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author | Erik Johnston <erik@matrix.org> | 2016-06-09 14:21:23 +0100 |
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committer | Erik Johnston <erik@matrix.org> | 2016-06-09 14:21:23 +0100 |
commit | ba0406d10da32ebebf4185f01841f236371e0ae8 (patch) | |
tree | 70f492094b7fb962a8161bd2304c6846b3ac3f40 /synapse/util/caches/response_cache.py | |
parent | Merge pull request #801 from ruma/readme-history-storage (diff) | |
parent | Change CHANGELOG (diff) | |
download | synapse-ba0406d10da32ebebf4185f01841f236371e0ae8.tar.xz |
Merge branch 'release-v0.16.0' of github.com:matrix-org/synapse v0.16.0
Diffstat (limited to 'synapse/util/caches/response_cache.py')
-rw-r--r-- | synapse/util/caches/response_cache.py | 46 |
1 files changed, 46 insertions, 0 deletions
diff --git a/synapse/util/caches/response_cache.py b/synapse/util/caches/response_cache.py new file mode 100644 index 0000000000..36686b479e --- /dev/null +++ b/synapse/util/caches/response_cache.py @@ -0,0 +1,46 @@ +# -*- coding: utf-8 -*- +# Copyright 2016 OpenMarket Ltd +# +# Licensed under the Apache License, Version 2.0 (the "License"); +# you may not use this file except in compliance with the License. +# You may obtain a copy of the License at +# +# http://www.apache.org/licenses/LICENSE-2.0 +# +# Unless required by applicable law or agreed to in writing, software +# distributed under the License is distributed on an "AS IS" BASIS, +# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +# See the License for the specific language governing permissions and +# limitations under the License. + +from synapse.util.async import ObservableDeferred + + +class ResponseCache(object): + """ + This caches a deferred response. Until the deferred completes it will be + returned from the cache. This means that if the client retries the request + while the response is still being computed, that original response will be + used rather than trying to compute a new response. + """ + + def __init__(self): + self.pending_result_cache = {} # Requests that haven't finished yet. + + def get(self, key): + result = self.pending_result_cache.get(key) + if result is not None: + return result.observe() + else: + return None + + def set(self, key, deferred): + result = ObservableDeferred(deferred, consumeErrors=True) + self.pending_result_cache[key] = result + + def remove(r): + self.pending_result_cache.pop(key, None) + return r + + result.addBoth(remove) + return result.observe() |