chrome/common/extensions/docs/server2/object_store.py

   1 # Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 # Use of this source code is governed by a BSD-style license that can be
   3 # found in the LICENSE file.
   4
   5 from future import Future
   6
   7 class _SingleGetFuture(object):
   8   def __init__(self, multi_get, key):
   9     self._future = multi_get
  10     self._key = key
  11
  12   def Get(self):
  13     return self._future.Get().get(self._key)
  14
  15 class ObjectStore(object):
  16   '''A class for caching picklable objects.
  17   '''
  18   def Get(self, key):
  19     '''Gets a |Future| with the value of |key| in the object store, or None
  20     if |key| is not in the object store.
  21     '''
  22     return Future(delegate=_SingleGetFuture(self.GetMulti([key]), key))
  23
  24   def GetMulti(self, keys):
  25     '''Gets a |Future| with values mapped to |keys| from the object store, with
  26     any keys not in the object store omitted.
  27     '''
  28     raise NotImplementedError(self.__class__)
  29
  30   def Set(self, key, value):
  31     '''Sets key -> value in the object store.
  32     '''
  33     self.SetMulti({ key: value })
  34
  35   def SetMulti(self, items):
  36     '''Atomically sets the mapping of keys to values in the object store.
  37     '''
  38     raise NotImplementedError(self.__class__)
  39
  40   def Del(self, key):
  41     '''Deletes a key from the object store.
  42     '''
  43     self.DelMulti([key])
  44
  45   def DelMulti(self, keys):
  46     '''Deletes |keys| from the object store.
  47     '''
  48     raise NotImplementedError(self.__class__)