reactor.tcp.netty.NettyTcpConnectionChannelInboundHandler.java Source code

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Here is the source code for reactor.tcp.netty.NettyTcpConnectionChannelInboundHandler.java

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/*
 * Copyright (c) 2011-2013 GoPivotal, Inc. All Rights Reserved.
 *
 * 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 reactor.tcp.netty;

import io.netty.buffer.ByteBuf;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInboundHandlerAdapter;
import reactor.io.Buffer;

/**
 * A {@link ChannelInboundHandlerAdapter} implementation that uses NettyTcpConnection.
 *
 * @author Jon Brisbin
 * @author Stephane Maldini
 */

class NettyTcpConnectionChannelInboundHandler extends ChannelInboundHandlerAdapter {

    private final NettyTcpConnection<?, ?> conn;

    private ByteBuf remainder;

    NettyTcpConnectionChannelInboundHandler(NettyTcpConnection<?, ?> conn) {
        this.conn = conn;
    }

    @Override
    public void channelRead(ChannelHandlerContext ctx, Object m) throws Exception {
        if (m instanceof ByteBuf) {
            ByteBuf data = (ByteBuf) m;

            if (remainder == null) {
                try {
                    passToConnection(data);
                } finally {
                    if (data.isReadable()) {
                        remainder = data;
                    } else {
                        data.release();
                    }
                }
            } else {
                if (!bufferHasSufficientCapacity(remainder, data)) {
                    ByteBuf combined = createCombinedBuffer(remainder, data, ctx);
                    remainder.release();
                    remainder = combined;
                } else {
                    remainder.writeBytes(data);
                }
                data.release();

                try {
                    passToConnection(remainder);
                } finally {
                    if (remainder.isReadable()) {
                        remainder.discardSomeReadBytes();
                    } else {
                        remainder.release();
                        remainder = null;
                    }
                }
            }
        }
    }

    private boolean bufferHasSufficientCapacity(ByteBuf receiver, ByteBuf provider) {
        return receiver.writerIndex() <= receiver.maxCapacity() - provider.readableBytes();
    }

    private ByteBuf createCombinedBuffer(ByteBuf partOne, ByteBuf partTwo, ChannelHandlerContext ctx) {
        ByteBuf combined = ctx.alloc().buffer(partOne.readableBytes() + partTwo.readableBytes());
        combined.writeBytes(partOne);
        combined.writeBytes(partTwo);
        return combined;
    }

    private void passToConnection(ByteBuf data) {
        Buffer b = new Buffer(data.nioBuffer());
        int start = b.position();
        conn.read(b);
        data.skipBytes(b.position() - start);
    }
}