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* 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.jena.shared.uuid ;
import java.net.NetworkInterface ;
import java.util.Enumeration ;
import java.util.Locale ;
import org.apache.jena.atlas.lib.BitsLong ;
import org.apache.jena.shared.uuid.JenaUUID.UUIDFormatException ;
/* RFC 4122 "A Universally Unique IDentifier (UUID) URN Namespace"
ftp://ftp.rfc-editor.org/in-notes/rfc4122.txt
Originally: http://www.opengroup.org/onlinepubs/009629399/apdxa.htm
http://en.wikipedia.org/wiki/Universally_unique_identifier
Version 1: hardware address and timebased:
60 bits of time
48 bits of nodeId
12 bits of clock sequence
2 bits variant
4 bits version
laid out as:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| time_low | 8 hex digits
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| time_mid | time_hi_and_version | 4-4
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|clk_seq_hi_res | clk_seq_low | node (0-1) | 4-
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| node (2-5) | 12
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Java5 introduced java.util.UUID but it does not include an timebased generator.
It provides an API to manipulate timebased UUIDs, and also factory methods for
vversion 4 (random) and version 3 (name based/MD5) or version 5 (name based/SHA1).
Version 2 is DCE Security version, with embedded POSIX UIDs.
Most significant long:
0xFFFFFFFF00000000 time_low
0x00000000FFFF0000 time_mid
0x000000000000F000 version
0x0000000000000FFF time_hi
Least significant long:
0xC000000000000000 variant C = 1100 (base 2)
0x3FFF000000000000 clock_seq 3 = 0011 (base 2)
0x0000FFFFFFFFFFFF node
Note on variant: despite the javadoc document, the variant is defined as the
top 3 bits of octet 8. But the low bit is a "don't care" in this variant
and is used by the clock.
*/
/* Java6: get MAC address:
NetworkInterface ni = NetworkInterface.getByInetAddress(address)
*/
/** Generator for timebased UUIDs (version 1, variant 2)
*/
public class UUID_V1_Gen implements UUIDFactory
{
// Constants
static final int versionHere = 1 ; // Version 1: time-based. This is one character hex string.
static final int variantHere = 2 ; // DCE varient
static final long maskTimeLow = 0xFFFFFFFF00000000L ;
static final long maskTimeMid = 0x00000000FFFF0000L ;
static final long maskTimeHigh = 0x0000000000000FFFL ;
static final long maskVersion = 0x000000000000F000L ;
static final long maskVariant = 0xC000000000000000L ;
static final long maskClockSeq = 0x3FFF000000000000L ;
static final long maskNode = 0x0000FFFFFFFFFFFFL ;
// Generator variables.
long gregorianTime = 0 ;
static final long UUIDS_PER_TICK = 100 ;
long uuids_this_tick = UUIDS_PER_TICK+1 ; // Force reset first time.
// Generator initial state
int clockSeq = 0 ;
private static final int CLOCK_BITS = 8 ;
long node = 0 ;
// Time control
private long lastTime = 0 ;
private long DELAY = 10 ; // Milliseconds
public UUID_V1_Gen() {
reset() ;
}
/** (Re)set the network id (a random number) and the timstamp */
@Override
public void reset() {
setInitialState() ;
setTime() ;
}
@Override
public JenaUUID generate()
{ return generateV1() ; }
public UUID_V1 generateV1() {
long timestamp = 0 ;
synchronized (this) {
if ( uuids_this_tick >= UUIDS_PER_TICK )
setTime() ;
timestamp = gregorianTime + uuids_this_tick ;
uuids_this_tick++ ;
}
return generate(timestamp) ;
}
/* 8-4-4-4-12 = 32+4 dashes = 36 chars
UUID = <time_low> "-" <time_mid> "-"
<time_high_and_version> "-"
<variant_and_sequence> "-"
<node>
time_low = 4*<hexOctet>
time_mid = 2*<hexOctet>
time_high_and_version = 2*<hexOctet>
variant_and_sequence = 2*<hexOctet>
node = 6*<hexOctet>
hexOctet = <hexDigit><hexDigit>
*/
@Override
public JenaUUID parse(String s) throws UUIDFormatException {
s = s.toLowerCase(Locale.ENGLISH) ;
if ( s.length() != 36 )
throw new UUIDFormatException("UUID string is not 36 chars long: it's " + s.length() + " [" + s + "]") ;
if ( s.charAt(8) != '-' && s.charAt(13) != '-' && s.charAt(18) != '-' && s.charAt(23) != '-' )
throw new UUIDFormatException("String does not have dashes in the right places: " + s) ;
UUID_V1 u = parse$(s) ;
if ( u.getVersion() != versionHere )
throw new UUIDFormatException("Wrong version (Expected: " + versionHere + "Got: " + u.getVersion() + "): " + s) ;
if ( u.getVariant() != variantHere )
throw new UUIDFormatException("Wrong version (Expected: " + variantHere + "Got: " + u.getVariant() + "): " + s) ;
return u ;
}
static UUID_V1 parse$(String s) {
// The UUID broken up into parts.
// 00000000-0000-0000-0000-000000000000
// ^ ^ ^ ^ ^
// Byte: 0 4 6 8 10
// Char: 0 9 14 19 24 including hyphens
int x = (int)BitsLong.unpack(s, 19, 23) ;
int variant = (x >>> 14) ;
int clockSeq = x & 0x3FFF ;
long timeHigh = BitsLong.unpack(s, 15, 18) ;
long timeMid = BitsLong.unpack(s, 9, 13) ;
long timeLow = BitsLong.unpack(s, 0, 8) ;
long node = BitsLong.unpack(s, 24, 36) ;
int version = (int)BitsLong.unpack(s, 14, 15) ;
return generate(version, variant, timeHigh, timeMid, timeLow, clockSeq, node) ;
}
// See LibUUID.toString(JenaUUID)
// The code here works on the specific fields and is kept for reference only.
private static String unparse(UUID_V1 uuid) {
int _variant = uuid.getVariant() ;
int _version = uuid.getVersion() ;
long timeHigh = uuid.getTimeHigh() ;
long timeMid = uuid.getTimeMid() ;
long timeLow = uuid.getTimeLow() ;
long node = uuid.getNode() ;
long clockSeq = uuid.getClockSequence() ;
StringBuffer sBuff = new StringBuffer() ;
JenaUUID.toHex(sBuff, timeLow, 4) ;
sBuff.append('-') ;
JenaUUID.toHex(sBuff, timeMid, 2) ;
sBuff.append('-') ;
JenaUUID.toHex(sBuff, _version << 12 | timeHigh, 2) ;
sBuff.append('-') ;
JenaUUID.toHex(sBuff, (long)_variant << 14 | clockSeq, 2) ;
sBuff.append('-') ;
JenaUUID.toHex(sBuff, node, 6) ;
return sBuff.toString() ;
}
private UUID_V1 generate(long timestamp) {
return generate(versionHere, variantHere, timestamp, clockSeq, node) ;
}
// Testing.
/*package*/ static UUID_V1 generate(int version, int variant, long timestamp, long clockSeq, long node) {
long timeHigh = timestamp >>> (60 - 12) ; // Top 12 bits of 60 bit number.
long timeMid = (timestamp >>> 32) & 0xFFFFL ; // 16 bits, bits 32-47
long timeLow = timestamp & 0xFFFFFFFFL ; // Low 32 bits
return generate(version, variant, timeHigh, timeMid, timeLow, clockSeq, node) ;
}
private static UUID_V1 generate(int version, int variant, long timeHigh, long timeMid, long timeLow, long clockSeq, long node) {
long mostSigBits = (timeLow << 32) | (timeMid << 16) | (version << 12) | timeHigh ;
long leastSigBits = (long)variant << 62 | (clockSeq << 48) | node ;
return new UUID_V1(mostSigBits, leastSigBits) ;
}
private void setTime() {
long time = 0 ;
// Wait for a clock tick.
synchronized (this) {
if ( lastTime == 0 )
lastTime = System.currentTimeMillis() ;
boolean done = false ;
while (!done) {
time = System.currentTimeMillis() ;
if ( time < lastTime + DELAY ) {
// pause for a while to wait for time to change
try {
Thread.sleep(DELAY) ;
} catch (java.lang.InterruptedException e) {} // ignore exception
continue ;
} else {
done = true ;
}
}
}
// We claim this tick just passed! 1 UUID per 100ns so ...
// UUIDS_PER_TICK = (time-lastTime)*10 ;
lastTime = time ;
uuids_this_tick = 0 ;
// Convert to the UUID base time (00:00:00.00, 15 October 1582)
// That's the date of the Gregorian calendar reforms
// See the text quoted for the number.
// Java base time is is January 1, 1970.
gregorianTime = time * 10 + 0x01B21DD213814000L ;
}
private void setInitialState() {
long random = LibUUID.makeRandom().nextLong() ;
clockSeq = 0 ;
if ( CLOCK_BITS != 0 )
clockSeq = (int)BitsLong.unpack(random, 48, (48 + CLOCK_BITS)) ;
// Get the MAC address of an interface.
// The loopback I/F does not have a MAC address.
try {
Enumeration<NetworkInterface> en = NetworkInterface.getNetworkInterfaces() ;
byte[] hwAddr = null ;
while(en.hasMoreElements()) {
NetworkInterface ni = en.nextElement() ;
if ( ni == null || ni.isLoopback() || ni.isPointToPoint() || ni.isVirtual() )
continue ;
hwAddr = ni.getHardwareAddress() ;
if ( hwAddr != null )
break ;
}
if ( hwAddr != null && hwAddr.length > 4 ) { // Length is a sanity check.
node = 0 ;
for ( byte bv : hwAddr ) {
node = (node << 8) | (bv&0xFF) ;
}
return ;
}
} catch (Exception ex) { } // Failed in some way. Fallback.
node = BitsLong.unpack(random, 0, 47) ; // Low 48bits, except groups address bit
node = BitsLong.set(node, 47) ; // Set group address bit
// Can also set the clock sequence number to increase the randomness.
// Use up to 13 bits for the clock (actually, it's 14 bits as
// strays into the variant).
// We use less to get a characteristic "-80??-" in the string
}
}