CodecAdapter.java

/*
 * Copyright 1999-2012 Alibaba Group.
 *
 * Licensed 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.alibaba.dubbo.remoting.transport.codec;

import java.io.IOException;

import com.alibaba.dubbo.common.io.UnsafeByteArrayInputStream;
import com.alibaba.dubbo.common.io.UnsafeByteArrayOutputStream;
import com.alibaba.dubbo.common.utils.Assert;
import com.alibaba.dubbo.remoting.Channel;
import com.alibaba.dubbo.remoting.Codec;
import com.alibaba.dubbo.remoting.Codec2;
import com.alibaba.dubbo.remoting.buffer.ChannelBuffer;

/**
 * @author <a href="mailto:gang.lvg@alibaba-inc.com">kimi</a>
 */
public class CodecAdapter implements Codec2 {
    
    private Codec codec;
    
    public CodecAdapter(Codec codec) {
        Assert.notNull(codec, "codec == null");
        this.codec = codec;
    }

    public void encode(Channel channel, ChannelBuffer buffer, Object message)
        throws IOException {
        UnsafeByteArrayOutputStream os = new UnsafeByteArrayOutputStream(1024);
        codec.encode(channel, os, message);
        buffer.writeBytes(os.toByteArray());
    }

    public Object decode(Channel channel, ChannelBuffer buffer) throws IOException {
        byte[] bytes = new byte[buffer.readableBytes()];
        int savedReaderIndex = buffer.readerIndex();
        buffer.readBytes(bytes);
        UnsafeByteArrayInputStream is = new UnsafeByteArrayInputStream(bytes);
        Object result = codec.decode(channel, is);
        buffer.readerIndex(savedReaderIndex + is.position());
        return result == Codec.NEED_MORE_INPUT ? DecodeResult.NEED_MORE_INPUT : result;
    }
    
    public Codec getCodec() {
        return codec;
    }
}