@Override
protected void doWrite(ChannelOutboundBuffer in) throws Exception {
for (; ; ) {
final int msgCount = in.size();
if (msgCount == 0) {
// Wrote all messages.
clearEpollOut();
break;
}
// Do gathering write if:
// * the outbound buffer contains more than one messages and
// * they are all buffers rather than a file region.
if (msgCount > 1) {
if (PlatformDependent.hasUnsafe()) {
// this means we can cast to EpollChannelOutboundBuffer and write the AdressEntry
// directly.
EpollChannelOutboundBuffer epollIn = (EpollChannelOutboundBuffer) in;
// Ensure the pending writes are made of memoryaddresses only.
AddressEntry[] addresses = epollIn.memoryAddresses();
if (addresses != null) {
writeBytesMultiple(epollIn, msgCount, addresses);
// We do not break the loop here even if the outbound buffer was flushed completely,
// because a user might have triggered another write and flush when we notify his or her
// listeners.
continue;
}
} else {
NioSocketChannelOutboundBuffer nioIn = (NioSocketChannelOutboundBuffer) in;
// Ensure the pending writes are made of memoryaddresses only.
ByteBuffer[] buffers = nioIn.nioBuffers();
if (buffers != null) {
writeBytesMultiple(nioIn, msgCount, buffers);
// We do not break the loop here even if the outbound buffer was flushed completely,
// because a user might have triggered another write and flush when we notify his or her
// listeners.
continue;
}
}
}
// The outbound buffer contains only one message or it contains a file region.
Object msg = in.current();
if (msg instanceof ByteBuf) {
ByteBuf buf = (ByteBuf) msg;
int readableBytes = buf.readableBytes();
if (readableBytes == 0) {
in.remove();
continue;
}
int expected = buf.readableBytes();
int localFlushedAmount = doWriteBytes(buf, expected);
in.progress(localFlushedAmount);
if (localFlushedAmount < expected) {
setEpollOut();
break;
}
if (!buf.isReadable()) {
in.remove();
}
} else if (msg instanceof DefaultFileRegion) {
DefaultFileRegion region = (DefaultFileRegion) msg;
long expected = region.count() - region.position();
long localFlushedAmount = doWriteFileRegion(region, expected);
in.progress(localFlushedAmount);
if (localFlushedAmount < expected) {
setEpollOut();
break;
}
if (region.transfered() >= region.count()) {
in.remove();
}
} else {
throw new UnsupportedOperationException(
"unsupported message type: " + StringUtil.simpleClassName(msg));
}
}
}
/**
* Write a {@link DefaultFileRegion}
*
* @param region the {@link DefaultFileRegion} from which the bytes should be written
* @return amount the amount of written bytes
*/
private long doWriteFileRegion(DefaultFileRegion region, long count) throws Exception {
return Native.sendfile(fd, region, region.transfered(), count);
}