1 # Copyright 2013 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 datetime import datetime, timedelta 6 from file_system import FileNotFoundError 7 from future import Future 8 from patcher import Patcher 9 10 _VERSION_CACHE_MAXAGE = timedelta(seconds=5) 11 12 ''' Append @version for keys to distinguish between different patchsets of 13 an issue. 14 ''' 15 def _MakeKey(path, version): 16 return '%s@%s' % (path, version) 17 18 def _ToObjectStoreValue(raw_value, version): 19 return dict((_MakeKey(key, version), raw_value[key]) 20 for key in raw_value) 21 22 def _FromObjectStoreValue(raw_value): 23 return dict((key[0:key.rfind('@')], raw_value[key]) for key in raw_value) 24 25 class _AsyncUncachedFuture(object): 26 def __init__(self, 27 version, 28 paths, 29 cached_value, 30 missing_paths, 31 fetch_delegate, 32 object_store): 33 self._version = version 34 self._paths = paths 35 self._cached_value = cached_value 36 self._missing_paths = missing_paths 37 self._fetch_delegate = fetch_delegate 38 self._object_store = object_store 39 40 def Get(self): 41 uncached_value = self._fetch_delegate.Get() 42 self._object_store.SetMulti(_ToObjectStoreValue(uncached_value, 43 self._version)) 44 45 for path in self._missing_paths: 46 if uncached_value.get(path) is None: 47 raise FileNotFoundError('File %s was not found in the patch.' % path) 48 self._cached_value[path] = uncached_value[path] 49 50 return self._cached_value 51 52 class CachingRietveldPatcher(Patcher): 53 ''' CachingRietveldPatcher implements a caching layer on top of |patcher|. 54 In theory, it can be used with any class that implements Patcher. But this 55 class assumes that applying to all patched files at once is more efficient 56 than applying to individual files. 57 ''' 58 def __init__(self, 59 rietveld_patcher, 60 object_store_creator, 61 test_datetime=datetime): 62 self._patcher = rietveld_patcher 63 def create_object_store(category): 64 return object_store_creator.Create( 65 CachingRietveldPatcher, 66 category='%s/%s' % (rietveld_patcher.GetIdentity(), category)) 67 self._version_object_store = create_object_store('version') 68 self._list_object_store = create_object_store('list') 69 self._file_object_store = create_object_store('file') 70 self._datetime = test_datetime 71 72 def GetVersion(self): 73 key = 'version' 74 value = self._version_object_store.Get(key).Get() 75 if value is not None: 76 version, time = value 77 if self._datetime.now() - time < _VERSION_CACHE_MAXAGE: 78 return version 79 80 version = self._patcher.GetVersion() 81 self._version_object_store.Set(key, 82 (version, self._datetime.now())) 83 return version 84 85 def GetPatchedFiles(self, version=None): 86 if version is None: 87 version = self.GetVersion() 88 patched_files = self._list_object_store.Get(version).Get() 89 if patched_files is not None: 90 return patched_files 91 92 patched_files = self._patcher.GetPatchedFiles(version) 93 self._list_object_store.Set(version, patched_files) 94 return patched_files 95 96 def Apply(self, paths, file_system, version=None): 97 if version is None: 98 version = self.GetVersion() 99 added, deleted, modified = self.GetPatchedFiles(version) 100 cached_value = _FromObjectStoreValue(self._file_object_store. 101 GetMulti([_MakeKey(path, version) for path in paths]).Get()) 102 missing_paths = list(set(paths) - set(cached_value.keys())) 103 if len(missing_paths) == 0: 104 return Future(value=cached_value) 105 106 return _AsyncUncachedFuture(version, 107 paths, 108 cached_value, 109 missing_paths, 110 self._patcher.Apply(set(added) | set(modified), 111 None, 112 version), 113 self._file_object_store) 114 115 def GetIdentity(self): 116 return self._patcher.GetIdentity() 117