81 lines
2.4 KiB
Python
81 lines
2.4 KiB
Python
"File-based cache backend"
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from django.core.cache.backends.simple import CacheClass as SimpleCacheClass
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import os, time, urllib
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try:
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import cPickle as pickle
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except ImportError:
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import pickle
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class CacheClass(SimpleCacheClass):
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def __init__(self, dir, params):
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self._dir = dir
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if not os.path.exists(self._dir):
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self._createdir()
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SimpleCacheClass.__init__(self, dir, params)
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del self._cache
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del self._expire_info
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def get(self, key, default=None):
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fname = self._key_to_file(key)
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try:
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f = open(fname, 'rb')
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exp = pickle.load(f)
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now = time.time()
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if exp < now:
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f.close()
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os.remove(fname)
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else:
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return pickle.load(f)
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except (IOError, OSError, EOFError, pickle.PickleError):
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pass
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return default
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def set(self, key, value, timeout=None):
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fname = self._key_to_file(key)
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if timeout is None:
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timeout = self.default_timeout
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try:
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filelist = os.listdir(self._dir)
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except (IOError, OSError):
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self._createdir()
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filelist = []
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if len(filelist) > self._max_entries:
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self._cull(filelist)
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try:
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f = open(fname, 'wb')
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now = time.time()
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pickle.dump(now + timeout, f, 2)
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pickle.dump(value, f, 2)
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except (IOError, OSError):
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pass
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def delete(self, key):
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try:
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os.remove(self._key_to_file(key))
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except (IOError, OSError):
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pass
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def has_key(self, key):
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return os.path.exists(self._key_to_file(key))
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def _cull(self, filelist):
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if self._cull_frequency == 0:
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doomed = filelist
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else:
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doomed = [k for (i, k) in enumerate(filelist) if i % self._cull_frequency == 0]
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for fname in doomed:
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try:
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os.remove(os.path.join(self._dir, fname))
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except (IOError, OSError):
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pass
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def _createdir(self):
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try:
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os.makedirs(self._dir)
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except OSError:
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raise EnvironmentError, "Cache directory '%s' does not exist and could not be created'" % self._dir
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def _key_to_file(self, key):
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return os.path.join(self._dir, urllib.quote_plus(key))
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