ResourceUsage.java

/**
 * Copyright 2016 Yahoo Inc.
 *
 * 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.yahoo.pulsar.common.policies.data.loadbalancer;

/**
 * POJO used to represents any system specific resource usage this is the format that load manager expects it in.
 *
 */
public class ResourceUsage {
    public double usage;
    public double limit;

    public ResourceUsage(double usage, double limit) {
        this.usage = usage;
        this.limit = limit;
    }

    public ResourceUsage() {

    }

    public void reset() {
        this.usage = -1;
        this.limit = -1;
    }

    /**
     * this may be wrong since we are comparing available and not the usage
     * 
     * @param o
     * @return
     */
    public int compareTo(ResourceUsage o) {
        double required = o.limit - o.usage;
        double available = limit - usage;
        return Double.compare(available, required);
    }

    public float percentUsage() {
        float proportion = 0;
        if (limit > 0) {
            proportion = ((float) usage) / ((float) limit);
        }
        return proportion * 100;
    }
}