Deal with tuple values set to MQ. Delete values once being used immediately...

Deal with tuple values set to MQ. Delete values once being used immediately and explicitly to reduce memory usage.

git-svn-id: https://svn.erp5.org/repos/neo/branches/prototype3@224 71dcc9de-d417-0410-9af5-da40c76e7ee4

neo/client/mq.py

@@ -74,6 +74,8 @@ class FIFO(object):
     if element is None:
       return None
     del self[element]
+    del element.next
+    del element.prev
     return element
     
   def __delitem__(self, element):
@@ -95,6 +97,13 @@ class Data(object):
   """
   pass
       
+def sizeof(o):
+  """This function returns the estimated size of an object."""
+  if isinstance(o, tuple):
+    return sum((len(s)+16 for s in o))
+  else:
+    return len(o)+16
+
 class MQ(object):
   """
     This class manages cached data by a variant of Multi-Queue.
@@ -142,7 +151,7 @@ class MQ(object):
     data = self._data[id]
     if data.level >= 0:
       value = data.value
-      self._size -= len(value) # XXX inaccurate
+      self._size -= sizeof(value) # XXX inaccurate
       self.store(id, value)
       return value
     raise KeyError(id)
@@ -160,13 +169,13 @@ class MQ(object):
       Evict an element to the history buffer.
     """
     data = self._data[id]
-    self._size -= len(data.value) # XXX inaccurate
+    self._size -= sizeof(data.value) # XXX inaccurate
     del self._cache_buffers[data.level][data.element]
     element = self._history_buffer.append()
     data.level = -1
     data.element = element
-    delattr(data, 'value')
-    delattr(data, 'expire_time')
+    del data.value
+    del data.expire_time
     element.data = data
     if len(self._history_buffer) > self._max_history_size:
       element = self._history_buffer.shift()
@@ -197,7 +206,8 @@ class MQ(object):
     data.counter = counter
     element.data = data
     self._data[id] = data
-    self._size += len(value) # XXX inaccurate
+    self._size += sizeof(value) # XXX inaccurate
+    del value
     
     self._time += 1
 
@@ -230,7 +240,8 @@ class MQ(object):
             break
           data = element.data
           del self._data[data.id]
-          size -= len(data.value) # XXX inaccurate
+          size -= sizeof(data.value) # XXX inaccurate
+	  del data.value
         if size <= max_size:
           break
       self._size = size