
for (Class<?> c = start; c != match; c = c.getSuperclass()) {
slots.add(new ClassDataSlot(
ObjectStreamClass.lookup(c, true), false));
}
start = match.getSuperclass();
}
// record descriptor/class pairing
slots.add(new ClassDataSlot(d.getVariantFor(match), true));
}
// add "no data" slot for any leftover unmatched classes
for (Class<?> c = start; c != end; c = c.getSuperclass()) {
slots.add(new ClassDataSlot(
ObjectStreamClass.lookup(c, true), false));
}
// order slots from superclass -> subclass
Collections.reverse(slots);
return slots.toArray(new ClassDataSlot[slots.size()]);
}
/**
* Returns aggregate size (in bytes) of marshalled primitive field values
* for represented class.
*/
int getPrimDataSize() {
return primDataSize;
}
/**
* Returns number of non-primitive serializable fields of represented
* class.
*/
int getNumObjFields() {
return numObjFields;
}
/**
* Fetches the serializable primitive field values of object obj and
* marshals them into byte array buf starting at offset 0. It is the
* responsibility of the caller to ensure that obj is of the proper type if
* non-null.
*/
void getPrimFieldValues(Object obj, byte[] buf) {
fieldRefl.getPrimFieldValues(obj, buf);
}
/**
* Sets the serializable primitive fields of object obj using values
* unmarshalled from byte array buf starting at offset 0. It is the
* responsibility of the caller to ensure that obj is of the proper type if
* non-null.
*/
void setPrimFieldValues(Object obj, byte[] buf) {
fieldRefl.setPrimFieldValues(obj, buf);
}
/**
* Fetches the serializable object field values of object obj and stores
* them in array vals starting at offset 0. It is the responsibility of
* the caller to ensure that obj is of the proper type if non-null.
*/
void getObjFieldValues(Object obj, Object[] vals) {
fieldRefl.getObjFieldValues(obj, vals);
}
/**
* Checks that the given values, from array vals starting at offset 0,
* are assignable to the given serializable object fields.
* @throws ClassCastException if any value is not assignable
*/
void checkObjFieldValueTypes(Object obj, Object[] vals) {
fieldRefl.checkObjectFieldValueTypes(obj, vals);
}
/**
* Sets the serializable object fields of object obj using values from
* array vals starting at offset 0. It is the responsibility of the caller
* to ensure that obj is of the proper type if non-null.
*/
void setObjFieldValues(Object obj, Object[] vals) {
fieldRefl.setObjFieldValues(obj, vals);
}
/**
* Calculates and sets serializable field offsets, as well as primitive
* data size and object field count totals. Throws InvalidClassException
* if fields are illegally ordered.
*/
private void computeFieldOffsets() throws InvalidClassException {
primDataSize = 0;
numObjFields = 0;
int firstObjIndex = -1;
for (int i = 0; i < fields.length; i++) {
ObjectStreamField f = fields[i];
switch (f.getTypeCode()) {
case 'Z', 'B' -> f.setOffset(primDataSize++);
case 'C', 'S' -> {
f.setOffset(primDataSize);
primDataSize += 2;
}
case 'I', 'F' -> {
f.setOffset(primDataSize);
primDataSize += 4;
}
case 'J', 'D' -> {
f.setOffset(primDataSize);
primDataSize += 8;
}
case '[', 'L' -> {
f.setOffset(numObjFields++);
if (firstObjIndex == -1) {
firstObjIndex = i;
}
}
default -> throw new InternalError();
}
}
if (firstObjIndex != -1 &&
firstObjIndex + numObjFields != fields.length)
{
throw new InvalidClassException(name, "illegal field order");
}
}
/**
* If given class is the same as the class associated with this class
* descriptor, returns reference to this class descriptor. Otherwise,
* returns variant of this class descriptor bound to given class.
*/
private ObjectStreamClass getVariantFor(Class<?> cl)
throws InvalidClassException
{
if (this.cl == cl) {
return this;
}
ObjectStreamClass desc = new ObjectStreamClass();
if (isProxy) {
desc.initProxy(cl, null, superDesc);
} else {
desc.initNonProxy(this, cl, null, superDesc);
}
return desc;
}
/**
* Returns public no-arg constructor of given class, or null if none found.
* Access checks are disabled on the returned constructor (if any), since
* the defining class may still be non-public.
*/
private static Constructor<?> getExternalizableConstructor(Class<?> cl) {
try {
Constructor<?> cons = cl.getDeclaredConstructor((Class<?>[]) null);
cons.setAccessible(true);
return ((cons.getModifiers() & Modifier.PUBLIC) != 0) ?
cons : null;
} catch (NoSuchMethodException ex) {
return null;
}
}
/**
* Returns subclass-accessible no-arg constructor of first non-serializable
* superclass, or null if none found. Access checks are disabled on the
* returned constructor (if any).
*/
private static Constructor<?> getSerializableConstructor(Class<?> cl) {
return reflFactory.newConstructorForSerialization(cl);
}
/**
* Returns the canonical constructor for the given record class, or null if
* the not found ( which should never happen for correctly generated record
* classes ).
*/
@SuppressWarnings("removal")
private static MethodHandle canonicalRecordCtr(Class<?> cls) {
assert cls.isRecord() : "Expected record, got: " + cls;
PrivilegedAction<MethodHandle> pa = () -> {
Class<?>[] paramTypes = Arrays.stream(cls.getRecordComponents())
.map(RecordComponent::getType)
.toArray(Class<?>[]::new);
try {
Constructor<?> ctr = cls.getDeclaredConstructor(paramTypes);
ctr.setAccessible(true);
return MethodHandles.lookup().unreflectConstructor(ctr);
} catch (IllegalAccessException | NoSuchMethodException e) {
return null;
}
};
return AccessController.doPrivileged(pa);
}
/**
* Returns the canonical constructor, if the local class equivalent of this
* stream class descriptor is a record class, otherwise null.
*/
MethodHandle getRecordConstructor() {
return canonicalCtr;
}
/**
* Returns non-static, non-abstract method with given signature provided it
* is defined by or accessible (via inheritance) by the given class, or
* null if no match found. Access checks are disabled on the returned
* method (if any).
*/
private static Method getInheritableMethod(Class<?> cl, String name,
Class<?>[] argTypes,
Class<?> returnType)
{
Method meth = null;
Class<?> defCl = cl;
while (defCl != null) {
try {
meth = defCl.getDeclaredMethod(name, argTypes);
break;
} catch (NoSuchMethodException ex) {
defCl = defCl.getSuperclass();
}
}
if ((meth == null) || (meth.getReturnType() != returnType)) {
return null;
}
meth.setAccessible(true);
int mods = meth.getModifiers();
if ((mods & (Modifier.STATIC | Modifier.ABSTRACT)) != 0) {
return null;
} else if ((mods & (Modifier.PUBLIC | Modifier.PROTECTED)) != 0) {
return meth;
} else if ((mods & Modifier.PRIVATE) != 0) {
return (cl == defCl) ? meth : null;
} else {
return packageEquals(cl, defCl) ? meth : null;
}
}
/**
* Returns non-static private method with given signature defined by given
* class, or null if none found. Access checks are disabled on the
* returned method (if any).
*/
private static Method getPrivateMethod(Class<?> cl, String name,
Class<?>[] argTypes,
Class<?> returnType)
{
try {
Method meth = cl.getDeclaredMethod(name, argTypes);
meth.setAccessible(true);
int mods = meth.getModifiers();
return ((meth.getReturnType() == returnType) &&
((mods & Modifier.STATIC) == 0) &&
((mods & Modifier.PRIVATE) != 0)) ? meth : null;
} catch (NoSuchMethodException ex) {
return null;
}
}
/**
* Returns true if classes are defined in the same runtime package, false
* otherwise.
*/
private static boolean packageEquals(Class<?> cl1, Class<?> cl2) {
return cl1.getClassLoader() == cl2.getClassLoader() &&
cl1.getPackageName() == cl2.getPackageName();
}
/**
* Compares class names for equality, ignoring package names. Returns true
* if class names equal, false otherwise.
*/
private static boolean classNamesEqual(String name1, String name2) {
int idx1 = name1.lastIndexOf('.') + 1;
int idx2 = name2.lastIndexOf('.') + 1;
int len1 = name1.length() - idx1;
int len2 = name2.length() - idx2;
return len1 == len2 &&
name1.regionMatches(idx1, name2, idx2, len1);
}
/**
* Returns JVM type signature for given list of parameters and return type.
*/
private static String getMethodSignature(Class<?>[] paramTypes,
Class<?> retType)
{
StringBuilder sb = new StringBuilder();
sb.append('(');
for (int i = 0; i < paramTypes.length; i++) {
sb.append(paramTypes[i].descriptorString());
}
sb.append(')');
sb.append(retType.descriptorString());
return sb.toString();
}
/**
* Convenience method for throwing an exception that is either a
* RuntimeException, Error, or of some unexpected type (in which case it is
* wrapped inside an IOException).
*/
private static void throwMiscException(Throwable th) throws IOException {
if (th instanceof RuntimeException) {
throw (RuntimeException) th;
} else if (th instanceof Error) {
throw (Error) th;
} else {
throw new IOException("unexpected exception type", th);
}
}
/**
* Returns ObjectStreamField array describing the serializable fields of
* the given class. Serializable fields backed by an actual field of the
* class are represented by ObjectStreamFields with corresponding non-null
* Field objects. Throws InvalidClassException if the (explicitly
* declared) serializable fields are invalid.
*/
private static ObjectStreamField[] getSerialFields(Class<?> cl)
throws InvalidClassException
{
if (!Serializable.class.isAssignableFrom(cl))
return NO_FIELDS;
ObjectStreamField[] fields;
if (cl.isRecord()) {
fields = getDefaultSerialFields(cl);
Arrays.sort(fields);
} else if (!Externalizable.class.isAssignableFrom(cl) &&
!Proxy.isProxyClass(cl) &&
!cl.isInterface()) {
if ((fields = getDeclaredSerialFields(cl)) == null) {
fields = getDefaultSerialFields(cl);
}
Arrays.sort(fields);
} else {
fields = NO_FIELDS;
}
return fields;
}
/**
* Returns serializable fields of given class as defined explicitly by a
* "serialPersistentFields" field, or null if no appropriate
* "serialPersistentFields" field is defined. Serializable fields backed
* by an actual field of the class are represented by ObjectStreamFields
* with corresponding non-null Field objects. For compatibility with past
* releases, a "serialPersistentFields" field with a null value is
* considered equivalent to not declaring "serialPersistentFields". Throws
* InvalidClassException if the declared serializable fields are
* invalid--e.g., if multiple fields share the same name.
*/
private static ObjectStreamField[] getDeclaredSerialFields(Class<?> cl)
throws InvalidClassException
{
ObjectStreamField[] serialPersistentFields = null;
try {
Field f = cl.getDeclaredField("serialPersistentFields");
int mask = Modifier.PRIVATE | Modifier.STATIC | Modifier.FINAL;
if ((f.getModifiers() & mask) == mask) {
f.setAccessible(true);
serialPersistentFields = (ObjectStreamField[]) f.get(null);
}
} catch (Exception ex) {
}
if (serialPersistentFields == null) {
return null;
} else if (serialPersistentFields.length == 0) {
return NO_FIELDS;
}
ObjectStreamField[] boundFields =
new ObjectStreamField[serialPersistentFields.length];
Set<String> fieldNames = HashSet.newHashSet(serialPersistentFields.length);
for (int i = 0; i < serialPersistentFields.length; i++) {
ObjectStreamField spf = serialPersistentFields[i];
String fname = spf.getName();
if (fieldNames.contains(fname)) {
throw new InvalidClassException(
"multiple serializable fields named " + fname);
}
fieldNames.add(fname);
try {
Field f = cl.getDeclaredField(fname);
if ((f.getType() == spf.getType()) &&
((f.getModifiers() & Modifier.STATIC) == 0))
{
boundFields[i] =
new ObjectStreamField(f, spf.isUnshared(), true);
}
} catch (NoSuchFieldException ex) {
}
if (boundFields[i] == null) {
boundFields[i] = new ObjectStreamField(
fname, spf.getType(), spf.isUnshared());
}
}
return boundFields;
}
/**
* Returns array of ObjectStreamFields corresponding to all non-static
* non-transient fields declared by given class. Each ObjectStreamField
* contains a Field object for the field it represents. If no default
* serializable fields exist, NO_FIELDS is returned.
*/
private static ObjectStreamField[] getDefaultSerialFields(Class<?> cl) {
Field[] clFields = cl.getDeclaredFields();
ArrayList<ObjectStreamField> list = new ArrayList<>();
int mask = Modifier.STATIC | Modifier.TRANSIENT;
for (int i = 0; i < clFields.length; i++) {
if ((clFields[i].getModifiers() & mask) == 0) {
list.add(new ObjectStreamField(clFields[i], false, true));
}
}
int size = list.size();
return (size == 0) ? NO_FIELDS :
list.toArray(new ObjectStreamField[size]);
}
/**
* Returns explicit serial version UID value declared by given class, or
* null if none.
*/
private static Long getDeclaredSUID(Class<?> cl) {
try {
Field f = cl.getDeclaredField("serialVersionUID");
int mask = Modifier.STATIC | Modifier.FINAL;
if ((f.getModifiers() & mask) == mask) {
f.setAccessible(true);
return f.getLong(null);
}
} catch (Exception ex) {
}
return null;
}
/**
* Computes the default serial version UID value for the given class.
*/
private static long computeDefaultSUID(Class<?> cl) {
if (!Serializable.class.isAssignableFrom(cl) || Proxy.isProxyClass(cl))
{
return 0L;
}
try {
ByteArrayOutputStream bout = new ByteArrayOutputStream();
DataOutputStream dout = new DataOutputStream(bout);
dout.writeUTF(cl.getName());
int classMods = cl.getModifiers() &
(Modifier.PUBLIC | Modifier.FINAL |
Modifier.INTERFACE | Modifier.ABSTRACT);
/*
* compensate for javac bug in which ABSTRACT bit was set for an
* interface only if the interface declared methods
*/
Method[] methods = cl.getDeclaredMethods();
if ((classMods & Modifier.INTERFACE) != 0) {
classMods = (methods.length > 0) ?
(classMods | Modifier.ABSTRACT) :
(classMods & ~Modifier.ABSTRACT);
}
dout.writeInt(classMods);
if (!cl.isArray()) {
/*
* compensate for change in 1.2FCS in which
* Class.getInterfaces() was modified to return Cloneable and
* Serializable for array classes.
*/
Class<?>[] interfaces = cl.getInterfaces();
String[] ifaceNames = new String[interfaces.length];
for (int i = 0; i < interfaces.length; i++) {
ifaceNames[i] = interfaces[i].getName();
}
Arrays.sort(ifaceNames);
for (int i = 0; i < ifaceNames.length; i++) {
dout.writeUTF(ifaceNames[i]);
}
}
Field[] fields = cl.getDeclaredFields();
MemberSignature[] fieldSigs = new MemberSignature[fields.length];
for (int i = 0; i < fields.length; i++) {
fieldSigs[i] = new MemberSignature(fields[i]);
}
Arrays.sort(fieldSigs, new Comparator<>() {
public int compare(MemberSignature ms1, MemberSignature ms2) {
return ms1.name.compareTo(ms2.name);
}
});
for (int i = 0; i < fieldSigs.length; i++) {
MemberSignature sig = fieldSigs[i];
int mods = sig.member.getModifiers() &
(Modifier.PUBLIC | Modifier.PRIVATE | Modifier.PROTECTED |
Modifier.STATIC | Modifier.FINAL | Modifier.VOLATILE |
Modifier.TRANSIENT);
if (((mods & Modifier.PRIVATE) == 0) ||
((mods & (Modifier.STATIC | Modifier.TRANSIENT)) == 0))
{
dout.writeUTF(sig.name);
dout.writeInt(mods);
dout.writeUTF(sig.signature);
}
}
if (hasStaticInitializer(cl)) {
dout.writeUTF("<clinit>");
dout.writeInt(Modifier.STATIC);
dout.writeUTF("()V");
}
Constructor<?>[] cons = cl.getDeclaredConstructors();
MemberSignature[] consSigs = new MemberSignature[cons.length];
for (int i = 0; i < cons.length; i++) {
consSigs[i] = new MemberSignature(cons[i]);
}
Arrays.sort(consSigs, new Comparator<>() {
public int compare(MemberSignature ms1, MemberSignature ms2) {
return ms1.signature.compareTo(ms2.signature);
}
});
for (int i = 0; i < consSigs.length; i++) {
MemberSignature sig = consSigs[i];
int mods = sig.member.getModifiers() &
(Modifier.PUBLIC | Modifier.PRIVATE | Modifier.PROTECTED |
Modifier.STATIC | Modifier.FINAL |
Modifier.SYNCHRONIZED | Modifier.NATIVE |
Modifier.ABSTRACT | Modifier.STRICT);
if ((mods & Modifier.PRIVATE) == 0) {
dout.writeUTF("<init>");
dout.writeInt(mods);
dout.writeUTF(sig.signature.replace('/', '.'));
}
}
MemberSignature[] methSigs = new MemberSignature[methods.length];
for (int i = 0; i < methods.length; i++) {
methSigs[i] = new MemberSignature(methods[i]);
}
Arrays.sort(methSigs, new Comparator<>() {
public int compare(MemberSignature ms1, MemberSignature ms2) {
int comp = ms1.name.compareTo(ms2.name);
if (comp == 0) {
comp = ms1.signature.compareTo(ms2.signature);
}
return comp;
}
});
for (int i = 0; i < methSigs.length; i++) {
MemberSignature sig = methSigs[i];
int mods = sig.member.getModifiers() &
(Modifier.PUBLIC | Modifier.PRIVATE | Modifier.PROTECTED |
Modifier.STATIC | Modifier.FINAL |
Modifier.SYNCHRONIZED | Modifier.NATIVE |
Modifier.ABSTRACT | Modifier.STRICT);
if ((mods & Modifier.PRIVATE) == 0) {
dout.writeUTF(sig.name);
dout.writeInt(mods);
dout.writeUTF(sig.signature.replace('/', '.'));
}
}
dout.flush();
MessageDigest md = MessageDigest.getInstance("SHA");
byte[] hashBytes = md.digest(bout.toByteArray());
long hash = 0;
for (int i = Math.min(hashBytes.length, 8) - 1; i >= 0; i--) {
hash = (hash << 8) | (hashBytes[i] & 0xFF);
}
return hash;
} catch (IOException ex) {
throw new InternalError(ex);
} catch (NoSuchAlgorithmException ex) {
throw new SecurityException(ex.getMessage());
}
}
/**
* Returns true if the given class defines a static initializer method,
* false otherwise.
*/
private static native boolean hasStaticInitializer(Class<?> cl);
/**
* Class for computing and caching field/constructor/method signatures
* during serialVersionUID calculation.
*/
private static final class MemberSignature {
public final Member member;
public final String name;
public final String signature;
public MemberSignature(Field field) {
member = field;
name = field.getName();
signature = field.getType().descriptorString();
}
public MemberSignature(Constructor<?> cons) {
member = cons;
name = cons.getName();
signature = getMethodSignature(
cons.getParameterTypes(), Void.TYPE);
}
public MemberSignature(Method meth) {
member = meth;
name = meth.getName();
signature = getMethodSignature(
meth.getParameterTypes(), meth.getReturnType());
}
}
/**
* Class for setting and retrieving serializable field values in batch.
*/
// REMIND: dynamically generate these?
private static final class FieldReflector {
/** handle for performing unsafe operations */
private static final Unsafe UNSAFE = Unsafe.getUnsafe();
/** fields to operate on */
private final ObjectStreamField[] fields;
/** number of primitive fields */
private final int numPrimFields;
/** unsafe field keys for reading fields - may contain dupes */
private final long[] readKeys;
/** unsafe fields keys for writing fields - no dupes */
private final long[] writeKeys;
/** field data offsets */
private final int[] offsets;
/** field type codes */
private final char[] typeCodes;
/** field types */
private final Class<?>[] types;
/**
* Constructs FieldReflector capable of setting/getting values from the
* subset of fields whose ObjectStreamFields contain non-null
* reflective Field objects. ObjectStreamFields with null Fields are
* treated as filler, for which get operations return default values
* and set operations discard given values.
*/
FieldReflector(ObjectStreamField[] fields) {
this.fields = fields;
int nfields = fields.length;
readKeys = new long[nfields];
writeKeys = new long[nfields];
offsets = new int[nfields];
typeCodes = new char[nfields];
ArrayList<Class<?>> typeList = new ArrayList<>();
Set<Long> usedKeys = new HashSet<>();
for (int i = 0; i < nfields; i++) {
ObjectStreamField f = fields[i];
Field rf = f.getField();
long key = (rf != null) ?
UNSAFE.objectFieldOffset(rf) : Unsafe.INVALID_FIELD_OFFSET;
readKeys[i] = key;
writeKeys[i] = usedKeys.add(key) ?
key : Unsafe.INVALID_FIELD_OFFSET;
offsets[i] = f.getOffset();
typeCodes[i] = f.getTypeCode();
if (!f.isPrimitive()) {
typeList.add((rf != null) ? rf.getType() : null);
}
}
types = typeList.toArray(new Class<?>[typeList.size()]);
numPrimFields = nfields - types.length;
}
/**
* Returns list of ObjectStreamFields representing fields operated on
* by this reflector. The shared/unshared values and Field objects
* contained by ObjectStreamFields in the list reflect their bindings
* to locally defined serializable fields.
*/
ObjectStreamField[] getFields() {
return fields;
}
/**
* Fetches the serializable primitive field values of object obj and
* marshals them into byte array buf starting at offset 0. The caller
* is responsible for ensuring that obj is of the proper type.
*/
void getPrimFieldValues(Object obj, byte[] buf) {
if (obj == null) {
throw new NullPointerException();
}
/* assuming checkDefaultSerialize() has been called on the class
* descriptor this FieldReflector was obtained from, no field keys
* in array should be equal to Unsafe.INVALID_FIELD_OFFSET.
*/
for (int i = 0; i < numPrimFields; i++) {
long key = readKeys[i];
int off = offsets[i];
switch (typeCodes[i]) {
case 'Z' -> ByteArray.setBoolean(buf, off, UNSAFE.getBoolean(obj, key));
case 'B' -> buf[off] = UNSAFE.getByte(obj, key);
case 'C' -> ByteArray.setChar(buf, off, UNSAFE.getChar(obj, key));
case 'S' -> ByteArray.setShort(buf, off, UNSAFE.getShort(obj, key));
case 'I' -> ByteArray.setInt(buf, off, UNSAFE.getInt(obj, key));
case 'F' -> ByteArray.setFloat(buf, off, UNSAFE.getFloat(obj, key));
case 'J' -> ByteArray.setLong(buf, off, UNSAFE.getLong(obj, key));
case 'D' -> ByteArray.setDouble(buf, off, UNSAFE.getDouble(obj, key));
default -> throw new InternalError();
}
}
}
/**
* Sets the serializable primitive fields of object obj using values
* unmarshalled from byte array buf starting at offset 0. The caller
* is responsible for ensuring that obj is of the proper type.
*/
void setPrimFieldValues(Object obj, byte[] buf) {
if (obj == null) {
throw new NullPointerException();
}
for (int i = 0; i < numPrimFields; i++) {
long key = writeKeys[i];
if (key == Unsafe.INVALID_FIELD_OFFSET) {
continue; // discard value
}
int off = offsets[i];
switch (typeCodes[i]) {
case 'Z' -> UNSAFE.putBoolean(obj, key, ByteArray.getBoolean(buf, off));
case 'B' -> UNSAFE.putByte(obj, key, buf[off]);
case 'C' -> UNSAFE.putChar(obj, key, ByteArray.getChar(buf, off));
case 'S' -> UNSAFE.putShort(obj, key, ByteArray.getShort(buf, off));
case 'I' -> UNSAFE.putInt(obj, key, ByteArray.getInt(buf, off));
case 'F' -> UNSAFE.putFloat(obj, key, ByteArray.getFloat(buf, off));
case 'J' -> UNSAFE.putLong(obj, key, ByteArray.getLong(buf, off));
case 'D' -> UNSAFE.putDouble(obj, key, ByteArray.getDouble(buf, off));
default -> throw new InternalError();
}
}
}
/**
* Fetches the serializable object field values of object obj and
* stores them in array vals starting at offset 0. The caller is
* responsible for ensuring that obj is of the proper type.
*/
void getObjFieldValues(Object obj, Object[] vals) {
if (obj == null) {
throw new NullPointerException();
}
/* assuming checkDefaultSerialize() has been called on the class
* descriptor this FieldReflector was obtained from, no field keys
* in array should be equal to Unsafe.INVALID_FIELD_OFFSET.
*/
for (int i = numPrimFields; i < fields.length; i++) {
vals[offsets[i]] = switch (typeCodes[i]) {
case 'L', '[' -> UNSAFE.getReference(obj, readKeys[i]);
default -> throw new InternalError();
};
}
}
/**
* Checks that the given values, from array vals starting at offset 0,
* are assignable to the given serializable object fields.
* @throws ClassCastException if any value is not assignable
*/
void checkObjectFieldValueTypes(Object obj, Object[] vals) {
setObjFieldValues(obj, vals, true);
}
/**
* Sets the serializable object fields of object obj using values from
* array vals starting at offset 0. The caller is responsible for
* ensuring that obj is of the proper type; however, attempts to set a
* field with a value of the wrong type will trigger an appropriate
* ClassCastException.
*/
void setObjFieldValues(Object obj, Object[] vals) {
setObjFieldValues(obj, vals, false);
}
private void setObjFieldValues(Object obj, Object[] vals, boolean dryRun) {
if (obj == null) {
throw new NullPointerException();
}
for (int i = numPrimFields; i < fields.length; i++) {
long key = writeKeys[i];
if (key == Unsafe.INVALID_FIELD_OFFSET) {
continue; // discard value
}
switch (typeCodes[i]) {
case 'L', '[' -> {
Object val = vals[offsets[i]];
if (val != null &&
!types[i - numPrimFields].isInstance(val))
{
Field f = fields[i].getField();
throw new ClassCastException(
"cannot assign instance of " +
val.getClass().getName() + " to field " +
f.getDeclaringClass().getName() + "." +
f.getName() + " of type " +
f.getType().getName() + " in instance of " +
obj.getClass().getName());
}
if (!dryRun)
UNSAFE.putReference(obj, key, val);
}
default -> throw new InternalError();
}
}
}
}
/**
* Matches given set of serializable fields with serializable fields
* described by the given local class descriptor, and returns a
* FieldReflector instance capable of setting/getting values from the
* subset of fields that match (non-matching fields are treated as filler,
* for which get operations return default values and set operations
* discard given values). Throws InvalidClassException if unresolvable
* type conflicts exist between the two sets of fields.
*/
private static FieldReflector getReflector(ObjectStreamField[] fields,
ObjectStreamClass localDesc)
throws InvalidClassException
{
// class irrelevant if no fields
Class<?> cl = (localDesc != null && fields.length > 0) ?
localDesc.cl : Void.class;
var clReflectors = Caches.reflectors.get(cl);
var key = new FieldReflectorKey(fields);
var reflector = clReflectors.get(key);
if (reflector == null) {
reflector = new FieldReflector(matchFields(fields, localDesc));
var oldReflector = clReflectors.putIfAbsent(key, reflector);
if (oldReflector != null) {
reflector = oldReflector;
}
}
return reflector;
}
/**
* FieldReflector cache lookup key. Keys are considered equal if they
* refer to equivalent field formats.
*/
private static class FieldReflectorKey {
private final String[] sigs;
private final int hash;
FieldReflectorKey(ObjectStreamField[] fields)
{
sigs = new String[2 * fields.length];
for (int i = 0, j = 0; i < fields.length; i++) {
ObjectStreamField f = fields[i];
sigs[j++] = f.getName();
sigs[j++] = f.getSignature();
}
hash = Arrays.hashCode(sigs);
}
public int hashCode() {
return hash;
}
public boolean equals(Object obj) {
return obj == this ||
obj instanceof FieldReflectorKey other &&
Arrays.equals(sigs, other.sigs);
}
}
/**
* Matches given set of serializable fields with serializable fields
* obtained from the given local class descriptor (which contain bindings
* to reflective Field objects). Returns list of ObjectStreamFields in
* which each ObjectStreamField whose signature matches that of a local
* field contains a Field object for that field; unmatched
* ObjectStreamFields contain null Field objects. Shared/unshared settings
* of the returned ObjectStreamFields also reflect those of matched local
* ObjectStreamFields. Throws InvalidClassException if unresolvable type
* conflicts exist between the two sets of fields.
*/
private static ObjectStreamField[] matchFields(ObjectStreamField[] fields,
ObjectStreamClass localDesc)
throws InvalidClassException
{
ObjectStreamField[] localFields = (localDesc != null) ?
localDesc.fields : NO_FIELDS;
/*
* Even if fields == localFields, we cannot simply return localFields
* here. In previous implementations of serialization,
* ObjectStreamField.getType() returned Object.class if the
* ObjectStreamField represented a non-primitive field and belonged to
* a non-local class descriptor. To preserve this (questionable)
* behavior, the ObjectStreamField instances returned by matchFields
* cannot report non-primitive types other than Object.class; hence
* localFields cannot be returned directly.
*/
ObjectStreamField[] matches = new ObjectStreamField[fields.length];
for (int i = 0; i < fields.length; i++) {
ObjectStreamField f = fields[i], m = null;
for (int j = 0; j < localFields.length; j++) {
ObjectStreamField lf = localFields[j];
if (f.getName().equals(lf.getName())) {
if ((f.isPrimitive() || lf.isPrimitive()) &&
f.getTypeCode() != lf.getTypeCode())
{
throw new InvalidClassException(localDesc.name,
"incompatible types for field " + f.getName());
}
if (lf.getField() != null) {
m = new ObjectStreamField(
lf.getField(), lf.isUnshared(), false);
} else {
m = new ObjectStreamField(
lf.getName(), lf.getSignature(), lf.isUnshared());
}
}
}
if (m == null) {
m = new ObjectStreamField(
f.getName(), f.getSignature(), false);
}
m.setOffset(f.getOffset());
matches[i] = m;
}
return matches;
}
/**
* A LRA cache of record deserialization constructors.
*/
@SuppressWarnings("serial")
private static final class DeserializationConstructorsCache
extends ConcurrentHashMap<DeserializationConstructorsCache.Key, MethodHandle> {
// keep max. 10 cached entries - when the 11th element is inserted the oldest
// is removed and 10 remains - 11 is the biggest map size where internal
// table of 16 elements is sufficient (inserting 12th element would resize it to 32)
private static final int MAX_SIZE = 10;
private Key.Impl first, last; // first and last in FIFO queue
DeserializationConstructorsCache() {
// start small - if there is more than one shape of ObjectStreamClass
// deserialized, there will typically be two (current version and previous version)
super(2);
}
MethodHandle get(ObjectStreamField[] fields) {
return get(new Key.Lookup(fields));
}
synchronized MethodHandle putIfAbsentAndGet(ObjectStreamField[] fields, MethodHandle mh) {
Key.Impl key = new Key.Impl(fields);
var oldMh = putIfAbsent(key, mh);
if (oldMh != null) return oldMh;
// else we did insert new entry -> link the new key as last
if (last == null) {
last = first = key;
} else {
last = (last.next = key);
}
// may need to remove first
if (size() > MAX_SIZE) {
assert first != null;
remove(first);
first = first.next;
if (first == null) {
last = null;
}
}
return mh;
}
// a key composed of ObjectStreamField[] names and types
abstract static class Key {
abstract int length();
abstract String fieldName(int i);
abstract Class<?> fieldType(int i);
@Override
public final int hashCode() {
int n = length();
int h = 0;
for (int i = 0; i < n; i++) h = h * 31 + fieldType(i).hashCode();
for (int i = 0; i < n; i++) h = h * 31 + fieldName(i).hashCode();
return h;
}
@Override
public final boolean equals(Object obj) {
if (!(obj instanceof Key other)) return false;
int n = length();
if (n != other.length()) return false;
for (int i = 0; i < n; i++) if (fieldType(i) != other.fieldType(i)) return false;
for (int i = 0; i < n; i++) if (!fieldName(i).equals(other.fieldName(i))) return false;
return true;
}
// lookup key - just wraps ObjectStreamField[]
static final class Lookup extends Key {
final ObjectStreamField[] fields;
Lookup(ObjectStreamField[] fields) { this.fields = fields; }
@Override
int length() { return fields.length; }
@Override
String fieldName(int i) { return fields[i].getName(); }
@Override
Class<?> fieldType(int i) { return fields[i].getType(); }
}
// real key - copies field names and types and forms FIFO queue in cache
static final class Impl extends Key {
Impl next;
final String[] fieldNames;
final Class<?>[] fieldTypes;
Impl(ObjectStreamField[] fields) {
this.fieldNames = new String[fields.length];
this.fieldTypes = new Class<?>[fields.length];
for (int i = 0; i < fields.length; i++) {
fieldNames[i] = fields[i].getName();
fieldTypes[i] = fields[i].getType();
}
}
@Override
int length() { return fieldNames.length; }
@Override
String fieldName(int i) { return fieldNames[i]; }
@Override
Class<?> fieldType(int i) { return fieldTypes[i]; }
}
}
}
/** Record specific support for retrieving and binding stream field values. */
static final class RecordSupport {
/**
* Returns canonical record constructor adapted to take two arguments:
* {@code (byte[] primValues, Object[] objValues)}
* and return
* {@code Object}
*/
@SuppressWarnings("removal")
static MethodHandle deserializationCtr(ObjectStreamClass desc) {
// check the cached value 1st
MethodHandle mh = desc.deserializationCtr;
if (mh != null) return mh;
mh = desc.deserializationCtrs.get(desc.getFields(false));
if (mh != null) return desc.deserializationCtr = mh;
// retrieve record components
RecordComponent[] recordComponents;
try {
Class<?> cls = desc.forClass();
PrivilegedExceptionAction<RecordComponent[]> pa = cls::getRecordComponents;
recordComponents = AccessController.doPrivileged(pa);
} catch (PrivilegedActionException e) {
throw new InternalError(e.getCause());
}
// retrieve the canonical constructor
// (T1, T2, ..., Tn):TR
mh = desc.getRecordConstructor();
// change return type to Object
// (T1, T2, ..., Tn):TR -> (T1, T2, ..., Tn):Object
mh = mh.asType(mh.type().changeReturnType(Object.class));
// drop last 2 arguments representing primValues and objValues arrays
// (T1, T2, ..., Tn):Object -> (T1, T2, ..., Tn, byte[], Object[]):Object
mh = MethodHandles.dropArguments(mh, mh.type().parameterCount(), byte[].class, Object[].class);
for (int i = recordComponents.length-1; i >= 0; i--) {
String name = recordComponents[i].getName();
Class<?> type = recordComponents[i].getType();
// obtain stream field extractor that extracts argument at
// position i (Ti+1) from primValues and objValues arrays
// (byte[], Object[]):Ti+1
MethodHandle combiner = streamFieldExtractor(name, type, desc);
// fold byte[] privValues and Object[] objValues into argument at position i (Ti+1)
// (..., Ti, Ti+1, byte[], Object[]):Object -> (..., Ti, byte[], Object[]):Object
mh = MethodHandles.foldArguments(mh, i, combiner);
}
// what we are left with is a MethodHandle taking just the primValues
// and objValues arrays and returning the constructed record instance
// (byte[], Object[]):Object
// store it into cache and return the 1st value stored
return desc.deserializationCtr =
desc.deserializationCtrs.putIfAbsentAndGet(desc.getFields(false), mh);
}
/** Returns the number of primitive fields for the given descriptor. */
private static int numberPrimValues(ObjectStreamClass desc) {
ObjectStreamField[] fields = desc.getFields();
int primValueCount = 0;
for (int i = 0; i < fields.length; i++) {
if (fields[i].isPrimitive())
primValueCount++;
else
break; // can be no more
}
return primValueCount;
}
/**
* Returns extractor MethodHandle taking the primValues and objValues arrays
* and extracting the argument of canonical constructor with given name and type
* or producing default value for the given type if the field is absent.
*/
private static MethodHandle streamFieldExtractor(String pName,
Class<?> pType,
ObjectStreamClass desc) {
ObjectStreamField[] fields = desc.getFields(false);
for (int i = 0; i < fields.length; i++) {
ObjectStreamField f = fields[i];
String fName = f.getName();
if (!fName.equals(pName))
continue;
Class<?> fType = f.getField().getType();
if (!pType.isAssignableFrom(fType))
throw new InternalError(fName + " unassignable, pType:" + pType + ", fType:" + fType);
if (f.isPrimitive()) {
// (byte[], int):fType
MethodHandle mh = PRIM_VALUE_EXTRACTORS.get(fType);
if (mh == null) {
throw new InternalError("Unexpected type: " + fType);
}
// bind offset
// (byte[], int):fType -> (byte[]):fType
mh = MethodHandles.insertArguments(mh, 1, f.getOffset());
// drop objValues argument
// (byte[]):fType -> (byte[], Object[]):fType
mh = MethodHandles.dropArguments(mh, 1, Object[].class);
// adapt return type to pType
// (byte[], Object[]):fType -> (byte[], Object[]):pType
if (pType != fType) {
mh = mh.asType(mh.type().changeReturnType(pType));
}
return mh;
} else { // reference
// (Object[], int):Object
MethodHandle mh = MethodHandles.arrayElementGetter(Object[].class);
// bind index
// (Object[], int):Object -> (Object[]):Object
mh = MethodHandles.insertArguments(mh, 1, i - numberPrimValues(desc));
// drop primValues argument
// (Object[]):Object -> (byte[], Object[]):Object
mh = MethodHandles.dropArguments(mh, 0, byte[].class);
// adapt return type to pType
// (byte[], Object[]):Object -> (byte[], Object[]):pType
if (pType != Object.class) {
mh = mh.asType(mh.type().changeReturnType(pType));
}
return mh;
}
}
// return default value extractor if no field matches pName
return MethodHandles.empty(MethodType.methodType(pType, byte[].class, Object[].class));
}
private static final Map<Class<?>, MethodHandle> PRIM_VALUE_EXTRACTORS;
static {
var lkp = MethodHandles.lookup();
try {
PRIM_VALUE_EXTRACTORS = Map.of(
byte.class, MethodHandles.arrayElementGetter(byte[].class),
short.class, lkp.findStatic(ByteArray.class, "getShort", MethodType.methodType(short.class, byte[].class, int.class)),
int.class, lkp.findStatic(ByteArray.class, "getInt", MethodType.methodType(int.class, byte[].class, int.class)),
long.class, lkp.findStatic(ByteArray.class, "getLong", MethodType.methodType(long.class, byte[].class, int.class)),
float.class, lkp.findStatic(ByteArray.class, "getFloat", MethodType.methodType(float.class, byte[].class, int.class)),
double.class, lkp.findStatic(ByteArray.class, "getDouble", MethodType.methodType(double.class, byte[].class, int.class)),
char.class, lkp.findStatic(ByteArray.class, "getChar", MethodType.methodType(char.class, byte[].class, int.class)),
boolean.class, lkp.findStatic(ByteArray.class, "getBoolean", MethodType.methodType(boolean.class, byte[].class, int.class))
);
} catch (NoSuchMethodException | IllegalAccessException e) {
throw new InternalError("Can't lookup " + ByteArray.class.getName() + ".getXXX", e);
}
}
}
}
/*
* Copyright (c) 1995, 2021, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
package java.net;
import java.io.IOException;
import java.io.UncheckedIOException;
import java.nio.channels.DatagramChannel;
import java.security.AccessController;
import java.security.PrivilegedExceptionAction;
import java.util.Enumeration;
import java.util.Objects;
import java.util.Set;
import java.util.Collections;
/**
* A multicast datagram socket that delegates socket operations to a
* {@link DatagramSocketImpl}.
*
* This class overrides every public method defined by {@link DatagramSocket}
* and {@link MulticastSocket}.
*/
final class NetMulticastSocket extends MulticastSocket {
/**
* Various states of this socket.
*/
private boolean bound = false;
private boolean closed = false;
private volatile boolean created;
private final Object closeLock = new Object();
/*
* The implementation of this DatagramSocket.
*/
private final DatagramSocketImpl impl;
/**
* Set when a socket is ST_CONNECTED until we are certain
* that any packets which might have been received prior
* to calling connect() but not read by the application
* have been read. During this time we check the source
* address of all packets received to be sure they are from
* the connected destination. Other packets are read but
* silently dropped.
*/
private boolean explicitFilter = false;
private int bytesLeftToFilter;
/*
* Connection state:
* ST_NOT_CONNECTED = socket not connected
* ST_CONNECTED = socket connected
*/
static final int ST_NOT_CONNECTED = 0;
static final int ST_CONNECTED = 1;
int connectState = ST_NOT_CONNECTED;
/*
* Connected address & port
*/
InetAddress connectedAddress = null;
int connectedPort = -1;
/**
* This constructor is also used by {@link DatagramSocket#DatagramSocket(DatagramSocketImpl)}.
* @param impl The impl used in this instance.
*/
NetMulticastSocket(DatagramSocketImpl impl) {
super((MulticastSocket) null);
this.impl = Objects.requireNonNull(impl);
}
/**
* Connects this socket to a remote socket address (IP address + port number).
* Binds socket if not already bound.
*
* @param address The remote address.
* @param port The remote port
* @throws SocketException if binding the socket fails.
*/
private synchronized void connectInternal(InetAddress address, int port) throws SocketException {
if (port < 0 || port > 0xFFFF) {
throw new IllegalArgumentException("connect: " + port);
}
if (address == null) {
throw new IllegalArgumentException("connect: null address");
}
checkAddress(address, "connect");
if (isClosed())
return;
@SuppressWarnings("removal")
SecurityManager security = System.getSecurityManager();
if (security != null) {
if (address.isMulticastAddress()) {
security.checkMulticast(address);
} else {
security.checkConnect(address.getHostAddress(), port);
security.checkAccept(address.getHostAddress(), port);
}
}
if (port == 0) {
throw new SocketException("Can't connect to port 0");
}
if (!isBound())
bind(new InetSocketAddress(0));
getImpl().connect(address, port);
// socket is now connected by the impl
connectState = ST_CONNECTED;
// Do we need to filter some packets?
int avail = getImpl().dataAvailable();
if (avail == -1) {
throw new SocketException();
}
explicitFilter = avail > 0;
if (explicitFilter) {
bytesLeftToFilter = getReceiveBufferSize();
}
connectedAddress = address;
connectedPort = port;
}
/**
* Return the {@code DatagramSocketImpl} attached to this socket,
* creating the socket if not already created.
*
* @return the {@code DatagramSocketImpl} attached to that
* DatagramSocket
* @throws SocketException if creating the socket fails
* @since 1.4
*/
final DatagramSocketImpl getImpl() throws SocketException {
if (!created) {
synchronized (this) {
if (!created) {
impl.create();
created = true;
}
}
}
return impl;
}
@Override
public synchronized void bind(SocketAddress addr) throws SocketException {
if (isClosed())
throw new SocketException("Socket is closed");
if (isBound())
throw new SocketException("already bound");
if (addr == null)
addr = new InetSocketAddress(0);
if (!(addr instanceof InetSocketAddress epoint))
throw new IllegalArgumentException("Unsupported address type!");
if (epoint.isUnresolved())
throw new SocketException("Unresolved address");
InetAddress iaddr = epoint.getAddress();
int port = epoint.getPort();
checkAddress(iaddr, "bind");
@SuppressWarnings("removal")
SecurityManager sec = System.getSecurityManager();
if (sec != null) {
sec.checkListen(port);
}
try {
getImpl().bind(port, iaddr);
} catch (SocketException e) {
getImpl().close();
throw e;
}
bound = true;
}
static void checkAddress(InetAddress addr, String op) {
if (addr == null) {
return;
}
if (!(addr instanceof Inet4Address || addr instanceof Inet6Address)) {
throw new IllegalArgumentException(op + ": invalid address type");
}
}
@Override
public void connect(InetAddress address, int port) {
try {
connectInternal(address, port);
} catch (SocketException se) {
throw new UncheckedIOException("connect failed", se);
}
}
@Override
public void connect(SocketAddress addr) throws SocketException {
if (addr == null)
throw new IllegalArgumentException("Address can't be null");
if (!(addr instanceof InetSocketAddress epoint))
throw new IllegalArgumentException("Unsupported address type");
if (epoint.isUnresolved())
throw new SocketException("Unresolved address");
connectInternal(epoint.getAddress(), epoint.getPort());
}
@Override
public void disconnect() {
synchronized (this) {
if (isClosed())
return;
if (connectState == ST_CONNECTED) {
impl.disconnect();
}
connectedAddress = null;
connectedPort = -1;
connectState = ST_NOT_CONNECTED;
explicitFilter = false;
}
}
@Override
public boolean isBound() {
return bound;
}
@Override
public boolean isConnected() {
return connectState != ST_NOT_CONNECTED;
}
@Override
public InetAddress getInetAddress() {
return connectedAddress;
}
@Override
public int getPort() {
return connectedPort;
}
@Override
public SocketAddress getRemoteSocketAddress() {
if (!isConnected())
return null;
return new InetSocketAddress(getInetAddress(), getPort());
}
@Override
public SocketAddress getLocalSocketAddress() {
if (isClosed())
return null;
if (!isBound())
return null;
return new InetSocketAddress(getLocalAddress(), getLocalPort());
}
@Override
public void send(DatagramPacket p) throws IOException {
synchronized (p) {
if (isClosed())
throw new SocketException("Socket is closed");
InetAddress packetAddress = p.getAddress();
int packetPort = p.getPort();
checkAddress(packetAddress, "send");
if (connectState == ST_NOT_CONNECTED) {
if (packetAddress == null) {
throw new IllegalArgumentException("Address not set");
}
if (packetPort < 0 || packetPort > 0xFFFF)
throw new IllegalArgumentException("port out of range: " + packetPort);
// check the address is ok with the security manager on every send.
@SuppressWarnings("removal")
SecurityManager security = System.getSecurityManager();
// The reason you want to synchronize on datagram packet
// is because you don't want an applet to change the address
// while you are trying to send the packet for example
// after the security check but before the send.
if (security != null) {
if (packetAddress.isMulticastAddress()) {
security.checkMulticast(packetAddress);
} else {
security.checkConnect(packetAddress.getHostAddress(),
packetPort);
}
}
if (packetPort == 0) {
throw new SocketException("Can't send to port 0");
}
} else {
// we're connected
if (packetAddress == null) {
p.setAddress(connectedAddress);
p.setPort(connectedPort);
} else if ((!packetAddress.equals(connectedAddress)) ||
packetPort != connectedPort) {
throw new IllegalArgumentException("connected address " +
"and packet address" +
" differ");
}
}
// Check whether the socket is bound
if (!isBound())
bind(new InetSocketAddress(0));
// call the method to send
getImpl().send(p);
}
}
@Override
public synchronized void receive(DatagramPacket p) throws IOException {
synchronized (p) {
if (!isBound())
bind(new InetSocketAddress(0));
if (connectState == ST_NOT_CONNECTED) {
// check the address is ok with the security manager before every recv.
@SuppressWarnings("removal")
SecurityManager security = System.getSecurityManager();
if (security != null) {
while (true) {
int peekPort = 0;
// peek at the packet to see who it is from.
DatagramPacket peekPacket = new DatagramPacket(new byte[1], 1);
peekPort = getImpl().peekData(peekPacket);
String peekAd = peekPacket.getAddress().getHostAddress();
try {
security.checkAccept(peekAd, peekPort);
// security check succeeded - so now break
// and recv the packet.
break;
} catch (SecurityException se) {
// Throw away the offending packet by consuming
// it in a tmp buffer.
DatagramPacket tmp = new DatagramPacket(new byte[1], 1);
getImpl().receive(tmp);
// silently discard the offending packet
// and continue: unknown/malicious
// entities on nets should not make
// runtime throw security exception and
// disrupt the applet by sending random
// datagram packets.
continue;
}
} // end of while
}
}
DatagramPacket tmp = null;
if (explicitFilter) {
// We have to do the filtering the old fashioned way since
// the native impl doesn't support connect or the connect
// via the impl failed, or .. "explicitFilter" may be set when
// a socket is connected via the impl, for a period of time
// when packets from other sources might be queued on socket.
boolean stop = false;
while (!stop) {
// peek at the packet to see who it is from.
DatagramPacket peekPacket = new DatagramPacket(new byte[1], 1);
int peekPort = getImpl().peekData(peekPacket);
InetAddress peekAddress = peekPacket.getAddress();
if ((!connectedAddress.equals(peekAddress)) || (connectedPort != peekPort)) {
// throw the packet away and silently continue
tmp = new DatagramPacket(
new byte[1024], 1024);
getImpl().receive(tmp);
if (explicitFilter) {
if (checkFiltering(tmp)) {
stop = true;
}
}
} else {
stop = true;
}
}
}
// If the security check succeeds, or the datagram is
// connected then receive the packet
getImpl().receive(p);
if (explicitFilter && tmp == null) {
// packet was not filtered, account for it here
checkFiltering(p);
}
}
}
private boolean checkFiltering(DatagramPacket p) throws SocketException {
bytesLeftToFilter -= p.getLength();
if (bytesLeftToFilter <= 0 || getImpl().dataAvailable() <= 0) {
explicitFilter = false;
return true;
}
return false;
}
@Override
public InetAddress getLocalAddress() {
if (isClosed())
return null;
InetAddress in;
try {
in = (InetAddress) getImpl().getOption(SocketOptions.SO_BINDADDR);
if (in.isAnyLocalAddress()) {
in = InetAddress.anyLocalAddress();
}
@SuppressWarnings("removal")
SecurityManager s = System.getSecurityManager();
if (s != null) {
s.checkConnect(in.getHostAddress(), -1);
}
} catch (Exception e) {
in = InetAddress.anyLocalAddress(); // "0.0.0.0"
}
return in;
}
@Override
public int getLocalPort() {
if (isClosed())
return -1;
try {
return getImpl().getLocalPort();
} catch (Exception e) {
return 0;
}
}
@Override
public synchronized void setSoTimeout(int timeout) throws SocketException {
if (isClosed())
throw new SocketException("Socket is closed");
if (timeout < 0)
throw new IllegalArgumentException("timeout < 0");
getImpl().setOption(SocketOptions.SO_TIMEOUT, timeout);
}
@Override
public synchronized int getSoTimeout() throws SocketException {
if (isClosed())
throw new SocketException("Socket is closed");
if (getImpl() == null)
return 0;
Object o = getImpl().getOption(SocketOptions.SO_TIMEOUT);
/* extra type safety */
if (o instanceof Integer) {
return ((Integer) o).intValue();
} else {
return 0;
}
}
@Override
public synchronized void setSendBufferSize(int size) throws SocketException {
if (!(size > 0)) {
throw new IllegalArgumentException("negative send size");
}
if (isClosed())
throw new SocketException("Socket is closed");
getImpl().setOption(SocketOptions.SO_SNDBUF, size);
}
@Override
public synchronized int getSendBufferSize() throws SocketException {
if (isClosed())
throw new SocketException("Socket is closed");
int result = 0;
Object o = getImpl().getOption(SocketOptions.SO_SNDBUF);
if (o instanceof Integer) {
result = ((Integer) o).intValue();
}
return result;
}
@Override
public synchronized void setReceiveBufferSize(int size) throws SocketException {
if (size <= 0) {
throw new IllegalArgumentException("invalid receive size");
}
if (isClosed())
throw new SocketException("Socket is closed");
getImpl().setOption(SocketOptions.SO_RCVBUF, size);
}
@Override
public synchronized int getReceiveBufferSize() throws SocketException {
if (isClosed())
throw new SocketException("Socket is closed");
int result = 0;
Object o = getImpl().getOption(SocketOptions.SO_RCVBUF);
if (o instanceof Integer) {
result = ((Integer) o).intValue();
}
return result;
}
@Override
public synchronized void setReuseAddress(boolean on) throws SocketException {
if (isClosed())
throw new SocketException("Socket is closed");
getImpl().setOption(SocketOptions.SO_REUSEADDR, Boolean.valueOf(on));
}
@Override
public synchronized boolean getReuseAddress() throws SocketException {
if (isClosed())
throw new SocketException("Socket is closed");
Object o = getImpl().getOption(SocketOptions.SO_REUSEADDR);
return ((Boolean) o).booleanValue();
}
@Override
public synchronized void setBroadcast(boolean on) throws SocketException {
if (isClosed())
throw new SocketException("Socket is closed");
getImpl().setOption(SocketOptions.SO_BROADCAST, Boolean.valueOf(on));
}
@Override
public synchronized boolean getBroadcast() throws SocketException {
if (isClosed())
throw new SocketException("Socket is closed");
return ((Boolean) (getImpl().getOption(SocketOptions.SO_BROADCAST))).booleanValue();
}
@Override
public synchronized void setTrafficClass(int tc) throws SocketException {
if (tc < 0 || tc > 255)
throw new IllegalArgumentException("tc is not in range 0 -- 255");
if (isClosed())
throw new SocketException("Socket is closed");
try {
getImpl().setOption(SocketOptions.IP_TOS, tc);
} catch (SocketException se) {
// not supported if socket already connected
// Solaris returns error in such cases
if (!isConnected())
throw se;
}
}
@Override
public synchronized int getTrafficClass() throws SocketException {
if (isClosed())
throw new SocketException("Socket is closed");
return ((Integer) (getImpl().getOption(SocketOptions.IP_TOS))).intValue();
}
@Override
public void close() {
synchronized (closeLock) {
if (isClosed())
return;
impl.close();
closed = true;
}
}
@Override
public boolean isClosed() {
synchronized (closeLock) {
return closed;
}
}
@Override
public <T> DatagramSocket setOption(SocketOption<T> name, T value)
throws IOException
{
Objects.requireNonNull(name);
if (isClosed())
throw new SocketException("Socket is closed");
getImpl().setOption(name, value);
return this;
}
@Override
public <T> T getOption(SocketOption<T> name) throws IOException {
Objects.requireNonNull(name);
if (isClosed())
throw new SocketException("Socket is closed");
return getImpl().getOption(name);
}
private volatile Set<SocketOption<?>> options;
private final Object optionsLock = new Object();
@Override
public Set<SocketOption<?>> supportedOptions() {
Set<SocketOption<?>> options = this.options;
if (options != null)
return options;
synchronized (optionsLock) {
options = this.options;
if (options != null) {
return options;
}
try {
DatagramSocketImpl impl = getImpl();
options = Collections.unmodifiableSet(impl.supportedOptions());
} catch (IOException e) {
options = Collections.emptySet();
}
return this.options = options;
}
}
// Multicast socket support
/**
* Used on some platforms to record if an outgoing interface
* has been set for this socket.
*/
private boolean interfaceSet;
/**
* The lock on the socket's TTL. This is for set/getTTL and
* send(packet,ttl).
*/
private final Object ttlLock = new Object();
/**
* The lock on the socket's interface - used by setInterface
* and getInterface
*/
private final Object infLock = new Object();
/**
* The "last" interface set by setInterface on this MulticastSocket
*/
private InetAddress infAddress = null;
@Deprecated
@Override
public void setTTL(byte ttl) throws IOException {
if (isClosed())
throw new SocketException("Socket is closed");
getImpl().setTTL(ttl);
}
@Override
public void setTimeToLive(int ttl) throws IOException {
if (ttl < 0 || ttl > 255) {
throw new IllegalArgumentException("ttl out of range");
}
if (isClosed())
throw new SocketException("Socket is closed");
getImpl().setTimeToLive(ttl);
}
@Deprecated
@Override
public byte getTTL() throws IOException {
if (isClosed())
throw new SocketException("Socket is closed");
return getImpl().getTTL();
}
@Override
public int getTimeToLive() throws IOException {
if (isClosed())
throw new SocketException("Socket is closed");
return getImpl().getTimeToLive();
}
@Override
@Deprecated
public void joinGroup(InetAddress mcastaddr) throws IOException {
if (isClosed()) {
throw new SocketException("Socket is closed");
}
checkAddress(mcastaddr, "joinGroup");
@SuppressWarnings("removal")
SecurityManager security = System.getSecurityManager();
if (security != null) {
security.checkMulticast(mcastaddr);
}
if (!mcastaddr.isMulticastAddress()) {
throw new SocketException("Not a multicast address");
}
/**
* required for some platforms where it's not possible to join
* a group without setting the interface first.
*/
NetworkInterface defaultInterface = NetworkInterface.getDefault();
if (!interfaceSet && defaultInterface != null) {
setNetworkInterface(defaultInterface);
}
getImpl().join(mcastaddr);
}
@Override
@Deprecated
public void leaveGroup(InetAddress mcastaddr) throws IOException {
if (isClosed()) {
throw new SocketException("Socket is closed");
}
checkAddress(mcastaddr, "leaveGroup");
@SuppressWarnings("removal")
SecurityManager security = System.getSecurityManager();
if (security != null) {
security.checkMulticast(mcastaddr);
}
if (!mcastaddr.isMulticastAddress()) {
throw new SocketException("Not a multicast address");
}
getImpl().leave(mcastaddr);
}
@Override
public void joinGroup(SocketAddress mcastaddr, NetworkInterface netIf)
throws IOException {
if (isClosed())
throw new SocketException("Socket is closed");
if (!(mcastaddr instanceof InetSocketAddress addr))
throw new IllegalArgumentException("Unsupported address type");
checkAddress(addr.getAddress(), "joinGroup");
@SuppressWarnings("removal")
SecurityManager security = System.getSecurityManager();
if (security != null) {
security.checkMulticast(addr.getAddress());
}
if (!addr.getAddress().isMulticastAddress()) {
throw new SocketException("Not a multicast address");
}
getImpl().joinGroup(mcastaddr, netIf);
}
@Override
public void leaveGroup(SocketAddress mcastaddr, NetworkInterface netIf)
throws IOException {
if (isClosed())
throw new SocketException("Socket is closed");
if (!(mcastaddr instanceof InetSocketAddress addr))
throw new IllegalArgumentException("Unsupported address type");
checkAddress(addr.getAddress(), "leaveGroup");
@SuppressWarnings("removal")
SecurityManager security = System.getSecurityManager();
if (security != null) {
security.checkMulticast(addr.getAddress());
}
if (!addr.getAddress().isMulticastAddress()) {
throw new SocketException("Not a multicast address");
}
getImpl().leaveGroup(mcastaddr, netIf);
}
@Override
@Deprecated
public void setInterface(InetAddress inf) throws SocketException {
if (isClosed()) {
throw new SocketException("Socket is closed");
}
checkAddress(inf, "setInterface");
synchronized (infLock) {
getImpl().setOption(SocketOptions.IP_MULTICAST_IF, inf);
infAddress = inf;
interfaceSet = true;
}
}
@Override
@Deprecated
public InetAddress getInterface() throws SocketException {
if (isClosed()) {
throw new SocketException("Socket is closed");
}
synchronized (infLock) {
InetAddress ia =
(InetAddress)getImpl().getOption(SocketOptions.IP_MULTICAST_IF);
/**
* No previous setInterface or interface can be
* set using setNetworkInterface
*/
if (infAddress == null) {
return ia;
}
/**
* Same interface set with setInterface?
*/
if (ia.equals(infAddress)) {
return ia;
}
/**
* Different InetAddress from what we set with setInterface
* so enumerate the current interface to see if the
* address set by setInterface is bound to this interface.
*/
try {
NetworkInterface ni = NetworkInterface.getByInetAddress(ia);
Enumeration<InetAddress> addrs = ni.getInetAddresses();
while (addrs.hasMoreElements()) {
InetAddress addr = addrs.nextElement();
if (addr.equals(infAddress)) {
return infAddress;
}
}
/**
* No match so reset infAddress to indicate that the
* interface has changed via means
*/
infAddress = null;
return ia;
} catch (Exception e) {
return ia;
}
}
}
@Override
public void setNetworkInterface(NetworkInterface netIf)
throws SocketException {
synchronized (infLock) {
getImpl().setOption(SocketOptions.IP_MULTICAST_IF2, netIf);
infAddress = null;
interfaceSet = true;
}
}
@Override
public NetworkInterface getNetworkInterface() throws SocketException {
NetworkInterface ni
= (NetworkInterface)getImpl().getOption(SocketOptions.IP_MULTICAST_IF2);
if (ni == null) {
InetAddress[] addrs = new InetAddress[1];
addrs[0] = InetAddress.anyLocalAddress();
return new NetworkInterface(addrs[0].getHostName(), 0, addrs);
} else {
return ni;
}
}
@Override
@Deprecated
public void setLoopbackMode(boolean disable) throws SocketException {
getImpl().setOption(SocketOptions.IP_MULTICAST_LOOP, Boolean.valueOf(disable));
}
@Override
@Deprecated
public boolean getLoopbackMode() throws SocketException {
return ((Boolean)getImpl().getOption(SocketOptions.IP_MULTICAST_LOOP)).booleanValue();
}
@SuppressWarnings("removal")
@Deprecated
@Override
public void send(DatagramPacket p, byte ttl)
throws IOException {
if (isClosed())
throw new SocketException("Socket is closed");
synchronized(ttlLock) {
synchronized(p) {
InetAddress packetAddress = p.getAddress();
checkAddress(packetAddress, "send");
if (connectState == NetMulticastSocket.ST_NOT_CONNECTED) {
if (packetAddress == null) {
throw new IllegalArgumentException("Address not set");
}
// Security manager makes sure that the multicast address
// is allowed one and that the ttl used is less
// than the allowed maxttl.
SecurityManager security = System.getSecurityManager();
if (security != null) {
if (packetAddress.isMulticastAddress()) {
security.checkMulticast(packetAddress, ttl);
} else {
security.checkConnect(packetAddress.getHostAddress(),
p.getPort());
}
}
} else {
// we're connected
if (packetAddress == null) {
p.setAddress(connectedAddress);
p.setPort(connectedPort);
} else if ((!packetAddress.equals(connectedAddress)) ||
p.getPort() != connectedPort) {
throw new IllegalArgumentException("connected address and packet address" +
" differ");
}
}
byte dttl = getTTL();
try {
if (ttl != dttl) {
// set the ttl
getImpl().setTTL(ttl);
}
if (p.getPort() == 0) {
throw new SocketException("Can't send to port 0");
}
// call the datagram method to send
getImpl().send(p);
} finally {
// set it back to default
if (ttl != dttl) {
getImpl().setTTL(dttl);
}
}
} // synch p
} //synch ttl
} //method
}
/*
* Copyright (c) 1995, 2023, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
package java.io;
import java.util.Objects;
/**
* A piped input stream should be connected
* to a piped output stream; the piped input
* stream then provides whatever data bytes
* are written to the piped output stream.
* Typically, data is read from a {@code PipedInputStream}
* object by one thread and data is written
* to the corresponding {@code PipedOutputStream}
* by some other thread. Attempting to use
* both objects from a single thread is not
* recommended, as it may deadlock the thread.
* The piped input stream contains a buffer,
* decoupling read operations from write operations,
* within limits.
* A pipe is said to be <a id="BROKEN"> <i>broken</i> </a> if a
* thread that was providing data bytes to the connected
* piped output stream is no longer alive.
*
* @author James Gosling
* @see java.io.PipedOutputStream
* @since 1.0
*/
public class PipedInputStream extends InputStream {
boolean closedByWriter;
volatile boolean closedByReader;
boolean connected;
/* REMIND: identification of the read and write sides needs to be
more sophisticated. Either using thread groups (but what about
pipes within a thread?) or using finalization (but it may be a
long time until the next GC). */
Thread readSide;
Thread writeSide;
private static final int DEFAULT_PIPE_SIZE = 1024;
/**
* The default size of the pipe's circular input buffer.
* @since 1.1
*/
// This used to be a constant before the pipe size was allowed
// to change. This field will continue to be maintained
// for backward compatibility.
protected static final int PIPE_SIZE = DEFAULT_PIPE_SIZE;
/**
* The circular buffer into which incoming data is placed.
* @since 1.1
*/
protected byte buffer[];
/**
* The index of the position in the circular buffer at which the
* next byte of data will be stored when received from the connected
* piped output stream. {@code in < 0} implies the buffer is empty,
* {@code in == out} implies the buffer is full
* @since 1.1
*/
protected int in = -1;
/**
* The index of the position in the circular buffer at which the next
* byte of data will be read by this piped input stream.
* @since 1.1
*/
protected int out = 0;
/**
* Creates a {@code PipedInputStream} so
* that it is connected to the piped output
* stream {@code src}. Data bytes written
* to {@code src} will then be available
* as input from this stream.
*
* @param src the stream to connect to.
* @throws IOException if an I/O error occurs.
*/
public PipedInputStream(PipedOutputStream src) throws IOException {
this(src, DEFAULT_PIPE_SIZE);
}
/**
* Creates a {@code PipedInputStream} so that it is
* connected to the piped output stream
* {@code src} and uses the specified pipe size for
* the pipe's buffer.
* Data bytes written to {@code src} will then
* be available as input from this stream.
*
* @param src the stream to connect to.
* @param pipeSize the size of the pipe's buffer.
* @throws IOException if an I/O error occurs.
* @throws IllegalArgumentException if {@code pipeSize <= 0}.
* @since 1.6
*/
public PipedInputStream(PipedOutputStream src, int pipeSize)
throws IOException {
initPipe(pipeSize);
connect(src);
}
/**
* Creates a {@code PipedInputStream} so
* that it is not yet {@linkplain #connect(java.io.PipedOutputStream)
* connected}.
* It must be {@linkplain java.io.PipedOutputStream#connect(
* java.io.PipedInputStream) connected} to a
* {@code PipedOutputStream} before being used.
*/
public PipedInputStream() {
initPipe(DEFAULT_PIPE_SIZE);
}
/**
* Creates a {@code PipedInputStream} so that it is not yet
* {@linkplain #connect(java.io.PipedOutputStream) connected} and
* uses the specified pipe size for the pipe's buffer.
* It must be {@linkplain java.io.PipedOutputStream#connect(
* java.io.PipedInputStream)
* connected} to a {@code PipedOutputStream} before being used.
*
* @param pipeSize the size of the pipe's buffer.
* @throws IllegalArgumentException if {@code pipeSize <= 0}.
* @since 1.6
*/
public PipedInputStream(int pipeSize) {
initPipe(pipeSize);
}
private void initPipe(int pipeSize) {
if (pipeSize <= 0) {
throw new IllegalArgumentException("Pipe Size <= 0");
}
buffer = new byte[pipeSize];
}
/**
* Causes this piped input stream to be connected
* to the piped output stream {@code src}.
* If this object is already connected to some
* other piped output stream, an {@code IOException}
* is thrown.
* <p>
* If {@code src} is an
* unconnected piped output stream and {@code snk}
* is an unconnected piped input stream, they
* may be connected by either the call:
*
* {@snippet lang=java :
* snk.connect(src)
* }
* <p>
* or the call:
*
* {@snippet lang=java :
* src.connect(snk)
* }
* <p>
* The two calls have the same effect.
*
* @param src The piped output stream to connect to.
* @throws IOException if an I/O error occurs.
*/
public void connect(PipedOutputStream src) throws IOException {
src.connect(this);
}
/**
* Receives a byte of data. This method will block if no input is
* available.
* @param b the byte being received
* @throws IOException If the pipe is <a href="#BROKEN"> {@code broken}</a>,
* {@link #connect(java.io.PipedOutputStream) unconnected},
* closed, or if an I/O error occurs.
* @since 1.1
*/
protected synchronized void receive(int b) throws IOException {
checkStateForReceive();
writeSide = Thread.currentThread();
if (in == out)
awaitSpace();
if (in < 0) {
in = 0;
out = 0;
}
buffer[in++] = (byte)(b & 0xFF);
if (in >= buffer.length) {
in = 0;
}
}
/**
* Receives data into an array of bytes. This method will
* block until some input is available.
* @param b the buffer into which the data is received
* @param off the start offset of the data
* @param len the maximum number of bytes received
* @throws IOException If the pipe is <a href="#BROKEN"> broken</a>,
* {@link #connect(java.io.PipedOutputStream) unconnected},
* closed, or if an I/O error occurs.
*/
synchronized void receive(byte[] b, int off, int len) throws IOException {
checkStateForReceive();
writeSide = Thread.currentThread();
int bytesToTransfer = len;
while (bytesToTransfer > 0) {
if (in == out)
awaitSpace();
int nextTransferAmount = 0;
if (out < in) {
nextTransferAmount = buffer.length - in;
} else if (in < out) {
if (in == -1) {
in = out = 0;
nextTransferAmount = buffer.length - in;
} else {
nextTransferAmount = out - in;
}
}
if (nextTransferAmount > bytesToTransfer)
nextTransferAmount = bytesToTransfer;
assert(nextTransferAmount > 0);
System.arraycopy(b, off, buffer, in, nextTransferAmount);
bytesToTransfer -= nextTransferAmount;
off += nextTransferAmount;
in += nextTransferAmount;
if (in >= buffer.length) {
in = 0;
}
}
}
private void checkStateForReceive() throws IOException {
if (!connected) {
throw new IOException("Pipe not connected");
} else if (closedByWriter || closedByReader) {
throw new IOException("Pipe closed");
} else if (readSide != null && !readSide.isAlive()) {
throw new IOException("Read end dead");
}
}
private void awaitSpace() throws IOException {
while (in == out) {
checkStateForReceive();
/* full: kick any waiting readers */
notifyAll();
try {
wait(1000);
} catch (InterruptedException ex) {
throw new java.io.InterruptedIOException();
}
}
}
/**
* Notifies all waiting threads that the last byte of data has been
* received.
*/
synchronized void receivedLast() {
closedByWriter = true;
notifyAll();
}
/**
* Reads the next byte of data from this piped input stream. The
* value byte is returned as an {@code int} in the range
* {@code 0} to {@code 255}.
* This method blocks until input data is available, the end of the
* stream is detected, or an exception is thrown.
*
* @return {@inheritDoc}
* @throws IOException if the pipe is
* {@link #connect(java.io.PipedOutputStream) unconnected},
* <a href="#BROKEN"> {@code broken}</a>, closed,
* or if an I/O error occurs.
*/
@Override
public synchronized int read() throws IOException {
if (!connected) {
throw new IOException("Pipe not connected");
} else if (closedByReader) {
throw new IOException("Pipe closed");
} else if (writeSide != null && !writeSide.isAlive()
&& !closedByWriter && (in < 0)) {
throw new IOException("Write end dead");
}
readSide = Thread.currentThread();
int trials = 2;
while (in < 0) {
if (closedByWriter) {
/* closed by writer, return EOF */
return -1;
}
if ((writeSide != null) && (!writeSide.isAlive()) && (--trials < 0)) {
throw new IOException("Pipe broken");
}
/* might be a writer waiting */
notifyAll();
try {
wait(1000);
} catch (InterruptedException ex) {
throw new java.io.InterruptedIOException();
}
}
int ret = buffer[out++] & 0xFF;
if (out >= buffer.length) {
out = 0;
}
if (in == out) {
/* now empty */
in = -1;
}
return ret;
}
/**
* Reads up to {@code len} bytes of data from this piped input
* stream into an array of bytes. Less than {@code len} bytes
* will be read if the end of the data stream is reached or if
* {@code len} exceeds the pipe's buffer size.
* If {@code len } is zero, then no bytes are read and 0 is returned;
* otherwise, the method blocks until at least 1 byte of input is
* available, end of the stream has been detected, or an exception is
* thrown.
*
* @param b {@inheritDoc}
* @param off {@inheritDoc}
* @param len {@inheritDoc}
* @return {@inheritDoc}
* @throws NullPointerException {@inheritDoc}
* @throws IndexOutOfBoundsException {@inheritDoc}
* @throws IOException if the pipe is <a href="#BROKEN"> {@code broken}</a>,
* {@link #connect(java.io.PipedOutputStream) unconnected},
* closed, or if an I/O error occurs.
*/
@Override
public synchronized int read(byte[] b, int off, int len) throws IOException {
if (b == null) {
throw new NullPointerException();
}
Objects.checkFromIndexSize(off, len, b.length);
if (len == 0) {
return 0;
}
/* possibly wait on the first character */
int c = read();
if (c < 0) {
return -1;
}
b[off] = (byte) c;
int rlen = 1;
while ((in >= 0) && (len > 1)) {
int available;
if (in > out) {
available = Math.min((buffer.length - out), (in - out));
} else {
available = buffer.length - out;
}
// A byte is read beforehand outside the loop
if (available > (len - 1)) {
available = len - 1;
}
System.arraycopy(buffer, out, b, off + rlen, available);
out += available;
rlen += available;
len -= available;
if (out >= buffer.length) {
out = 0;
}
if (in == out) {
/* now empty */
in = -1;
}
}
return rlen;
}
/**
* Returns the number of bytes that can be read from this input
* stream without blocking.
*
* @return the number of bytes that can be read from this input stream
* without blocking, or {@code 0} if this input stream has been
* closed by invoking its {@link #close()} method, or if the pipe
* is {@link #connect(java.io.PipedOutputStream) unconnected}, or
* <a href="#BROKEN"> {@code broken}</a>.
*
* @throws IOException {@inheritDoc}
* @since 1.0.2
*/
@Override
public synchronized int available() throws IOException {
if(in < 0)
return 0;
else if(in == out)
return buffer.length;
else if (in > out)
return in - out;
else
return in + buffer.length - out;
}
/**
* {@inheritDoc}
*
* @throws IOException {@inheritDoc}
*/
@Override
public void close() throws IOException {
closedByReader = true;
synchronized (this) {
in = -1;
}
}
}
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