/*
* 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:
*
* 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 com.couchbase.client.deps.io.netty.handler.codec.memcache.binary;
import io.netty.buffer.ByteBuf;
import io.netty.channel.ChannelHandlerContext;
import io.netty.handler.codec.MessageToByteEncoder;
import com.couchbase.client.deps.io.netty.handler.codec.memcache.AbstractMemcacheObjectEncoder;
import io.netty.util.CharsetUtil;
/**
* A {@link MessageToByteEncoder} that encodes binary memache messages into bytes.
*/
public abstract class AbstractBinaryMemcacheEncoder<M extends BinaryMemcacheMessage>
extends AbstractMemcacheObjectEncoder<M> {
/**
* Every binary memcache message has at least a 24 bytes header.
*/
private static final int DEFAULT_BUFFER_SIZE = 24;
@Override
protected ByteBuf encodeMessage(ChannelHandlerContext ctx, M msg) {
ByteBuf buf = ctx.alloc().buffer(DEFAULT_BUFFER_SIZE);
encodeHeader(buf, msg);
encodeExtras(buf, msg.getExtras());
encodeKey(buf, msg.getKey());
return buf;
}
/**
* Encode the extras.
*
* @param buf the {@link ByteBuf} to write into.
* @param extras the extras to encode.
*/
private static void encodeExtras(ByteBuf buf, ByteBuf extras) {
if (extras == null || !extras.isReadable()) {
return;
}
buf.writeBytes(extras);
extras.release();
}
/**
* Encode the key.
*
* @param buf the {@link ByteBuf} to write into.
* @param key the key to encode.
*/
private static void encodeKey(ByteBuf buf, String key) {
if (key == null || key.isEmpty()) {
return;
}
buf.writeBytes(key.getBytes(CharsetUtil.UTF_8));
}
/**
* Encode the header.
* <p/>
* This methods needs to be implemented by a sub class because the header is different
* for both requests and responses.
*
* @param buf the {@link ByteBuf} to write into.
* @param msg the message to encode.
*/
protected abstract void encodeHeader(ByteBuf buf, M msg);
}