Source code for swh.storage

# Copyright (C) 2015-2020  The Software Heritage developers
# See the AUTHORS file at the top-level directory of this distribution
# License: GNU General Public License version 3, or any later version
# See top-level LICENSE file for more information

import importlib
from typing import TYPE_CHECKING, Any, Dict, List
import warnings

if TYPE_CHECKING:
    from .interface import StorageInterface


STORAGE_IMPLEMENTATIONS = {
    "remote": ".api.client.RemoteStorage",
    "memory": ".in_memory.InMemoryStorage",
    "cassandra": ".cassandra.CassandraStorage",
    "postgresql": ".postgresql.storage.Storage",
    # deprecated
    "local": ".postgresql.storage.Storage",
    # proxy storages
    "buffer": ".proxies.buffer.BufferingProxyStorage",
    "counter": ".proxies.counter.CountingProxyStorage",
    "filter": ".proxies.filter.FilteringProxyStorage",
    "retry": ".proxies.retry.RetryingProxyStorage",
    "tenacious": ".proxies.tenacious.TenaciousProxyStorage",
    "validate": ".proxies.validate.ValidatingProxyStorage",
}


[docs]def get_storage(cls: str, **kwargs) -> "StorageInterface": """Get a storage object of class `storage_class` with arguments `storage_args`. Args: cls (str): storage's class, can be: - ``local`` to use a postgresql database - ``cassandra`` to use a cassandra database - ``remote`` to connect to a swh-storage server - ``memory`` for an in-memory storage, useful for fast tests - ``filter``, ``buffer``, ... to use specific storage "proxies", see their respective documentations args (dict): dictionary with keys Returns: an instance of swh.storage.Storage or compatible class Raises: ValueError if passed an unknown storage class. """ if "args" in kwargs: warnings.warn( 'Explicit "args" key is deprecated, use keys directly instead.', DeprecationWarning, ) kwargs = kwargs["args"] if cls == "pipeline": return get_storage_pipeline(**kwargs) if cls == "local": warnings.warn( 'The "local" storage class is deprecated, use "postgresql" instead.', DeprecationWarning, ) class_path = STORAGE_IMPLEMENTATIONS.get(cls) if class_path is None: raise ValueError( "Unknown storage class `%s`. Supported: %s" % (cls, ", ".join(STORAGE_IMPLEMENTATIONS)) ) (module_path, class_name) = class_path.rsplit(".", 1) module = importlib.import_module(module_path, package=__package__) Storage = getattr(module, class_name) check_config = kwargs.pop("check_config", {}) storage = Storage(**kwargs) if check_config: if not storage.check_config(**check_config): raise EnvironmentError("storage check config failed") return storage
[docs]def get_storage_pipeline( steps: List[Dict[str, Any]], check_config=None ) -> "StorageInterface": """Recursively get a storage object that may use other storage objects as backends. Args: steps (List[dict]): List of dicts that may be used as kwargs for `get_storage`. Returns: an instance of swh.storage.Storage or compatible class Raises: ValueError if passed an unknown storage class. """ storage_config = None for step in reversed(steps): if "args" in step: warnings.warn( 'Explicit "args" key is deprecated, use keys directly ' "instead.", DeprecationWarning, ) step = { "cls": step["cls"], **step["args"], } if storage_config: step["storage"] = storage_config step["check_config"] = check_config storage_config = step if storage_config is None: raise ValueError("'pipeline' has no steps.") return get_storage(**storage_config)