src/chrome/common/extensions/docs/server2/features_bundle.py

   1 # Copyright 2013 The Chromium Authors. All rights reserved.
   2 # Use of this source code is governed by a BSD-style license that can be
   3 # found in the LICENSE file.
   4
   5 import features_utility
   6 import svn_constants
   7 from third_party.json_schema_compiler.json_parse import Parse
   8
   9
  10 def _AddPlatformsFromDependencies(feature, features_bundle):
  11   features_map = {
  12     'api': features_bundle.GetAPIFeatures(),
  13     'manifest': features_bundle.GetManifestFeatures(),
  14     'permission': features_bundle.GetPermissionFeatures()
  15   }
  16   dependencies = feature.get('dependencies')
  17   if dependencies is None:
  18     return ['apps', 'extensions']
  19   platforms = set()
  20   for dependency in dependencies:
  21     dep_type, dep_name = dependency.split(':')
  22     dependency_features = features_map[dep_type]
  23     dependency_feature = dependency_features.get(dep_name)
  24     # If the dependency can't be resolved, it is inaccessible and therefore
  25     # so is this feature.
  26     if dependency_feature is None:
  27       return []
  28     platforms = platforms.union(dependency_feature['platforms'])
  29   feature['platforms'] = list(platforms)
  30
  31
  32 class _FeaturesCache(object):
  33   def __init__(self, file_system, compiled_fs_factory, *json_paths):
  34     self._file_system = file_system
  35     self._cache = compiled_fs_factory.Create(
  36         file_system, self._CreateCache, type(self))
  37     self._json_path = json_paths[0]
  38     self._extra_paths = json_paths[1:]
  39
  40   def _CreateCache(self, _, features_json):
  41     features = features_utility.Parse(Parse(features_json))
  42     for path in self._extra_paths:
  43       extra_json = self._file_system.ReadSingle(path).Get()
  44       features = features_utility.MergedWith(
  45           features_utility.Parse(Parse(extra_json)), features)
  46     return features
  47
  48   def GetFeatures(self):
  49     if self._json_path is None:
  50       return {}
  51     return self._cache.GetFromFile(self._json_path).Get()
  52
  53
  54 class FeaturesBundle(object):
  55   '''Provides access to properties of API, Manifest, and Permission features.
  56   '''
  57   def __init__(self, file_system, compiled_fs_factory, object_store_creator):
  58     self._api_cache = _FeaturesCache(
  59         file_system,
  60         compiled_fs_factory,
  61         svn_constants.API_FEATURES_PATH)
  62     self._manifest_cache = _FeaturesCache(
  63         file_system,
  64         compiled_fs_factory,
  65         svn_constants.MANIFEST_FEATURES_PATH,
  66         svn_constants.MANIFEST_JSON_PATH)
  67     self._permission_cache = _FeaturesCache(
  68         file_system,
  69         compiled_fs_factory,
  70         svn_constants.PERMISSION_FEATURES_PATH,
  71         svn_constants.PERMISSIONS_JSON_PATH)
  72     self._object_store = object_store_creator.Create(_FeaturesCache, 'features')
  73
  74   def GetPermissionFeatures(self):
  75     return self._permission_cache.GetFeatures()
  76
  77   def GetManifestFeatures(self):
  78     return self._manifest_cache.GetFeatures()
  79
  80   def GetAPIFeatures(self):
  81     api_features = self._object_store.Get('api_features').Get()
  82     if api_features is None:
  83       api_features = self._api_cache.GetFeatures()
  84       # TODO(rockot): Handle inter-API dependencies more gracefully.
  85       # Not yet a problem because there is only one such case (windows -> tabs).
  86       # If we don't store this value before annotating platforms, inter-API
  87       # dependencies will lead to infinite recursion.
  88       self._object_store.Set('api_features', api_features)
  89       for feature in api_features.itervalues():
  90         _AddPlatformsFromDependencies(feature, self)
  91       self._object_store.Set('api_features', api_features)
  92     return api_features