]> jfr.im git - yt-dlp.git/blob - yt_dlp/downloader/http.py
Standardize retry mechanism (#1649)
[yt-dlp.git] / yt_dlp / downloader / http.py
1 import http.client
2 import os
3 import random
4 import socket
5 import ssl
6 import time
7 import urllib.error
8
9 from .common import FileDownloader
10 from ..utils import (
11 ContentTooShortError,
12 RetryManager,
13 ThrottledDownload,
14 XAttrMetadataError,
15 XAttrUnavailableError,
16 encodeFilename,
17 int_or_none,
18 parse_http_range,
19 sanitized_Request,
20 try_call,
21 write_xattr,
22 )
23
24 RESPONSE_READ_EXCEPTIONS = (
25 TimeoutError,
26 socket.timeout, # compat: py < 3.10
27 ConnectionError,
28 ssl.SSLError,
29 http.client.HTTPException
30 )
31
32
33 class HttpFD(FileDownloader):
34 def real_download(self, filename, info_dict):
35 url = info_dict['url']
36 request_data = info_dict.get('request_data', None)
37
38 class DownloadContext(dict):
39 __getattr__ = dict.get
40 __setattr__ = dict.__setitem__
41 __delattr__ = dict.__delitem__
42
43 ctx = DownloadContext()
44 ctx.filename = filename
45 ctx.tmpfilename = self.temp_name(filename)
46 ctx.stream = None
47
48 # Do not include the Accept-Encoding header
49 headers = {'Youtubedl-no-compression': 'True'}
50 add_headers = info_dict.get('http_headers')
51 if add_headers:
52 headers.update(add_headers)
53
54 is_test = self.params.get('test', False)
55 chunk_size = self._TEST_FILE_SIZE if is_test else (
56 self.params.get('http_chunk_size')
57 or info_dict.get('downloader_options', {}).get('http_chunk_size')
58 or 0)
59
60 ctx.open_mode = 'wb'
61 ctx.resume_len = 0
62 ctx.block_size = self.params.get('buffersize', 1024)
63 ctx.start_time = time.time()
64
65 # parse given Range
66 req_start, req_end, _ = parse_http_range(headers.get('Range'))
67
68 if self.params.get('continuedl', True):
69 # Establish possible resume length
70 if os.path.isfile(encodeFilename(ctx.tmpfilename)):
71 ctx.resume_len = os.path.getsize(
72 encodeFilename(ctx.tmpfilename))
73
74 ctx.is_resume = ctx.resume_len > 0
75
76 class SucceedDownload(Exception):
77 pass
78
79 class RetryDownload(Exception):
80 def __init__(self, source_error):
81 self.source_error = source_error
82
83 class NextFragment(Exception):
84 pass
85
86 def establish_connection():
87 ctx.chunk_size = (random.randint(int(chunk_size * 0.95), chunk_size)
88 if not is_test and chunk_size else chunk_size)
89 if ctx.resume_len > 0:
90 range_start = ctx.resume_len
91 if req_start is not None:
92 # offset the beginning of Range to be within request
93 range_start += req_start
94 if ctx.is_resume:
95 self.report_resuming_byte(ctx.resume_len)
96 ctx.open_mode = 'ab'
97 elif req_start is not None:
98 range_start = req_start
99 elif ctx.chunk_size > 0:
100 range_start = 0
101 else:
102 range_start = None
103 ctx.is_resume = False
104
105 if ctx.chunk_size:
106 chunk_aware_end = range_start + ctx.chunk_size - 1
107 # we're not allowed to download outside Range
108 range_end = chunk_aware_end if req_end is None else min(chunk_aware_end, req_end)
109 elif req_end is not None:
110 # there's no need for chunked downloads, so download until the end of Range
111 range_end = req_end
112 else:
113 range_end = None
114
115 if try_call(lambda: range_start > range_end):
116 ctx.resume_len = 0
117 ctx.open_mode = 'wb'
118 raise RetryDownload(Exception(f'Conflicting range. (start={range_start} > end={range_end})'))
119
120 if try_call(lambda: range_end >= ctx.content_len):
121 range_end = ctx.content_len - 1
122
123 request = sanitized_Request(url, request_data, headers)
124 has_range = range_start is not None
125 if has_range:
126 request.add_header('Range', f'bytes={int(range_start)}-{int_or_none(range_end) or ""}')
127 # Establish connection
128 try:
129 ctx.data = self.ydl.urlopen(request)
130 # When trying to resume, Content-Range HTTP header of response has to be checked
131 # to match the value of requested Range HTTP header. This is due to a webservers
132 # that don't support resuming and serve a whole file with no Content-Range
133 # set in response despite of requested Range (see
134 # https://github.com/ytdl-org/youtube-dl/issues/6057#issuecomment-126129799)
135 if has_range:
136 content_range = ctx.data.headers.get('Content-Range')
137 content_range_start, content_range_end, content_len = parse_http_range(content_range)
138 # Content-Range is present and matches requested Range, resume is possible
139 if range_start == content_range_start and (
140 # Non-chunked download
141 not ctx.chunk_size
142 # Chunked download and requested piece or
143 # its part is promised to be served
144 or content_range_end == range_end
145 or content_len < range_end):
146 ctx.content_len = content_len
147 if content_len or req_end:
148 ctx.data_len = min(content_len or req_end, req_end or content_len) - (req_start or 0)
149 return
150 # Content-Range is either not present or invalid. Assuming remote webserver is
151 # trying to send the whole file, resume is not possible, so wiping the local file
152 # and performing entire redownload
153 self.report_unable_to_resume()
154 ctx.resume_len = 0
155 ctx.open_mode = 'wb'
156 ctx.data_len = ctx.content_len = int_or_none(ctx.data.info().get('Content-length', None))
157 except urllib.error.HTTPError as err:
158 if err.code == 416:
159 # Unable to resume (requested range not satisfiable)
160 try:
161 # Open the connection again without the range header
162 ctx.data = self.ydl.urlopen(
163 sanitized_Request(url, request_data, headers))
164 content_length = ctx.data.info()['Content-Length']
165 except urllib.error.HTTPError as err:
166 if err.code < 500 or err.code >= 600:
167 raise
168 else:
169 # Examine the reported length
170 if (content_length is not None
171 and (ctx.resume_len - 100 < int(content_length) < ctx.resume_len + 100)):
172 # The file had already been fully downloaded.
173 # Explanation to the above condition: in issue #175 it was revealed that
174 # YouTube sometimes adds or removes a few bytes from the end of the file,
175 # changing the file size slightly and causing problems for some users. So
176 # I decided to implement a suggested change and consider the file
177 # completely downloaded if the file size differs less than 100 bytes from
178 # the one in the hard drive.
179 self.report_file_already_downloaded(ctx.filename)
180 self.try_rename(ctx.tmpfilename, ctx.filename)
181 self._hook_progress({
182 'filename': ctx.filename,
183 'status': 'finished',
184 'downloaded_bytes': ctx.resume_len,
185 'total_bytes': ctx.resume_len,
186 }, info_dict)
187 raise SucceedDownload()
188 else:
189 # The length does not match, we start the download over
190 self.report_unable_to_resume()
191 ctx.resume_len = 0
192 ctx.open_mode = 'wb'
193 return
194 elif err.code < 500 or err.code >= 600:
195 # Unexpected HTTP error
196 raise
197 raise RetryDownload(err)
198 except urllib.error.URLError as err:
199 if isinstance(err.reason, ssl.CertificateError):
200 raise
201 raise RetryDownload(err)
202 # In urllib.request.AbstractHTTPHandler, the response is partially read on request.
203 # Any errors that occur during this will not be wrapped by URLError
204 except RESPONSE_READ_EXCEPTIONS as err:
205 raise RetryDownload(err)
206
207 def close_stream():
208 if ctx.stream is not None:
209 if not ctx.tmpfilename == '-':
210 ctx.stream.close()
211 ctx.stream = None
212
213 def download():
214 data_len = ctx.data.info().get('Content-length', None)
215
216 # Range HTTP header may be ignored/unsupported by a webserver
217 # (e.g. extractor/scivee.py, extractor/bambuser.py).
218 # However, for a test we still would like to download just a piece of a file.
219 # To achieve this we limit data_len to _TEST_FILE_SIZE and manually control
220 # block size when downloading a file.
221 if is_test and (data_len is None or int(data_len) > self._TEST_FILE_SIZE):
222 data_len = self._TEST_FILE_SIZE
223
224 if data_len is not None:
225 data_len = int(data_len) + ctx.resume_len
226 min_data_len = self.params.get('min_filesize')
227 max_data_len = self.params.get('max_filesize')
228 if min_data_len is not None and data_len < min_data_len:
229 self.to_screen(
230 f'\r[download] File is smaller than min-filesize ({data_len} bytes < {min_data_len} bytes). Aborting.')
231 return False
232 if max_data_len is not None and data_len > max_data_len:
233 self.to_screen(
234 f'\r[download] File is larger than max-filesize ({data_len} bytes > {max_data_len} bytes). Aborting.')
235 return False
236
237 byte_counter = 0 + ctx.resume_len
238 block_size = ctx.block_size
239 start = time.time()
240
241 # measure time over whole while-loop, so slow_down() and best_block_size() work together properly
242 now = None # needed for slow_down() in the first loop run
243 before = start # start measuring
244
245 def retry(e):
246 close_stream()
247 ctx.resume_len = (byte_counter if ctx.tmpfilename == '-'
248 else os.path.getsize(encodeFilename(ctx.tmpfilename)))
249 raise RetryDownload(e)
250
251 while True:
252 try:
253 # Download and write
254 data_block = ctx.data.read(block_size if not is_test else min(block_size, data_len - byte_counter))
255 except RESPONSE_READ_EXCEPTIONS as err:
256 retry(err)
257
258 byte_counter += len(data_block)
259
260 # exit loop when download is finished
261 if len(data_block) == 0:
262 break
263
264 # Open destination file just in time
265 if ctx.stream is None:
266 try:
267 ctx.stream, ctx.tmpfilename = self.sanitize_open(
268 ctx.tmpfilename, ctx.open_mode)
269 assert ctx.stream is not None
270 ctx.filename = self.undo_temp_name(ctx.tmpfilename)
271 self.report_destination(ctx.filename)
272 except OSError as err:
273 self.report_error('unable to open for writing: %s' % str(err))
274 return False
275
276 if self.params.get('xattr_set_filesize', False) and data_len is not None:
277 try:
278 write_xattr(ctx.tmpfilename, 'user.ytdl.filesize', str(data_len).encode())
279 except (XAttrUnavailableError, XAttrMetadataError) as err:
280 self.report_error('unable to set filesize xattr: %s' % str(err))
281
282 try:
283 ctx.stream.write(data_block)
284 except OSError as err:
285 self.to_stderr('\n')
286 self.report_error('unable to write data: %s' % str(err))
287 return False
288
289 # Apply rate limit
290 self.slow_down(start, now, byte_counter - ctx.resume_len)
291
292 # end measuring of one loop run
293 now = time.time()
294 after = now
295
296 # Adjust block size
297 if not self.params.get('noresizebuffer', False):
298 block_size = self.best_block_size(after - before, len(data_block))
299
300 before = after
301
302 # Progress message
303 speed = self.calc_speed(start, now, byte_counter - ctx.resume_len)
304 if ctx.data_len is None:
305 eta = None
306 else:
307 eta = self.calc_eta(start, time.time(), ctx.data_len - ctx.resume_len, byte_counter - ctx.resume_len)
308
309 self._hook_progress({
310 'status': 'downloading',
311 'downloaded_bytes': byte_counter,
312 'total_bytes': ctx.data_len,
313 'tmpfilename': ctx.tmpfilename,
314 'filename': ctx.filename,
315 'eta': eta,
316 'speed': speed,
317 'elapsed': now - ctx.start_time,
318 'ctx_id': info_dict.get('ctx_id'),
319 }, info_dict)
320
321 if data_len is not None and byte_counter == data_len:
322 break
323
324 if speed and speed < (self.params.get('throttledratelimit') or 0):
325 # The speed must stay below the limit for 3 seconds
326 # This prevents raising error when the speed temporarily goes down
327 if ctx.throttle_start is None:
328 ctx.throttle_start = now
329 elif now - ctx.throttle_start > 3:
330 if ctx.stream is not None and ctx.tmpfilename != '-':
331 ctx.stream.close()
332 raise ThrottledDownload()
333 elif speed:
334 ctx.throttle_start = None
335
336 if not is_test and ctx.chunk_size and ctx.content_len is not None and byte_counter < ctx.content_len:
337 ctx.resume_len = byte_counter
338 # ctx.block_size = block_size
339 raise NextFragment()
340
341 if ctx.stream is None:
342 self.to_stderr('\n')
343 self.report_error('Did not get any data blocks')
344 return False
345 if ctx.tmpfilename != '-':
346 ctx.stream.close()
347
348 if data_len is not None and byte_counter != data_len:
349 err = ContentTooShortError(byte_counter, int(data_len))
350 retry(err)
351
352 self.try_rename(ctx.tmpfilename, ctx.filename)
353
354 # Update file modification time
355 if self.params.get('updatetime', True):
356 info_dict['filetime'] = self.try_utime(ctx.filename, ctx.data.info().get('last-modified', None))
357
358 self._hook_progress({
359 'downloaded_bytes': byte_counter,
360 'total_bytes': byte_counter,
361 'filename': ctx.filename,
362 'status': 'finished',
363 'elapsed': time.time() - ctx.start_time,
364 'ctx_id': info_dict.get('ctx_id'),
365 }, info_dict)
366
367 return True
368
369 for retry in RetryManager(self.params.get('retries'), self.report_retry):
370 try:
371 establish_connection()
372 return download()
373 except RetryDownload as err:
374 retry.error = err.source_error
375 continue
376 except NextFragment:
377 retry.error = None
378 retry.attempt -= 1
379 continue
380 except SucceedDownload:
381 return True
382 except: # noqa: E722
383 close_stream()
384 raise
385 return False