_ Git - youtube-dl/blob - youtube_dl/downloader/fragment.py

   1 from __future__ import division, unicode_literals
   2
   3 import os
   4 import time
   5 import json
   6
   7 from .common import FileDownloader
   8 from .http import HttpFD
   9 from ..utils import (
  10     error_to_compat_str,
  11     encodeFilename,
  12     sanitize_open,
  13     sanitized_Request,
  14 )
  15
  16
  17 class HttpQuietDownloader(HttpFD):
  18     def to_screen(self, *args, **kargs):
  19         pass
  20
  21
  22 class FragmentFD(FileDownloader):
  23     """
  24     A base file downloader class for fragmented media (e.g. f4m/m3u8 manifests).
  25
  26     Available options:
  27
  28     fragment_retries:   Number of times to retry a fragment for HTTP error (DASH
  29                         and hlsnative only)
  30     skip_unavailable_fragments:
  31                         Skip unavailable fragments (DASH and hlsnative only)
  32     keep_fragments:     Keep downloaded fragments on disk after downloading is
  33                         finished
  34
  35     For each incomplete fragment download youtube-dl keeps on disk a special
  36     bookkeeping file with download state and metadata (in future such files will
  37     be used for any incomplete download handled by youtube-dl). This file is
  38     used to properly handle resuming, check download file consistency and detect
  39     potential errors. The file has a .ytdl extension and represents a standard
  40     JSON file of the following format:
  41
  42     extractor:
  43         Dictionary of extractor related data. TBD.
  44
  45     downloader:
  46         Dictionary of downloader related data. May contain following data:
  47             current_fragment:
  48                 Dictionary with current (being downloaded) fragment data:
  49                 index:  Index of current fragment among all fragments
  50             fragment_count:
  51                 Total count of fragments
  52     """
  53
  54     def report_retry_fragment(self, err, frag_index, count, retries):
  55         self.to_screen(
  56             '[download] Got server HTTP error: %s. Retrying fragment %d (attempt %d of %s)...'
  57             % (error_to_compat_str(err), frag_index, count, self.format_retries(retries)))
  58
  59     def report_skip_fragment(self, frag_index):
  60         self.to_screen('[download] Skipping fragment %d...' % frag_index)
  61
  62     def _prepare_url(self, info_dict, url):
  63         headers = info_dict.get('http_headers')
  64         return sanitized_Request(url, None, headers) if headers else url
  65
  66     def _prepare_and_start_frag_download(self, ctx):
  67         self._prepare_frag_download(ctx)
  68         self._start_frag_download(ctx)
  69
  70     @staticmethod
  71     def __do_ytdl_file(ctx):
  72         return not ctx['live'] and not ctx['tmpfilename'] == '-'
  73
  74     def _read_ytdl_file(self, ctx):
  75         stream, _ = sanitize_open(self.ytdl_filename(ctx['filename']), 'r')
  76         ctx['fragment_index'] = json.loads(stream.read())['downloader']['current_fragment']['index']
  77         stream.close()
  78
  79     def _write_ytdl_file(self, ctx):
  80         frag_index_stream, _ = sanitize_open(self.ytdl_filename(ctx['filename']), 'w')
  81         downloader = {
  82             'current_fragment': {
  83                 'index': ctx['fragment_index'],
  84             },
  85         }
  86         if ctx.get('fragment_count') is not None:
  87             downloader['fragment_count'] = ctx['fragment_count']
  88         frag_index_stream.write(json.dumps({'downloader': downloader}))
  89         frag_index_stream.close()
  90
  91     def _download_fragment(self, ctx, frag_url, info_dict, headers=None):
  92         fragment_filename = '%s-Frag%d' % (ctx['tmpfilename'], ctx['fragment_index'])
  93         success = ctx['dl'].download(fragment_filename, {
  94             'url': frag_url,
  95             'http_headers': headers or info_dict.get('http_headers'),
  96         })
  97         if not success:
  98             return False, None
  99         down, frag_sanitized = sanitize_open(fragment_filename, 'rb')
 100         ctx['fragment_filename_sanitized'] = frag_sanitized
 101         frag_content = down.read()
 102         down.close()
 103         return True, frag_content
 104
 105     def _append_fragment(self, ctx, frag_content):
 106         try:
 107             ctx['dest_stream'].write(frag_content)
 108         finally:
 109             if self.__do_ytdl_file(ctx):
 110                 self._write_ytdl_file(ctx)
 111             if not self.params.get('keep_fragments', False):
 112                 os.remove(ctx['fragment_filename_sanitized'])
 113             del ctx['fragment_filename_sanitized']
 114
 115     def _prepare_frag_download(self, ctx):
 116         if 'live' not in ctx:
 117             ctx['live'] = False
 118         self.to_screen(
 119             '[%s] Total fragments: %s'
 120             % (self.FD_NAME, ctx['total_frags'] if not ctx['live'] else 'unknown (live)'))
 121         self.report_destination(ctx['filename'])
 122         dl = HttpQuietDownloader(
 123             self.ydl,
 124             {
 125                 'continuedl': True,
 126                 'quiet': True,
 127                 'noprogress': True,
 128                 'ratelimit': self.params.get('ratelimit'),
 129                 'retries': self.params.get('retries', 0),
 130                 'nopart': self.params.get('nopart', False),
 131                 'test': self.params.get('test', False),
 132             }
 133         )
 134         tmpfilename = self.temp_name(ctx['filename'])
 135         open_mode = 'wb'
 136         resume_len = 0
 137
 138         # Establish possible resume length
 139         if os.path.isfile(encodeFilename(tmpfilename)):
 140             open_mode = 'ab'
 141             resume_len = os.path.getsize(encodeFilename(tmpfilename))
 142
 143         # Should be initialized before ytdl file check
 144         ctx.update({
 145             'tmpfilename': tmpfilename,
 146             'fragment_index': 0,
 147         })
 148
 149         if self.__do_ytdl_file(ctx):
 150             if os.path.isfile(encodeFilename(self.ytdl_filename(ctx['filename']))):
 151                 self._read_ytdl_file(ctx)
 152             else:
 153                 self._write_ytdl_file(ctx)
 154             if ctx['fragment_index'] > 0:
 155                 assert resume_len > 0
 156             else:
 157                 assert resume_len == 0
 158
 159         dest_stream, tmpfilename = sanitize_open(tmpfilename, open_mode)
 160
 161         ctx.update({
 162             'dl': dl,
 163             'dest_stream': dest_stream,
 164             'tmpfilename': tmpfilename,
 165             # Total complete fragments downloaded so far in bytes
 166             'complete_frags_downloaded_bytes': resume_len,
 167         })
 168
 169     def _start_frag_download(self, ctx):
 170         total_frags = ctx['total_frags']
 171         # This dict stores the download progress, it's updated by the progress
 172         # hook
 173         state = {
 174             'status': 'downloading',
 175             'downloaded_bytes': ctx['complete_frags_downloaded_bytes'],
 176             'fragment_index': ctx['fragment_index'],
 177             'fragment_count': total_frags,
 178             'filename': ctx['filename'],
 179             'tmpfilename': ctx['tmpfilename'],
 180         }
 181
 182         start = time.time()
 183         ctx.update({
 184             'started': start,
 185             # Amount of fragment's bytes downloaded by the time of the previous
 186             # frag progress hook invocation
 187             'prev_frag_downloaded_bytes': 0,
 188         })
 189
 190         def frag_progress_hook(s):
 191             if s['status'] not in ('downloading', 'finished'):
 192                 return
 193
 194             time_now = time.time()
 195             state['elapsed'] = time_now - start
 196             frag_total_bytes = s.get('total_bytes') or 0
 197             if not ctx['live']:
 198                 estimated_size = (
 199                     (ctx['complete_frags_downloaded_bytes'] + frag_total_bytes) /
 200                     (state['fragment_index'] + 1) * total_frags)
 201                 state['total_bytes_estimate'] = estimated_size
 202
 203             if s['status'] == 'finished':
 204                 state['fragment_index'] += 1
 205                 ctx['fragment_index'] = state['fragment_index']
 206                 state['downloaded_bytes'] += frag_total_bytes - ctx['prev_frag_downloaded_bytes']
 207                 ctx['complete_frags_downloaded_bytes'] = state['downloaded_bytes']
 208                 ctx['prev_frag_downloaded_bytes'] = 0
 209             else:
 210                 frag_downloaded_bytes = s['downloaded_bytes']
 211                 state['downloaded_bytes'] += frag_downloaded_bytes - ctx['prev_frag_downloaded_bytes']
 212                 if not ctx['live']:
 213                     state['eta'] = self.calc_eta(
 214                         start, time_now, estimated_size,
 215                         state['downloaded_bytes'])
 216                 state['speed'] = s.get('speed') or ctx.get('speed')
 217                 ctx['speed'] = state['speed']
 218                 ctx['prev_frag_downloaded_bytes'] = frag_downloaded_bytes
 219             self._hook_progress(state)
 220
 221         ctx['dl'].add_progress_hook(frag_progress_hook)
 222
 223         return start
 224
 225     def _finish_frag_download(self, ctx):
 226         ctx['dest_stream'].close()
 227         if self.__do_ytdl_file(ctx):
 228             ytdl_filename = encodeFilename(self.ytdl_filename(ctx['filename']))
 229             if os.path.isfile(ytdl_filename):
 230                 os.remove(ytdl_filename)
 231         elapsed = time.time() - ctx['started']
 232         self.try_rename(ctx['tmpfilename'], ctx['filename'])
 233         fsize = os.path.getsize(encodeFilename(ctx['filename']))
 234
 235         self._hook_progress({
 236             'downloaded_bytes': fsize,
 237             'total_bytes': fsize,
 238             'filename': ctx['filename'],
 239             'status': 'finished',
 240             'elapsed': elapsed,
 241         })