Synnefo

    """Abstract backend class.

    This class serves as a reference for actual implementations.

    The purpose of the backend is to provide the necessary functions

    for handling data and metadata.

    It is responsible for the actual storage and retrieval of information.

    Note that the account level is always valid as it is checked

    from another subsystem.

    When not replacing metadata/groups/policy, keys with empty values

    should be deleted.

        'default_account_policy': A dictionary with default account policy

                                  settings

        'default_container_policy': A dictionary with default container policy

                                    settings

        Keyword arguments:

    def get_account_meta(self, user, account, domain, until=None,

                         include_user_defined=True, external_quota=None):

            'external_quota': The quota computed from external quota holder

                              mechanism

        Keyword arguments:

        """Return a dictionary with the user groups defined for the account.

            'versioning': Can be 'auto', 'manual' or 'none' (default: 'manual')

    def list_containers(self, user, account, marker=None, limit=10000,

                        shared=False, until=None, public=False):

        Keyword arguments:

    def list_container_meta(self, user, account, container, domain,

                            until=None):

        """Return a list of the container's object meta keys for a domain.

    def get_container_meta(self, user, account, container, domain, until=None,

                           include_user_defined=True):

    def update_container_meta(self, user, account, container, domain, meta,

                              replace=False):

        Keyword arguments:

            'versioning': Can be 'auto', 'manual' or 'none' (default: 'manual')

    def update_container_policy(self, user, account, container, policy,

                                replace=False):

    def put_container(self, user, account, container, policy=None):

    def delete_container(self, user, account, container, until=None,

                         delimiter=None):

        Keyword arguments:

            'delimiter': If not None, deletes the container contents starting

                         with the delimiter

    def list_objects(self, user, account, container, prefix='', delimiter=None,

                     marker=None, limit=10000, virtual=True, domain=None,

                     keys=None, shared=False, until=None, size_range=None,

                     public=False):

        """List (object name, object version_id) under a container.

        Keyword arguments:

            'delimiter': Return unique names before 'delimiter' and

                         after 'prefix'

                       If set, the result will include all names after 'prefix'

    def list_object_meta(self, user, account, container, prefix='',

                         delimiter=None, marker=None, limit=10000,

                         virtual=True, domain=None, keys=None, shared=False,

                         until=None, size_range=None, public=False):

        """Return a list of metadata dicts of objects under a container.

        """Return a list of paths enforce permissions under a container.

        """Return a mapping of object paths to public ids under a container."""

    def get_object_meta(self, user, account, container, name, domain,

                        version=None, include_user_defined=True):

            'modified_by': The user that committed the object

                           (version requested)

            'uuid': A unique identifier that persists data or metadata updates

                    and renames

    def update_object_meta(self, user, account, container, name, domain, meta,

                           replace=False):

        """Update object metadata for a domain and return the new version.

    def update_object_permissions(self, user, account, container, name,

                                  permissions):

    def update_object_hashmap(self, user, account, container, name, size, type,

                              hashmap, checksum, domain, meta=None,

                              replace_meta=False, permissions=None):

        """Create/update an object's hashmap and return the new version.

    def update_object_checksum(self, user, account, container, name, version,

                               checksum):

    def copy_object(self, user, src_account, src_container, src_name,

                    dest_account, dest_container, dest_name, type, domain,

                    meta=None, replace_meta=False, permissions=None,

                    src_version=None, delimiter=None):

            'meta': Dictionary with metadata to change from source

                    to destination

            'delimiter': Copy objects whose path starts with

                         src_name + delimiter

    def move_object(self, user, src_account, src_container, src_name,

                    dest_account, dest_container, dest_name, type, domain,

                    meta=None, replace_meta=False, permissions=None,

                    delimiter=None):

            'meta': Dictionary with metadata to change from source

                    to destination

            'delimiter': Move objects whose path starts with

                         src_name + delimiter

    def delete_object(self, user, account, container, name, until=None,

                      delimiter=None):

            'delimiter': Delete objects whose path starting with

                         name + delimiter

        """Return a list of all object (version, version_timestamp) tuples.

    def get_domain_objects(self, domain, user=None):

        """Return a list of tuples for objects under the domain.

        Parameters:

            'user': return only objects accessible to the user.

        """