--- a/UUID.st	Fri Apr 20 17:17:19 2012 +0200
+++ b/UUID.st	Fri Apr 20 17:18:41 2012 +0200
@@ -373,7 +373,15 @@
 !
 
 node
-    ^ self copyFrom:11 to:16
+    "answer the node (ethernet) address of this uuid"
+
+    ^ (ByteArray new:6) replaceFrom:1 to:6 with:self startingAt:11.
+
+    "
+       (self allInstances 
+            select:[:e| e isTimestampUUID] 
+            thenCollect:[:e| e node]) asBag
+    "
 !
 
 timeHighAndVersion
@@ -386,6 +394,39 @@
 
 timeMid
     ^ self unsignedShortAt:5 bigEndian:true
+!
+
+timestamp
+    "Get the UTC timestamp, when the UUID has been created.
+     This is only valid for timestampUUIDs"
+
+    |low med high dtssUtcTime|
+
+    low := self unsignedLongAt:1 bigEndian:true.
+    med := self unsignedShortAt:5 bigEndian:true.
+    high := (self unsignedShortAt:7 bigEndian:true) bitAnd:16rFFF.
+
+    dtssUtcTime := low + ((med + (high bitShift:16)) bitShift:32).
+
+    ^ Timestamp utcMillisecondsSince1970:(dtssUtcTime//10000)-12219292800000.
+
+    "
+        self genTimestampUUID timestamp
+
+        (self allInstances asSet asArray select:[:e| e isTimestampUUID] 
+                                            thenCollect:[:e| e timestamp]) sort
+    "
+!
+
+version
+    "the version number of the uuid"
+
+    ^ ((self at:7) bitAnd:16rF0) bitShift:-4.
+
+    "
+        self genTimestampUUID version
+        self genRandomUUID version
+    "
 ! !
 
 !UUID methodsFor:'converting'!
@@ -452,18 +493,30 @@
 !UUID methodsFor:'copying'!
 
 deepCopy
+    "I am never changed, after I have been created.
+     So there is no need to make a copy"
+
     ^ self
 !
 
 deepCopyUsing:aDictionary postCopySelector:postCopySelector
+    "I am never changed, after I have been created.
+     So there is no need to make a copy"
+
     ^ self
 !
 
 shallowCopy
+    "I am never changed, after I have been created.
+     So there is no need to make a copy"
+
     ^ self
 !
 
 simpleDeepCopy
+    "I am never changed, after I have been created.
+     So there is no need to make a copy"
+
     ^ self
 ! !
 
@@ -472,6 +525,11 @@
 genRandomUUID
     "answer a randomly generated uuid as defined in RFC4122 section 4.4"
 
+    (self at:7) ~~ 0 ifTrue:[
+        "once created, an UUID is immutable"
+        self noModificationError.
+    ].
+
     self replaceFrom:1 to:16 with:(RandomGenerator new nextBytes:16).
     "multiplex the 4 bit version number (Version 4 -> Random UUID) in high bits of byte 7"
     self at:7 put:(((self at:7) bitAnd:16r0F) bitOr:16r40).
@@ -479,6 +537,8 @@
 
     "
       self new genRandomUUID
+
+      self genRandomUUID genRandomUUID
     "
 
     "
@@ -511,6 +571,11 @@
         self error:'no mac address - cannot generate UUID'.
     ].
 
+    (self at:7) ~~ 0 ifTrue:[
+        "once created, an UUID is immutable"
+        self noModificationError.
+    ].
+
     "use 60 bit counter of 100ns ticks since 00:00:00 15.oct 1582 (sigh)"
     utcTime := self class getDtssUtcTime.
 
@@ -558,6 +623,7 @@
 
     "
       self new genTimestampUUID
+      self genTimestampUUID genTimestampUUID
     "
 
     "
@@ -705,14 +771,20 @@
     "
 ! !
 
+!UUID methodsFor:'queries'!
+
+isTimestampUUID
+    ^ self version == 1
+! !
+
 !UUID class methodsFor:'documentation'!
 
 version
-    ^ '$Header: /cvs/stx/stx/libbasic2/UUID.st,v 1.36 2011-12-26 12:43:06 cg Exp $'
+    ^ '$Header: /cvs/stx/stx/libbasic2/UUID.st,v 1.37 2012-04-20 15:18:41 stefan Exp $'
 !
 
 version_CVS
-    ^ '$Header: /cvs/stx/stx/libbasic2/UUID.st,v 1.36 2011-12-26 12:43:06 cg Exp $'
+    ^ '$Header: /cvs/stx/stx/libbasic2/UUID.st,v 1.37 2012-04-20 15:18:41 stefan Exp $'
 ! !
 
 UUID initialize!