48 lines
1.4 KiB
Python
48 lines
1.4 KiB
Python
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"Thread-safe in-memory cache backend."
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from django.core.cache.backends.simple import CacheClass as SimpleCacheClass
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from django.utils.synch import RWLock
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import copy, time
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class CacheClass(SimpleCacheClass):
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def __init__(self, host, params):
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SimpleCacheClass.__init__(self, host, params)
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self._lock = RWLock()
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def get(self, key, default=None):
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should_delete = False
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self._lock.reader_enters()
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try:
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now = time.time()
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exp = self._expire_info.get(key)
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if exp is None:
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return default
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elif exp < now:
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should_delete = True
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else:
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return copy.deepcopy(self._cache[key])
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finally:
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self._lock.reader_leaves()
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if should_delete:
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self._lock.writer_enters()
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try:
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del self._cache[key]
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del self._expire_info[key]
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return default
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finally:
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self._lock.writer_leaves()
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def set(self, key, value, timeout=None):
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self._lock.writer_enters()
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try:
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SimpleCacheClass.set(self, key, value, timeout)
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finally:
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self._lock.writer_leaves()
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def delete(self, key):
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self._lock.writer_enters()
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try:
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SimpleCacheClass.delete(self, key)
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finally:
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self._lock.writer_leaves()
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