383ea0326ae103b5d5e0b62ed9c3cb18510c5b9e,distributed/comm/tcp.py,TCP,write,#TCP#Any#Any#Any#,229

Before Change

        try:
            nframes = len(frames)
            lengths = [nbytes(frame) for frame in frames]
            length_bytes = struct.pack(f"Q{nframes}Q", nframes, *lengths)

            frames = [length_bytes, *frames]
            lengths = [len(length_bytes), *lengths]

            if sum(lengths) < 2 ** 17:  // 128kiB
                // small enough, send in one go
                stream.write(b"".join(frames))
            else:
                // avoid large memcpy, send in many
                for frame, frame_bytes in zip(frames, lengths):
                    // Can"t wait for the write() Future as it may be lost
                    // ("If write is called again before that Future has resolved,
                    //   the previous future will be orphaned and will never resolve")
                    if frame_bytes:
                        future = stream.write(frame)
                        bytes_since_last_yield += frame_bytes
                        if bytes_since_last_yield > 32e6:
                            await future
                            bytes_since_last_yield = 0
        except StreamClosedError as e:
            self.stream = None
            self._closed = True
            if not shutting_down():

After Change

        frames_nbytes = sum(map(nbytes, frames))

        header = pack_frames_prelude(frames)
        header = struct.pack("Q", nbytes(header) + frames_nbytes) + header

        frames = [header, *frames]
        frames_nbytes += nbytes(header)

        if frames_nbytes < 2 ** 17:  // 128kiB
            // small enough, send in one go
            frames = [b"".join(frames)]

        try:
            // trick to enque all frames for writing beforehand
            for each_frame in frames:
                each_frame_nbytes = nbytes(each_frame)
                if each_frame_nbytes:
                    stream._write_buffer.append(each_frame)
                    stream._total_write_index += each_frame_nbytes

            // start writing frames
            stream.write(b"")
        except StreamClosedError as e:
            self.stream = None
            self._closed = True

Instances