add generation_time property to ObjectId instances

Mike Dirolf · Mike Dirolf · commit b35cec3db541 · 2009-12-03T17:12:38.000-05:00
diff --git a/pymongo/objectid.py b/pymongo/objectid.py
@@ -14,6 +14,7 @@
 
 """Representation of an ObjectId for Mongo."""
 
+import datetime
 import threading
 import types
 import time
@@ -159,9 +160,21 @@ def get_binary(self):
         """Get the binary representation of this ObjectId.
         """
         return self.__id
-
     binary = property(get_binary)
 
+    def generation_time(self):
+        """A :class:`datetime.datetime` instance representing the time of
+        generation for this :class:`ObjectId`.
+
+        The :class:`datetime.datetime` is always naive and represents the
+        generation time in UTC. It is precise to the second.
+
+        .. versionadded:: 1.1.2+
+        """
+        t = struct.unpack(">i", self.__id[0:4])[0]
+        return datetime.datetime.utcfromtimestamp(t)
+    generation_time = property(generation_time)
+
     def __str__(self):
         return self.__id.encode("hex")
 
diff --git a/test/test_objectid.py b/test/test_objectid.py
@@ -14,6 +14,7 @@
 
 """Tests for the objectid module."""
 
+import datetime
 import unittest
 import sys
 sys.path[0:0] = [""]
@@ -104,6 +105,11 @@ def test_multiprocessing(self):
             self.assert_(id not in map)
             map[id] = True
 
+    def test_generation_time(self):
+        d1 = datetime.datetime.utcnow()
+        d2 = ObjectId().generation_time
+
+        self.assert_(d2 - d1 < datetime.timedelta(seconds = 2))
 
 if __name__ == "__main__":
     unittest.main()
