[Zope3-checkins] CVS: Zope3/src/zope/app - datetimeutils.py:1.5

[Jim Fulton]

Update of /cvs-repository/Zope3/src/zope/app
In directory cvs.zope.org:/tmp/cvs-serv25358/src/zope/app

Modified Files:
	datetimeutils.py 
Log Message:
Made zope.appp.datetimeutils.tzinfo objects pickleable.

Also arranged that there would be only one tzinfo object for a 
given offset.


=== Zope3/src/zope/app/datetimeutils.py 1.4 => 1.5 ===
--- Zope3/src/zope/app/datetimeutils.py:1.4	Wed Jan  8 15:18:26 2003
+++ Zope3/src/zope/app/datetimeutils.py	Thu Jan  9 13:29:48 2003
@@ -954,30 +954,53 @@
 parse = parser.parse
 time = parser.time
 
+######################################################################
+# Time-zone info based soley on offsets
+#
+# Share tzinfos for the same offset 
+
 from datetime import tzinfo as _tzinfo, timedelta as _timedelta
-_ZERO = _timedelta(0)
-class tzinfo(_tzinfo):
 
-    __slots__ = ('offset', )
+class _tzinfo(_tzinfo):
 
-    def __init__(self, offset):
-        if isinstance(offset, int):
-            offset = _timedelta(minutes=offset)
-        self.offset = offset
+    def __init__(self, minutes):
+        if abs(minutes) > 1439:
+            raise ValueError("Time-zone offset is too large,", minutes)
+        self.__minutes = minutes
+        self.__offset = _timedelta(minutes=minutes)
+
+    def utcoffset(self, dt):
+        return self.__offset
+
+    def __reduce__(self):
+        return tzinfo, (self.__minutes, )
+
+    def dst(self, dt):
+        return None
+    
+    def tzname(self, dt):
+        return None
 
-    def utcoffset(self, dt=None):
-        return self.offset
+    def __repr__(self):
+        return 'tzinfo(%d)' % self.__minutes
 
-    __getstate__ = utcoffset
-    __setstate__ = __init__
 
-    def dst(self, dt): return _ZERO
-    def tzname(self, dt): return ''
+def tzinfo(offset, _tzinfos = {}):
 
-    def __repr__(self):
-        minutes = self.offset.days * 24 * 60  + self.offset.seconds // 60
-        return 'tzinfo(%d)' % minutes
+    info = _tzinfos.get(offset)
+    if info is None:
+        # We haven't seen this one before. we need to save it.
+
+        # Use setdefault to avoid a race condition and make sure we have
+        # only one
+        info = _tzinfos.setdefault(offset, _tzinfo(offset))
+
+    return info
+
+tzinfo.__safe_for_unpickling__ = True
 
+#
+######################################################################
 
 from datetime import datetime as _datetime
 def parseDatetimetz(string):