Add --rate-limit program option

diff --git a/youtube-dl b/youtube-dl
index 135d14809554a592101ef6b9100dd41bb3dcce7f..4dea34376bba4b87dfcf4ff7a47fd570ec906549 100755 (executable)
--- a/youtube-dl
+++ b/youtube-dl
@@ -78,6 +78,7 @@ class FileDownloader(object):
        format:         Video format code.
        outtmpl:        Template for output names.
        ignoreerrors:   Do not stop on download errors.
+       ratelimit:      Download speed limit, in bytes/sec.
        """
 
        _params = None
@@ -149,6 +150,16 @@ class FileDownloader(object):
                        return int(new_min)
                return int(rate)
 
+       @staticmethod
+       def parse_bytes(bytestr):
+               """Parse a string indicating a byte quantity into a long integer."""
+               matchobj = re.match(r'(?i)^(\d+(?:\.\d+)?)([kMGTPEZY]?)$', bytestr)
+               if matchobj is None:
+                       return None
+               number = float(matchobj.group(1))
+               multiplier = 1024.0 ** 'bkmgtpezy'.index(matchobj.group(2).lower())
+               return long(round(number * multiplier))
+
        def set_params(self, params):
                """Sets parameters."""
                if type(params) != dict:
@@ -193,6 +204,19 @@ class FileDownloader(object):
                        raise DownloadError(message)
                return 1
 
+       def slow_down(self, start_time, byte_counter):
+               """Sleep if the download speed is over the rate limit."""
+               rate_limit = self._params.get('ratelimit', None)
+               if rate_limit is None or byte_counter == 0:
+                       return
+               now = time.time()
+               elapsed = now - start_time
+               if elapsed <= 0.0:
+                       return
+               speed = float(byte_counter) / elapsed
+               if speed > rate_limit:
+                       time.sleep((byte_counter - rate_limit * (now - start_time)) / rate_limit)
+
        def report_destination(self, filename):
                """Report destination filename."""
                self.to_stdout('[download] Destination: %s' % filename)
@@ -296,6 +320,9 @@ class FileDownloader(object):
                        stream.write(data_block)
                        block_size = self.best_block_size(after - before, data_block_len)
 
+                       # Apply rate limit
+                       self.slow_down(start, byte_counter)
+
                self.report_finish()
                if data_len is not None and str(byte_counter) != data_len:
                        raise ValueError('Content too short: %s/%s bytes' % (byte_counter, data_len))
@@ -575,6 +602,8 @@ if __name__ == '__main__':
                                action='store_const', dest='format', help='alias for -f 17', const='17')
                parser.add_option('-i', '--ignore-errors',
                                action='store_true', dest='ignoreerrors', help='continue on download errors', default=False)
+               parser.add_option('-r', '--rate-limit',
+                               dest='ratelimit', metavar='L', help='download rate limit (e.g. 50k or 44.6m)')
                (opts, args) = parser.parse_args()
 
                # Conflicting, missing and erroneous options
@@ -590,6 +619,11 @@ if __name__ == '__main__':
                        sys.exit('ERROR: using title conflicts with using literal title')
                if opts.username is not None and opts.password is None:
                        opts.password = getpass.getpass('Type account password and press return:')
+               if opts.ratelimit is not None:
+                       numeric_limit = FileDownloader.parse_bytes(opts.ratelimit)
+                       if numeric_limit is None:
+                               sys.exit('ERROR: invalid rate limit specified')
+                       opts.ratelimit = numeric_limit
 
                # Information extractors
                youtube_ie = YoutubeIE()
@@ -609,6 +643,7 @@ if __name__ == '__main__':
                                or (opts.useliteral and '%(title)s-%(id)s.%(ext)s')
                                or '%(id)s.%(ext)s'),
                        'ignoreerrors': opts.ignoreerrors,
+                       'ratelimit': opts.ratelimit,
                        })
                fd.add_info_extractor(youtube_ie)
                retcode = fd.download(args)