1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
|
# -*- 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
import sys
import six
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()
defer.returnValue(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:
t, v, tb = sys.exc_info()
try:
os.remove(fname)
except Exception:
pass
six.reraise(t, v, tb)
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):
defer.returnValue(FileResponder(open(local_path, "rb")))
for provider in self.storage_providers:
res = yield provider.fetch(path, file_info)
if res:
defer.returnValue(res)
defer.returnValue(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):
defer.returnValue(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()
defer.returnValue(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()
|
