/*
* 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.
*/
package org.apache.usergrid.persistence.index.utils;
import java.util.Collections;
import java.util.List;
import java.util.Random;
import java.util.UUID;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.concurrent.locks.ReentrantLock;
import com.fasterxml.uuid.EthernetAddress;
import com.fasterxml.uuid.UUIDComparator;
import static com.fasterxml.uuid.impl.UUIDUtil.BYTE_OFFSET_CLOCK_HI;
import static com.fasterxml.uuid.impl.UUIDUtil.BYTE_OFFSET_CLOCK_LO;
import static com.fasterxml.uuid.impl.UUIDUtil.BYTE_OFFSET_CLOCK_MID;
import static com.fasterxml.uuid.impl.UUIDUtil.BYTE_OFFSET_CLOCK_SEQUENCE;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import static org.apache.commons.codec.binary.Base64.decodeBase64;
import static org.apache.commons.codec.binary.Base64.encodeBase64URLSafeString;
import static org.apache.usergrid.persistence.index.utils.ConversionUtils.bytes;
import static org.apache.usergrid.persistence.index.utils.ConversionUtils.uuid;
public class UUIDUtils {
private static final Logger logger = LoggerFactory.getLogger( UUIDUtils.class );
private static final int[] MICROS = new int[1000];
static {
for ( int x = 0; x < 1000; x++ ) {
MICROS[x] = x * 10;
}
}
private static ReentrantLock tsLock = new ReentrantLock( true );
public static final UUID ZERO_UUID = new UUID( 0, 0 );
private static long timestampMillisNow = System.currentTimeMillis();
private static AtomicInteger currentMicrosPoint = new AtomicInteger( 0 );
private static AtomicInteger customMicrosPointer = new AtomicInteger( 0 );
/**
* Return the "next" UUID in micro second resolution. <b>WARNING</b>: this is designed to return the next unique
* timestamped UUID for this JVM. Depending on velocity of the call, this method may block internally to insure that
* "now" is kept in sync with the UUIDs being generated by this call.
* <p/>
* In other words, we will intentionally burn CPU insuring that this method is not executed more than 10k -1 times
* per millisecond and guarantee that those microseconds held within are sequential.
* <p/>
* If we did not do this, you would get <b>timestamp collision</b> even though the UUIDs will technically be
* 'unique.'
*/
public static java.util.UUID newTimeUUID() {
// get & inc counter, but roll on 1k (because we divide by 10 on retrieval)
// if count + currentMicro > 1k, block and roll
tsLock.lock();
long ts = System.currentTimeMillis();
if ( ts > timestampMillisNow ) {
timestampMillisNow = ts;
currentMicrosPoint.set( 0 );
}
int pointer = currentMicrosPoint.getAndIncrement();
try {
if ( pointer > 990 ) {
TimeUnit.MILLISECONDS.sleep( 1L );
}
}
catch ( Exception ex ) {
logger.error("Error getting new Time UUID", ex);
}
finally {
tsLock.unlock();
}
return newTimeUUID( ts, MICROS[pointer] );
}
private static final long KCLOCK_OFFSET = 0x01b21dd213814000L;
private static final long KCLOCK_MULTIPLIER_L = 10000L;
private static final Random CLOCK_SEQ_RANDOM = new Random();
// 14 bits of randomness
private static int getRandomClockSequence() {
return CLOCK_SEQ_RANDOM.nextInt() & 0x3FFF;
}
private static void setTimestamp( long timestamp, byte[] uuidBytes, int clockSeq, int timeOffset ) {
timestamp *= KCLOCK_MULTIPLIER_L;
timestamp += KCLOCK_OFFSET;
timestamp += timeOffset;
// Set random clock sequence
uuidBytes[BYTE_OFFSET_CLOCK_SEQUENCE] = ( byte ) ( clockSeq >> 8 );
uuidBytes[BYTE_OFFSET_CLOCK_SEQUENCE + 1] = ( byte ) clockSeq;
// Set variant
uuidBytes[BYTE_OFFSET_CLOCK_SEQUENCE] &= 0x3F;
uuidBytes[BYTE_OFFSET_CLOCK_SEQUENCE] |= 0x80;
setTime( uuidBytes, timestamp );
}
@SuppressWarnings("all")
private static void setTime( byte[] uuidBytes, long timestamp ) {
// Time fields aren't nicely split across the UUID, so can't just
// linearly dump the stamp:
int clockHi = ( int ) ( timestamp >>> 32 );
int clockLo = ( int ) timestamp;
uuidBytes[BYTE_OFFSET_CLOCK_HI] = ( byte ) ( clockHi >>> 24 );
uuidBytes[BYTE_OFFSET_CLOCK_HI + 1] = ( byte ) ( clockHi >>> 16 );
uuidBytes[BYTE_OFFSET_CLOCK_MID] = ( byte ) ( clockHi >>> 8 );
uuidBytes[BYTE_OFFSET_CLOCK_MID + 1] = ( byte ) clockHi;
uuidBytes[BYTE_OFFSET_CLOCK_LO] = ( byte ) ( clockLo >>> 24 );
uuidBytes[BYTE_OFFSET_CLOCK_LO + 1] = ( byte ) ( clockLo >>> 16 );
uuidBytes[BYTE_OFFSET_CLOCK_LO + 2] = ( byte ) ( clockLo >>> 8 );
uuidBytes[BYTE_OFFSET_CLOCK_LO + 3] = ( byte ) clockLo;
// Set version
uuidBytes[BYTE_OFFSET_CLOCK_HI] &= 0x0F;
uuidBytes[BYTE_OFFSET_CLOCK_HI] |= 0x10;
}
/**
* Generate a timeuuid with the given timestamp in milliseconds and the time offset. Useful when you need to
* generate sequential UUIDs for the same period in time. I.E
* <p/>
* newTimeUUID(1000, 0) <br/> newTimeUUID(1000, 1) <br /> newTimeUUID(1000, 2) <br />
* <p/>
* etc.
* <p/>
* Only use this method if you are absolutely sure you need it. When it doubt use the method without the timestamp
* offset
*
* @param ts The timestamp in milliseconds
* @param timeoffset The offset, which should always be <= 10000. If you go beyond this range, the millisecond will
* be incremented since this is beyond the possible values when coverrting from millis to 1/10 microseconds stored
* in the time uuid.
*/
public static UUID newTimeUUID( long ts, int timeoffset ) {
if ( ts == 0 ) {
return newTimeUUID();
}
byte[] uuidBytes = new byte[16];
// 47 bits of randomness
EthernetAddress eth = EthernetAddress.constructMulticastAddress();
eth.toByteArray( uuidBytes, 10 );
setTimestamp( ts, uuidBytes, getRandomClockSequence(), timeoffset );
return uuid( uuidBytes );
}
/**
* Generate a new UUID with the given time stamp in milliseconds. This method guarantees that subsequent calls will
* be of increasing value chronologically. If a large number of subsequent calls are made to this method (>1000)
* with the same timestamp, you will have non-unique temporal values stored in your UUID.
*/
public static UUID newTimeUUID( long ts ) {
tsLock.lock();
int pointer = customMicrosPointer.getAndIncrement();
try {
if ( pointer > 990 ) {
customMicrosPointer.set( 0 );
}
}
finally {
tsLock.unlock();
}
return newTimeUUID( ts, MICROS[pointer] );
}
public static UUID minTimeUUID( long ts ) {
byte[] uuidBytes = new byte[16];
setTimestamp( ts, uuidBytes, 0, 0 );
return uuid( uuidBytes );
}
public static UUID maxTimeUUID( long ts ) {
byte[] uuidBytes = new byte[16];
uuidBytes[10] = ( byte ) 0xFF;
uuidBytes[11] = ( byte ) 0xFF;
uuidBytes[12] = ( byte ) 0xFF;
uuidBytes[13] = ( byte ) 0xFF;
uuidBytes[14] = ( byte ) 0xFF;
uuidBytes[15] = ( byte ) 0xFF;
setTimestamp( ts, uuidBytes, 0x3FFF, 0x1FFF );
return uuid( uuidBytes );
}
/** Returns the minimum UUID */
public static UUID min( UUID first, UUID second ) {
if ( first == null ) {
if ( second == null ) {
return null;
}
return second;
}
if ( second == null ) {
return first;
}
if ( compare( first, second ) < 0 ) {
return first;
}
return second;
}
/** Returns the minimum UUID */
public static UUID max( UUID first, UUID second ) {
if ( first == null ) {
if ( second == null ) {
return null;
}
return second;
}
if ( second == null ) {
return first;
}
if ( compare( first, second ) < 0 ) {
return second;
}
return first;
}
/** Returns a UUID that is -1 of the passed uuid, sorted by time uuid only */
public static UUID decrement( UUID uuid ) {
if ( !isTimeBased( uuid ) ) {
throw new IllegalArgumentException( "The uuid must be a time type" );
}
//timestamp is in the 60 bit timestamp
long timestamp = uuid.timestamp();
timestamp--;
if ( timestamp < 0 ) {
throw new IllegalArgumentException( "You must specify a time uuid with a timestamp > 0" );
}
//get our bytes, then set the smaller timestamp into it
byte[] uuidBytes = bytes( uuid );
setTime( uuidBytes, timestamp );
return uuid( uuidBytes );
}
public static boolean isTimeBased( UUID uuid ) {
if ( uuid == null ) {
return false;
}
return uuid.version() == 1;
}
public static long getTimestampInMillis( UUID uuid ) {
if ( uuid == null ) {
return 0;
}
long t = uuid.timestamp();
return ( t - KCLOCK_OFFSET ) / KCLOCK_MULTIPLIER_L;
}
public static long getTimestampInMicros( UUID uuid ) {
if ( uuid == null ) {
return 0;
}
long t = uuid.timestamp();
return ( t - KCLOCK_OFFSET ) / 10;
}
public static UUID tryGetUUID( String s ) {
if ( s == null ) {
return null;
}
if ( s.length() != 36 ) {
return null;
}
// 8-4-4-4-12
// 0-7,8,9-12,13,14-17,18,19-22,23,24-35
if ( s.charAt( 8 ) != '-' ) {
return null;
}
if ( s.charAt( 13 ) != '-' ) {
return null;
}
if ( s.charAt( 18 ) != '-' ) {
return null;
}
if ( s.charAt( 23 ) != '-' ) {
return null;
}
UUID uuid = null;
try {
uuid = UUID.fromString( s );
}
catch ( Exception e ) {
logger.info( "Could not convert String {} into a UUID", s, e );
}
return uuid;
}
public static boolean isUUID( String s ) {
return tryGetUUID( s ) != null;
}
public static UUID tryExtractUUID( String s ) {
if ( s == null ) {
return null;
}
if ( s.length() < 36 ) {
return null;
}
return tryGetUUID( s.substring( 0, 36 ) );
}
public static UUID tryExtractUUID( String s, int offset ) {
if ( s == null ) {
return null;
}
if ( ( s.length() - offset ) < 36 ) {
return null;
}
return tryGetUUID( s.substring( offset, offset + 36 ) );
}
public static String toBase64( UUID id ) {
if ( id == null ) {
return null;
}
return encodeBase64URLSafeString( bytes( id ) );
}
public static UUID fromBase64( String str ) {
if ( str == null ) {
return null;
}
byte[] bytes = decodeBase64( str );
if ( bytes.length != 16 ) {
return null;
}
return uuid( bytes );
}
public static int compare( UUID u1, UUID u2 ) {
return UUIDComparator.staticCompare( u1, u2 );
}
public static List<UUID> sort( List<UUID> uuids ) {
Collections.sort( uuids, new UUIDComparator() );
return uuids;
}
}