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

chrome/common/extensions/docs/server2/api_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 json
 import logging
 import os
+import time
 
 from file_system import FileNotFoundError
 from handlebar_dict_generator import HandlebarDictGenerator
 import third_party.json_schema_compiler.json_comment_eater as json_comment_eater
 import third_party.json_schema_compiler.model as model
 import third_party.json_schema_compiler.idl_schema as idl_schema
 import third_party.json_schema_compiler.idl_parser as idl_parser
 
 class _LazySamplesGetter(object):
   """This class is needed so that an extensions API page does not have to fetch
@@ skipping 12 matching lines @@
   """
   class Factory(object):
     def __init__(self, cache_builder, base_path, samples_factory):
       self._permissions_cache = cache_builder.build(self._LoadPermissions)
       self._json_cache = cache_builder.build(self._LoadJsonAPI)
       self._idl_cache = cache_builder.build(self._LoadIdlAPI)
       self._samples_factory = samples_factory
       self._base_path = base_path
 
     def Create(self, request):
-      return APIDataSource(self._permissions_cache,
-                           self._json_cache,
-                           self._idl_cache,
+      return APIDataSource(self._permissions_cache.ScopeToRequest(),
+                           self._json_cache.ScopeToRequest(),
+                           self._idl_cache.ScopeToRequest(),
                            self._base_path,
                            self._samples_factory.Create(request))
 
     def _LoadPermissions(self, json_str):
       return json.loads(json_comment_eater.Nom(json_str))
 
     def _LoadJsonAPI(self, api):
       return HandlebarDictGenerator(json.loads(json_comment_eater.Nom(api))[0])
 
     def _LoadIdlAPI(self, api):
@@ skipping 36 matching lines @@
       # http://crbug.com/142011.
       'samples': None # _LazySamplesGetter(path, self._samples)
     }
     return_dict.update(handlebar.Generate())
     return return_dict
 
   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("ApiDataSource: %sms", (time.time() - start_time) * 1000)
+
+  def _do_get(self, key):
     path, ext = os.path.splitext(key)
     unix_name = model.UnixName(path)
     json_path = unix_name + '.json'
     idl_path = unix_name + '.idl'
     try:
       return self._GenerateHandlebarContext(
           self._json_cache.GetFromFile(self._base_path + '/' + json_path),
           path)
     except FileNotFoundError:
       try:
         return self._GenerateHandlebarContext(
             self._idl_cache.GetFromFile(self._base_path + '/' + idl_path),
             path)
       except FileNotFoundError:
         raise