Extension docs server: many changes to bring down the latency of the server,

chrome/common/extensions/docs/server2/template_data_source.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.
 
 import logging
+import time
 
 from docs_server_utils import FormatKey
 from file_system import FileNotFoundError
+from request_scoped_fs_cache import RequestScopedFsCache
 from third_party.handlebar import Handlebar
 
 EXTENSIONS_URL = '/chrome/extensions'
 
 def _MakeChannelDict(channel_name):
   return {
     'showWarning': channel_name != 'stable',
     'channels': [
       { 'name': 'Stable', 'path': 'stable' },
       { 'name': 'Dev',    'path': 'dev' },
@@ skipping 15 matching lines @@
   a Factory to cheaply construct these.
   """
 
   class Factory(object):
     """A factory to create lightweight TemplateDataSource instances bound to
     individual Requests.
     """
     def __init__(self,
                  channel_name,
                  api_data_source_factory,
-                 api_list_data_source,
-                 intro_data_source,
+                 api_list_data_source_factory,
+                 intro_data_source_factory,
                  samples_data_source_factory,
                  cache_builder,
                  public_template_path,
                  private_template_path):
       self._branch_info = _MakeChannelDict(channel_name)
       self._api_data_source_factory = api_data_source_factory
-      self._api_list_data_source = api_list_data_source
-      self._intro_data_source = intro_data_source
+      self._api_list_data_source_factory = api_list_data_source_factory
+      self._intro_data_source_factory = intro_data_source_factory
       self._samples_data_source_factory = samples_data_source_factory
       self._cache = cache_builder.build(Handlebar)
       self._public_template_path = public_template_path
       self._private_template_path = private_template_path
       self._static_resources = (
           (('/' + channel_name) if channel_name != 'local' else '') + '/static')
 
     def Create(self, request):
       """Returns a new TemplateDataSource bound to |request|.
       """
       return TemplateDataSource(
           self._branch_info,
           self._api_data_source_factory.Create(request),
-          self._api_list_data_source,
-          self._intro_data_source,
+          self._api_list_data_source_factory.Create(),
+          self._intro_data_source_factory.Create(),
           self._samples_data_source_factory.Create(request),
-          self._cache,
+          self._cache.ScopeToRequest(),
           self._public_template_path,
           self._private_template_path,
           self._static_resources,
           request)
 
   def __init__(self,
                branch_info,
                api_data_source,
                api_list_data_source,
                intro_data_source,
                samples_data_source,
                cache,
                public_template_path,
                private_template_path,
                static_resources,
                request):
     self._branch_info = branch_info
     self._api_list_data_source = api_list_data_source
     self._intro_data_source = intro_data_source
     self._samples_data_source = samples_data_source
     self._api_data_source = api_data_source
     self._cache = cache
     self._public_template_path = public_template_path
     self._private_template_path = private_template_path
     self._static_resources = static_resources
     self._request = request
 
   def Render(self, template_name):
+    start_time = time.time()
+    try:
+      return self._DoRender(template_name)
+    finally:
+      logging.info("RENDER: %sms", (time.time() - start_time) * 1000)
+
+  def _DoRender(self, template_name):
     """This method will render a template named |template_name|, fetching all
     the partial templates needed from |self._cache|. Partials are retrieved
     from the TemplateDataSource with the |get| method.
     """
     template = self.GetTemplate(self._public_template_path, template_name)
     if not template:
       return ''
       # TODO error handling
     return template.render({
       'api_list': self._api_list_data_source,
       'apis': self._api_data_source,
       'branchInfo': self._branch_info,
       'intros': self._intro_data_source,
       'partials': self,
       'samples': self._samples_data_source,
       'static': self._static_resources,
       'apps_title': 'Apps',
       'extensions_title': 'Extensions',
       'true': True,
       'false': False
     }).text
 
   def __getitem__(self, key):
     return self.get(key)
 
   def get(self, key):
+    start_time = time.time()
+    try:
+      return self._do_get(key)
+    finally:
+      logging.info("TemplateDataSource: %sms", (time.time() - start_time) * 1000)
+
+  def _do_get(self, key):
     return self.GetTemplate(self._private_template_path, key)
 
   def GetTemplate(self, base_path, template_name):
     real_path = FormatKey(template_name)
     try:
       return self._cache.GetFromFile(base_path + '/' + real_path)
     except FileNotFoundError as e:
       logging.error(e)
       return None