state: add environment persistency with UUID

trivial/trivial_test.go

 package trivial_test
 
 import (
         . "launchpad.net/gocheck"
         "launchpad.net/juju-core/trivial"
         "strings"
         "testing"
         "time"
 )
 
@@ skipping 89 matching lines @@
         cdata := trivial.Gzip(data)
         c.Assert(len(cdata) < len(data), Equals, true)
         data1, err := trivial.Gunzip(cdata)
         c.Assert(err, IsNil)
         c.Assert(data1, DeepEquals, data)
 
         data1, err = trivial.Gunzip(compressedData)
         c.Assert(err, IsNil)
         c.Assert(data1, DeepEquals, data)
 }
+
+func (trivialSuite) TestUUID(c *C) {
+        uuid, err := trivial.NewUUID()
+        c.Assert(err, IsNil)
+        uuidCopy := uuid.Copy()
+        uuidRaw := uuid.Raw()
+        uuidStr := uuid.String()
+        c.Assert(uuidRaw, HasLen, 16)
+        c.Assert(uuidStr, Matches, "[0-9a-f]{8}-[0-9a-f]{4}-4[0-9a-f]{3}-[8,9,a,b][0-9a-f]{3}-[0-9a-f]{12}")
+        uuid[0] = 0x00
+        uuidCopy[0] = 0xFF
+        c.Assert(uuid, Not(DeepEquals), uuidCopy)
+        uuidRaw[0] = 0xFF
+        c.Assert(uuid, Not(DeepEquals), uuidRaw)
+        nextUUID, err := trivial.NewUUID()
+        c.Assert(err, IsNil)
+        c.Assert(uuid, Not(DeepEquals), nextUUID)
+}