from __future__ import unicode_literals
import errno
try:
import concurrent.futures
can_threaded_download = True
except ImportError:
can_threaded_download = False
from ..downloader import _get_real_downloader
from .fragment import FragmentFD
from ..compat import compat_urllib_error
from ..utils import (
DownloadError,
sanitize_open,
urljoin,
)
class DashSegmentsFD(FragmentFD):
"""
Download segments in a DASH manifest. External downloaders can take over
the fragment downloads by supporting the 'dash_frag_urls' protocol
"""
FD_NAME = 'dashsegments'
def real_download(self, filename, info_dict):
fragment_base_url = info_dict.get('fragment_base_url')
fragments = info_dict['fragments'][:1] if self.params.get(
'test', False) else info_dict['fragments']
real_downloader = _get_real_downloader(info_dict, 'dash_frag_urls', self.params, None)
ctx = {
'filename': filename,
'total_frags': len(fragments),
}
if real_downloader:
self._prepare_external_frag_download(ctx)
else:
self._prepare_and_start_frag_download(ctx)
fragment_retries = self.params.get('fragment_retries', 0)
skip_unavailable_fragments = self.params.get('skip_unavailable_fragments', True)
fragments_to_download = []
frag_index = 0
for i, fragment in enumerate(fragments):
frag_index += 1
if frag_index <= ctx['fragment_index']:
continue
fragment_url = fragment.get('url')
if not fragment_url:
assert fragment_base_url
fragment_url = urljoin(fragment_base_url, fragment['path'])
fragments_to_download.append({
'frag_index': frag_index,
'index': i,
'url': fragment_url,
})
if real_downloader:
self.to_screen(
'[%s] Fragment downloads will be delegated to %s' % (self.FD_NAME, real_downloader.get_basename()))
info_copy = info_dict.copy()
info_copy['fragments'] = fragments_to_download
fd = real_downloader(self.ydl, self.params)
# TODO: Make progress updates work without hooking twice
# for ph in self._progress_hooks:
# fd.add_progress_hook(ph)
success = fd.real_download(filename, info_copy)
if not success:
return False
else:
def download_fragment(fragment):
i = fragment['index']
frag_index = fragment['frag_index']
fragment_url = fragment['url']
ctx['fragment_index'] = frag_index
# In DASH, the first segment contains necessary headers to
# generate a valid MP4 file, so always abort for the first segment
fatal = i == 0 or not skip_unavailable_fragments
count = 0
while count <= fragment_retries:
try:
success, frag_content = self._download_fragment(ctx, fragment_url, info_dict)
if not success:
return False, frag_index
break
except compat_urllib_error.HTTPError as err:
# YouTube may often return 404 HTTP error for a fragment causing the
# whole download to fail. However if the same fragment is immediately
# retried with the same request data this usually succeeds (1-2 attempts
# is usually enough) thus allowing to download the whole file successfully.
# To be future-proof we will retry all fragments that fail with any
# HTTP error.
count += 1
if count <= fragment_retries:
self.report_retry_fragment(err, frag_index, count, fragment_retries)
except DownloadError:
# Don't retry fragment if error occurred during HTTP downloading
# itself since it has own retry settings
if not fatal:
break
raise
if count > fragment_retries:
if not fatal:
return False, frag_index
ctx['dest_stream'].close()
self.report_error('Giving up after %s fragment retries' % fragment_retries)
return False, frag_index
return frag_content, frag_index
def append_fragment(frag_content, frag_index):
fatal = frag_index == 1 or not skip_unavailable_fragments
if frag_content:
fragment_filename = '%s-Frag%d' % (ctx['tmpfilename'], frag_index)
try:
file, frag_sanitized = sanitize_open(fragment_filename, 'rb')
ctx['fragment_filename_sanitized'] = frag_sanitized
file.close()
self._append_fragment(ctx, frag_content)
return True
except EnvironmentError as ose:
if ose.errno != errno.ENOENT:
raise
# FileNotFoundError
if not fatal:
self.report_skip_fragment(frag_index)
return True
else:
ctx['dest_stream'].close()
self.report_error(
'fragment %s not found, unable to continue' % frag_index)
return False
else:
if not fatal:
self.report_skip_fragment(frag_index)
return True
else:
ctx['dest_stream'].close()
self.report_error(
'fragment %s not found, unable to continue' % frag_index)
return False
max_workers = self.params.get('concurrent_fragment_downloads', 1)
if can_threaded_download and max_workers > 1:
self.report_warning('The download speed shown is only of one thread. This is a known issue')
_download_fragment = lambda f: (f, download_fragment(f)[1])
with concurrent.futures.ThreadPoolExecutor(max_workers) as pool:
futures = [pool.submit(_download_fragment, fragment) for fragment in fragments_to_download]
# timeout must be 0 to return instantly
done, not_done = concurrent.futures.wait(futures, timeout=0)
try:
while not_done:
# Check every 1 second for KeyboardInterrupt
freshly_done, not_done = concurrent.futures.wait(not_done, timeout=1)
done |= freshly_done
except KeyboardInterrupt:
for future in not_done:
future.cancel()
# timeout must be none to cancel
concurrent.futures.wait(not_done, timeout=None)
raise KeyboardInterrupt
for fragment, frag_index in map(lambda x: x.result(), futures):
fragment_filename = '%s-Frag%d' % (ctx['tmpfilename'], frag_index)
down, frag_sanitized = sanitize_open(fragment_filename, 'rb')
fragment['fragment_filename_sanitized'] = frag_sanitized
frag_content = down.read()
down.close()
result = append_fragment(frag_content, frag_index)
if not result:
return False
else:
for fragment in fragments_to_download:
frag_content, frag_index = download_fragment(fragment)
result = append_fragment(frag_content, frag_index)
if not result:
return False
self._finish_frag_download(ctx)
return True