__init__.py 文件源码

def _download_range(self, bucket, key, filename,
                        part_size, num_parts, callback, part_index):
        try:
            range_param = self._calculate_range_param(
                part_size, part_index, num_parts)

            max_attempts = self._config.num_download_attempts
            last_exception = None
            for i in range(max_attempts):
                try:
                    logger.debug("Making get_object call.")
                    response = self._client.get_object(
                        Bucket=bucket, Key=key, Range=range_param)
                    streaming_body = StreamReaderProgress(
                        response['Body'], callback)
                    buffer_size = 1024 * 16
                    current_index = part_size * part_index
                    for chunk in iter(lambda: streaming_body.read(buffer_size),
                                      b''):
                        self._ioqueue.put((current_index, chunk))
                        current_index += len(chunk)
                    return
                except (socket.timeout, socket.error,
                        ReadTimeoutError, IncompleteReadError) as e:
                    logger.debug("Retrying exception caught (%s), "
                                 "retrying request, (attempt %s / %s)", e, i,
                                 max_attempts, exc_info=True)
                    last_exception = e
                    continue
            raise RetriesExceededError(last_exception)
        finally:
            logger.debug("EXITING _download_range for part: %s", part_index)