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##############################################################################
#
# Copyright (c) 1996-1998, Digital Creations, Fredericksburg, VA, USA.
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are
# met:
#
# o Redistributions of source code must retain the above copyright
# notice, this list of conditions, and the disclaimer that follows.
#
# o Redistributions in binary form must reproduce the above copyright
# notice, this list of conditions, and the following disclaimer in
# the documentation and/or other materials provided with the
# distribution.
#
# o Neither the name of Digital Creations nor the names of its
# contributors may be used to endorse or promote products derived
# from this software without specific prior written permission.
#
#
# THIS SOFTWARE IS PROVIDED BY DIGITAL CREATIONS AND CONTRIBUTORS *AS IS*
# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
# TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
# PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL DIGITAL
# CREATIONS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
# INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
# BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
# OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
# ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR
# TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
# USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
# DAMAGE.
#
#
# If you have questions regarding this software, contact:
#
# Digital Creations, L.C.
# 910 Princess Ann Street
# Fredericksburge, Virginia 22401
#
# info@digicool.com
#
# (540) 371-6909
#
##############################################################################
__doc__='''PickleJar Object Cache
$Id: PickleCache.py,v 1.4 1998/10/23 21:41:24 jim Exp $'''
__version__='$Revision: 1.4 $'[11:-2]
from sys import getrefcount
class PickleCache:
def __init__(self, cache_size, cache_age=1000):
if cache_size < 1: cache_size=1
self.cache_size=cache_size
self.data, self.cache_ids, self.cache_location ={}, [], 0
for a in 'keys', 'items', 'values', 'has_key':
setattr(self,a,getattr(self.data,a))
def __getitem__(self, key):
cache=self.data
v=cache[key]
# Do cache GC
n=min(len(cache)/self.cache_size,10)
if n:
l=self.cache_location
ids=self.cache_ids
while n:
if not l:
ids=self.cache_ids=cache.keys()
l=len(ids)
l=l-1
n=n-1
id=ids[l]
if getrefcount(cache[id]) <= 2:
del cache[id]
self.cache_location=l
return v
def __setitem__(self, key, v): self.data[key]=v
def __delitem__(self, key): del self.data[key]
def __len__(self): return len(self.data)
def values(self): return self.data.values()
def full_sweep(self):
cache=self.data
for id in cache.keys():
if getrefcount(cache[id]) <= 2: del cache[id]
def minimize(self):
cache=self.data
keys=cache.keys()
rc=getrefcount
last=None
l=len(cache)
while l != last:
for id in keys():
if rc(cache[id]) <= 2: del cache[id]
cache[id]._p_deactivate()
l=len(cache)
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