| # 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 copy import deepcopy |
| |
| def Parse(features_json): |
| '''Standardize the raw features file json |features_json| into a more regular |
| format. Return a dictionary of features, keyed by name. Each feature is |
| guaranteed to have a 'name' attribute and a 'platforms' attribute that is a |
| list of platforms the feature is relevant to. Valid platforms are 'app' or |
| 'extension'. Other optional keys may be present in each feature. |
| |
| Features with a 'whitelist' are only relevant to apps or extensions on that |
| whitelist and are not included in the retured features dictionary. |
| ''' |
| features = {} |
| |
| for name, value in features_json.iteritems(): |
| # Some feature names corrispond to a list; force a list down to a single |
| # feature by removing entries that have a 'whitelist'. |
| if isinstance(value, list): |
| values = [subvalue for subvalue in value if not 'whitelist' in subvalue] |
| if values: |
| value = values[0] |
| else: |
| continue |
| |
| if 'whitelist' in value: |
| continue |
| |
| features[name] = { 'platforms': [] } |
| |
| platforms = value.pop('extension_types') |
| if platforms == 'all' or 'platform_app' in platforms: |
| features[name]['platforms'].append('app') |
| if platforms == 'all' or 'extension' in platforms: |
| features[name]['platforms'].append('extension') |
| |
| features[name]['name'] = name |
| features[name].update(value) |
| |
| return features |
| |
| def Filtered(features, platform=None): |
| '''Create a new features dictionary from |features| that contains only items |
| relevant to |platform|. Items retained are deepcopied. Returns new features |
| dictionary. |
| ''' |
| filtered_features = {} |
| |
| for name, feature in features.iteritems(): |
| if not platform or platform in feature['platforms']: |
| filtered_features[name] = deepcopy(feature) |
| |
| return filtered_features |
| |
| def MergedWith(features, other): |
| '''Merge |features| with an additional dictionary to create a new features |
| dictionary. If a feature is common to both |features| and |other|, then it is |
| merged using the standard dictionary update instead of being overwritten. |
| Returns the new features dictionary. |
| ''' |
| for key, value in other.iteritems(): |
| if key in features: |
| features[key].update(value) |
| else: |
| features[key] = value |
| |
| return features |