Docserver: Consolidate features caching and access.

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

-# Copyright 2013 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.
-
-from itertools import ifilter
-from operator import itemgetter
-
-import features_utility as features
-from third_party.json_schema_compiler.json_parse import Parse
-
-def _ListifyPermissions(permissions):
-  '''Filter out any permissions that do not have a description or with a name
-  that ends with Private then sort permissions features by name into a list.
-  '''
-  def filter_permissions(perm):
-    return 'description' in perm and not perm['name'].endswith('Private')
-
-  return sorted(
-      ifilter(filter_permissions, permissions.values()),
-      key=itemgetter('name'))
-
-def _AddDependencyDescriptions(permissions, api_features):
-  '''Use |api_features| to determine the dependencies APIs have on permissions.
-  Add descriptions to |permissions| based on those dependencies.
-  '''
-  for name, permission in permissions.iteritems():
-    # Don't overwrite the description created by expanding a partial template.
-    if 'partial' in permission or not permission['platforms']:
-      continue
-
-    has_deps = False
-    if name in api_features:
-      for dependency in api_features[name].get('dependencies', ()):
-        if dependency.startswith('permission:'):
-          has_deps = True
-
-    if has_deps:
-      permission['partial'] = 'permissions/generic_description'
-
-class PermissionsDataSource(object):
-  '''Load and format permissions features to be used by templates. Requries a
-  template data source be set before use.
-  '''
-  def __init__(self,
-               compiled_fs_factory,
-               file_system,
-               api_features_path,
-               permissions_features_path,
-               permissions_json_path):
-    self._api_features_path = api_features_path
-    self._permissions_features_path = permissions_features_path
-    self._permissions_json_path = permissions_json_path
-    self._file_system = file_system
-    self._cache = compiled_fs_factory.Create(
-        self._CreatePermissionsDataSource, PermissionsDataSource)
-
-  def SetTemplateDataSource(self, template_data_source_factory):
-    '''Initialize a template data source to be used to render partial templates
-    into descriptions for permissions. Must be called before .get
-    '''
-    self._template_data_source = template_data_source_factory.Create(
-        None, {})
-
-  def _CreatePermissionsDataSource(self, _, content):
-    '''Combine the contents of |_permissions_json_path| and
-    |_permissions_features_path|. Filter into lists, one for extensions and
-    one for apps.
-    '''
-    api_features = Parse(self._file_system.ReadSingle(self._api_features_path))
-
-    def filter_for_platform(permissions, platform):
-      return _ListifyPermissions(features.Filtered(permissions, platform))
-
-    permissions_json = Parse(self._file_system.ReadSingle(
-        self._permissions_json_path))
-    permission_features = features.MergedWith(
-        features.Parse(Parse(content)), permissions_json)
-
-    _AddDependencyDescriptions(permission_features, api_features)
-    # Turn partial templates into descriptions, ensure anchors are set.
-    for permission in permission_features.values():
-      if not 'anchor' in permission:
-        permission['anchor'] = permission['name']
-      if 'partial' in permission:
-        permission['description'] = self._template_data_source.get(
-            permission['partial'])
-        del permission['partial']
-
-    return {
-      'declare_apps': filter_for_platform(permission_features, 'app'),
-      'declare_extensions': filter_for_platform(
-          permission_features, 'extension')
-    }
-
-  def get(self, key):
-    return self._cache.GetFromFile(self._permissions_features_path)[key]