Docserver: achieve online vs offline (cron vs instance) behaviour at the object

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

 # Copyright (c) 2012 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 from fnmatch import fnmatch
 import logging
 import mimetypes
 import traceback
 import os
 
@@ skipping 13 matching lines @@
 from local_file_system import LocalFileSystem
 from object_store_creator import ObjectStoreCreator
 from offline_file_system import OfflineFileSystem
 from path_canonicalizer import PathCanonicalizer
 from reference_resolver import ReferenceResolver
 from samples_data_source import SamplesDataSource
 from sidenav_data_source import SidenavDataSource
 from subversion_file_system import SubversionFileSystem
 import svn_constants
 from template_data_source import TemplateDataSource
-from third_party.json_schema_compiler.memoize import memoize
 from third_party.json_schema_compiler.model import UnixName
 import url_constants
 
 def _IsSamplesDisabled():
   return IsDevServer()
 
+def _CreateBranchUtility(start_configuration):
+  return BranchUtility(
+      url_constants.OMAHA_PROXY_URL,
+      AppEngineUrlFetcher(),
+      ObjectStoreCreator.SharedFactory(GetAppVersion(),
+                                       start_configuration))
+
+def _CreateGithubFileSystem(start_configuration):
+  # Slight hack: creating a github file system is pointless if samples are
+  # disabled, since it's only used for apps samples.
+  if _IsSamplesDisabled():
+    return EmptyDirFileSystem()
+  return GithubFileSystem(
+      AppEngineUrlFetcher(url_constants.GITHUB_URL),
+      AppEngineBlobstore(),
+      ObjectStoreCreator.SharedFactory(GetAppVersion(),
+                                       start_configuration))
+
 class ServerInstance(object):
-  # Lazily create so we don't create github file systems unnecessarily in
-  # tests.
-  branch_utility = None
-  github_file_system = None
-
   @staticmethod
-  @memoize
-  def GetOrCreateOffline(channel):
-    '''Gets/creates a local ServerInstance, meaning that only resources local to
+  def CreateOffline(channel,
+                    host_file_system_type=SubversionFileSystem,
+                    app_samples_file_system=None):
+    '''Creates a local ServerInstance, meaning that only resources local to
     the server - memcache, object store, etc, are queried. This amounts to not
     setting up the subversion nor github file systems.
     '''
-    branch_utility = ServerInstance._GetOrCreateBranchUtility()
+    start_configuration = ObjectStoreCreator.START_POPULATED
+
+    branch_utility = _CreateBranchUtility(start_configuration)
     branch = branch_utility.GetBranchNumberForChannelName(channel)
-    object_store_creator_factory = ObjectStoreCreator.Factory(GetAppVersion(),
-                                                              branch)
+    object_store_creator_factory = ObjectStoreCreator.Factory(
+        GetAppVersion(),
+        branch,
+        start_configuration)
+
+    if app_samples_file_system is None:
+      app_samples_file_system = _CreateGithubFileSystem(start_configuration)
+
     # No svn nor github file systems. Rely on the crons to fill the caches, and
     # for the caches to exist.
     return ServerInstance(
         channel,
         object_store_creator_factory,
-        CachingFileSystem(OfflineFileSystem(SubversionFileSystem),
-                          object_store_creator_factory,
-                          use_existing_values=True),
-        # TODO(kalman): convert GithubFileSystem to be wrappable in a
-        # CachingFileSystem so that it can be replaced with an
-        # OfflineFileSystem. Currently GFS doesn't set the child versions of
-        # stat requests so it doesn't.
-        ServerInstance._GetOrCreateGithubFileSystem())
+        CachingFileSystem(OfflineFileSystem(host_file_system_type),
+                          object_store_creator_factory),
+        app_samples_file_system)
 
   @staticmethod
-  def CreateOnline(channel):
+  def CreateOnline(channel,
+                   host_file_system=None,
+                   app_samples_file_system=None):
     '''Creates/creates an online server instance, meaning that both local and
     subversion/github resources are queried.
     '''
-    branch_utility = ServerInstance._GetOrCreateBranchUtility()
+    start_configuration = ObjectStoreCreator.START_EMPTY
+
+    branch_utility = _CreateBranchUtility(start_configuration)
     branch = branch_utility.GetBranchNumberForChannelName(channel)
 
     if branch == 'trunk':
       svn_url = '/'.join((url_constants.SVN_TRUNK_URL,
                           'src',
                           svn_constants.EXTENSIONS_PATH))
     else:
       svn_url = '/'.join((url_constants.SVN_BRANCH_URL,
                           branch,
                           'src',
                           svn_constants.EXTENSIONS_PATH))
 
     viewvc_url = svn_url.replace(url_constants.SVN_URL,
                                  url_constants.VIEWVC_URL)
 
-    object_store_creator_factory = ObjectStoreCreator.Factory(GetAppVersion(),
-                                                              branch)
+    object_store_creator_factory = ObjectStoreCreator.Factory(
+        GetAppVersion(),
+        branch,
+        start_configuration)
 
-    svn_file_system = CachingFileSystem(
-        SubversionFileSystem(AppEngineUrlFetcher(svn_url),
-                             AppEngineUrlFetcher(viewvc_url)),
-        object_store_creator_factory)
+    if host_file_system is None:
+      host_file_system = SubversionFileSystem(AppEngineUrlFetcher(svn_url),
+                                              AppEngineUrlFetcher(viewvc_url))
+    cached_host_file_system = CachingFileSystem(host_file_system,
+                                                object_store_creator_factory)
+
+    if app_samples_file_system is None:
+      app_samples_file_system = _CreateGithubFileSystem(start_configuration)
 
     return ServerInstance(channel,
                           object_store_creator_factory,
-                          svn_file_system,
-                          ServerInstance._GetOrCreateGithubFileSystem())
+                          cached_host_file_system,
+                          app_samples_file_system)
 
   @staticmethod
-  def CreateForTest(file_system):
+  def CreateForTest(host_file_system):
     return ServerInstance('test',
                           ObjectStoreCreator.TestFactory(),
-                          file_system,
-                          None)
-
-  @staticmethod
-  def _GetOrCreateBranchUtility():
-    if ServerInstance.branch_utility is None:
-      ServerInstance.branch_utility = BranchUtility(
-          url_constants.OMAHA_PROXY_URL,
-          AppEngineUrlFetcher())
-    return ServerInstance.branch_utility
-
-  @staticmethod
-  def _GetOrCreateGithubFileSystem():
-    # Initialising github is pointless if samples are disabled, since it's only
-    # used for apps samples.
-    if ServerInstance.github_file_system is None:
-      if _IsSamplesDisabled():
-        ServerInstance.github_file_system = EmptyDirFileSystem()
-      else:
-        ServerInstance.github_file_system = GithubFileSystem(
-            AppEngineUrlFetcher(url_constants.GITHUB_URL),
-            AppEngineBlobstore())
-    return ServerInstance.github_file_system
+                          host_file_system,
+                          EmptyDirFileSystem())
 
   def __init__(self,
                channel,
                object_store_creator_factory,
-               svn_file_system,
-               github_file_system):
-    self.svn_file_system = svn_file_system
+               host_file_system,
+               app_samples_file_system):
+    self.host_file_system = host_file_system
 
-    self.github_file_system = github_file_system
+    self.app_samples_file_system = app_samples_file_system
 
     self.compiled_fs_factory = CompiledFileSystem.Factory(
-        svn_file_system,
+        host_file_system,
         object_store_creator_factory)
 
     self.api_list_data_source_factory = APIListDataSource.Factory(
         self.compiled_fs_factory,
         svn_constants.API_PATH,
         svn_constants.PUBLIC_TEMPLATE_PATH)
 
     self.api_data_source_factory = APIDataSource.Factory(
         self.compiled_fs_factory,
         svn_constants.API_PATH)
 
     self.ref_resolver_factory = ReferenceResolver.Factory(
         self.api_data_source_factory,
         self.api_list_data_source_factory,
         object_store_creator_factory)
 
     self.api_data_source_factory.SetReferenceResolverFactory(
         self.ref_resolver_factory)
 
     # Note: samples are super slow in the dev server because it doesn't support
     # async fetch, so disable them. If you actually want to test samples, then
     # good luck, and modify _IsSamplesDisabled at the top.
     if _IsSamplesDisabled():
-      svn_fs_for_samples = EmptyDirFileSystem()
+      extension_samples_fs = EmptyDirFileSystem()
     else:
-      svn_fs_for_samples = self.svn_file_system
+      extension_samples_fs = self.host_file_system
     self.samples_data_source_factory = SamplesDataSource.Factory(
         channel,
-        svn_fs_for_samples,
-        self.github_file_system,
+        extension_samples_fs,
+        self.app_samples_file_system,
         self.ref_resolver_factory,
         object_store_creator_factory,
         svn_constants.EXAMPLES_PATH)
 
     self.api_data_source_factory.SetSamplesDataSourceFactory(
         self.samples_data_source_factory)
 
     self.intro_data_source_factory = IntroDataSource.Factory(
         self.compiled_fs_factory,
         self.ref_resolver_factory,
@@ skipping 17 matching lines @@
 
     self.example_zipper = ExampleZipper(
         self.compiled_fs_factory,
         svn_constants.DOCS_PATH)
 
     self.path_canonicalizer = PathCanonicalizer(
         channel,
         self.compiled_fs_factory)
 
     self.content_cache = self.compiled_fs_factory.CreateIdentity(ServerInstance)