org.rahmanj.sandshrew.SpdyClientStreamIdHandler.java Source code

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Here is the source code for org.rahmanj.sandshrew.SpdyClientStreamIdHandler.java

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/*
* Copyright 2014 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 org.rahmanj.sandshrew;

import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelOutboundHandlerAdapter;
import io.netty.channel.ChannelPromise;
import io.netty.handler.codec.http.HttpHeaders;
import io.netty.handler.codec.http.HttpMessage;
import io.netty.handler.codec.spdy.SpdyHttpHeaders;
import io.netty.handler.codec.spdy.SpdyHttpHeaders.Names;

/**
 * Adds a unique client stream ID to the SPDY header. Client stream IDs MUST be odd.
 */
public class SpdyClientStreamIdHandler extends ChannelOutboundHandlerAdapter {
    private int currentStreamId = 1;

    public boolean acceptOutboundMessage(Object msg) {
        return msg instanceof HttpMessage;
    }

    /**
     * Handle writes by updating the stream identifier in accordance with the SPDY spec
     * @param ctx {@link ChannelHandlerContext} for this channel
     * @param msg {@link HttpMessage} to write
     * @param promise {@link ChannelPromise}
     */
    @Override
    public void write(ChannelHandlerContext ctx, Object msg, ChannelPromise promise) {
        if (acceptOutboundMessage(msg)) {
            HttpMessage httpMsg = (HttpMessage) msg;
            if (!httpMsg.headers().contains(SpdyHttpHeaders.Names.STREAM_ID)) {
                HttpHeaders.setIntHeader(httpMsg, Names.STREAM_ID, currentStreamId);
                // Client stream IDs are always odd
                currentStreamId += 2;
            }
        }

        // Flush down the remainder of the pipeline
        ctx.write(msg, promise);
    }
}