anonymousland-synapse/synapse/media/storage_provider.py

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# Copyright 2018-2021 The Matrix.org Foundation C.I.C.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import abc
import logging
import os
import shutil
from typing import TYPE_CHECKING, Callable, Optional
from synapse.config._base import Config
from synapse.logging.context import defer_to_thread, run_in_background
from synapse.util.async_helpers import maybe_awaitable
from ._base import FileInfo, Responder
from .media_storage import FileResponder
logger = logging.getLogger(__name__)
if TYPE_CHECKING:
from synapse.server import HomeServer
class StorageProvider(metaclass=abc.ABCMeta):
"""A storage provider is a service that can store uploaded media and
retrieve them.
"""
@abc.abstractmethod
async def store_file(self, path: str, file_info: FileInfo) -> None:
"""Store the file described by file_info. The actual contents can be
retrieved by reading the file in file_info.upload_path.
Args:
path: Relative path of file in local cache
file_info: The metadata of the file.
"""
@abc.abstractmethod
async def fetch(self, path: str, file_info: FileInfo) -> Optional[Responder]:
"""Attempt to fetch the file described by file_info and stream it
into writer.
Args:
path: Relative path of file in local cache
file_info: The metadata of the file.
Returns:
Returns a Responder if the provider has the file, otherwise returns None.
"""
class StorageProviderWrapper(StorageProvider):
"""Wraps a storage provider and provides various config options
Args:
backend: The storage provider to wrap.
store_local: Whether to store new local files or not.
store_synchronous: Whether to wait for file to be successfully
uploaded, or todo the upload in the background.
store_remote: Whether remote media should be uploaded
"""
def __init__(
self,
backend: StorageProvider,
store_local: bool,
store_synchronous: bool,
store_remote: bool,
):
self.backend = backend
self.store_local = store_local
self.store_synchronous = store_synchronous
self.store_remote = store_remote
def __str__(self) -> str:
return "StorageProviderWrapper[%s]" % (self.backend,)
async def store_file(self, path: str, file_info: FileInfo) -> None:
if not file_info.server_name and not self.store_local:
return None
if file_info.server_name and not self.store_remote:
return None
if file_info.url_cache:
# The URL preview cache is short lived and not worth offloading or
# backing up.
return None
if self.store_synchronous:
# store_file is supposed to return an Awaitable, but guard
# against improper implementations.
await maybe_awaitable(self.backend.store_file(path, file_info)) # type: ignore
else:
# TODO: Handle errors.
async def store() -> None:
try:
return await maybe_awaitable(
self.backend.store_file(path, file_info)
)
except Exception:
logger.exception("Error storing file")
run_in_background(store)
async def fetch(self, path: str, file_info: FileInfo) -> Optional[Responder]:
if file_info.url_cache:
# Files in the URL preview cache definitely aren't stored here,
# so avoid any potentially slow I/O or network access.
return None
# store_file is supposed to return an Awaitable, but guard
# against improper implementations.
return await maybe_awaitable(self.backend.fetch(path, file_info))
class FileStorageProviderBackend(StorageProvider):
"""A storage provider that stores files in a directory on a filesystem.
Args:
hs
config: The config returned by `parse_config`.
"""
def __init__(self, hs: "HomeServer", config: str):
self.hs = hs
self.cache_directory = hs.config.media.media_store_path
self.base_directory = config
def __str__(self) -> str:
return "FileStorageProviderBackend[%s]" % (self.base_directory,)
async def store_file(self, path: str, file_info: FileInfo) -> None:
"""See StorageProvider.store_file"""
primary_fname = os.path.join(self.cache_directory, path)
backup_fname = os.path.join(self.base_directory, path)
dirname = os.path.dirname(backup_fname)
os.makedirs(dirname, exist_ok=True)
# mypy needs help inferring the type of the second parameter, which is generic
shutil_copyfile: Callable[[str, str], str] = shutil.copyfile
await defer_to_thread(
self.hs.get_reactor(),
shutil_copyfile,
primary_fname,
backup_fname,
)
async def fetch(self, path: str, file_info: FileInfo) -> Optional[Responder]:
"""See StorageProvider.fetch"""
backup_fname = os.path.join(self.base_directory, path)
if os.path.isfile(backup_fname):
return FileResponder(open(backup_fname, "rb"))
return None
@staticmethod
def parse_config(config: dict) -> str:
"""Called on startup to parse config supplied. This should parse
the config and raise if there is a problem.
The returned value is passed into the constructor.
In this case we only care about a single param, the directory, so let's
just pull that out.
"""
return Config.ensure_directory(config["directory"])