bundles/org.eclipse.core.resources/src/org/eclipse/core/internal/utils/UniversalUniqueIdentifier.java - platform/eclipse.platform.resources - Git at Google

 /*******************************************************************************
  * Copyright (c) 2000, 2016 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
  * http://www.eclipse.org/legal/epl-v10.html
  *
  * Contributors:
  *     IBM Corporation - initial API and implementation
  *     Mickael Istria (Red Hat Inc.) - Bug 488938, 488937
  *******************************************************************************/
 package org.eclipse.core.internal.utils;

 import java.io.*;
 import java.math.BigInteger;
 import java.net.InetAddress;
 import java.net.UnknownHostException;
 import java.security.SecureRandom;
 import java.util.GregorianCalendar;
 import java.util.Random;

 public class UniversalUniqueIdentifier implements java.io.Serializable {

 	/**
 	 * All serializable objects should have a stable serialVersionUID
 	 */
 	private static final long serialVersionUID = 1L;

 	/* INSTANCE FIELDS =============================================== */

 	private byte[] fBits = new byte[BYTES_SIZE];

 	/* NON-FINAL PRIVATE STATIC FIELDS =============================== */

 	private static BigInteger fgPreviousClockValue;
 	private static int fgClockAdjustment = 0;
 	private static int fgClockSequence = -1;
 	private static byte[] nodeAddress;

 	static {
 		nodeAddress = computeNodeAddress();
 	}

 	/* PRIVATE STATIC FINAL FIELDS =================================== */

 	private static Random fgRandomNumberGenerator = new Random();

 	/* PUBLIC STATIC FINAL FIELDS ==================================== */

 	public static final int BYTES_SIZE = 16;
 	public static final byte[] UNDEFINED_UUID_BYTES = new byte[16];
 	public static final int MAX_CLOCK_SEQUENCE = 0x4000;
 	public static final int MAX_CLOCK_ADJUSTMENT = 0x7FFF;
 	public static final int TIME_FIELD_START = 0;
 	public static final int TIME_FIELD_STOP = 6;
 	public static final int TIME_HIGH_AND_VERSION = 7;
 	public static final int CLOCK_SEQUENCE_HIGH_AND_RESERVED = 8;
 	public static final int CLOCK_SEQUENCE_LOW = 9;
 	public static final int NODE_ADDRESS_START = 10;
 	public static final int NODE_ADDRESS_BYTE_SIZE = 6;

 	public static final int BYTE_MASK = 0xFF;

 	public static final int HIGH_NIBBLE_MASK = 0xF0;

 	public static final int LOW_NIBBLE_MASK = 0x0F;

 	public static final int SHIFT_NIBBLE = 4;

 	public static final int ShiftByte = 8;

 	/**
 	 UniversalUniqueIdentifier default constructor returns a
 	 new instance that has been initialized to a unique value.
 	 */
 	public UniversalUniqueIdentifier() {
 		this.setVersion(1);
 		this.setVariant(1);
 		this.setTimeValues();
 		this.setNode(getNodeAddress());
 	}

 	/**
 	 Constructor that accepts the bytes to use for the instance.&nbsp;&nbsp; The format
 	 of the byte array is compatible with the <code>toBytes()</code> method.

 	 <p>The constructor returns the undefined uuid if the byte array is invalid.

 	 @see #toBytes()
 	 @see #BYTES_SIZE
 	 */
 	public UniversalUniqueIdentifier(byte[] byteValue) {
 		fBits = new byte[BYTES_SIZE];
 		if (byteValue.length >= BYTES_SIZE)
 			System.arraycopy(byteValue, 0, fBits, 0, BYTES_SIZE);
 	}

 	private void appendByteString(StringBuilder buffer, byte value) {
 		String hexString;

 		if (value < 0)
 			hexString = Integer.toHexString(256 + value);
 		else
 			hexString = Integer.toHexString(value);
 		if (hexString.length() == 1)
 			buffer.append("0"); //$NON-NLS-1$
 		buffer.append(hexString);
 	}

 	private static BigInteger clockValueNow() {
 		GregorianCalendar now = new GregorianCalendar();
 		BigInteger nowMillis = BigInteger.valueOf(now.getTime().getTime());
 		BigInteger baseMillis = BigInteger.valueOf(now.getGregorianChange().getTime());

 		return (nowMillis.subtract(baseMillis).multiply(BigInteger.valueOf(10000L)));
 	}

 	public static int compareTime(byte[] fBits1, byte[] fBits2) {
 		for (int i = TIME_FIELD_STOP; i >= 0; i--)
 			if (fBits1[i] != fBits2[i])
 				return (0xFF & fBits1[i]) - (0xFF & fBits2[i]);
 		return 0;
 	}

 	/**
 	 * Answers the node address attempting to mask the IP
 	 * address of this machine.
 	 *
 	 * @return byte[] the node address
 	 */
 	private static byte[] computeNodeAddress() {

 		byte[] address = new byte[NODE_ADDRESS_BYTE_SIZE];

 		// Seed the secure randomizer with some oft-varying inputs
 		int thread = Thread.currentThread().hashCode();
 		long time = System.currentTimeMillis();
 		int objectId = System.identityHashCode(""); //$NON-NLS-1$
 		ByteArrayOutputStream byteOut = new ByteArrayOutputStream();
 		DataOutputStream out = new DataOutputStream(byteOut);
 		byte[] ipAddress = getIPAddress();

 		try {
 			if (ipAddress != null)
 				out.write(ipAddress);
 			out.write(thread);
 			out.writeLong(time);
 			out.write(objectId);
 			out.close();
 		} catch (IOException exc) {
 			//ignore the failure, we're just trying to come up with a random seed
 		}
 		byte[] rand = byteOut.toByteArray();

 		SecureRandom randomizer = new SecureRandom(rand);
 		randomizer.nextBytes(address);

 		// set the MSB of the first octet to 1 to distinguish from IEEE node addresses
 		address[0] = (byte) (address[0] | (byte) 0x80);

 		return address;
 	}

 	@Override
 	public boolean equals(Object obj) {
 		if (this == obj)
 			return true;
 		if (!(obj instanceof UniversalUniqueIdentifier))
 			return false;

 		byte[] other = ((UniversalUniqueIdentifier) obj).fBits;
 		if (fBits == other)
 			return true;
 		if (fBits.length != other.length)
 			return false;
 		for (int i = 0; i < fBits.length; i++) {
 			if (fBits[i] != other[i])
 				return false;
 		}
 		return true;
 	}

 	/**
 	 Answers the IP address of the local machine using the
 	 Java API class <code>InetAddress</code>.

 	 @return byte[] the network address in network order
 	 @see    java.net.InetAddress#getLocalHost()
 	 @see    java.net.InetAddress#getAddress()
 	 */
 	protected static byte[] getIPAddress() {
 		try {
 			return InetAddress.getLocalHost().getAddress();
 		} catch (UnknownHostException e) {
 			//valid for this to be thrown be a machine with no IP connection
 			//It is VERY important NOT to throw this exception
 			return null;
 		} catch (ArrayIndexOutOfBoundsException e) {
 			// there appears to be a bug in the VM if there is an alias
 			// see bug 354820. As above it is important not to throw this
 			return null;
 		}
 	}

 	private static byte[] getNodeAddress() {
 		return nodeAddress;
 	}

 	@Override
 	public int hashCode() {
 		return fBits[0] + fBits[3] + fBits[7] + fBits[11] + fBits[15];
 	}

 	private static int nextClockSequence() {

 		if (fgClockSequence == -1)
 			fgClockSequence = (int) (fgRandomNumberGenerator.nextDouble() * MAX_CLOCK_SEQUENCE);

 		fgClockSequence = (fgClockSequence + 1) % MAX_CLOCK_SEQUENCE;

 		return fgClockSequence;
 	}

 	private static BigInteger nextTimestamp() {

 		BigInteger timestamp = clockValueNow();
 		int timestampComparison;

 		timestampComparison = timestamp.compareTo(fgPreviousClockValue);

 		if (timestampComparison == 0) {
 			if (fgClockAdjustment == MAX_CLOCK_ADJUSTMENT) {
 				while (timestamp.compareTo(fgPreviousClockValue) == 0)
 					timestamp = clockValueNow();
 				timestamp = nextTimestamp();
 			} else
 				fgClockAdjustment++;
 		} else {
 			fgClockAdjustment = 0;

 			if (timestampComparison < 0)
 				nextClockSequence();
 		}

 		return timestamp;
 	}

 	private void setClockSequence(int clockSeq) {
 		int clockSeqHigh = (clockSeq >>> ShiftByte) & LOW_NIBBLE_MASK;
 		int reserved = fBits[CLOCK_SEQUENCE_HIGH_AND_RESERVED] & HIGH_NIBBLE_MASK;

 		fBits[CLOCK_SEQUENCE_HIGH_AND_RESERVED] = (byte) (reserved | clockSeqHigh);
 		fBits[CLOCK_SEQUENCE_LOW] = (byte) (clockSeq & BYTE_MASK);
 	}

 	protected void setNode(byte[] bytes) {

 		for (int index = 0; index < NODE_ADDRESS_BYTE_SIZE; index++)
 			fBits[index + NODE_ADDRESS_START] = bytes[index];
 	}

 	private void setTimestamp(BigInteger timestamp) {
 		BigInteger value = timestamp;
 		BigInteger bigByte = BigInteger.valueOf(256L);
 		BigInteger[] results;
 		int version;
 		int timeHigh;

 		for (int index = TIME_FIELD_START; index < TIME_FIELD_STOP; index++) {
 			results = value.divideAndRemainder(bigByte);
 			value = results[0];
 			fBits[index] = (byte) results[1].intValue();
 		}
 		version = fBits[TIME_HIGH_AND_VERSION] & HIGH_NIBBLE_MASK;
 		timeHigh = value.intValue() & LOW_NIBBLE_MASK;
 		fBits[TIME_HIGH_AND_VERSION] = (byte) (timeHigh | version);
 	}

 	protected synchronized void setTimeValues() {
 		this.setTimestamp(timestamp());
 		this.setClockSequence(fgClockSequence);
 	}

 	protected int setVariant(int variantIdentifier) {
 		int clockSeqHigh = fBits[CLOCK_SEQUENCE_HIGH_AND_RESERVED] & LOW_NIBBLE_MASK;
 		int variant = variantIdentifier & LOW_NIBBLE_MASK;

 		fBits[CLOCK_SEQUENCE_HIGH_AND_RESERVED] = (byte) ((variant << SHIFT_NIBBLE) | clockSeqHigh);
 		return (variant);
 	}

 	protected void setVersion(int versionIdentifier) {
 		int timeHigh = fBits[TIME_HIGH_AND_VERSION] & LOW_NIBBLE_MASK;
 		int version = versionIdentifier & LOW_NIBBLE_MASK;

 		fBits[TIME_HIGH_AND_VERSION] = (byte) (timeHigh | (version << SHIFT_NIBBLE));
 	}

 	private static BigInteger timestamp() {
 		BigInteger timestamp;

 		if (fgPreviousClockValue == null) {
 			fgClockAdjustment = 0;
 			nextClockSequence();
 			timestamp = clockValueNow();
 		} else
 			timestamp = nextTimestamp();

 		fgPreviousClockValue = timestamp;
 		return fgClockAdjustment == 0 ? timestamp : timestamp.add(BigInteger.valueOf(fgClockAdjustment));
 	}

 	/**
 	 This representation is compatible with the (byte[]) constructor.

 	 @see #UniversalUniqueIdentifier(byte[])
 	 */
 	public byte[] toBytes() {
 		byte[] result = new byte[fBits.length];

 		System.arraycopy(fBits, 0, result, 0, fBits.length);
 		return result;
 	}

 	@Override
 	public String toString() {
 		StringBuilder buffer = new StringBuilder();
 		for (byte bit : fBits)
 			appendByteString(buffer, bit);
 		return buffer.toString();
 	}

 	public String toStringAsBytes() {
 		StringBuilder result = new StringBuilder("{"); //$NON-NLS-1$

 		for (int i = 0; i < fBits.length; i++) {
 			result.append(fBits[i]);
 			if (i < fBits.length + 1)
 				result.append(',');
 		}
 		result.append('}');
 		return result.toString();
 	}
 }
	/*******************************************************************************
	* Copyright (c) 2000, 2016 IBM Corporation and others.
	* All rights reserved. This program and the accompanying materials
	* are made available under the terms of the Eclipse Public License v1.0
	* which accompanies this distribution, and is available at
	* http://www.eclipse.org/legal/epl-v10.html
	*
	* Contributors:
	* IBM Corporation - initial API and implementation
	* Mickael Istria (Red Hat Inc.) - Bug 488938, 488937
	*******************************************************************************/
	package org.eclipse.core.internal.utils;

	import java.io.*;
	import java.math.BigInteger;
	import java.net.InetAddress;
	import java.net.UnknownHostException;
	import java.security.SecureRandom;
	import java.util.GregorianCalendar;
	import java.util.Random;

	public class UniversalUniqueIdentifier implements java.io.Serializable {

	/**
	* All serializable objects should have a stable serialVersionUID
	*/
	private static final long serialVersionUID = 1L;

	/* INSTANCE FIELDS =============================================== */

	private byte[] fBits = new byte[BYTES_SIZE];

	/* NON-FINAL PRIVATE STATIC FIELDS =============================== */

	private static BigInteger fgPreviousClockValue;
	private static int fgClockAdjustment = 0;
	private static int fgClockSequence = -1;
	private static byte[] nodeAddress;

	static {
	nodeAddress = computeNodeAddress();
	}

	/* PRIVATE STATIC FINAL FIELDS =================================== */

	private static Random fgRandomNumberGenerator = new Random();

	/* PUBLIC STATIC FINAL FIELDS ==================================== */

	public static final int BYTES_SIZE = 16;
	public static final byte[] UNDEFINED_UUID_BYTES = new byte[16];
	public static final int MAX_CLOCK_SEQUENCE = 0x4000;
	public static final int MAX_CLOCK_ADJUSTMENT = 0x7FFF;
	public static final int TIME_FIELD_START = 0;
	public static final int TIME_FIELD_STOP = 6;
	public static final int TIME_HIGH_AND_VERSION = 7;
	public static final int CLOCK_SEQUENCE_HIGH_AND_RESERVED = 8;
	public static final int CLOCK_SEQUENCE_LOW = 9;
	public static final int NODE_ADDRESS_START = 10;
	public static final int NODE_ADDRESS_BYTE_SIZE = 6;

	public static final int BYTE_MASK = 0xFF;

	public static final int HIGH_NIBBLE_MASK = 0xF0;

	public static final int LOW_NIBBLE_MASK = 0x0F;

	public static final int SHIFT_NIBBLE = 4;

	public static final int ShiftByte = 8;

	/**
	UniversalUniqueIdentifier default constructor returns a
	new instance that has been initialized to a unique value.
	*/
	public UniversalUniqueIdentifier() {
	this.setVersion(1);
	this.setVariant(1);
	this.setTimeValues();
	this.setNode(getNodeAddress());
	}

	/**
	Constructor that accepts the bytes to use for the instance.   The format
	of the byte array is compatible with the <code>toBytes()</code> method.

	<p>The constructor returns the undefined uuid if the byte array is invalid.

	@see #toBytes()
	@see #BYTES_SIZE
	*/
	public UniversalUniqueIdentifier(byte[] byteValue) {
	fBits = new byte[BYTES_SIZE];
	if (byteValue.length >= BYTES_SIZE)
	System.arraycopy(byteValue, 0, fBits, 0, BYTES_SIZE);
	}

	private void appendByteString(StringBuilder buffer, byte value) {
	String hexString;

	if (value < 0)
	hexString = Integer.toHexString(256 + value);
	else
	hexString = Integer.toHexString(value);
	if (hexString.length() == 1)
	buffer.append("0"); //$NON-NLS-1$
	buffer.append(hexString);
	}

	private static BigInteger clockValueNow() {
	GregorianCalendar now = new GregorianCalendar();
	BigInteger nowMillis = BigInteger.valueOf(now.getTime().getTime());
	BigInteger baseMillis = BigInteger.valueOf(now.getGregorianChange().getTime());

	return (nowMillis.subtract(baseMillis).multiply(BigInteger.valueOf(10000L)));
	}

	public static int compareTime(byte[] fBits1, byte[] fBits2) {
	for (int i = TIME_FIELD_STOP; i >= 0; i--)
	if (fBits1[i] != fBits2[i])
	return (0xFF & fBits1[i]) - (0xFF & fBits2[i]);
	return 0;
	}

	/**
	* Answers the node address attempting to mask the IP
	* address of this machine.
	*
	* @return byte[] the node address
	*/
	private static byte[] computeNodeAddress() {

	byte[] address = new byte[NODE_ADDRESS_BYTE_SIZE];

	// Seed the secure randomizer with some oft-varying inputs
	int thread = Thread.currentThread().hashCode();
	long time = System.currentTimeMillis();
	int objectId = System.identityHashCode(""); //$NON-NLS-1$
	ByteArrayOutputStream byteOut = new ByteArrayOutputStream();
	DataOutputStream out = new DataOutputStream(byteOut);
	byte[] ipAddress = getIPAddress();

	try {
	if (ipAddress != null)
	out.write(ipAddress);
	out.write(thread);
	out.writeLong(time);
	out.write(objectId);
	out.close();
	} catch (IOException exc) {
	//ignore the failure, we're just trying to come up with a random seed
	}
	byte[] rand = byteOut.toByteArray();

	SecureRandom randomizer = new SecureRandom(rand);
	randomizer.nextBytes(address);

	// set the MSB of the first octet to 1 to distinguish from IEEE node addresses
	address[0] = (byte) (address[0] \| (byte) 0x80);

	return address;
	}

	@Override
	public boolean equals(Object obj) {
	if (this == obj)
	return true;
	if (!(obj instanceof UniversalUniqueIdentifier))
	return false;

	byte[] other = ((UniversalUniqueIdentifier) obj).fBits;
	if (fBits == other)
	return true;
	if (fBits.length != other.length)
	return false;
	for (int i = 0; i < fBits.length; i++) {
	if (fBits[i] != other[i])
	return false;
	}
	return true;
	}

	/**
	Answers the IP address of the local machine using the
	Java API class <code>InetAddress</code>.

	@return byte[] the network address in network order
	@see java.net.InetAddress#getLocalHost()
	@see java.net.InetAddress#getAddress()
	*/
	protected static byte[] getIPAddress() {
	try {
	return InetAddress.getLocalHost().getAddress();
	} catch (UnknownHostException e) {
	//valid for this to be thrown be a machine with no IP connection
	//It is VERY important NOT to throw this exception
	return null;
	} catch (ArrayIndexOutOfBoundsException e) {
	// there appears to be a bug in the VM if there is an alias
	// see bug 354820. As above it is important not to throw this
	return null;
	}
	}

	private static byte[] getNodeAddress() {
	return nodeAddress;
	}

	@Override
	public int hashCode() {
	return fBits[0] + fBits[3] + fBits[7] + fBits[11] + fBits[15];
	}

	private static int nextClockSequence() {

	if (fgClockSequence == -1)
	fgClockSequence = (int) (fgRandomNumberGenerator.nextDouble() * MAX_CLOCK_SEQUENCE);

	fgClockSequence = (fgClockSequence + 1) % MAX_CLOCK_SEQUENCE;

	return fgClockSequence;
	}

	private static BigInteger nextTimestamp() {

	BigInteger timestamp = clockValueNow();
	int timestampComparison;

	timestampComparison = timestamp.compareTo(fgPreviousClockValue);

	if (timestampComparison == 0) {
	if (fgClockAdjustment == MAX_CLOCK_ADJUSTMENT) {
	while (timestamp.compareTo(fgPreviousClockValue) == 0)
	timestamp = clockValueNow();
	timestamp = nextTimestamp();
	} else
	fgClockAdjustment++;
	} else {
	fgClockAdjustment = 0;

	if (timestampComparison < 0)
	nextClockSequence();
	}

	return timestamp;
	}

	private void setClockSequence(int clockSeq) {
	int clockSeqHigh = (clockSeq >>> ShiftByte) & LOW_NIBBLE_MASK;
	int reserved = fBits[CLOCK_SEQUENCE_HIGH_AND_RESERVED] & HIGH_NIBBLE_MASK;

	fBits[CLOCK_SEQUENCE_HIGH_AND_RESERVED] = (byte) (reserved \| clockSeqHigh);
	fBits[CLOCK_SEQUENCE_LOW] = (byte) (clockSeq & BYTE_MASK);
	}

	protected void setNode(byte[] bytes) {

	for (int index = 0; index < NODE_ADDRESS_BYTE_SIZE; index++)
	fBits[index + NODE_ADDRESS_START] = bytes[index];
	}

	private void setTimestamp(BigInteger timestamp) {
	BigInteger value = timestamp;
	BigInteger bigByte = BigInteger.valueOf(256L);
	BigInteger[] results;
	int version;
	int timeHigh;

	for (int index = TIME_FIELD_START; index < TIME_FIELD_STOP; index++) {
	results = value.divideAndRemainder(bigByte);
	value = results[0];
	fBits[index] = (byte) results[1].intValue();
	}
	version = fBits[TIME_HIGH_AND_VERSION] & HIGH_NIBBLE_MASK;
	timeHigh = value.intValue() & LOW_NIBBLE_MASK;
	fBits[TIME_HIGH_AND_VERSION] = (byte) (timeHigh \| version);
	}

	protected synchronized void setTimeValues() {
	this.setTimestamp(timestamp());
	this.setClockSequence(fgClockSequence);
	}

	protected int setVariant(int variantIdentifier) {
	int clockSeqHigh = fBits[CLOCK_SEQUENCE_HIGH_AND_RESERVED] & LOW_NIBBLE_MASK;
	int variant = variantIdentifier & LOW_NIBBLE_MASK;

	fBits[CLOCK_SEQUENCE_HIGH_AND_RESERVED] = (byte) ((variant << SHIFT_NIBBLE) \| clockSeqHigh);
	return (variant);
	}

	protected void setVersion(int versionIdentifier) {
	int timeHigh = fBits[TIME_HIGH_AND_VERSION] & LOW_NIBBLE_MASK;
	int version = versionIdentifier & LOW_NIBBLE_MASK;

	fBits[TIME_HIGH_AND_VERSION] = (byte) (timeHigh \| (version << SHIFT_NIBBLE));
	}

	private static BigInteger timestamp() {
	BigInteger timestamp;

	if (fgPreviousClockValue == null) {
	fgClockAdjustment = 0;
	nextClockSequence();
	timestamp = clockValueNow();
	} else
	timestamp = nextTimestamp();

	fgPreviousClockValue = timestamp;
	return fgClockAdjustment == 0 ? timestamp : timestamp.add(BigInteger.valueOf(fgClockAdjustment));
	}

	/**
	This representation is compatible with the (byte[]) constructor.

	@see #UniversalUniqueIdentifier(byte[])
	*/
	public byte[] toBytes() {
	byte[] result = new byte[fBits.length];

	System.arraycopy(fBits, 0, result, 0, fBits.length);
	return result;
	}

	@Override
	public String toString() {
	StringBuilder buffer = new StringBuilder();
	for (byte bit : fBits)
	appendByteString(buffer, bit);
	return buffer.toString();
	}

	public String toStringAsBytes() {
	StringBuilder result = new StringBuilder("{"); //$NON-NLS-1$

	for (int i = 0; i < fBits.length; i++) {
	result.append(fBits[i]);
	if (i < fBits.length + 1)
	result.append(',');
	}
	result.append('}');
	return result.toString();
	}
	}