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- # -*- coding: utf-8 -*-
- # Copyright 2018 New Vecotr Ltd
- #
- # 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 contextlib
- import logging
- import os
- import shutil
- from twisted.internet import defer
- from twisted.protocols.basic import FileSender
- from synapse.logging.context import defer_to_thread, make_deferred_yieldable
- from synapse.util.file_consumer import BackgroundFileConsumer
- from ._base import Responder
- logger = logging.getLogger(__name__)
- class MediaStorage(object):
- """Responsible for storing/fetching files from local sources.
- Args:
- hs (synapse.server.Homeserver)
- local_media_directory (str): Base path where we store media on disk
- filepaths (MediaFilePaths)
- storage_providers ([StorageProvider]): List of StorageProvider that are
- used to fetch and store files.
- """
- def __init__(self, hs, local_media_directory, filepaths, storage_providers):
- self.hs = hs
- self.local_media_directory = local_media_directory
- self.filepaths = filepaths
- self.storage_providers = storage_providers
- @defer.inlineCallbacks
- def store_file(self, source, file_info):
- """Write `source` to the on disk media store, and also any other
- configured storage providers
- Args:
- source: A file like object that should be written
- file_info (FileInfo): Info about the file to store
- Returns:
- Deferred[str]: the file path written to in the primary media store
- """
- with self.store_into_file(file_info) as (f, fname, finish_cb):
- # Write to the main repository
- yield defer_to_thread(
- self.hs.get_reactor(), _write_file_synchronously, source, f
- )
- yield finish_cb()
- return fname
- @contextlib.contextmanager
- def store_into_file(self, file_info):
- """Context manager used to get a file like object to write into, as
- described by file_info.
- Actually yields a 3-tuple (file, fname, finish_cb), where file is a file
- like object that can be written to, fname is the absolute path of file
- on disk, and finish_cb is a function that returns a Deferred.
- fname can be used to read the contents from after upload, e.g. to
- generate thumbnails.
- finish_cb must be called and waited on after the file has been
- successfully been written to. Should not be called if there was an
- error.
- Args:
- file_info (FileInfo): Info about the file to store
- Example:
- with media_storage.store_into_file(info) as (f, fname, finish_cb):
- # .. write into f ...
- yield finish_cb()
- """
- path = self._file_info_to_path(file_info)
- fname = os.path.join(self.local_media_directory, path)
- dirname = os.path.dirname(fname)
- if not os.path.exists(dirname):
- os.makedirs(dirname)
- finished_called = [False]
- @defer.inlineCallbacks
- def finish():
- for provider in self.storage_providers:
- yield provider.store_file(path, file_info)
- finished_called[0] = True
- try:
- with open(fname, "wb") as f:
- yield f, fname, finish
- except Exception:
- try:
- os.remove(fname)
- except Exception:
- pass
- raise
- if not finished_called:
- raise Exception("Finished callback not called")
- @defer.inlineCallbacks
- def fetch_media(self, file_info):
- """Attempts to fetch media described by file_info from the local cache
- and configured storage providers.
- Args:
- file_info (FileInfo)
- Returns:
- Deferred[Responder|None]: Returns a Responder if the file was found,
- otherwise None.
- """
- path = self._file_info_to_path(file_info)
- local_path = os.path.join(self.local_media_directory, path)
- if os.path.exists(local_path):
- return FileResponder(open(local_path, "rb"))
- for provider in self.storage_providers:
- res = yield provider.fetch(path, file_info)
- if res:
- logger.debug("Streaming %s from %s", path, provider)
- return res
- return None
- @defer.inlineCallbacks
- def ensure_media_is_in_local_cache(self, file_info):
- """Ensures that the given file is in the local cache. Attempts to
- download it from storage providers if it isn't.
- Args:
- file_info (FileInfo)
- Returns:
- Deferred[str]: Full path to local file
- """
- path = self._file_info_to_path(file_info)
- local_path = os.path.join(self.local_media_directory, path)
- if os.path.exists(local_path):
- return local_path
- dirname = os.path.dirname(local_path)
- if not os.path.exists(dirname):
- os.makedirs(dirname)
- for provider in self.storage_providers:
- res = yield provider.fetch(path, file_info)
- if res:
- with res:
- consumer = BackgroundFileConsumer(
- open(local_path, "wb"), self.hs.get_reactor()
- )
- yield res.write_to_consumer(consumer)
- yield consumer.wait()
- return local_path
- raise Exception("file could not be found")
- def _file_info_to_path(self, file_info):
- """Converts file_info into a relative path.
- The path is suitable for storing files under a directory, e.g. used to
- store files on local FS under the base media repository directory.
- Args:
- file_info (FileInfo)
- Returns:
- str
- """
- if file_info.url_cache:
- if file_info.thumbnail:
- return self.filepaths.url_cache_thumbnail_rel(
- media_id=file_info.file_id,
- width=file_info.thumbnail_width,
- height=file_info.thumbnail_height,
- content_type=file_info.thumbnail_type,
- method=file_info.thumbnail_method,
- )
- return self.filepaths.url_cache_filepath_rel(file_info.file_id)
- if file_info.server_name:
- if file_info.thumbnail:
- return self.filepaths.remote_media_thumbnail_rel(
- server_name=file_info.server_name,
- file_id=file_info.file_id,
- width=file_info.thumbnail_width,
- height=file_info.thumbnail_height,
- content_type=file_info.thumbnail_type,
- method=file_info.thumbnail_method,
- )
- return self.filepaths.remote_media_filepath_rel(
- file_info.server_name, file_info.file_id
- )
- if file_info.thumbnail:
- return self.filepaths.local_media_thumbnail_rel(
- media_id=file_info.file_id,
- width=file_info.thumbnail_width,
- height=file_info.thumbnail_height,
- content_type=file_info.thumbnail_type,
- method=file_info.thumbnail_method,
- )
- return self.filepaths.local_media_filepath_rel(file_info.file_id)
- def _write_file_synchronously(source, dest):
- """Write `source` to the file like `dest` synchronously. Should be called
- from a thread.
- Args:
- source: A file like object that's to be written
- dest: A file like object to be written to
- """
- source.seek(0) # Ensure we read from the start of the file
- shutil.copyfileobj(source, dest)
- class FileResponder(Responder):
- """Wraps an open file that can be sent to a request.
- Args:
- open_file (file): A file like object to be streamed ot the client,
- is closed when finished streaming.
- """
- def __init__(self, open_file):
- self.open_file = open_file
- def write_to_consumer(self, consumer):
- return make_deferred_yieldable(
- FileSender().beginFileTransfer(self.open_file, consumer)
- )
- def __exit__(self, exc_type, exc_val, exc_tb):
- self.open_file.close()
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