| # Copyright 2010 Gentoo Foundation |
| # Distributed under the terms of the GNU General Public License v2 |
| |
| __all__ = ( |
| 'features_set', |
| ) |
| |
| class features_set(object): |
| """ |
| Provides relevant set operations needed for access and modification of |
| config.features. The FEATURES variable is automatically synchronized |
| upon modification. |
| |
| Modifications result in a permanent override that will cause the change |
| to propagate to the incremental stacking mechanism in config.regenerate(). |
| This eliminates the need to call config.backup_changes() when FEATURES |
| is modified, since any overrides are guaranteed to persist despite calls |
| to config.reset(). |
| """ |
| |
| def __init__(self, settings): |
| self._settings = settings |
| self._features = set() |
| |
| def __contains__(self, k): |
| return k in self._features |
| |
| def __iter__(self): |
| return iter(self._features) |
| |
| def _sync_env_var(self): |
| self._settings['FEATURES'] = ' '.join(sorted(self._features)) |
| |
| def add(self, k): |
| self._settings.modifying() |
| self._settings._features_overrides.append(k) |
| if k not in self._features: |
| self._features.add(k) |
| self._sync_env_var() |
| |
| def update(self, values): |
| self._settings.modifying() |
| values = list(values) |
| self._settings._features_overrides.extend(values) |
| need_sync = False |
| for k in values: |
| if k in self._features: |
| continue |
| self._features.add(k) |
| need_sync = True |
| if need_sync: |
| self._sync_env_var() |
| |
| def remove(self, k): |
| """ |
| This never raises KeyError, since it records a permanent override |
| that will prevent the given flag from ever being added again by |
| incremental stacking in config.regenerate(). |
| """ |
| self.discard(k) |
| |
| def discard(self, k): |
| self._settings.modifying() |
| self._settings._features_overrides.append('-' + k) |
| if k in self._features: |
| self._features.remove(k) |
| self._sync_env_var() |
