def _read_at()

in alibabacloud_oss_v2/filelike.py [0:0]

• 24 lines of code
• 10 McCabe index (conditional complexity)

    def _read_at(self, offset, n):
        nodata_val = b""
        empty_values = (b"")

        if offset >= self._size_in_bytes:
            return nodata_val

        # Special case for when the number of bytes to read is unspecified.
        if n is None or n < 0:
            current_size = 0
            chunks = []
            while True:
                chunk = self._next_chunk(offset + current_size)
                if chunk is None:
                    continue
                if chunk in empty_values:
                    nodata_val = chunk
                    break
                current_size += len(chunk)
                chunks.append(chunk)
            return b"".join(chunks) or nodata_val

        # The number of bytes to read is specified, return at most n bytes.
        b = bytearray(n.__index__())
        got = self._read_at_into(offset, b)
        if got is None:
            return None
        del b[got:]
        return bytes(b)