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

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

Index: chrome/common/extensions/docs/server2/api_list_data_source.py
diff --git a/chrome/common/extensions/docs/server2/api_list_data_source.py b/chrome/common/extensions/docs/server2/api_list_data_source.py
index 8d00f6652f85647264d06e885a79cf72b6a886b9..484122c62ece9d84f1626ecb26b3de1a1eb425bd 100644
--- a/chrome/common/extensions/docs/server2/api_list_data_source.py
+++ b/chrome/common/extensions/docs/server2/api_list_data_source.py
@@ -4,6 +4,7 @@
 
 import logging
 import os
+import time
 
 from file_system import FileNotFoundError
 import third_party.json_schema_compiler.model as model
@@ -15,51 +16,68 @@ IGNORED_FILES = [
 ]
 
 class APIListDataSource(object):
+  class Factory(object):
+    def __init__(self, cache_builder, file_system, api_path, public_path):
+      self._cache = cache_builder.build(self._ListAPIs)
+      self._file_system = file_system
+      def Normalize(string):
+        return string if string.endswith('/') else (string + '/')
+      self._api_path = Normalize(api_path)
+      self._public_path = Normalize(public_path)
+
+    def _GetAPIsInSubdirectory(self, api_names, doc_type):
+      public_templates = self._file_system.ReadSingle(
+          self._public_path + doc_type + '/')
+      template_names = [os.path.splitext(name)[0]
+                        for name in public_templates]
+      experimental_apis = []
+      chrome_apis = []
+      for template_name in sorted(template_names):
+        if template_name in IGNORED_FILES:
+          continue
+        if model.UnixName(template_name) in api_names:
+          if template_name.startswith('experimental'):
+            experimental_apis.append({
+              'name': template_name.replace('_', '.')
+            })
+          else:
+            chrome_apis.append({ 'name': template_name.replace('_', '.') })
+      chrome_apis[-1]['last'] = True
+      experimental_apis[-1]['last'] = True
+      return {
+        'chrome': chrome_apis,
+        'experimental': experimental_apis
+      }
+
+    def _ListAPIs(self, apis):
+      api_names = set(SanitizeAPIName(name, self._api_path) for name in apis)
+      return {
+        'apps': self._GetAPIsInSubdirectory(api_names, 'apps'),
+        'extensions': self._GetAPIsInSubdirectory(api_names, 'extensions')
+      }
+
+    def Create(self):
+      return APIListDataSource(self._cache.ScopeToRequest(), self._api_path)
+
   """ This class creates a list of chrome.* APIs and chrome.experimental.* APIs
   that are used in the api_index.html and experimental.html pages.
   """
-  def __init__(self, cache_builder, file_system, api_path, public_path):
-    self._cache = cache_builder.build(self._ListAPIs)
-    self._file_system = file_system
-    self._api_path = api_path + '/'
-    self._public_path = public_path + '/'
-
-  def _GetAPIsInSubdirectory(self, api_names, doc_type):
-    public_templates = self._file_system.ReadSingle(
-        self._public_path + doc_type + '/')
-    template_names = [os.path.splitext(name)[0]
-                      for name in public_templates]
-    experimental_apis = []
-    chrome_apis = []
-    for template_name in sorted(template_names):
-      if template_name in IGNORED_FILES:
-        continue
-      if model.UnixName(template_name) in api_names:
-        if template_name.startswith('experimental'):
-          experimental_apis.append({
-            'name': template_name.replace('_', '.')
-          })
-        else:
-          chrome_apis.append({ 'name': template_name.replace('_', '.') })
-    chrome_apis[-1]['last'] = True
-    experimental_apis[-1]['last'] = True
-    return {
-      'chrome': chrome_apis,
-      'experimental': experimental_apis
-    }
-
-  def _ListAPIs(self, apis):
-    api_names = set(SanitizeAPIName(name, self._api_path) for name in apis)
-    return {
-      'apps': self._GetAPIsInSubdirectory(api_names, 'apps'),
-      'extensions': self._GetAPIsInSubdirectory(api_names, 'extensions')
-    }
+  def __init__(self, cache, api_path):
+    self._cache = cache
+    self._api_path = api_path
 
   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("ApiListDataSource: %sms", (time.time() - start_time) * 1000)
+
+  def _do_get(self, key):
     try:
       return self._cache.GetFromFileListing(self._api_path)[key]
     except FileNotFoundError as e:
-      raise ValueError(str(e) + ': Error listing files for "%s".' % key)
+      raise ValueError('%s: Error listing files for "%s".' % (e, key))