这是netty源码包中的一个例子，我打印了writeindex，我测试了一个客户端，我想知道
public class DiscardClientHandler extends SimpleChannelUpstreamHandler {
...
@Override
public void channelConnected(ChannelHandlerContext ctx, ChannelStateEvent e) {
// Send the initial messages.
generateTraffic(e);
}
@Override
public void channelInterestChanged(ChannelHandlerContext ctx, ChannelStateEvent e) {
// Keep sending messages whenever the current socket buffer has room.
generateTraffic(e);
}
private void generateTraffic(ChannelStateEvent e) {
// Keep generating traffic until the channel is unwritable.
// A channel becomes unwritable when its internal buffer is full.
// If you keep writing messages ignoring this property,
// you will end up with an OutOfMemoryError.
Channel channel = e.getChannel();
while (channel.isWritable()) {
ChannelBuffer m = nextMessage();
if (m == null) {
break;
}
channel.write(m);
}
}
以上是克林特代码...
public class DiscardServerHandler extends SimpleChannelUpstreamHandler {
@Override
public void messageReceived(ChannelHandlerContext ctx, MessageEvent e) {
// Discard received data silently by doing nothing.
ChannelBuffer cb = (ChannelBuffer) e.getMessage();
transferredBytes += cb.readableBytes();
System.out.println("-=-=- " + transferredBytes + "-=-" + cb.writerIndex() + "-=- " + e.getMessage().toString());
}
-=-=- 679039232-=-65536-=- BigEndianHeapChannelBuffer(ridx=0, widx=65536, cap=65536)
-=-=- 679072768-=-33536-=- BigEndianHeapChannelBuffer(ridx=0, widx=33536, cap=33536)
-=-=- 679105792-=-33024-=- BigEndianHeapChannelBuffer(ridx=0, widx=33024, cap=33024)
...
-=-=- 679298816-=-256-=- BigEndianHeapChannelBuffer(ridx=0, widx=256, cap=256)
-=-=- 679299072-=-256-=- BigEndianHeapChannelBuffer(ridx=0, widx=256, cap=256)
-=-=- 679299328-=-256-=- BigEndianHeapChannelBuffer(ridx=0, widx=256, cap=256)
...
-=-=- 679600640-=-65536-=- BigEndianHeapChannelBuffer(ridx=0, widx=65536, cap=65536)
-=-=- 679634176-=-33536-=- BigEndianHeapChannelBuffer(ridx=0, widx=33536, cap=33536)
-=-=- 679640576-=-6400-=- BigEndianHeapChannelBuffer(ridx=0, widx=6400, cap=6400)
....
我测试了一个客户，我想知道：
- 为什么 writeIndex 有时是 256，有时是 65536？
- 为什么最大的是65536？
private ChannelBuffer nextMessage() { return ChannelBuffers.wrappedBuffer(content);//内容大小为256 } 我希望一个客户端使用相同的通道缓冲区，一个writeindex增加序列？我对吗？