__init__.py
# 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 warnings
STORAGE_IMPLEMENTATION = {
"pipeline",
"local",
"remote",
"memory",
"filter",
"buffer",
"retry",
"validate",
"cassandra",
}
def get_storage(cls, **kwargs):
"""Get a storage object of class `storage_class` with arguments
`storage_args`.
Args:
storage (dict): dictionary with keys:
- cls (str): storage's class, either local, remote, memory, filter,
buffer
- args (dict): dictionary with keys
Returns:
an instance of swh.storage.Storage or compatible class
Raises:
ValueError if passed an unknown storage class.
"""
if cls not in STORAGE_IMPLEMENTATION:
raise ValueError(
"Unknown storage class `%s`. Supported: %s"
% (cls, ", ".join(STORAGE_IMPLEMENTATION))
)
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 == "remote":
from .api.client import RemoteStorage as Storage
elif cls == "local":
from .storage import Storage
elif cls == "cassandra":
from .cassandra import CassandraStorage as Storage
elif cls == "memory":
from .in_memory import InMemoryStorage as Storage
elif cls == "filter":
from .filter import FilteringProxyStorage as Storage
elif cls == "buffer":
from .buffer import BufferingProxyStorage as Storage
elif cls == "retry":
from .retry import RetryingProxyStorage as Storage
elif cls == "validate":
from .validate import ValidatingProxyStorage as Storage
return Storage(**kwargs)
def get_storage_pipeline(steps):
"""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
storage_config = step
return get_storage(**storage_config)