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authorPaul Borman <borman@google.com>2011-08-08 11:45:10 -0700
committerPaul Borman <borman@google.com>2011-08-08 11:45:10 -0700
commite130d97558da97862b63559fa31be05c88ce3cc7 (patch)
tree0ef4d1d6ab8ed9f108ad5091c0da5246959f5e70 /version1.go
downloadgoogle-uuid-e130d97558da97862b63559fa31be05c88ce3cc7.tar.gz
Initial checking of the go-uuid code.
Diffstat (limited to 'version1.go')
-rw-r--r--version1.go52
1 files changed, 52 insertions, 0 deletions
diff --git a/version1.go b/version1.go
new file mode 100644
index 0000000..6f92fda
--- /dev/null
+++ b/version1.go
@@ -0,0 +1,52 @@
+// Copyright 2011 Google Inc. All rights reserved.
+// Author: borman@google.com (Paul Borman)
+//
+// Licensed 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 uuid
+
+import (
+ "encoding/binary"
+)
+
+// NewUUID returns a Version 1 UUID based on the current NodeID and clock
+// sequence, and the current time. If the NodeID has not been set by SetNodeID
+// or SetNodeInterface then it will be set automatically. If the NodeID cannot
+// be set NewUUID returns nil. If clock sequence has not been set by
+// SetClockSequence then it will be set automatically. If GetTime fails to
+// return the current NewUUID returns nil.
+func NewUUID() UUID {
+ if nodeID == nil {
+ SetNodeInterface("")
+ }
+
+ now, err := GetTime()
+ if err != nil {
+ return nil
+ }
+
+ uuid := make([]byte, 16)
+
+ time_low := uint32(now & 0xffffffff)
+ time_mid := uint16((now >> 32) & 0xffff)
+ time_hi := uint16((now >> 48) & 0x0fff)
+ time_hi |= 0x1000 // Version 1
+
+ binary.BigEndian.PutUint32(uuid[0:], time_low)
+ binary.BigEndian.PutUint16(uuid[4:], time_mid)
+ binary.BigEndian.PutUint16(uuid[6:], time_hi)
+ binary.BigEndian.PutUint16(uuid[8:], clock_seq)
+ copy(uuid[10:], nodeID)
+
+ return uuid
+}