package gtPlusPlus.api.objects.random;
import java.io.IOException;
import java.net.InetAddress;
import java.util.Random;
import java.util.UUID;
/**
*
* Implement modified version of Apache's OpenJPA UUID generator.
* This UUID generator is paired with a Blum-Blum-Shub random number generator
* which in itself is seeded by custom SecureRandom.
*
* The UUID generator class has been converted from a static factory to an instanced factory.
*
*/
// ========================================= APACHE BLOCK =========================================
/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
/**
* UUID value generator. Type 1 generator is based on the time-based generator
* in the Apache Commons Id project: http://jakarta.apache.org/commons/sandbox
* /id/uuid.html The type 4 generator uses the standard Java UUID generator.
*
* The type 1 code has been vastly simplified and modified to replace the
* ethernet address of the host machine with the IP, since we do not want to
* require native libs and Java cannot access the MAC address directly.
*
* In spirit, implements the IETF UUID draft specification, found here:<br />
* http://www1.ics.uci.edu/~ejw/authoring/uuid-guid/draft-leach-uuids-guids-01
* .txt
*
* @author Abe White, Kevin Sutter
* @since 0.3.3
*/
public class UUIDGenerator {
// supported UUID types
public static final int TYPE1 = 1;
public static final int TYPE4 = 4;
// indexes within the uuid array for certain boundaries
private static final byte IDX_TIME_HI = 6;
private static final byte IDX_TYPE = 6; // multiplexed
private static final byte IDX_TIME_MID = 4;
private static final byte IDX_TIME_LO = 0;
private static final byte IDX_TIME_SEQ = 8;
private static final byte IDX_VARIATION = 8; // multiplexed
// indexes and lengths within the timestamp for certain boundaries
private static final byte TS_TIME_LO_IDX = 4;
private static final byte TS_TIME_LO_LEN = 4;
private static final byte TS_TIME_MID_IDX = 2;
private static final byte TS_TIME_MID_LEN = 2;
private static final byte TS_TIME_HI_IDX = 0;
private static final byte TS_TIME_HI_LEN = 2;
// offset to move from 1/1/1970, which is 0-time for Java, to gregorian
// 0-time 10/15/1582, and multiplier to go from 100nsec to msec units
private static final long GREG_OFFSET = 0xB1D069B5400L;
private static final long MILLI_MULT = 10000L;
// type of UUID -- time based
private static final byte TYPE_TIME_BASED = 0x10;
// random number generator used to reduce conflicts with other JVMs, and
// hasher for strings.
private Random RANDOM;
// 4-byte IP address + 2 random bytes to compensate for the fact that
// the MAC address is usually 6 bytes
private byte[] IP;
// counter is initialized to 0 and is incremented for each uuid request
// within the same timestamp window.
private int _counter;
// current timestamp (used to detect multiple uuid requests within same
// timestamp)
private long _currentMillis;
// last used millis time, and a semi-random sequence that gets reset
// when it overflows
private long _lastMillis = 0L;
private static final int MAX_14BIT = 0x3FFF;
private short _seq = 0;
private boolean type1Initialized = false; /*
* Initializer for type 1 UUIDs. Creates random generator and genenerates
* the node portion of the UUID using the IP address.
*/
private synchronized void initializeForType1() {
if (type1Initialized == true) {
return;
}
// note that secure random is very slow the first time
// it is used; consider switching to a standard random
RANDOM = CSPRNG_DO_NOT_USE.generate();
_seq = (short) RANDOM.nextInt(MAX_14BIT);
byte[] ip = null;
try {
ip = InetAddress.getLocalHost().getAddress();
} catch (IOException ioe) {
throw new RuntimeException(ioe);
}
IP = new byte[6];
RANDOM.nextBytes(IP);
// OPENJPA-2055: account for the fact that 'getAddress'
// may return an IPv6 address which is 16 bytes wide.
for (int i = 0; i < ip.length; ++i) {
IP[2 + (i % 4)] ^= ip[i];
}
type1Initialized = true;
}
/**
* Return a unique UUID value.
*/
public byte[] next(int type) {
if (type == TYPE4) {
return createType4();
}
return createType1();
}
/*
* Creates a type 1 UUID
*/
public byte[] createType1() {
if (type1Initialized == false) {
initializeForType1();
}
// set ip addr
byte[] uuid = new byte[16];
System.arraycopy(IP, 0, uuid, 10, IP.length);
// Set time info. Have to do this processing within a synchronized
// block because of the statics...
long now = 0;
synchronized (UUIDGenerator.class) {
// Get the time to use for this uuid. This method has the side
// effect of modifying the clock sequence, as well.
now = getTime();
// Insert the resulting clock sequence into the uuid
uuid[IDX_TIME_SEQ] = (byte) ((_seq & 0x3F00) >>> 8);
uuid[IDX_VARIATION] |= 0x80;
uuid[IDX_TIME_SEQ + 1] = (byte) (_seq & 0xFF);
}
// have to break up time because bytes are spread through uuid
byte[] timeBytes = Bytes.toBytes(now);
// Copy time low
System.arraycopy(timeBytes, TS_TIME_LO_IDX, uuid, IDX_TIME_LO, TS_TIME_LO_LEN);
// Copy time mid
System.arraycopy(timeBytes, TS_TIME_MID_IDX, uuid, IDX_TIME_MID, TS_TIME_MID_LEN);
// Copy time hi
System.arraycopy(timeBytes, TS_TIME_HI_IDX, uuid, IDX_TIME_HI, TS_TIME_HI_LEN);
// Set version (time-based)
uuid[IDX_TYPE] |= TYPE_TIME_BASED; // 0001 0000
return uuid;
}
/*
* Creates a type 4 UUID
*/
private byte[] createType4() {
UUID type4 = UUID.randomUUID();
byte[] uuid = new byte[16];
longToBytes(type4.getMostSignificantBits(), uuid, 0);
longToBytes(type4.getLeastSignificantBits(), uuid, 8);
return uuid;
}
/*
* Converts a long to byte values, setting them in a byte array
* at a given starting position.
*/
private void longToBytes(long longVal, byte[] buf, int sPos) {
sPos += 7;
for (int i = 0; i < 8; i++) buf[sPos - i] = (byte) (longVal >>> (i * 8));
}
/**
* Return the next unique uuid value as a 16-character string.
*/
public String nextString(int type) {
byte[] bytes = next(type);
try {
return new String(bytes, "ISO-8859-1");
} catch (Exception e) {
return new String(bytes);
}
}
/**
* Return the next unique uuid value as a 32-character hex string.
*/
public String nextHex(int type) {
return Base16Encoder.encode(next(type));
}
/**
* Get the timestamp to be used for this uuid. Must be called from
* a synchronized block.
*
* @return long timestamp
*/
// package-visibility for testing
private long getTime() {
if (RANDOM == null) initializeForType1();
long newTime = getUUIDTime();
if (newTime <= _lastMillis) {
incrementSequence();
newTime = getUUIDTime();
}
_lastMillis = newTime;
return newTime;
}
/**
* Gets the appropriately modified timestamep for the UUID. Must be called
* from a synchronized block.
*
* @return long timestamp in 100ns intervals since the Gregorian change
* offset
*/
private long getUUIDTime() {
if (_currentMillis != System.currentTimeMillis()) {
_currentMillis = System.currentTimeMillis();
_counter = 0; // reset counter
}
// check to see if we have created too many uuid's for this timestamp
if (_counter + 1 >= MILLI_MULT) {
// Original algorithm threw exception. Seemed like overkill.
// Let's just increment the timestamp instead and start over...
_currentMillis++;
_counter = 0;
}
// calculate time as current millis plus offset times 100 ns ticks
long currentTime = (_currentMillis + GREG_OFFSET) * MILLI_MULT;
// return the uuid time plus the artificial tick counter incremented
return currentTime + _counter++;
}
/**
* Increments the clock sequence for this uuid. Must be called from a
* synchronized block.
*/
private void incrementSequence() {
// increment, but if it's greater than its 14-bits, reset it
if (++_seq > MAX_14BIT) {
_seq = (short) RANDOM.nextInt(MAX_14BIT); // semi-random
}
}
// Add Dependant classes internally
/**
* This class came from the Apache Commons Id sandbox project in support
* of the UUIDGenerator implementation.
*
* <p>Static methods for managing byte arrays (all methods follow Big
* Endian order where most significant bits are in front).</p>
*/
public static final class Bytes {
/**
* <p>Hide constructor in utility class.</p>
*/
private Bytes() {}
/**
* Appends two bytes array into one.
*
* @param a A byte[].
* @param b A byte[].
* @return A byte[].
*/
public static byte[] append(byte[] a, byte[] b) {
byte[] z = new byte[a.length + b.length];
System.arraycopy(a, 0, z, 0, a.length);
System.arraycopy(b, 0, z, a.length, b.length);
return z;
}
/**
* Returns a 8-byte array built from a long.
*
* @param n The number to convert.
* @return A byte[].
*/
public static byte[] toBytes(long n) {
return toBytes(n, new byte[8]);
}
/**
* Build a 8-byte array from a long. No check is performed on the
* array length.
*
* @param n The number to convert.
* @param b The array to fill.
* @return A byte[].
*/
public static byte[] toBytes(long n, byte[] b) {
b[7] = (byte) (n);
n >>>= 8;
b[6] = (byte) (n);
n >>>= 8;
b[5] = (byte) (n);
n >>>= 8;
b[4] = (byte) (n);
n >>>= 8;
b[3] = (byte) (n);
n >>>= 8;
b[2] = (byte) (n);
n >>>= 8;
b[1] = (byte) (n);
n >>>= 8;
b[0] = (byte) (n);
return b;
}
/**
* Build a long from first 8 bytes of the array.
*
* @param b The byte[] to convert.
* @return A long.
*/
public static long toLong(byte[] b) {
return ((((long) b[7]) & 0xFF)
+ ((((long) b[6]) & 0xFF) << 8)
+ ((((long) b[5]) & 0xFF) << 16)
+ ((((long) b[4]) & 0xFF) << 24)
+ ((((long) b[3]) & 0xFF) << 32)
+ ((((long) b[2]) & 0xFF) << 40)
+ ((((long) b[1]) & 0xFF) << 48)
+ ((((long) b[0]) & 0xFF) << 56));
}
/**
* Compares two byte arrays for equality.
*
* @param a A byte[].
* @param b A byte[].
* @return True if the arrays have identical contents.
*/
public static boolean areEqual(byte[] a, byte[] b) {
int aLength = a.length;
if (aLength != b.length) {
return false;
}
for (int i = 0; i < aLength; i++) {
if (a[i] != b[i]) {
return false;
}
}
return true;
}
/**
* <p>Compares two byte arrays as specified by <code>Comparable</code>.
*
* @param lhs - left hand value in the comparison operation.
* @param rhs - right hand value in the comparison operation.
* @return a negative integer, zero, or a positive integer as
* <code>lhs</code> is less than, equal to, or greater than
* <code>rhs</code>.
*/
public static int compareTo(byte[] lhs, byte[] rhs) {
if (lhs == rhs) {
return 0;
}
if (lhs == null) {
return -1;
}
if (rhs == null) {
return +1;
}
if (lhs.length != rhs.length) {
return ((lhs.length < rhs.length) ? -1 : +1);
}
for (int i = 0; i < lhs.length; i++) {
if (lhs[i] < rhs[i]) {
return -1;
} else if (lhs[i] > rhs[i]) {
return 1;
}
}
return 0;
}
/**
* Build a short from first 2 bytes of the array.
*
* @param b The byte[] to convert.
* @return A short.
*/
public static short toShort(byte[] b) {
return (short) ((b[1] & 0xFF) + ((b[0] & 0xFF) << 8));
}
}
/**
* Base 16 encoder.
*
* @author Marc Prud'hommeaux
*/
public static final class Base16Encoder {
private static final char[] HEX = new char[] {
'0', '1', '2', '3', '4', '5', '6', '7',
'8', '9', 'A', 'B', 'C', 'D', 'E', 'F'
};
/**
* Convert bytes to a base16 string.
*/
public static String encode(byte[] byteArray) {
StringBuilder hexBuffer = new StringBuilder(byteArray.length * 2);
for (int i = 0; i < byteArray.length; i++)
for (int j = 1; j >= 0; j--) hexBuffer.append(HEX[(byteArray[i] >> (j * 4)) & 0xF]);
return hexBuffer.toString();
}
/**
* Convert a base16 string into a byte array.
*/
public static byte[] decode(String s) {
int len = s.length();
byte[] r = new byte[len / 2];
for (int i = 0; i < r.length; i++) {
int digit1 = s.charAt(i * 2), digit2 = s.charAt(i * 2 + 1);
if (digit1 >= '0' && digit1 <= '9') digit1 -= '0';
else if (digit1 >= 'A' && digit1 <= 'F') digit1 -= 'A' - 10;
if (digit2 >= '0' && digit2 <= '9') digit2 -= '0';
else if (digit2 >= 'A' && digit2 <= 'F') digit2 -= 'A' - 10;
r[i] = (byte) ((digit1 << 4) + digit2);
}
return r;
}
}
}
// ========================================= APACHE BLOCK =========================================