Optionally set the expected final filesize of a download as an xattribute.

Requires python-xattr and a filesystem that supports user xattributes.

youtube_dl/FileDownloader.py

@@ -11,6 +11,10 @@ if os.name == 'nt':
 
 from .utils import *
 
+try:
+    import xattr
+except ImportError:
+    pass
 
 class FileDownloader(object):
     """File Downloader class.
@@ -39,6 +43,7 @@ class FileDownloader(object):
     test:              Download only first bytes to test the downloader.
     min_filesize:      Skip files smaller than this size
     max_filesize:      Skip files larger than this size
+    setxattrfilesize:  Set ytdl.filesize user xattribute with expected size.
     """
 
     params = None
@@ -499,11 +504,17 @@ class FileDownloader(object):
                 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(u'unable to open for writing: %s' % str(err))
                     return False
+                if self.params.get('setxattrfilesize', False) and data_len is not None:
+                    try:
+                        xattr.setxattr(tmpfilename, 'user.ytdl.filesize', str(data_len))
+                    except (OSError, IOError) as err:
+                        self.report_error(u'unable to set filesize xattr: %s' % str(err))
+                filename = self.undo_temp_name(tmpfilename)
+                self.report_destination(filename)
+
             try:
                 stream.write(data_block)
             except (IOError, OSError) as err:

youtube_dl/__init__.py

@@ -44,6 +44,12 @@ import sys
 import warnings
 import platform
 
+try:
+    import xattr
+    xattr_available = True
+except ImportError:
+    xattr_available = False
+
 from .utils import *
 from .update import update_self
 from .version import __version__
@@ -306,6 +312,10 @@ def parseOpts(overrideArguments=None):
     filesystem.add_option('--write-thumbnail',
             action='store_true', dest='writethumbnail',
             help='write thumbnail image to disk', default=False)
+    filesystem.add_option('-X','--xattr-filesize',
+            action='store_true', dest='setxattrfilesize',
+            help='set ytdl_filesize file xattr with expected filesize',
+            default=False)
 
 
     postproc.add_option('-x', '--extract-audio', action='store_true', dest='extractaudio', default=False,
@@ -508,6 +518,9 @@ def _real_main(argv=None):
         date = DateRange.day(opts.date)
     else:
         date = DateRange(opts.dateafter, opts.datebefore)
+    if opts.setxattrfilesize:
+        if not xattr_available:
+            parser.error(u'setting filesize xattr requested but python xattr is not available')
 
     if sys.version_info < (3,):
         # In Python 2, sys.argv is a bytestring (also note http://bugs.python.org/issue2128 for Windows systems)
@@ -579,6 +592,7 @@ def _real_main(argv=None):
         'min_filesize': opts.min_filesize,
         'max_filesize': opts.max_filesize,
         'daterange': date,
+        'setxattrfilesize': opts.setxattrfilesize,
         })
 
     if opts.verbose: