From: Sergey M․ Date: Sat, 26 Aug 2017 16:55:48 +0000 (+0700) Subject: [http] Rework HTTP downloader X-Git-Url: http://git.bitcoin.ninja/index.cgi?p=youtube-dl;a=commitdiff_plain;h=a3c3a1e12898a57fc2323e4c7cc37ace35482ecf [http] Rework HTTP downloader * Simplify code and split into separate routines to facilitate maintaining * Make retry mechanism work on errors during actual download not only during connection establishment phase * Retry on ECONNRESET and ETIMEDOUT during reading data from network * Retry on content too short and various timeout errors * Show error description on retry * Closes #506, closes #809, closes #2849, closes #4240, closes #6023, closes #8625, closes #9483 --- diff --git a/youtube_dl/downloader/common.py b/youtube_dl/downloader/common.py index 77242dacc..75b8166c5 100644 --- a/youtube_dl/downloader/common.py +++ b/youtube_dl/downloader/common.py @@ -304,11 +304,11 @@ class FileDownloader(object): """Report attempt to resume at given byte.""" self.to_screen('[download] Resuming download at byte %s' % resume_len) - def report_retry(self, count, retries): + def report_retry(self, err, count, retries): """Report retry in case of HTTP error 5xx""" self.to_screen( - '[download] Got server HTTP error. Retrying (attempt %d of %s)...' - % (count, self.format_retries(retries))) + '[download] Got server HTTP error: %s. Retrying (attempt %d of %s)...' + % (error_to_compat_str(err), count, self.format_retries(retries))) def report_file_already_downloaded(self, file_name): """Report file has already been fully downloaded.""" diff --git a/youtube_dl/downloader/http.py b/youtube_dl/downloader/http.py index af405b950..8a6638cc2 100644 --- a/youtube_dl/downloader/http.py +++ b/youtube_dl/downloader/http.py @@ -22,8 +22,16 @@ from ..utils import ( class HttpFD(FileDownloader): def real_download(self, filename, info_dict): url = info_dict['url'] - tmpfilename = self.temp_name(filename) - stream = None + + class DownloadContext(dict): + __getattr__ = dict.get + __setattr__ = dict.__setitem__ + __delattr__ = dict.__delitem__ + + ctx = DownloadContext() + ctx.filename = filename + ctx.tmpfilename = self.temp_name(filename) + ctx.stream = None # Do not include the Accept-Encoding header headers = {'Youtubedl-no-compression': 'True'} @@ -38,46 +46,51 @@ class HttpFD(FileDownloader): if is_test: request.add_header('Range', 'bytes=0-%s' % str(self._TEST_FILE_SIZE - 1)) - # Establish possible resume length - if os.path.isfile(encodeFilename(tmpfilename)): - resume_len = os.path.getsize(encodeFilename(tmpfilename)) - else: - resume_len = 0 - - open_mode = 'wb' - if resume_len != 0: - if self.params.get('continuedl', True): - self.report_resuming_byte(resume_len) - request.add_header('Range', 'bytes=%d-' % resume_len) - open_mode = 'ab' - else: - resume_len = 0 + ctx.open_mode = 'wb' + ctx.resume_len = 0 + + if self.params.get('continuedl', True): + # Establish possible resume length + if os.path.isfile(encodeFilename(ctx.tmpfilename)): + ctx.resume_len = os.path.getsize(encodeFilename(ctx.tmpfilename)) count = 0 retries = self.params.get('retries', 0) - while count <= retries: + + class SucceedDownload(Exception): + pass + + class RetryDownload(Exception): + def __init__(self, source_error): + self.source_error = source_error + + def establish_connection(): + if ctx.resume_len != 0: + self.report_resuming_byte(ctx.resume_len) + request.add_header('Range', 'bytes=%d-' % ctx.resume_len) + ctx.open_mode = 'ab' # Establish connection try: - data = self.ydl.urlopen(request) + ctx.data = self.ydl.urlopen(request) # When trying to resume, Content-Range HTTP header of response has to be checked # to match the value of requested Range HTTP header. This is due to a webservers # that don't support resuming and serve a whole file with no Content-Range # set in response despite of requested Range (see # https://github.com/rg3/youtube-dl/issues/6057#issuecomment-126129799) - if resume_len > 0: - content_range = data.headers.get('Content-Range') + if ctx.resume_len > 0: + content_range = ctx.data.headers.get('Content-Range') if content_range: content_range_m = re.search(r'bytes (\d+)-', content_range) # Content-Range is present and matches requested Range, resume is possible - if content_range_m and resume_len == int(content_range_m.group(1)): - break + if content_range_m and ctx.resume_len == int(content_range_m.group(1)): + return # Content-Range is either not present or invalid. Assuming remote webserver is # trying to send the whole file, resume is not possible, so wiping the local file # and performing entire redownload self.report_unable_to_resume() - resume_len = 0 - open_mode = 'wb' - break + ctx.resume_len = 0 + ctx.open_mode = 'wb' + return except (compat_urllib_error.HTTPError, ) as err: if (err.code < 500 or err.code >= 600) and err.code != 416: # Unexpected HTTP error @@ -86,15 +99,15 @@ class HttpFD(FileDownloader): # Unable to resume (requested range not satisfiable) try: # Open the connection again without the range header - data = self.ydl.urlopen(basic_request) - content_length = data.info()['Content-Length'] + ctx.data = self.ydl.urlopen(basic_request) + content_length = ctx.data.info()['Content-Length'] except (compat_urllib_error.HTTPError, ) as err: if err.code < 500 or err.code >= 600: raise else: # Examine the reported length if (content_length is not None and - (resume_len - 100 < int(content_length) < resume_len + 100)): + (ctx.resume_len - 100 < int(content_length) < ctx.resume_len + 100)): # The file had already been fully downloaded. # Explanation to the above condition: in issue #175 it was revealed that # YouTube sometimes adds or removes a few bytes from the end of the file, @@ -102,152 +115,184 @@ class HttpFD(FileDownloader): # I decided to implement a suggested change and consider the file # completely downloaded if the file size differs less than 100 bytes from # the one in the hard drive. - self.report_file_already_downloaded(filename) - self.try_rename(tmpfilename, filename) + self.report_file_already_downloaded(ctx.filename) + self.try_rename(ctx.tmpfilename, ctx.filename) self._hook_progress({ - 'filename': filename, + 'filename': ctx.filename, 'status': 'finished', - 'downloaded_bytes': resume_len, - 'total_bytes': resume_len, + 'downloaded_bytes': ctx.resume_len, + 'total_bytes': ctx.resume_len, }) - return True + raise SucceedDownload() else: # The length does not match, we start the download over self.report_unable_to_resume() - resume_len = 0 - open_mode = 'wb' - break - except socket.error as e: - if e.errno != errno.ECONNRESET: + ctx.resume_len = 0 + ctx.open_mode = 'wb' + return + raise RetryDownload(err) + except socket.error as err: + if err.errno != errno.ECONNRESET: # Connection reset is no problem, just retry raise + raise RetryDownload(err) + + def download(): + data_len = ctx.data.info().get('Content-length', None) + + # Range HTTP header may be ignored/unsupported by a webserver + # (e.g. extractor/scivee.py, extractor/bambuser.py). + # However, for a test we still would like to download just a piece of a file. + # To achieve this we limit data_len to _TEST_FILE_SIZE and manually control + # block size when downloading a file. + if is_test and (data_len is None or int(data_len) > self._TEST_FILE_SIZE): + data_len = self._TEST_FILE_SIZE + + if data_len is not None: + data_len = int(data_len) + ctx.resume_len + min_data_len = self.params.get('min_filesize') + max_data_len = self.params.get('max_filesize') + if min_data_len is not None and data_len < min_data_len: + self.to_screen('\r[download] File is smaller than min-filesize (%s bytes < %s bytes). Aborting.' % (data_len, min_data_len)) + return False + if max_data_len is not None and data_len > max_data_len: + self.to_screen('\r[download] File is larger than max-filesize (%s bytes > %s bytes). Aborting.' % (data_len, max_data_len)) + return False - # Retry - count += 1 - if count <= retries: - self.report_retry(count, retries) - - if count > retries: - self.report_error('giving up after %s retries' % retries) - return False - - data_len = data.info().get('Content-length', None) - - # Range HTTP header may be ignored/unsupported by a webserver - # (e.g. extractor/scivee.py, extractor/bambuser.py). - # However, for a test we still would like to download just a piece of a file. - # To achieve this we limit data_len to _TEST_FILE_SIZE and manually control - # block size when downloading a file. - if is_test and (data_len is None or int(data_len) > self._TEST_FILE_SIZE): - data_len = self._TEST_FILE_SIZE - - if data_len is not None: - data_len = int(data_len) + resume_len - min_data_len = self.params.get('min_filesize') - max_data_len = self.params.get('max_filesize') - if min_data_len is not None and data_len < min_data_len: - self.to_screen('\r[download] File is smaller than min-filesize (%s bytes < %s bytes). Aborting.' % (data_len, min_data_len)) - return False - if max_data_len is not None and data_len > max_data_len: - self.to_screen('\r[download] File is larger than max-filesize (%s bytes > %s bytes). Aborting.' % (data_len, max_data_len)) - return False - - byte_counter = 0 + resume_len - block_size = self.params.get('buffersize', 1024) - start = time.time() + byte_counter = 0 + ctx.resume_len + block_size = self.params.get('buffersize', 1024) + start = time.time() - # measure time over whole while-loop, so slow_down() and best_block_size() work together properly - now = None # needed for slow_down() in the first loop run - before = start # start measuring - while True: + # measure time over whole while-loop, so slow_down() and best_block_size() work together properly + now = None # needed for slow_down() in the first loop run + before = start # start measuring - # Download and write - data_block = data.read(block_size if not is_test else min(block_size, data_len - byte_counter)) - byte_counter += len(data_block) + def retry(e): + if ctx.tmpfilename != '-': + ctx.stream.close() + ctx.stream = None + ctx.resume_len = os.path.getsize(encodeFilename(ctx.tmpfilename)) + raise RetryDownload(e) - # exit loop when download is finished - if len(data_block) == 0: - break + while True: + try: + # Download and write + data_block = ctx.data.read(block_size if not is_test else min(block_size, data_len - byte_counter)) + # socket.timeout is a subclass of socket.error but may not have + # errno set + except socket.timeout as e: + retry(e) + except socket.error as e: + if e.errno not in (errno.ECONNRESET, errno.ETIMEDOUT): + raise + retry(e) + + byte_counter += len(data_block) + + # exit loop when download is finished + if len(data_block) == 0: + break + + # Open destination file just in time + if ctx.stream is None: + try: + ctx.stream, ctx.tmpfilename = sanitize_open( + ctx.tmpfilename, ctx.open_mode) + assert ctx.stream is not None + ctx.filename = self.undo_temp_name(ctx.tmpfilename) + self.report_destination(ctx.filename) + except (OSError, IOError) as err: + self.report_error('unable to open for writing: %s' % str(err)) + return False + + if self.params.get('xattr_set_filesize', False) and data_len is not None: + try: + write_xattr(ctx.tmpfilename, 'user.ytdl.filesize', str(data_len).encode('utf-8')) + except (XAttrUnavailableError, XAttrMetadataError) as err: + self.report_error('unable to set filesize xattr: %s' % str(err)) - # Open destination file just in time - if stream is None: try: - (stream, tmpfilename) = sanitize_open(tmpfilename, open_mode) - assert stream is not None - filename = self.undo_temp_name(tmpfilename) - self.report_destination(filename) - except (OSError, IOError) as err: - self.report_error('unable to open for writing: %s' % str(err)) + ctx.stream.write(data_block) + except (IOError, OSError) as err: + self.to_stderr('\n') + self.report_error('unable to write data: %s' % str(err)) return False - if self.params.get('xattr_set_filesize', False) and data_len is not None: - try: - write_xattr(tmpfilename, 'user.ytdl.filesize', str(data_len).encode('utf-8')) - except (XAttrUnavailableError, XAttrMetadataError) as err: - self.report_error('unable to set filesize xattr: %s' % str(err)) - - try: - stream.write(data_block) - except (IOError, OSError) as err: + # Apply rate limit + self.slow_down(start, now, byte_counter - ctx.resume_len) + + # end measuring of one loop run + now = time.time() + after = now + + # Adjust block size + if not self.params.get('noresizebuffer', False): + block_size = self.best_block_size(after - before, len(data_block)) + + before = after + + # Progress message + speed = self.calc_speed(start, now, byte_counter - ctx.resume_len) + if data_len is None: + eta = None + else: + eta = self.calc_eta(start, time.time(), data_len - ctx.resume_len, byte_counter - ctx.resume_len) + + self._hook_progress({ + 'status': 'downloading', + 'downloaded_bytes': byte_counter, + 'total_bytes': data_len, + 'tmpfilename': ctx.tmpfilename, + 'filename': ctx.filename, + 'eta': eta, + 'speed': speed, + 'elapsed': now - start, + }) + + if is_test and byte_counter == data_len: + break + + if ctx.stream is None: self.to_stderr('\n') - self.report_error('unable to write data: %s' % str(err)) + self.report_error('Did not get any data blocks') return False + if ctx.tmpfilename != '-': + ctx.stream.close() - # Apply rate limit - self.slow_down(start, now, byte_counter - resume_len) + if data_len is not None and byte_counter != data_len: + err = ContentTooShortError(byte_counter, int(data_len)) + if count <= retries: + retry(err) + raise err - # end measuring of one loop run - now = time.time() - after = now + self.try_rename(ctx.tmpfilename, ctx.filename) - # Adjust block size - if not self.params.get('noresizebuffer', False): - block_size = self.best_block_size(after - before, len(data_block)) - - before = after - - # Progress message - speed = self.calc_speed(start, now, byte_counter - resume_len) - if data_len is None: - eta = None - else: - eta = self.calc_eta(start, time.time(), data_len - resume_len, byte_counter - resume_len) + # Update file modification time + if self.params.get('updatetime', True): + info_dict['filetime'] = self.try_utime(ctx.filename, ctx.data.info().get('last-modified', None)) self._hook_progress({ - 'status': 'downloading', 'downloaded_bytes': byte_counter, - 'total_bytes': data_len, - 'tmpfilename': tmpfilename, - 'filename': filename, - 'eta': eta, - 'speed': speed, - 'elapsed': now - start, + 'total_bytes': byte_counter, + 'filename': ctx.filename, + 'status': 'finished', + 'elapsed': time.time() - start, }) - if is_test and byte_counter == data_len: - break - - if stream is None: - self.to_stderr('\n') - self.report_error('Did not get any data blocks') - return False - if tmpfilename != '-': - stream.close() - - if data_len is not None and byte_counter != data_len: - raise ContentTooShortError(byte_counter, int(data_len)) - self.try_rename(tmpfilename, filename) - - # Update file modification time - if self.params.get('updatetime', True): - info_dict['filetime'] = self.try_utime(filename, data.info().get('last-modified', None)) - - self._hook_progress({ - 'downloaded_bytes': byte_counter, - 'total_bytes': byte_counter, - 'filename': filename, - 'status': 'finished', - 'elapsed': time.time() - start, - }) - - return True + return True + + while count <= retries: + try: + establish_connection() + download() + return True + except RetryDownload as e: + count += 1 + if count <= retries: + self.report_retry(e.source_error, count, retries) + continue + except SucceedDownload: + return True + + self.report_error('giving up after %s retries' % retries) + return False