| 1 | "File-based cache backend"
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| 2 |
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| 3 | from django.core.cache.backends.simple import CacheClass as SimpleCacheClass
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| 4 | import os, time, urllib
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| 5 | try:
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| 6 | import cPickle as pickle
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| 7 | except ImportError:
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| 8 | import pickle
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| 9 |
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| 10 | class CacheClass(SimpleCacheClass):
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| 11 | def __init__(self, dir, params):
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| 12 | self._dir = dir
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| 13 | if not os.path.exists(self._dir):
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| 14 | self._createdir()
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| 15 | SimpleCacheClass.__init__(self, dir, params)
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| 16 | del self._cache
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| 17 | del self._expire_info
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| 18 |
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| 19 | def get(self, key, default=None):
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| 20 | fname = self._key_to_file(key)
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| 21 | try:
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| 22 | f = open(fname, 'rb')
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| 23 | exp = pickle.load(f)
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| 24 | now = time.time()
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| 25 | if exp < now:
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| 26 | f.close()
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| 27 | os.remove(fname)
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| 28 | else:
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| 29 | return pickle.load(f)
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| 30 | except (IOError, OSError, EOFError, pickle.PickleError):
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| 31 | pass
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| 32 | return default
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| 33 |
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| 34 | def set(self, key, value, timeout=None):
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| 35 | fname = self._key_to_file(key)
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| 36 | if timeout is None:
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| 37 | timeout = self.default_timeout
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| 38 |
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| 39 | namespacedir = os.path.dirname(fname)
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| 40 | try:
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| 41 | filelist = os.listdir(namespacedir)
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| 42 | except (IOError, OSError):
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| 43 | self._createdir(namespacedir)
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| 44 | filelist = []
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| 45 | if len(filelist) > self._max_entries:
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| 46 | self._cull(filelist)
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| 47 |
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| 48 | try:
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| 49 | f = open(fname, 'wb')
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| 50 | now = time.time()
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| 51 | pickle.dump(now + timeout, f, 2)
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| 52 | pickle.dump(value, f, 2)
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| 53 | except (IOError, OSError):
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| 54 | pass
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| 55 |
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| 56 | def delete(self, key):
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| 57 | try:
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| 58 | os.remove(self._key_to_file(key))
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| 59 | except (IOError, OSError):
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| 60 | pass
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| 61 |
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| 62 | def has_key(self, key):
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| 63 | return os.path.exists(self._key_to_file(key))
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| 64 |
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| 65 | def _cull(self, filelist):
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| 66 | if self._cull_frequency == 0:
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| 67 | doomed = filelist
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| 68 | else:
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| 69 | doomed = [k for (i, k) in enumerate(filelist) if i % self._cull_frequency == 0]
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| 70 | for fname in doomed:
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| 71 | try:
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| 72 | os.remove(os.path.join(self._dir, fname))
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| 73 | except (IOError, OSError):
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| 74 | pass
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| 75 |
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| 76 | def _createdir(self, dir = None):
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| 77 | if dir == None:
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| 78 | dir = self._dir
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| 79 | try:
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| 80 | os.makedirs(dir)
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| 81 | except OSError:
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| 82 | raise EnvironmentError, "Cache directory '%s' does not exist and could not be created'" % self._dir
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| 83 |
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| 84 | def _key_to_file(self, key):
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| 85 | return os.path.join(self._dir, (key))
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