com.barchart.netty.server.pipeline.CapabilitiesHandler.java Source code

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Here is the source code for com.barchart.netty.server.pipeline.CapabilitiesHandler.java

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/**
 * Copyright (C) 2011-2014 Barchart, Inc. <http://www.barchart.com/>
 *
 * All rights reserved. Licensed under the OSI BSD License.
 *
 * http://www.opensource.org/licenses/bsd-license.php
 */
package com.barchart.netty.server.pipeline;

import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInboundHandlerAdapter;

import java.util.Arrays;
import java.util.HashSet;
import java.util.Set;

import com.barchart.netty.common.messages.Capabilities;
import com.barchart.netty.common.messages.Version;
import com.barchart.netty.common.messages.VersionRequest;
import com.barchart.netty.common.messages.VersionResponse;
import com.barchart.netty.common.metadata.VersionAware;

/**
 * Channel handler that immediately writes a Capabilities message to the client
 * on connect.
 */
public class CapabilitiesHandler extends ChannelInboundHandlerAdapter implements VersionAware {

    private final Version version;
    private final Version minVersion;
    private final Set<String> capabilities;

    private Version activeVersion;

    public CapabilitiesHandler(final Version version_, final Version minVersion_, final String... capabilities_) {

        version = version_;
        minVersion = minVersion_;
        capabilities = new HashSet<String>(Arrays.asList(capabilities_));

    }

    /*
     * Server can't broadcast before client sends messages due to websocket bug:
     *
     * https://github.com/netty/netty/issues/2173
     */

    // @Override
    // public void channelActive(final ChannelHandlerContext ctx) throws
    // Exception {
    //
    // ctx.writeAndFlush(new Capabilities() {
    //
    // @Override
    // public Set<String> capabilities() {
    // return capabilities;
    // }
    //
    // @Override
    // public Version version() {
    // return version;
    // }
    //
    // @Override
    // public Version minVersion() {
    // return minVersion;
    // }
    //
    // });
    //
    // ctx.fireChannelActive();
    //
    // }

    @Override
    public void channelRead(final ChannelHandlerContext ctx, final Object msg) throws Exception {

        if (msg instanceof Capabilities) {

            ctx.writeAndFlush(new Capabilities() {

                @Override
                public Set<String> capabilities() {
                    return capabilities;
                }

                @Override
                public Version version() {
                    return version;
                }

                @Override
                public Version minVersion() {
                    return minVersion;
                }

            });

        } else if (msg instanceof VersionRequest) {

            final VersionRequest request = (VersionRequest) msg;

            final Version v = request.version();

            if (minVersion.lessThanOrEqual(v) && version.greaterThanOrEqual(v)) {

                activeVersion = v;

                ctx.writeAndFlush(new VersionResponse() {

                    @Override
                    public boolean success() {
                        return true;
                    }

                    @Override
                    public Version version() {
                        return v;
                    }

                });

            } else {

                ctx.writeAndFlush(new VersionResponse() {

                    @Override
                    public boolean success() {
                        return false;
                    }

                    @Override
                    public Version version() {
                        return version;
                    }

                });

            }

        } else {

            ctx.fireChannelRead(msg);

        }

    }

    @Override
    public Version version() {
        return activeVersion;
    }

}