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Diffstat (limited to 'src/main/java/gtPlusPlus/api/objects/random/UUIDGenerator.java')
| -rw-r--r-- | src/main/java/gtPlusPlus/api/objects/random/UUIDGenerator.java | 449 |
1 files changed, 449 insertions, 0 deletions
diff --git a/src/main/java/gtPlusPlus/api/objects/random/UUIDGenerator.java b/src/main/java/gtPlusPlus/api/objects/random/UUIDGenerator.java new file mode 100644 index 0000000000..fec92368f8 --- /dev/null +++ b/src/main/java/gtPlusPlus/api/objects/random/UUIDGenerator.java @@ -0,0 +1,449 @@ +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 final static 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 final static 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 ========================================= + |