/
WebSocketProtocolHandler.java
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/
WebSocketProtocolHandler.java
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/*
* Copyright 2013 The Netty Project
*
* The Netty Project licenses this file to you under the Apache License,
* version 2.0 (the "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at:
*
* https://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*/
package io.netty.handler.codec.http.websocketx;
import io.netty.channel.ChannelHandlerContext;
import io.netty.handler.codec.MessageToMessageDecoder;
import io.netty.util.ReferenceCountUtil;
import io.netty.util.concurrent.Future;
import io.netty.util.concurrent.Promise;
import java.nio.channels.ClosedChannelException;
import java.util.concurrent.TimeUnit;
abstract class WebSocketProtocolHandler extends MessageToMessageDecoder<WebSocketFrame> {
private final boolean dropPongFrames;
private final WebSocketCloseStatus closeStatus;
private final long forceCloseTimeoutMillis;
private Promise<Void> closeSent;
/**
* Creates a new {@link WebSocketProtocolHandler} that will <i>drop</i> {@link PongWebSocketFrame}s.
*/
WebSocketProtocolHandler() {
this(true);
}
/**
* Creates a new {@link WebSocketProtocolHandler}, given a parameter that determines whether or not to drop {@link
* PongWebSocketFrame}s.
*
* @param dropPongFrames
* {@code true} if {@link PongWebSocketFrame}s should be dropped
*/
WebSocketProtocolHandler(boolean dropPongFrames) {
this(dropPongFrames, null, 0L);
}
WebSocketProtocolHandler(boolean dropPongFrames,
WebSocketCloseStatus closeStatus,
long forceCloseTimeoutMillis) {
this.dropPongFrames = dropPongFrames;
this.closeStatus = closeStatus;
this.forceCloseTimeoutMillis = forceCloseTimeoutMillis;
}
@Override
protected void decode(ChannelHandlerContext ctx, WebSocketFrame frame) throws Exception {
if (frame instanceof PingWebSocketFrame) {
frame.content().retain();
ctx.channel().writeAndFlush(new PongWebSocketFrame(frame.content()));
readIfNeeded(ctx);
return;
}
if (frame instanceof PongWebSocketFrame && dropPongFrames) {
readIfNeeded(ctx);
return;
}
ctx.fireChannelRead(frame.retain());
}
private static void readIfNeeded(ChannelHandlerContext ctx) {
if (!ctx.channel().config().isAutoRead()) {
ctx.read();
}
}
@Override
public Future<Void> close(final ChannelHandlerContext ctx) {
if (closeStatus == null || !ctx.channel().isActive()) {
return ctx.close();
}
final Future<Void> future = closeSent == null ?
write(ctx, new CloseWebSocketFrame(closeStatus)) : closeSent.asFuture();
flush(ctx);
applyCloseSentTimeout(ctx);
Promise<Void> promise = ctx.newPromise();
future.addListener(f -> ctx.close().cascadeTo(promise));
return promise.asFuture();
}
@Override
public Future<Void> write(final ChannelHandlerContext ctx, Object msg) {
if (closeSent != null) {
ReferenceCountUtil.release(msg);
return ctx.newFailedFuture(new ClosedChannelException());
}
if (msg instanceof CloseWebSocketFrame) {
Promise<Void> promise = ctx.newPromise();
closeSent(promise);
ctx.write(msg).cascadeTo(closeSent);
return promise.asFuture();
}
return ctx.write(msg);
}
void closeSent(Promise<Void> promise) {
closeSent = promise;
}
private void applyCloseSentTimeout(ChannelHandlerContext ctx) {
if (closeSent.isDone() || forceCloseTimeoutMillis < 0) {
return;
}
Future<?> timeoutTask = ctx.executor().schedule(() -> {
if (!closeSent.isDone()) {
closeSent.tryFailure(buildHandshakeException("send close frame timed out"));
}
}, forceCloseTimeoutMillis, TimeUnit.MILLISECONDS);
closeSent.asFuture().addListener(future -> timeoutTask.cancel());
}
/**
* Returns a {@link WebSocketHandshakeException} that depends on which client or server pipeline
* this handler belongs. Should be overridden in implementation otherwise a default exception is used.
*/
protected WebSocketHandshakeException buildHandshakeException(String message) {
return new WebSocketHandshakeException(message);
}
@Override
public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
ctx.fireExceptionCaught(cause);
ctx.close();
}
}