Bump version number

interrupted downloads will properly resume and append to the previously downloaded data, instead of overwriting the file.

There's some error checking - if the length of the file to be download matches the length of the previously downloaded data, we report that this file has already been downloaded and do nothing.

If there is some other HTTP 416 'Requested range not satisfiable' error, we simply re-download the whole file (reverting to the original functionality)

All other HTTP errors are simply raised.

Resuming does not override -w (--nooverwrite), since it is not clear what should happen if file on disk is larger than file to be downloaded.

Thus, -c does nothing if -w is present.

LATEST_VERSION

@@ -1 +1 @@
-2009.05.25
+2009.05.30

youtube-dl

@@ -114,6 +114,7 @@ class FileDownloader(object):
 	ignoreerrors:	Do not stop on download errors.
 	ratelimit:	Download speed limit, in bytes/sec.
 	nooverwrites:	Prevent overwriting files.
+	continuedl:	Try to continue downloads if possible.
 	"""
 
 	params = None
@@ -182,13 +183,13 @@ class FileDownloader(object):
 		new_min = max(bytes / 2.0, 1.0)
 		new_max = min(max(bytes * 2.0, 1.0), 4194304) # Do not surpass 4 MB
 		if elapsed_time < 0.001:
-			return int(new_max)
+			return long(new_max)
 		rate = bytes / elapsed_time
 		if rate > new_max:
-			return int(new_max)
+			return long(new_max)
 		if rate < new_min:
-			return int(new_min)
-		return int(rate)
+			return long(new_min)
+		return long(rate)
 
 	@staticmethod
 	def parse_bytes(bytestr):
@@ -266,6 +267,18 @@ class FileDownloader(object):
 		"""Report download progress."""
 		self.to_stdout(u'\r[download] %s of %s at %s ETA %s' %
 				(percent_str, data_len_str, speed_str, eta_str), skip_eol=True)
+
+	def report_resuming_byte(self, resume_len):
+		"""Report attemtp to resume at given byte."""
+		self.to_stdout(u'[download] Resuming download at byte %s' % resume_len)
+	
+	def report_file_already_downloaded(self, file_name):
+		"""Report file has already been fully downloaded."""
+		self.to_stdout(u'[download] %s has already been downloaded' % file_name)
+	
+	def report_unable_to_resume(self):
+		"""Report it was impossible to resume download."""
+		self.to_stdout(u'[download] Unable to resume')
 	
 	def report_finish(self):
 		"""Report download finished."""
@@ -306,7 +319,7 @@ class FileDownloader(object):
 			return
 
 		try:
-			outstream = open(filename, 'wb')
+			outstream = open(filename, 'ab')
 		except (OSError, IOError), err:
 			self.trouble('ERROR: unable to open for writing: %s' % str(err))
 			return
@@ -367,8 +380,32 @@ class FileDownloader(object):
 				break
 	
 	def _do_download(self, stream, url):
+		basic_request = urllib2.Request(url, None, std_headers)
 		request = urllib2.Request(url, None, std_headers)
-		data = urllib2.urlopen(request)
+
+		# Resume transfer if filesize is non-zero
+		resume_len = stream.tell()
+		if self.params['continuedl'] and resume_len != 0:
+			self.report_resuming_byte(resume_len)
+			request.add_header('Range','bytes=%d-' % resume_len)
+		else:
+			stream.close()
+			stream = open(stream.name,'wb')
+		try:
+			data = urllib2.urlopen(request)
+		except urllib2.HTTPError, e:
+			if not e.code == 416: #  416 is 'Requested range not satisfiable'
+				raise
+			data = urllib2.urlopen(basic_request)
+			content_length = data.info()['Content-Length']
+			if content_length is not None and long(content_length) == resume_len:
+				self.report_file_already_downloaded(stream.name)
+				return
+			else:
+				self.report_unable_to_resume()
+				stream.close()
+				stream = open(stream.name,'wb')
+
 		data_len = data.info().get('Content-length', None)
 		data_len_str = self.format_bytes(data_len)
 		byte_counter = 0
@@ -859,7 +896,7 @@ class YoutubeSearchIE(InfoExtractor):
 			return
 		else:
 			try:
-				n = int(prefix)
+				n = long(prefix)
 				if n <= 0:
 					self._downloader.trouble(u'ERROR: invalid download number %s for query "%s"' % (n, query))
 					return
@@ -868,7 +905,7 @@ class YoutubeSearchIE(InfoExtractor):
 					n = self._max_youtube_results
 				self._download_n_results(query, n)
 				return
-			except ValueError: # parsing prefix as int fails
+			except ValueError: # parsing prefix as integer fails
 				self._download_n_results(query, 1)
 				return
 
@@ -1029,7 +1066,7 @@ if __name__ == '__main__':
 		# Parse command line
 		parser = optparse.OptionParser(
 			usage='Usage: %prog [options] url...',
-			version='2009.05.25',
+			version='2009.05.30',
 			conflict_handler='resolve',
 		)
 
@@ -1053,7 +1090,7 @@ if __name__ == '__main__':
 
 		video_format = optparse.OptionGroup(parser, 'Video Format Options')
 		video_format.add_option('-f', '--format',
-				action='append', dest='format', metavar='FMT', help='video format code')
+				action='store', dest='format', metavar='FMT', help='video format code')
 		video_format.add_option('-b', '--best-quality',
 				action='store_const', dest='format', help='download the best quality video possible', const='0')
 		video_format.add_option('-m', '--mobile-version',
@@ -1084,6 +1121,8 @@ if __name__ == '__main__':
 				dest='batchfile', metavar='F', help='file containing URLs to download')
 		filesystem.add_option('-w', '--no-overwrites',
 				action='store_true', dest='nooverwrites', help='do not overwrite files', default=False)
+		filesystem.add_option('-c', '--continue',
+				action='store_true', dest='continue_dl', help='resume partially downloaded files', default=False)
 		parser.add_option_group(filesystem)
 
 		(opts, args) = parser.parse_args()
@@ -1141,6 +1180,7 @@ if __name__ == '__main__':
 			'ignoreerrors': opts.ignoreerrors,
 			'ratelimit': opts.ratelimit,
 			'nooverwrites': opts.nooverwrites,
+			'continuedl': opts.continue_dl,
 			})
 		fd.add_info_extractor(youtube_search_ie)
 		fd.add_info_extractor(youtube_pl_ie)