/usr/lib/python2.7/dist-packages/Cheetah/CacheRegion.py is in python-cheetah 2.4.4-4.
This file is owned by root:root, with mode 0o644.
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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 | # $Id: CacheRegion.py,v 1.3 2006/01/28 04:19:30 tavis_rudd Exp $
'''
Cache holder classes for Cheetah:
Cache regions are defined using the #cache Cheetah directive. Each
cache region can be viewed as a dictionary (keyed by cacheRegionID)
handling at least one cache item (the default one). It's possible to add
cacheItems in a region by using the `varyBy` #cache directive parameter as
in the following example::
#def getArticle
this is the article content.
#end def
#cache varyBy=$getArticleID()
$getArticle($getArticleID())
#end cache
The code above will generate a CacheRegion and add new cacheItem for each value
of $getArticleID().
'''
try:
from hashlib import md5
except ImportError:
from md5 import md5
import time
import Cheetah.CacheStore
class CacheItem(object):
'''
A CacheItem is a container storing:
- cacheID (string)
- refreshTime (timestamp or None) : last time the cache was refreshed
- data (string) : the content of the cache
'''
def __init__(self, cacheItemID, cacheStore):
self._cacheItemID = cacheItemID
self._cacheStore = cacheStore
self._refreshTime = None
self._expiryTime = 0
def hasExpired(self):
return (self._expiryTime and time.time() > self._expiryTime)
def setExpiryTime(self, time):
self._expiryTime = time
def getExpiryTime(self):
return self._expiryTime
def setData(self, data):
self._refreshTime = time.time()
self._cacheStore.set(self._cacheItemID, data, self._expiryTime)
def getRefreshTime(self):
return self._refreshTime
def getData(self):
assert self._refreshTime
return self._cacheStore.get(self._cacheItemID)
def renderOutput(self):
"""Can be overridden to implement edge-caching"""
return self.getData() or ""
def clear(self):
self._cacheStore.delete(self._cacheItemID)
self._refreshTime = None
class _CacheDataStoreWrapper(object):
def __init__(self, dataStore, keyPrefix):
self._dataStore = dataStore
self._keyPrefix = keyPrefix
def get(self, key):
return self._dataStore.get(self._keyPrefix+key)
def delete(self, key):
self._dataStore.delete(self._keyPrefix+key)
def set(self, key, val, time=0):
self._dataStore.set(self._keyPrefix+key, val, time=time)
class CacheRegion(object):
'''
A `CacheRegion` stores some `CacheItem` instances.
This implementation stores the data in the memory of the current process.
If you need a more advanced data store, create a cacheStore class that works
with Cheetah's CacheStore protocol and provide it as the cacheStore argument
to __init__. For example you could use
Cheetah.CacheStore.MemcachedCacheStore, a wrapper around the Python
memcached API (http://www.danga.com/memcached).
'''
_cacheItemClass = CacheItem
def __init__(self, regionID, templateCacheIdPrefix='', cacheStore=None):
self._isNew = True
self._regionID = regionID
self._templateCacheIdPrefix = templateCacheIdPrefix
if not cacheStore:
cacheStore = Cheetah.CacheStore.MemoryCacheStore()
self._cacheStore = cacheStore
self._wrappedCacheDataStore = _CacheDataStoreWrapper(
cacheStore, keyPrefix=templateCacheIdPrefix+':'+regionID+':')
self._cacheItems = {}
def isNew(self):
return self._isNew
def clear(self):
" drop all the caches stored in this cache region "
for cacheItemId in self._cacheItems.keys():
cacheItem = self._cacheItems[cacheItemId]
cacheItem.clear()
del self._cacheItems[cacheItemId]
def getCacheItem(self, cacheItemID):
""" Lazy access to a cacheItem
Try to find a cache in the stored caches. If it doesn't
exist, it's created.
Returns a `CacheItem` instance.
"""
cacheItemID = md5(str(cacheItemID)).hexdigest()
if cacheItemID not in self._cacheItems:
cacheItem = self._cacheItemClass(
cacheItemID=cacheItemID, cacheStore=self._wrappedCacheDataStore)
self._cacheItems[cacheItemID] = cacheItem
self._isNew = False
return self._cacheItems[cacheItemID]
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