[#1533] Introduce ByteBufHolder.duplicate() and make use of it in DefaultChannelGroup.write(...)

buffer/src/main/java/io/netty/buffer/ByteBufHolder.java

@@ -32,6 +32,11 @@ public interface ByteBufHolder extends ReferenceCounted {
      */
     ByteBufHolder copy();
 
+    /**
+     * Duplicate the {@link ByteBufHolder}. Be aware that this will not automatically call {@link #retain()}.
+     */
+    ByteBufHolder duplicate();
+
     @Override
     ByteBufHolder retain();
 

buffer/src/main/java/io/netty/buffer/DefaultByteBufHolder.java

@@ -45,6 +45,11 @@ public class DefaultByteBufHolder implements ByteBufHolder {
         return new DefaultByteBufHolder(data.copy());
     }
 
+    @Override
+    public ByteBufHolder duplicate() {
+        return new DefaultByteBufHolder(data.duplicate());
+    }
+
     @Override
     public int refCnt() {
         return data.refCnt();

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

@@ -100,4 +100,13 @@ public class DefaultFullHttpRequest extends DefaultHttpRequest implements FullHt
         copy.trailingHeaders().set(trailingHeaders());
         return copy;
     }
+
+    @Override
+    public FullHttpRequest duplicate() {
+        DefaultFullHttpRequest duplicate = new DefaultFullHttpRequest(
+                getProtocolVersion(), getMethod(), getUri(), content().duplicate());
+        duplicate.headers().set(headers());
+        duplicate.trailingHeaders().set(trailingHeaders());
+        return duplicate;
+    }
 }

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

@@ -95,4 +95,13 @@ public class DefaultFullHttpResponse extends DefaultHttpResponse implements Full
         copy.trailingHeaders().set(trailingHeaders());
         return copy;
     }
+
+    @Override
+    public FullHttpResponse duplicate() {
+        DefaultFullHttpResponse duplicate = new DefaultFullHttpResponse(getProtocolVersion(), getStatus(),
+                content().duplicate());
+        duplicate.headers().set(headers());
+        duplicate.trailingHeaders().set(trailingHeaders());
+        return duplicate;
+    }
 }

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

@@ -44,6 +44,11 @@ public class DefaultHttpContent extends DefaultHttpObject implements HttpContent
         return new DefaultHttpContent(content.copy());
     }
 
+    @Override
+    public HttpContent duplicate() {
+        return new DefaultHttpContent(content.duplicate());
+    }
+
     @Override
     public int refCnt() {
         return content.refCnt();

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

@@ -54,6 +54,13 @@ public class DefaultLastHttpContent extends DefaultHttpContent implements LastHt
         return copy;
     }
 
+    @Override
+    public LastHttpContent duplicate() {
+        DefaultLastHttpContent copy = new DefaultLastHttpContent(content().duplicate());
+        copy.trailingHeaders().set(trailingHeaders());
+        return copy;
+    }
+
     @Override
     public LastHttpContent retain(int increment) {
         super.retain(increment);

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

@@ -30,6 +30,9 @@ public interface HttpContent extends HttpObject, ByteBufHolder {
     @Override
     HttpContent copy();
 
+    @Override
+    HttpContent duplicate();
+
     @Override
     HttpContent retain();
 

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

@@ -39,6 +39,11 @@ public interface LastHttpContent extends HttpContent {
             return EMPTY_LAST_CONTENT;
         }
 
+        @Override
+        public LastHttpContent duplicate() {
+            return this;
+        }
+
         @Override
         public HttpHeaders trailingHeaders() {
             return HttpHeaders.EMPTY_HEADERS;

codec-http/src/main/java/io/netty/handler/codec/http/multipart/Attribute.java

@@ -34,6 +34,9 @@ public interface Attribute extends HttpData {
     @Override
     Attribute copy();
 
+    @Override
+    Attribute duplicate();
+
     @Override
     Attribute retain();
 

codec-http/src/main/java/io/netty/handler/codec/http/multipart/DiskAttribute.java

@@ -155,6 +155,21 @@ public class DiskAttribute extends AbstractDiskHttpData implements Attribute {
         return attr;
     }
 
+    @Override
+    public Attribute duplicate() {
+        DiskAttribute attr = new DiskAttribute(getName());
+        attr.setCharset(getCharset());
+        ByteBuf content = content();
+        if (content != null) {
+            try {
+                attr.setContent(content.duplicate());
+            } catch (IOException e) {
+                throw new ChannelException(e);
+            }
+        }
+        return attr;
+    }
+
     @Override
     public Attribute retain(int increment) {
         super.retain(increment);

codec-http/src/main/java/io/netty/handler/codec/http/multipart/DiskFileUpload.java

@@ -178,6 +178,21 @@ public class DiskFileUpload extends AbstractDiskHttpData implements FileUpload {
         return upload;
     }
 
+    @Override
+    public FileUpload duplicate() {
+        DiskFileUpload upload = new DiskFileUpload(getName(),
+                getFilename(), getContentType(), getContentTransferEncoding(), getCharset(), size);
+        ByteBuf buf = content();
+        if (buf != null) {
+            try {
+                upload.setContent(buf.duplicate());
+            } catch (IOException e) {
+                throw new ChannelException(e);
+            }
+        }
+        return upload;
+    }
+
     @Override
     public FileUpload retain(int increment) {
         super.retain(increment);

codec-http/src/main/java/io/netty/handler/codec/http/multipart/FileUpload.java

@@ -59,6 +59,9 @@ public interface FileUpload extends HttpData {
     @Override
     FileUpload copy();
 
+    @Override
+    FileUpload duplicate();
+
     @Override
     FileUpload retain();
 

codec-http/src/main/java/io/netty/handler/codec/http/multipart/HttpData.java

@@ -180,6 +180,9 @@ public interface HttpData extends InterfaceHttpData, ByteBufHolder {
     @Override
     HttpData copy();
 
+    @Override
+    HttpData duplicate();
+
     @Override
     HttpData retain();
 

codec-http/src/main/java/io/netty/handler/codec/http/multipart/HttpPostRequestEncoder.java

@@ -1145,6 +1145,15 @@ public class HttpPostRequestEncoder implements ChunkedMessageInput<HttpContent>
             return copy;
         }
 
+        @Override
+        public FullHttpRequest duplicate() {
+            DefaultFullHttpRequest duplicate = new DefaultFullHttpRequest(
+                    getProtocolVersion(), getMethod(), getUri(), content().duplicate());
+            duplicate.headers().set(headers());
+            duplicate.trailingHeaders().set(trailingHeaders());
+            return duplicate;
+        }
+
         @Override
         public FullHttpRequest retain(int increment) {
             content.retain(increment);

codec-http/src/main/java/io/netty/handler/codec/http/multipart/MemoryAttribute.java

@@ -116,6 +116,21 @@ public class MemoryAttribute extends AbstractMemoryHttpData implements Attribute
         return attr;
     }
 
+    @Override
+    public Attribute duplicate() {
+        MemoryAttribute attr = new MemoryAttribute(getName());
+        attr.setCharset(getCharset());
+        ByteBuf content = content();
+        if (content != null) {
+            try {
+                attr.setContent(content.duplicate());
+            } catch (IOException e) {
+                throw new ChannelException(e);
+            }
+        }
+        return attr;
+    }
+
     @Override
     public Attribute retain() {
         super.retain();

codec-http/src/main/java/io/netty/handler/codec/http/multipart/MemoryFileUpload.java

@@ -145,6 +145,21 @@ public class MemoryFileUpload extends AbstractMemoryHttpData implements FileUplo
         return upload;
     }
 
+    @Override
+    public FileUpload duplicate() {
+        MemoryFileUpload upload = new MemoryFileUpload(getName(), getFilename(), getContentType(),
+                getContentTransferEncoding(), getCharset(), size);
+        ByteBuf buf = content();
+        if (buf != null) {
+            try {
+                upload.setContent(buf.duplicate());
+                return upload;
+            } catch (IOException e) {
+                throw new ChannelException(e);
+            }
+        }
+        return upload;
+    }
     @Override
     public FileUpload retain() {
         super.retain();

codec-http/src/main/java/io/netty/handler/codec/http/multipart/MixedAttribute.java

@@ -204,6 +204,11 @@ public class MixedAttribute implements Attribute {
         return attribute.copy();
     }
 
+    @Override
+    public Attribute duplicate() {
+        return attribute.duplicate();
+    }
+
     @Override
     public ByteBuf content() {
         return attribute.content();

codec-http/src/main/java/io/netty/handler/codec/http/multipart/MixedFileUpload.java

@@ -230,6 +230,11 @@ public class MixedFileUpload implements FileUpload {
         return fileUpload.copy();
     }
 
+    @Override
+    public FileUpload duplicate() {
+        return fileUpload.duplicate();
+    }
+
     @Override
     public ByteBuf content() {
         return fileUpload.content();

codec-http/src/main/java/io/netty/handler/codec/http/websocketx/BinaryWebSocketFrame.java

@@ -59,6 +59,11 @@ public class BinaryWebSocketFrame extends WebSocketFrame {
         return new BinaryWebSocketFrame(isFinalFragment(), rsv(), content().copy());
     }
 
+    @Override
+    public BinaryWebSocketFrame duplicate() {
+        return new BinaryWebSocketFrame(isFinalFragment(), rsv(), content().duplicate());
+    }
+
     @Override
     public BinaryWebSocketFrame retain() {
         super.retain();

codec-http/src/main/java/io/netty/handler/codec/http/websocketx/CloseWebSocketFrame.java

@@ -143,6 +143,11 @@ public class CloseWebSocketFrame extends WebSocketFrame {
         return new CloseWebSocketFrame(isFinalFragment(), rsv(), content().copy());
     }
 
+    @Override
+    public CloseWebSocketFrame duplicate() {
+        return new CloseWebSocketFrame(isFinalFragment(), rsv(), content().duplicate());
+    }
+
     @Override
     public CloseWebSocketFrame retain() {
         super.retain();

codec-http/src/main/java/io/netty/handler/codec/http/websocketx/ContinuationWebSocketFrame.java

@@ -124,6 +124,11 @@ public class ContinuationWebSocketFrame extends WebSocketFrame {
         return new ContinuationWebSocketFrame(isFinalFragment(), rsv(), content().copy(), aggregatedText());
     }
 
+    @Override
+    public ContinuationWebSocketFrame duplicate() {
+        return new ContinuationWebSocketFrame(isFinalFragment(), rsv(), content().duplicate(), aggregatedText());
+    }
+
     @Override
     public ContinuationWebSocketFrame retain() {
         super.retain();

codec-http/src/main/java/io/netty/handler/codec/http/websocketx/PingWebSocketFrame.java

@@ -59,6 +59,11 @@ public class PingWebSocketFrame extends WebSocketFrame {
         return new PingWebSocketFrame(isFinalFragment(), rsv(), content().copy());
     }
 
+    @Override
+    public PingWebSocketFrame duplicate() {
+        return new PingWebSocketFrame(isFinalFragment(), rsv(), content().duplicate());
+    }
+
     @Override
     public PingWebSocketFrame retain() {
         super.retain();

codec-http/src/main/java/io/netty/handler/codec/http/websocketx/PongWebSocketFrame.java

@@ -59,6 +59,11 @@ public class PongWebSocketFrame extends WebSocketFrame {
         return new PongWebSocketFrame(isFinalFragment(), rsv(), content().copy());
     }
 
+    @Override
+    public PongWebSocketFrame duplicate() {
+        return new PongWebSocketFrame(isFinalFragment(), rsv(), content().duplicate());
+    }
+
     @Override
     public PongWebSocketFrame retain() {
         super.retain();

codec-http/src/main/java/io/netty/handler/codec/http/websocketx/TextWebSocketFrame.java

@@ -99,6 +99,11 @@ public class TextWebSocketFrame extends WebSocketFrame {
         return new TextWebSocketFrame(isFinalFragment(), rsv(), content().copy());
     }
 
+    @Override
+    public TextWebSocketFrame duplicate() {
+        return new TextWebSocketFrame(isFinalFragment(), rsv(), content().duplicate());
+    }
+
     @Override
     public TextWebSocketFrame retain() {
         super.retain();

codec-http/src/main/java/io/netty/handler/codec/http/websocketx/WebSocketFrame.java

@@ -62,6 +62,9 @@ public abstract class WebSocketFrame extends DefaultByteBufHolder {
     @Override
     public abstract WebSocketFrame copy();
 
+    @Override
+    public abstract WebSocketFrame duplicate();
+
     @Override
     public String toString() {
         return getClass().getSimpleName() + "(data: " + content().toString() + ')';

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

@@ -85,6 +85,13 @@ public class DefaultSpdyDataFrame extends DefaultSpdyStreamFrame implements Spdy
         return frame;
     }
 
+    @Override
+    public SpdyDataFrame duplicate() {
+        SpdyDataFrame frame = new DefaultSpdyDataFrame(getStreamId(), content().duplicate());
+        frame.setLast(isLast());
+        return frame;
+    }
+
     @Override
     public int refCnt() {
         return data.refCnt();

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

@@ -42,6 +42,9 @@ public interface SpdyDataFrame extends ByteBufHolder, SpdyStreamFrame {
     @Override
     SpdyDataFrame copy();
 
+    @Override
+    SpdyDataFrame duplicate();
+
     @Override
     SpdyDataFrame retain();
 

codec-http/src/test/java/io/netty/handler/codec/http/multipart/AbstractMemoryHttpDataTest.java

@@ -82,6 +82,11 @@ public class AbstractMemoryHttpDataTest {
             throw new UnsupportedOperationException("Should never be called.");
         }
 
+        @Override
+        public HttpData duplicate() {
+            throw new UnsupportedOperationException("Should never be called.");
+        }
+
         @Override
         public int compareTo(InterfaceHttpData o) {
             throw new UnsupportedOperationException("Should never be called.");

transport-sctp/src/main/java/io/netty/channel/sctp/SctpMessage.java

@@ -135,6 +135,15 @@ public final class SctpMessage extends DefaultByteBufHolder {
         }
     }
 
+    @Override
+    public SctpMessage duplicate() {
+        if (msgInfo == null) {
+            return new SctpMessage(protocolIdentifier, streamIdentifier, content().duplicate());
+        } else {
+            return new SctpMessage(msgInfo, content().copy());
+        }
+    }
+
     @Override
     public SctpMessage retain() {
         super.retain();

transport/src/main/java/io/netty/channel/group/DefaultChannelGroup.java

@@ -251,7 +251,7 @@ public class DefaultChannelGroup extends AbstractSet<Channel> implements Channel
         if (message instanceof ByteBuf) {
             return ((ByteBuf) message).duplicate().retain();
         } else if (message instanceof ByteBufHolder) {
-            return ((ByteBufHolder) message).copy();
+            return ((ByteBufHolder) message).duplicate().retain();
         } else {
             return ReferenceCountUtil.retain(message);
         }

transport/src/main/java/io/netty/channel/socket/DatagramPacket.java

@@ -47,6 +47,11 @@ public final class DatagramPacket
         return new DatagramPacket(content().copy(), recipient(), sender());
     }
 
+    @Override
+    public DatagramPacket duplicate() {
+        return new DatagramPacket(content().duplicate(), recipient(), sender());
+    }
+
     @Override
     public DatagramPacket retain() {
         super.retain();