| # Copyright 2013 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 appengine_wrappers import IsDevServer |
| from branch_utility import BranchUtility |
| from compiled_file_system import CompiledFileSystem |
| from empty_dir_file_system import EmptyDirFileSystem |
| from github_file_system_provider import GithubFileSystemProvider |
| from host_file_system_provider import HostFileSystemProvider |
| from third_party.json_schema_compiler.memoize import memoize |
| from render_servlet import RenderServlet |
| from object_store_creator import ObjectStoreCreator |
| from server_instance import ServerInstance |
| |
| class OfflineRenderServletDelegate(RenderServlet.Delegate): |
| '''AppEngine instances should never need to call out to SVN. That should only |
| ever be done by the cronjobs, which then write the result into DataStore, |
| which is as far as instances look. To enable this, crons can pass a custom |
| (presumably online) ServerInstance into Get(). |
| |
| Why? SVN is slow and a bit flaky. Cronjobs failing is annoying but temporary. |
| Instances failing affects users, and is really bad. |
| |
| Anyway - to enforce this, we actually don't give instances access to SVN. If |
| anything is missing from datastore, it'll be a 404. If the cronjobs don't |
| manage to catch everything - uhoh. On the other hand, we'll figure it out |
| pretty soon, and it also means that legitimate 404s are caught before a round |
| trip to SVN. |
| ''' |
| def __init__(self, delegate): |
| self._delegate = delegate |
| |
| @memoize |
| def CreateServerInstance(self): |
| object_store_creator = ObjectStoreCreator(start_empty=False) |
| branch_utility = self._delegate.CreateBranchUtility(object_store_creator) |
| host_file_system_provider = self._delegate.CreateHostFileSystemProvider( |
| object_store_creator, |
| offline=True) |
| github_file_system_provider = self._delegate.CreateGithubFileSystemProvider( |
| object_store_creator) |
| return ServerInstance(object_store_creator, |
| CompiledFileSystem.Factory(object_store_creator), |
| branch_utility, |
| host_file_system_provider, |
| github_file_system_provider) |
| |
| class InstanceServlet(object): |
| '''Servlet for running on normal AppEngine instances. |
| Create this via GetConstructor() so that cache state can be shared amongst |
| them via the memoizing Delegate. |
| ''' |
| class Delegate(object): |
| '''Allow runtime dependencies to be overriden for testing. |
| ''' |
| def CreateBranchUtility(self, object_store_creator): |
| return BranchUtility.Create(object_store_creator) |
| |
| def CreateHostFileSystemProvider(self, object_store_creator, **optargs): |
| return HostFileSystemProvider(object_store_creator, **optargs) |
| |
| def CreateGithubFileSystemProvider(self, object_store_creator): |
| return GithubFileSystemProvider(object_store_creator) |
| |
| @staticmethod |
| def GetConstructor(delegate_for_test=None): |
| render_servlet_delegate = OfflineRenderServletDelegate( |
| delegate_for_test or InstanceServlet.Delegate()) |
| return lambda request: RenderServlet(request, render_servlet_delegate) |
| |
| # NOTE: if this were a real Servlet it would implement a Get() method, but |
| # GetConstructor returns an appropriate lambda function (Request -> Servlet). |