/*
 * Copyright 2012 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:
 *
 *   http://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.protobuf;

import com.google.protobuf.Message;
import com.google.protobuf.MessageLite;
import com.google.protobuf.MessageLiteOrBuilder;
import io.netty.buffer.ByteBuf;
import io.netty.channel.ChannelHandler.Sharable;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelPipeline;
import io.netty.handler.codec.LengthFieldBasedFrameDecoder;
import io.netty.handler.codec.LengthFieldPrepender;
import io.netty.handler.codec.MessageToByteEncoder;

/**
 * Encodes the requested <a href="http://code.google.com/p/protobuf/">Google
 * Protocol Buffers</a> {@link Message} and {@link MessageLite} into a
 * {@link ByteBuf}. A typical setup for TCP/IP would be:
 * <pre>
 * {@link ChannelPipeline} pipeline = ...;
 *
 * // Decoders
 * pipeline.addLast("frameDecoder",
 *                  new {@link LengthFieldBasedFrameDecoder}(1048576, 0, 4, 0, 4));
 * pipeline.addLast("protobufDecoder",
 *                  new {@link ProtobufDecoder}(MyMessage.getDefaultInstance()));
 *
 * // Encoder
 * pipeline.addLast("frameEncoder", new {@link LengthFieldPrepender}(4));
 * pipeline.addLast("protobufEncoder", new {@link ProtobufEncoder}());
 * </pre>
 * and then you can use a {@code MyMessage} instead of a {@link ByteBuf}
 * as a message:
 * <pre>
 * void messageReceived({@link ChannelHandlerContext} ctx, MyMessage req) {
 *     MyMessage res = MyMessage.newBuilder().setText(
 *                               "Did you say '" + req.getText() + "'?").build();
 *     ch.write(res);
 * }
 * </pre>
 */
@Sharable
public class ProtobufEncoder extends MessageToByteEncoder<MessageLiteOrBuilder> {

    @Override
    protected void encode(ChannelHandlerContext ctx, MessageLiteOrBuilder msg, ByteBuf out) throws Exception {
        if (msg instanceof MessageLite) {
            out.writeBytes(((MessageLite) msg).toByteArray());
            return;
        }
        if (msg instanceof MessageLite.Builder) {
            out.writeBytes(((MessageLite.Builder) msg).build().toByteArray());
        }
    }
}

@@ -1107,35 +1107,38 @@
 .codec.MessageTo
-Byt
+Messag
 eEncoder;%0A%0A/**%0A 
@@ -1132,16 +1132,59 @@
 coder;%0A%0A
+import static io.netty.buffer.Unpooled.*;%0A%0A
 /**%0A * E
@@ -2276,19 +2276,22 @@
 essageTo
-Byt
+Messag
 eEncoder
@@ -2344,20 +2344,22 @@
 otected 
-void
+Object
  encode(
@@ -2413,21 +2413,8 @@
  msg
-, ByteBuf out
 ) th
@@ -2480,38 +2480,44 @@
             
-out.writeBytes
+return wrappedBuffer
 (((MessageLi
@@ -2545,28 +2545,8 @@
 ));%0A
-            return;%0A
     
@@ -2617,22 +2617,28 @@
     
-out.writeBytes
+return wrappedBuffer
 (((M
@@ -2692,20 +2692,41 @@
 ;%0A        %7D%0A
+        return null;%0A
     %7D%0A%7D%0A

Revert "Let ProtobufEncoder extend MessageToByteEncoder which makes more sense. Related to [#1222]"