doWrite() — netty Function Reference

Architecture documentation for the doWrite() function in QuicheQuicChannel.java from the netty codebase.

Function java Buffer Allocators calls 3

Entity Profile

Buffer→ Allocators→ doWrite() — netty Function Reference

Dependency Diagram

graph TD
  94bdb859_cdac_c82f_fdeb_766b4f22314a["doWrite()"]
  3c534d05_bb5b_c991_5e03_7ec94e739cf7["QuicheQuicChannel"]
  94bdb859_cdac_c82f_fdeb_766b4f22314a -->|defined in| 3c534d05_bb5b_c991_5e03_7ec94e739cf7
  61f8fdce_72e6_29ed_0ac0_46f9f3d61c4c["sendDatagram()"]
  94bdb859_cdac_c82f_fdeb_766b4f22314a -->|calls| 61f8fdce_72e6_29ed_0ac0_46f9f3d61c4c
  d21171a6_3135_05f4_7ac2_3fd3258ddab8["forceFlushParent()"]
  94bdb859_cdac_c82f_fdeb_766b4f22314a -->|calls| d21171a6_3135_05f4_7ac2_3fd3258ddab8
  d7575fb7_9073_0e3e_6ab3_7d2612f1eb16["flushParent()"]
  94bdb859_cdac_c82f_fdeb_766b4f22314a -->|calls| d7575fb7_9073_0e3e_6ab3_7d2612f1eb16
  style 94bdb859_cdac_c82f_fdeb_766b4f22314a fill:#6366f1,stroke:#818cf8,color:#fff

Relationship Graph

Source Code

codec-classes-quic/src/main/java/io/netty/handler/codec/quic/QuicheQuicChannel.java lines 668–741

    @Override
    protected void doWrite(ChannelOutboundBuffer channelOutboundBuffer) throws Exception {
        if (!supportsDatagram) {
            throw new UnsupportedOperationException("Datagram extension is not supported");
        }
        boolean sendSomething = false;
        boolean retry = false;
        QuicheQuicConnection conn = connection;
        try {
            for (;;) {
                ByteBuf buffer = (ByteBuf) channelOutboundBuffer.current();
                if (buffer == null) {
                    break;
                }

                int readable = buffer.readableBytes();
                if (readable == 0) {
                    // Skip empty buffers.
                    channelOutboundBuffer.remove();
                    continue;
                }

                final int res;
                if (!buffer.isDirect() || buffer.nioBufferCount() > 1) {
                    ByteBuf tmpBuffer = alloc().directBuffer(readable);
                    try {
                        tmpBuffer.writeBytes(buffer, buffer.readerIndex(), readable);
                        res = sendDatagram(conn, tmpBuffer);
                    } finally {
                        tmpBuffer.release();
                    }
                } else {
                    res = sendDatagram(conn, buffer);
                }
                if (res >= 0) {
                    channelOutboundBuffer.remove();
                    sendSomething = true;
                    retry = false;
                } else {
                    if (res == Quiche.QUICHE_ERR_BUFFER_TOO_SHORT) {
                        retry = false;
                        channelOutboundBuffer.remove(new BufferUnderflowException());
                    } else if (res == Quiche.QUICHE_ERR_INVALID_STATE) {
                        throw new UnsupportedOperationException("Remote peer does not support Datagram extension");
                    } else if (res == Quiche.QUICHE_ERR_DONE) {
                        if (retry) {
                            // We already retried and it didn't work. Let's drop the datagrams on the floor.
                            for (;;) {
                                if (!channelOutboundBuffer.remove()) {
                                    // The buffer is empty now.
                                    return;
                                }
                            }
                        }
                        // Set sendSomething to false a we will call connectionSend() now.
                        sendSomething = false;
                        // If this returned DONE we couldn't write anymore. This happens if the internal queue
                        // is full. In this case we should call quiche_conn_send(...) and so make space again.
                        if (connectionSend(conn) != SendResult.NONE) {
                            forceFlushParent();
                        }
                        // Let's try again to write the message.
                        retry = true;
                    } else {
                        throw Quiche.convertToException(res);
                    }
                }
            }
        } finally {
            if (sendSomething && connectionSend(conn) != SendResult.NONE) {
                flushParent();
            }
        }
    }