examples/engine/src/main/java/org/apache/qpid/proton/examples/FlowController.java

/*
 *
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF 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.apache.qpid.proton.examples;

import org.apache.qpid.proton.engine.BaseHandler;
import org.apache.qpid.proton.engine.Delivery;
import org.apache.qpid.proton.engine.Event;
import org.apache.qpid.proton.engine.Link;
import org.apache.qpid.proton.engine.Receiver;

/**
 * FlowController
 *
 */

public class FlowController extends BaseHandler
{

    final private int window;

    public FlowController(int window) {
        this.window = window;
    }

    private void topUp(Receiver rcv) {
        int delta = window - rcv.getCredit();
        rcv.flow(delta);
    }

    @Override
    public void onLinkLocalOpen(Event evt) {
        Link link = evt.getLink();
        if (link instanceof Receiver) {
            topUp((Receiver) link);
        }
    }

    @Override
    public void onLinkRemoteOpen(Event evt) {
        Link link = evt.getLink();
        if (link instanceof Receiver) {
            topUp((Receiver) link);
        }
    }

    @Override
    public void onLinkFlow(Event evt) {
        Link link = evt.getLink();
        if (link instanceof Receiver) {
            topUp((Receiver) link);
        }
    }

    @Override
    public void onDelivery(Event evt) {
        Link link = evt.getLink();
        if (link instanceof Receiver) {
            topUp((Receiver) link);
        }
    }

}