def __ProcessResponse(self, response):
"""Process this response (by updating self and writing to self.stream)."""
if response.status_code not in self._ACCEPTABLE_STATUSES:
raise exceptions.TransferRetryError(response.content)
if response.status_code in (httplib.OK, httplib.PARTIAL_CONTENT):
self.stream.write(response.content)
self.__progress += response.length
if response.info and 'content-encoding' in response.info:
# TODO: Handle the case where this changes over a download.
self.__encoding = response.info['content-encoding']
elif response.status_code == httplib.NO_CONTENT:
# It's important to write something to the stream for the case
# of a 0-byte download to a file, as otherwise python won't
# create the file.
self.stream.write('')
return response
def GetRange(self, start, end=None, additional_headers=None):
"""Retrieve a given byte range from this download, inclusive.
Range must be of one of these three forms:
* 0 <= start, end = None: Fetch from start to the end of the file.
* 0 <= start <= end: Fetch the bytes from start to end.
* start < 0, end = None: Fetch the last -start bytes of the file.
(These variations correspond to those described in the HTTP 1.1
protocol for range headers in RFC 2616, sec. 14.35.1.)
Args:
start: (int) Where to start fetching bytes. (See above.)
end: (int, optional) Where to stop fetching bytes. (See above.)
additional_headers: (bool, optional) Any additional headers to
pass with the request.
Returns:
None. Streams bytes into self.stream.
"""
self.EnsureInitialized()
progress_end_normalized = False
if self.total_size is not None:
progress, end = self.__NormalizeStartEnd(start, end)
progress_end_normalized = True
else:
progress = start
while not progress_end_normalized or progress < end:
response = self.__GetChunk(progress,
end=end,
additional_headers=additional_headers)
if not progress_end_normalized:
self.__SetTotal(response.info)
progress, end = self.__NormalizeStartEnd(start, end)
progress_end_normalized = True
response = self.__ProcessResponse(response)
progress += response.length
if not response:
raise exceptions.TransferRetryError(
'Zero bytes unexpectedly returned in download response')
