Source code for

# coding=utf-8
import logging

[docs]class ResourceCache(object): """A :class:`~oldman.resource.cache.ResourceCache` object caches :class:`~oldman.resource.Resource` objects. It interfaces a :class:`dogpile.cache.region.CacheRegion` front-end object. If not `None`, `cache_region` must be already configured, i.e. mapped to a back-end (like `Memcache <>`_ or `Redis <>`_). See `the official list of back-ends <>`_ supported by `dogpile.cache <>`_. When `cache_region` is None, no effective caching is done. However, methods :func:`~oldman.resource.cache.ResourceCache.get_resource`, :func:`~oldman.resource.cache.ResourceCache.set_resource` and :func:`~oldman.resource.cache.ResourceCache.remove_resource` can still safely be called. They just have no effect. :param cache_region: :class:`dogpile.cache.region.CacheRegion` object. This object must already be configured. Defaults to None (no cache). """ def __init__(self, cache_region): self._region = cache_region self._logger = logging.getLogger(__name__) @property
[docs] def cache_region(self): """:class:`dogpile.cache.region.CacheRegion` object. May be `None`.""" return self._region
[docs] def is_active(self): """:return: `True` if the `cache_region` is active.""" return self._region is not None
[docs] def change_cache_region(self, cache_region): """Replaces the `cache_region` attribute. :param cache_region: :class:`dogpile.cache.region.CacheRegion` object. May be `None`. """ self._region = cache_region
[docs] def get_resource(self, id): """Gets a :class:`~oldman.resource.Resource` object from the cache. :param id: IRI of the resource. :return: :class:`~oldman.resource.Resource` object or `None` if not found. """ if id is None or self._region is None: return None resource = self._region.get(unicode(id)) if resource: self._logger.debug(u"%s found in the cache." % return resource return None
[docs] def set_resource(self, resource): """Adds or updates a :class:`~oldman.resource.Resource` object in the cache. Its key is its `ìd`. :param resource: :class:`~oldman.resource.Resource` object to add to the cache (or update). """ if self._region is not None: self._region.set(unicode(, resource) self._logger.debug(u"%s cached." %
[docs] def remove_resource(self, resource): """Removes a :class:`~oldman.resource.Resource` object from the cache. Indempotent (no problem if the :class:`~oldman.resource.Resource` object is not the cache). Does nothing if `cache_region` is `None`. :param resource: :class:`~oldman.resource.Resource` object to remove from the cache.""" if self._region is not None: self._region.delete(unicode( self._logger.debug(u"%s removed from the cache." %
[docs] def remove_resource_from_id(self, id): """:func:`~oldman.resource.cache.ResourceCache.remove_resource` is usually preferred. Indempotent and does nothing if `cache_region` is `None`. :param id: IRI of the resource to remove from the cache. """ if self._region is not None: self._region.delete(unicode(id)) self._logger.debug(u"%s removed from the cache." % id)
[docs] def invalidate_cache(self): """See :func:`dogpile.cache.region.CacheRegion.invalidate`. .. admonition:: Cache invalidation Please note that this method is not supported by some :class:`dogpile.cache.api.CacheBackend` objects. In such a case, this method has no effect so entries must be removed **explicitly** from their keys. """ if self._region is not None: self._region.invalidate()