Example #1
0
 def __init__(self):
     self.__storage = None
     self.__policies = []
     self._transformation_reader = None
     self.reader_factory = None
     self.writer_factory = None
     self.add_policy(StoragePolicy())
     self.cache = ObjectCache()
Example #2
0
 def __init__(self):
     self.__storage = None
     self.__policies = []
     self._transformation_reader = None
     self.reader_factory = None
     self.writer_factory = None
     self.add_policy(StoragePolicy())
     self.cache = ObjectCache()
Example #3
0
class PersistenceManager(object):
    implements(IPersistenceManager)
    _UNIQUE = object()
    
    def __init__(self):
        self.__storage = None
        self.__policies = []
        self._transformation_reader = None
        self.reader_factory = None
        self.writer_factory = None
        self.add_policy(StoragePolicy())
        self.cache = ObjectCache()
    def get_cache(self):
        return self.cache
    def get_storage(self):
        return self.__storage
    def get_policy(self):
        return self.__policies[0]
    def get_policies(self):
        return self.__policies[:]
    def get_reader_factory(self):
        return self.reader_factory
    def get_writer_factory(self):
        return self.writer_factory
    def set_reader_factory(self, factory):
        self.reader_factory = factory
        self._transformation_reader = factory()
        self._transformation_reader.set_manager(self)
    def set_writer_factory(self, factory):
        self.writer_factory = factory
    def set_storage(self, storage):
        if not IStorage.providedBy(storage):
            raise TypeError('Storage instance must provide IStorage.')
        if self.storage is not None:
            self.storage.commit()
        self.__storage = storage
        storage.set_manager(self)
    def add_policy(self, policy):
        if not IStoragePolicy.providedBy(policy):
            raise TypeError('Policy instance must provide IStoragePolicy.')
        if policy in self.__policies:
            raise TypeError('Policy already exists in manager.')
        policy.set_manager(self)
        self.__policies.append(policy)
    def remove_policy(self, policy):
        if policy is self.__policies[0]:
            raise TypeError('Cannot remove default policy.')
        self.__policies.remove(policy)
    storage = property(get_storage, set_storage)    
    policy = property(get_policy)
    policies = property(get_policies)
    def new_oid(self):
        return self.storage.generate_oid()
    def get_oid(self, instance):
        print 'get_oid(%s)' % (instance,)
        if isinstance(instance, _never_persistent):
            print '\t-> None, is instance of _never_persistent'
            return None
        if type(instance) in (dict, list):
            print '\t-> None, type in dict, list'
            return None
        if not IPersistent.providedBy(instance):
            print '\t-> None, IPersistent not provided by instance'
            return None
        persistent = IPersistentObject(instance)
        if persistent.get_oid() is None:
            self._configure_persistence(persistent)
            persistent.set_loaded()
            persistent.set_unsaved()
        elif not persistent.is_persistent():
            print '\t-> None, not persistent.is_persistent()'
            return None
        oid = persistent.get_oid()
        print '\t%s OID => %s' % (instance, oid)
        return oid
    def _configure_persistence(self, persistent, oid = None):
        manager = persistent.get_manager()
        if manager is None:
            persistent.set_manager(self)
        elif manager is not self:
            raise TypeError('Object has different manager')
        if persistent.get_oid() is None:
            if oid is None:
                oid = self.new_oid()
            persistent.set_oid(oid)
        persistent.enable_persistence()
    def get_object(self, oid):
        print 'Getting %s' % oid
        if not self.cache.has_instance(oid):
            print '\tcreating deferred for %s' % oid
            deferred = DeferredObject(self.load, oid)
            self.cache.add_instance(oid, deferred)
        instance = self.cache.as_instance(oid)
        print '\tget_object(%s) -> %s' % (oid, instance)
        return instance
    def load(self, oid):
        print 'Loading %s' % oid
        instance = self.cache.get_instance(oid, None)
        if instance is None or isinstance(instance, DeferredObject):
            transformation = self.storage.load_record(oid)
            instance = self._transformation_reader.read(transformation)
            persistent = IPersistentObject(instance)
            self._configure_persistence(persistent, oid)
            persistent.set_loaded()
            persistent.set_saved()
            instance = persistent.get_object()
        else: 
            print '\tloaded from cache!'
        print '\tload(%s) -> %s' % (oid, instance)
        return instance
    def store(self, instance):
        written = {}
        persistent = IPersistentObject(instance)
        oid = persistent.get_oid()
        instance = persistent.get_object()
        print 'Store %s with OID %s' % (instance, oid)
        transformation_writer = self.writer_factory(instance)
        transformation_writer.set_manager(self)
        for instance in transformation_writer:
            persistent = IPersistentObject(instance)
            oid = persistent.get_oid()
            if written.has_key(oid):
                continue
            if persistent.is_persistent() and not persistent.is_saved():
                instance = persistent.get_object()
                transformation = transformation_writer.write(instance)
                print '\t-> storing %s with OID %s' % (instance, oid)
                self.storage.store_record(oid, transformation)
                written[oid] = None
                persistent.set_saved()
                self.cache.add_instance(oid, instance)
            else: print '\t-> not storing %s with OID %s' % (instance, oid)
    def make_persistent(self, instance):
        print 'Make persistent called with %s' % (instance,)
        if not IPersistent.providedBy(instance):
            print '\tIPersistent not provided, directly providing'
            directly_provides(instance, IPersistent)
        persistent = IPersistentObject(instance)
        self._configure_persistence(persistent)
        persistent.set_unsaved()
        self.notify_modified(instance)
    def make_persistent_type(self, klass):
        if not inspect.isclass(klass):
            raise TypeError('Argument must be class.')
        if not IPersistent.implementedBy(klass):
            class_implements(klass, IPersistent)
    def make_transient(self, instance):
        persistent = IPersistentObject(instance)
        persistent.disable_persistence()
        persistent.clear_manager()
    def commit_changes(self):
        for policy in self.policies:
            policy.commit()
    def commit_storage(self):
        self.storage.commit()
    def commit(self):
        self.commit_changes()
        self.commit_storage()
    def terminate(self):
        for policy in self.policies:
            policy.terminate()
        self.storage.terminate()
    def notify_modified(self, instance):
        persistent = IPersistentObject(instance)
        self.policy.note_modified(persistent)
Example #4
0
class PersistenceManager(object):
    implements(IPersistenceManager)
    _UNIQUE = object()

    def __init__(self):
        self.__storage = None
        self.__policies = []
        self._transformation_reader = None
        self.reader_factory = None
        self.writer_factory = None
        self.add_policy(StoragePolicy())
        self.cache = ObjectCache()

    def get_cache(self):
        return self.cache

    def get_storage(self):
        return self.__storage

    def get_policy(self):
        return self.__policies[0]

    def get_policies(self):
        return self.__policies[:]

    def get_reader_factory(self):
        return self.reader_factory

    def get_writer_factory(self):
        return self.writer_factory

    def set_reader_factory(self, factory):
        self.reader_factory = factory
        self._transformation_reader = factory()
        self._transformation_reader.set_manager(self)

    def set_writer_factory(self, factory):
        self.writer_factory = factory

    def set_storage(self, storage):
        if not IStorage.providedBy(storage):
            raise TypeError('Storage instance must provide IStorage.')
        if self.storage is not None:
            self.storage.commit()
        self.__storage = storage
        storage.set_manager(self)

    def add_policy(self, policy):
        if not IStoragePolicy.providedBy(policy):
            raise TypeError('Policy instance must provide IStoragePolicy.')
        if policy in self.__policies:
            raise TypeError('Policy already exists in manager.')
        policy.set_manager(self)
        self.__policies.append(policy)

    def remove_policy(self, policy):
        if policy is self.__policies[0]:
            raise TypeError('Cannot remove default policy.')
        self.__policies.remove(policy)

    storage = property(get_storage, set_storage)
    policy = property(get_policy)
    policies = property(get_policies)

    def new_oid(self):
        return self.storage.generate_oid()

    def get_oid(self, instance):
        print 'get_oid(%s)' % (instance, )
        if isinstance(instance, _never_persistent):
            print '\t-> None, is instance of _never_persistent'
            return None
        if type(instance) in (dict, list):
            print '\t-> None, type in dict, list'
            return None
        if not IPersistent.providedBy(instance):
            print '\t-> None, IPersistent not provided by instance'
            return None
        persistent = IPersistentObject(instance)
        if persistent.get_oid() is None:
            self._configure_persistence(persistent)
            persistent.set_loaded()
            persistent.set_unsaved()
        elif not persistent.is_persistent():
            print '\t-> None, not persistent.is_persistent()'
            return None
        oid = persistent.get_oid()
        print '\t%s OID => %s' % (instance, oid)
        return oid

    def _configure_persistence(self, persistent, oid=None):
        manager = persistent.get_manager()
        if manager is None:
            persistent.set_manager(self)
        elif manager is not self:
            raise TypeError('Object has different manager')
        if persistent.get_oid() is None:
            if oid is None:
                oid = self.new_oid()
            persistent.set_oid(oid)
        persistent.enable_persistence()

    def get_object(self, oid):
        print 'Getting %s' % oid
        if not self.cache.has_instance(oid):
            print '\tcreating deferred for %s' % oid
            deferred = DeferredObject(self.load, oid)
            self.cache.add_instance(oid, deferred)
        instance = self.cache.as_instance(oid)
        print '\tget_object(%s) -> %s' % (oid, instance)
        return instance

    def load(self, oid):
        print 'Loading %s' % oid
        instance = self.cache.get_instance(oid, None)
        if instance is None or isinstance(instance, DeferredObject):
            transformation = self.storage.load_record(oid)
            instance = self._transformation_reader.read(transformation)
            persistent = IPersistentObject(instance)
            self._configure_persistence(persistent, oid)
            persistent.set_loaded()
            persistent.set_saved()
            instance = persistent.get_object()
        else:
            print '\tloaded from cache!'
        print '\tload(%s) -> %s' % (oid, instance)
        return instance

    def store(self, instance):
        written = {}
        persistent = IPersistentObject(instance)
        oid = persistent.get_oid()
        instance = persistent.get_object()
        print 'Store %s with OID %s' % (instance, oid)
        transformation_writer = self.writer_factory(instance)
        transformation_writer.set_manager(self)
        for instance in transformation_writer:
            persistent = IPersistentObject(instance)
            oid = persistent.get_oid()
            if written.has_key(oid):
                continue
            if persistent.is_persistent() and not persistent.is_saved():
                instance = persistent.get_object()
                transformation = transformation_writer.write(instance)
                print '\t-> storing %s with OID %s' % (instance, oid)
                self.storage.store_record(oid, transformation)
                written[oid] = None
                persistent.set_saved()
                self.cache.add_instance(oid, instance)
            else:
                print '\t-> not storing %s with OID %s' % (instance, oid)

    def make_persistent(self, instance):
        print 'Make persistent called with %s' % (instance, )
        if not IPersistent.providedBy(instance):
            print '\tIPersistent not provided, directly providing'
            directly_provides(instance, IPersistent)
        persistent = IPersistentObject(instance)
        self._configure_persistence(persistent)
        persistent.set_unsaved()
        self.notify_modified(instance)

    def make_persistent_type(self, klass):
        if not inspect.isclass(klass):
            raise TypeError('Argument must be class.')
        if not IPersistent.implementedBy(klass):
            class_implements(klass, IPersistent)

    def make_transient(self, instance):
        persistent = IPersistentObject(instance)
        persistent.disable_persistence()
        persistent.clear_manager()

    def commit_changes(self):
        for policy in self.policies:
            policy.commit()

    def commit_storage(self):
        self.storage.commit()

    def commit(self):
        self.commit_changes()
        self.commit_storage()

    def terminate(self):
        for policy in self.policies:
            policy.terminate()
        self.storage.terminate()

    def notify_modified(self, instance):
        persistent = IPersistentObject(instance)
        self.policy.note_modified(persistent)