io.netty.channel.ChannelOutboundBuffer#nioBuffers ( )源码实例Demo

/**
 * Attempt to write multiple {@link ByteBuf} objects.
 * @param in the collection which contains objects to write.
 * @return The value that should be decremented from the write quantum which starts at
 * {@link ChannelConfig#getWriteSpinCount()}. The typical use cases are as follows:
 * <ul>
 *     <li>0 - if no write was attempted. This is appropriate if an empty {@link ByteBuf} (or other empty content)
 *     is encountered</li>
 *     <li>1 - if a single call to write data was made to the OS</li>
 *     <li>{@link ChannelUtils#WRITE_STATUS_SNDBUF_FULL} - if an attempt to write data was made to the OS, but no
 *     data was accepted</li>
 * </ul>
 * @throws Exception If an I/O error occurs.
 */
private int doWriteMultiple(ChannelOutboundBuffer in) throws Exception {
    final long maxBytesPerGatheringWrite = config().getMaxBytesPerGatheringWrite();
    if (PlatformDependent.hasUnsafe()) {
        IovArray array = ((KQueueEventLoop) eventLoop()).cleanArray();
        array.maxBytes(maxBytesPerGatheringWrite);
        in.forEachFlushedMessage(array);

        if (array.count() >= 1) {
            // TODO: Handle the case where cnt == 1 specially.
            return writeBytesMultiple(in, array);
        }
    } else {
        ByteBuffer[] buffers = in.nioBuffers();
        int cnt = in.nioBufferCount();
        if (cnt >= 1) {
            // TODO: Handle the case where cnt == 1 specially.
            return writeBytesMultiple(in, buffers, cnt, in.nioBufferSize(), maxBytesPerGatheringWrite);
        }
    }
    // cnt == 0, which means the outbound buffer contained empty buffers only.
    in.removeBytes(0);
    return 0;
}
 

/**
 * Attempt to write multiple {@link ByteBuf} objects.
 * @param in the collection which contains objects to write.
 * @return The value that should be decremented from the write quantum which starts at
 * {@link ChannelConfig#getWriteSpinCount()}. The typical use cases are as follows:
 * <ul>
 *     <li>0 - if no write was attempted. This is appropriate if an empty {@link ByteBuf} (or other empty content)
 *     is encountered</li>
 *     <li>1 - if a single call to write data was made to the OS</li>
 *     <li>{@link ChannelUtils#WRITE_STATUS_SNDBUF_FULL} - if an attempt to write data was made to the OS, but
 *     no data was accepted</li>
 * </ul>
 * @throws Exception If an I/O error occurs.
 */
private int doWriteMultiple(ChannelOutboundBuffer in) throws Exception {
    final long maxBytesPerGatheringWrite = config().getMaxBytesPerGatheringWrite();
    if (PlatformDependent.hasUnsafe()) {
        IovArray array = ((EpollEventLoop) eventLoop()).cleanArray();
        array.maxBytes(maxBytesPerGatheringWrite);
        in.forEachFlushedMessage(array);

        if (array.count() >= 1) {
            // TODO: Handle the case where cnt == 1 specially.
            return writeBytesMultiple(in, array);
        }
    } else {
        ByteBuffer[] buffers = in.nioBuffers();
        int cnt = in.nioBufferCount();
        if (cnt >= 1) {
            // TODO: Handle the case where cnt == 1 specially.
            return writeBytesMultiple(in, buffers, cnt, in.nioBufferSize(), maxBytesPerGatheringWrite);
        }
    }
    // cnt == 0, which means the outbound buffer contained empty buffers only.
    in.removeBytes(0);
    return 0;
}