Reorganize request code to make it a bit more robust

diff --git a/youtube-dl b/youtube-dl
index 8cfa6dfd622d81e8ac0453af7fe2b63c82810bb7..cf0336e56c7bfc377eefcbcb339ca788801243a0 100755 (executable)
--- a/youtube-dl
+++ b/youtube-dl
@@ -287,16 +287,6 @@ class FileDownloader(object):
                multiplier = 1024.0 ** 'bkmgtpezy'.index(matchobj.group(2).lower())
                return long(round(number * multiplier))
 
-       @staticmethod
-       def verify_url(url):
-               """Verify a URL is valid and data could be downloaded. Return real data URL."""
-               request = urllib2.Request(url, None, std_headers)
-               data = urllib2.urlopen(request)
-               data.read(1)
-               url = data.geturl()
-               data.close()
-               return url
-
        def add_info_extractor(self, ie):
                """Add an InfoExtractor object to the end of the list."""
                self._ies.append(ie)
@@ -396,13 +386,6 @@ class FileDownloader(object):
                """Process a single dictionary returned by an InfoExtractor."""
                # Do nothing else if in simulate mode
                if self.params.get('simulate', False):
-                       # Verify URL if it's an HTTP one
-                       if info_dict['url'].startswith('http'):
-                               try:
-                                       self.verify_url(info_dict['url'].encode('utf-8')).decode('utf-8')
-                               except (OSError, IOError, urllib2.URLError, httplib.HTTPException, socket.error), err:
-                                       raise UnavailableVideoError
-
                        # Forced printings
                        if self.params.get('forcetitle', False):
                                print info_dict['title'].encode(preferredencoding(), 'xmlcharrefreplace')
@@ -539,32 +522,43 @@ class FileDownloader(object):
 
                count = 0
                retries = self.params.get('retries', 0)
-               while True:
+               while count <= retries:
                        # Establish connection
                        try:
                                data = urllib2.urlopen(request)
                                break
                        except (urllib2.HTTPError, ), err:
-                               if err.code == 503:
-                                       # Retry in case of HTTP error 503
-                                       count += 1
-                                       if count <= retries:
-                                               self.report_retry(count, retries)
-                                               continue
-                               if err.code != 416: #  416 is 'Requested range not satisfiable'
+                               if err.code != 503 and err.code != 416:
+                                       # Unexpected HTTP error
                                        raise
-                               # Unable to resume
-                               data = urllib2.urlopen(basic_request)
-                               content_length = data.info()['Content-Length']
-
-                               if content_length is not None and long(content_length) == resume_len:
-                                       # Because the file had already been fully downloaded
-                                       self.report_file_already_downloaded(filename)
-                                       return True
-                               else:
-                                       # Because the server didn't let us
-                                       self.report_unable_to_resume()
-                                       open_mode = 'wb'
+                               elif err.code == 416:
+                                       # Unable to resume (requested range not satisfiable)
+                                       try:
+                                               # Open the connection again without the range header
+                                               data = urllib2.urlopen(basic_request)
+                                               content_length = data.info()['Content-Length']
+                                       except (urllib2.HTTPError, ), err:
+                                               if err.code != 503:
+                                                       raise
+                                       else:
+                                               # Examine the reported length
+                                               if content_length is not None and long(content_length) == resume_len:
+                                                       # The file had already been fully downloaded
+                                                       self.report_file_already_downloaded(filename)
+                                                       return True
+                                               else:
+                                                       # The length does not match, we start the download over
+                                                       self.report_unable_to_resume()
+                                                       open_mode = 'wb'
+                                                       break
+                       # Retry
+                       count += 1
+                       if count <= retries:
+                               self.report_retry(count, retries)
+
+               if count > retries:
+                       self.trouble(u'ERROR: giving up after %s retries' % retries)
+                       return False
 
                data_len = data.info().get('Content-length', None)
                data_len_str = self.format_bytes(data_len)