Class _StreamSlice

googleapiclient/http.py:783–820

Truncated stream. Takes a stream and presents a stream that is a slice of the original stream. This is used when uploading media in chunks. In later versions of Python a stream can be passed to httplib in place of the string of data to send. The problem is that httplib just blindly

class _StreamSlice(object):
    """Truncated stream.

    Takes a stream and presents a stream that is a slice of the original stream.
    This is used when uploading media in chunks. In later versions of Python a
    stream can be passed to httplib in place of the string of data to send. The
    problem is that httplib just blindly reads to the end of the stream. This
    wrapper presents a virtual stream that only reads to the end of the chunk.
    """

    def __init__(self, stream, begin, chunksize):
        """Constructor.

        Args:
          stream: (io.Base, file object), the stream to wrap.
          begin: int, the seek position the chunk begins at.
          chunksize: int, the size of the chunk.
        """
        self._stream = stream
        self._begin = begin
        self._chunksize = chunksize
        self._stream.seek(begin)

    def read(self, n=-1):
        """Read n bytes.

        Args:
          n, int, the number of bytes to read.

        Returns:
          A string of length 'n', or less if EOF is reached.
        """
        # The data left available to read sits in [cur, end)
        cur = self._stream.tell()
        end = self._begin + self._chunksize
        if n == -1 or cur + n > end:
            n = end - cur
        return self._stream.read(n)


class HttpRequest(object):