Extension docs server: APIDataSource

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 json
-import logging
-import os
-import time
-
 from third_party.handlebar import Handlebar
 
 class TemplateDataSource(object):
-  def __init__(self, fetcher, base_paths, cache_timeout_seconds):
-    logging.info('Template data source created: %s %d' %
-        (' '.join(base_paths), cache_timeout_seconds))
-    self._fetcher = fetcher
-    self._template_cache = {}
+  """This class fetches and compiles templates using the fetcher passed in with
+  |cache_builder|.
+  """
+  def __init__(self, cache_builder, base_paths):
+    self._cache = cache_builder.build(self._LoadTemplate)
     self._base_paths = base_paths
-    self._cache_timeout_seconds = cache_timeout_seconds
+
+  def _LoadTemplate(self, template):
+    return Handlebar(template)
 
   def Render(self, template_name, context):
     """This method will render a template named |template_name|, fetching all
-    the partial templates needed with |self._fetcher|. Partials are retrieved
+    the partial templates needed from |self._cache|. Partials are retrieved
     from the TemplateDataSource with the |get| method.
     """
     template = self.get(template_name)
     if not template:
       return ''
       # TODO error handling
-    return template.render(json.loads(context), {'templates': self}).text
-
-  class _CachedTemplate(object):
-    def __init__(self, template, expiry):
-      self.template = template
-      self._expiry = expiry
-
-    def HasExpired(self):
-      return time.time() > self._expiry
+    return template.render(context, {'templates': self}).text
 
   def __getitem__(self, key):
     return self.get(key)
 
   def get(self, key):
     index = key.rfind('.html')
     if index > 0:
       key = key[:index]
-    path = key + '.html'
-    if key in self._template_cache:
-      if self._template_cache[key].HasExpired():
-        self._template_cache.pop(key)
-    if key not in self._template_cache:
-      logging.info('Template cache miss for: ' + path)
-      compiled_template = None
-      for base_path in self._base_paths:
-        try:
-          template = self._fetcher.FetchResource(base_path + path).content
-          compiled_template = Handlebar(template)
-          self._template_cache[key] = self._CachedTemplate(
-              compiled_template,
-              time.time() + self._cache_timeout_seconds)
-          break
-        except:
-          pass
-
-    return compiled_template
+    real_path = key + '.html'
+    for base_path in self._base_paths:
+      try:
+        return self._cache.get(base_path + '/' + real_path)
+      except:
+        pass
+    return None