Let CombinedChannelDuplexHandler correctly handle exceptionCaught. Re…

…lated to [netty#4528]

Motivation:

ChannelInboundHandler and ChannelOutboundHandler both can implement exceptionCaught(...) method and so we need to dispatch to both of them.

Modifications:

- Correctly first dispatch exceptionCaught to the ChannelInboundHandler but also make sure the next handler it will be dispatched to will be the ChannelOutboundHandler
- Add removeInboundHandler() and removeOutboundHandler() which allows to remove one of the combined handlers
- Let *Codec extends it and not ChannelHandlerAppender
- Remove ChannelHandlerAppender

Result:

Correctly handle events and also have same behavior as in 4.0

codec-http/src/main/java/io/netty/handler/codec/http/HttpClientCodec.java

@@ -17,11 +17,10 @@
 
 import io.netty.buffer.ByteBuf;
 import io.netty.channel.Channel;
-import io.netty.channel.ChannelHandlerAppender;
 import io.netty.channel.ChannelHandlerContext;
 import io.netty.channel.ChannelPipeline;
+import io.netty.channel.CombinedChannelDuplexHandler;
 import io.netty.handler.codec.PrematureChannelClosureException;
-import io.netty.util.internal.OneTimeTask;
 
 import java.util.ArrayDeque;
 import java.util.List;
@@ -42,7 +41,8 @@
  *
  * @see HttpServerCodec
  */
-public final class HttpClientCodec extends ChannelHandlerAppender implements HttpClientUpgradeHandler.SourceCodec {
+public final class HttpClientCodec extends CombinedChannelDuplexHandler<HttpResponseDecoder, HttpRequestEncoder>
+        implements HttpClientUpgradeHandler.SourceCodec {
 
     /** A queue that is used for correlating a request and a response. */
     private final Queue<HttpMethod> queue = new ArrayDeque<HttpMethod>();
@@ -83,8 +83,7 @@ public HttpClientCodec(
     public HttpClientCodec(
             int maxInitialLineLength, int maxHeaderSize, int maxChunkSize, boolean failOnMissingResponse,
             boolean validateHeaders) {
-        add(new Decoder(maxInitialLineLength, maxHeaderSize, maxChunkSize, validateHeaders));
-        add(new Encoder());
+        init(new Decoder(maxInitialLineLength, maxHeaderSize, maxChunkSize, validateHeaders), new Encoder());
         this.failOnMissingResponse = failOnMissingResponse;
     }
 
@@ -95,36 +94,15 @@ public HttpClientCodec(
     @Override
     public void upgradeFrom(ChannelHandlerContext ctx) {
         final ChannelPipeline p = ctx.pipeline();
-        // Remove the decoder later so that the decoder can enter the 'UPGRADED' state and forward the remaining data.
-        ctx.executor().execute(new OneTimeTask() {
-            @Override
-            public void run() {
-                p.remove(decoder());
-            }
-        });
-        p.remove(encoder());
-    }
-
-    /**
-     * Returns the encoder of this codec.
-     */
-    public HttpRequestEncoder encoder() {
-        return handlerAt(1);
-    }
-
-    /**
-     * Returns the decoder of this codec.
-     */
-    public HttpResponseDecoder decoder() {
-        return handlerAt(0);
+        p.remove(this);
     }
 
     public void setSingleDecode(boolean singleDecode) {
-        decoder().setSingleDecode(singleDecode);
+        inboundHandler().setSingleDecode(singleDecode);
     }
 
     public boolean isSingleDecode() {
-        return decoder().isSingleDecode();
+        return inboundHandler().isSingleDecode();
     }
 
     private final class Encoder extends HttpRequestEncoder {

codec-http/src/main/java/io/netty/handler/codec/http/HttpServerCodec.java

@@ -15,18 +15,17 @@
  */
 package io.netty.handler.codec.http;
 
-import io.netty.channel.ChannelHandlerAppender;
 import io.netty.channel.ChannelHandlerContext;
-
+import io.netty.channel.CombinedChannelDuplexHandler;
 
 /**
  * A combination of {@link HttpRequestDecoder} and {@link HttpResponseEncoder}
  * which enables easier server side HTTP implementation.
  *
  * @see HttpClientCodec
  */
-public final class HttpServerCodec extends ChannelHandlerAppender implements
-        HttpServerUpgradeHandler.SourceCodec {
+public final class HttpServerCodec extends CombinedChannelDuplexHandler<HttpRequestDecoder, HttpResponseEncoder>
+        implements HttpServerUpgradeHandler.SourceCodec {
 
     /**
      * Creates a new instance with the default decoder options
@@ -58,21 +57,6 @@ public HttpServerCodec(int maxInitialLineLength, int maxHeaderSize, int maxChunk
      */
     @Override
     public void upgradeFrom(ChannelHandlerContext ctx) {
-        ctx.pipeline().remove(HttpRequestDecoder.class);
-        ctx.pipeline().remove(HttpResponseEncoder.class);
-    }
-
-    /**
-     * Returns the encoder of this codec.
-     */
-    public HttpResponseEncoder encoder() {
-        return handlerAt(1);
-    }
-
-    /**
-     * Returns the decoder of this codec.
-     */
-    public HttpRequestDecoder decoder() {
-        return handlerAt(0);
+        ctx.pipeline().remove(this);
     }
 }

codec-http/src/main/java/io/netty/handler/codec/spdy/SpdyHttpCodec.java

@@ -15,12 +15,12 @@
  */
 package io.netty.handler.codec.spdy;
 
-import io.netty.channel.ChannelHandlerAppender;
+import io.netty.channel.CombinedChannelDuplexHandler;
 
 /**
  * A combination of {@link SpdyHttpDecoder} and {@link SpdyHttpEncoder}
  */
-public final class SpdyHttpCodec extends ChannelHandlerAppender {
+public final class SpdyHttpCodec extends CombinedChannelDuplexHandler<SpdyHttpDecoder, SpdyHttpEncoder> {
     /**
      * Creates a new instance with the specified decoder options.
      */

codec-memcache/src/main/java/io/netty/handler/codec/memcache/binary/BinaryMemcacheClientCodec.java

@@ -16,8 +16,8 @@
 package io.netty.handler.codec.memcache.binary;
 
 import io.netty.buffer.ByteBuf;
-import io.netty.channel.ChannelHandlerAppender;
 import io.netty.channel.ChannelHandlerContext;
+import io.netty.channel.CombinedChannelDuplexHandler;
 import io.netty.handler.codec.PrematureChannelClosureException;
 import io.netty.handler.codec.memcache.LastMemcacheContent;
 
@@ -35,7 +35,8 @@
  * content, which defaults to 8192. This chunk size is the maximum, so if smaller chunks arrive they
  * will be passed up the pipeline and not queued up to the chunk size.
  */
-public final class BinaryMemcacheClientCodec extends ChannelHandlerAppender {
+public final class BinaryMemcacheClientCodec extends
+        CombinedChannelDuplexHandler<BinaryMemcacheResponseDecoder, BinaryMemcacheRequestEncoder> {
 
     private final boolean failOnMissingResponse;
     private final AtomicLong requestResponseCounter = new AtomicLong();
@@ -64,8 +65,7 @@ public BinaryMemcacheClientCodec(int decodeChunkSize) {
      */
     public BinaryMemcacheClientCodec(int decodeChunkSize, boolean failOnMissingResponse) {
         this.failOnMissingResponse = failOnMissingResponse;
-        add(new Decoder(decodeChunkSize));
-        add(new Encoder());
+        init(new Decoder(decodeChunkSize), new Encoder());
     }
 
     private final class Encoder extends BinaryMemcacheRequestEncoder {

codec-memcache/src/main/java/io/netty/handler/codec/memcache/binary/BinaryMemcacheServerCodec.java

@@ -15,7 +15,7 @@
  */
 package io.netty.handler.codec.memcache.binary;
 
-import io.netty.channel.ChannelHandlerAppender;
+import io.netty.channel.CombinedChannelDuplexHandler;
 
 /**
  * The full server codec that combines the correct encoder and decoder.
@@ -24,14 +24,14 @@
  * Internally, it combines the {@link BinaryMemcacheRequestDecoder} and the
  * {@link BinaryMemcacheResponseEncoder} to request decoding and response encoding.
  */
-public class BinaryMemcacheServerCodec extends ChannelHandlerAppender {
+public class BinaryMemcacheServerCodec extends
+        CombinedChannelDuplexHandler<BinaryMemcacheRequestDecoder, BinaryMemcacheResponseEncoder> {
 
     public BinaryMemcacheServerCodec() {
         this(AbstractBinaryMemcacheDecoder.DEFAULT_MAX_CHUNK_SIZE);
     }
 
     public BinaryMemcacheServerCodec(int decodeChunkSize) {
-        add(new BinaryMemcacheRequestDecoder(decodeChunkSize));
-        add(new BinaryMemcacheResponseEncoder());
+        super(new BinaryMemcacheRequestDecoder(decodeChunkSize), new BinaryMemcacheResponseEncoder());
     }
 }

handler-proxy/src/main/java/io/netty/handler/proxy/HttpProxyHandler.java

@@ -101,12 +101,12 @@ protected void addCodec(ChannelHandlerContext ctx) throws Exception {
 
     @Override
     protected void removeEncoder(ChannelHandlerContext ctx) throws Exception {
-        ctx.pipeline().remove(codec.encoder());
+        codec.removeOutboundHandler();
     }
 
     @Override
     protected void removeDecoder(ChannelHandlerContext ctx) throws Exception {
-        ctx.pipeline().remove(codec.decoder());
+        codec.removeInboundHandler();
     }
 
     @Override

handler-proxy/src/test/java/io/netty/handler/proxy/HttpProxyServer.java

@@ -83,7 +83,7 @@ private boolean authenticate(ChannelHandlerContext ctx, FullHttpRequest req) {
         }
 
         ctx.pipeline().remove(HttpObjectAggregator.class);
-        ctx.pipeline().remove(HttpRequestDecoder.class);
+        ctx.pipeline().get(HttpServerCodec.class).removeInboundHandler();
 
         boolean authzSuccess = false;
         if (username != null) {
@@ -128,7 +128,7 @@ protected boolean handleProxyProtocol(ChannelHandlerContext ctx, Object msg) thr
             }
 
             ctx.write(res);
-            ctx.pipeline().remove(HttpResponseEncoder.class);
+            ctx.pipeline().get(HttpServerCodec.class).removeOutboundHandler();
             return true;
         }
 
@@ -158,7 +158,7 @@ protected boolean handleProxyProtocol(ChannelHandlerContext ctx, Object msg) thr
             }
 
             ctx.write(res);
-            ctx.pipeline().remove(HttpResponseEncoder.class);
+            ctx.pipeline().get(HttpServerCodec.class).removeOutboundHandler();
 
             if (sendGreeting) {
                 ctx.write(Unpooled.copiedBuffer("0\n", CharsetUtil.US_ASCII));