LinearDelay.java

/*
 * Copyright (c) 2016 Couchbase, 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.couchbase.client.core.time;

import java.util.concurrent.TimeUnit;

/**
 * Delay which increases linearly for every attempt.
 *
 * @author Michael Nitschinger
 * @since 1.1.0
 */
public class LinearDelay extends Delay {

    private final double growBy;
    private final long lower;
    private final long upper;

    LinearDelay(TimeUnit unit, long upper, long lower, double growBy) {
        super(unit);

        this.growBy = growBy;
        this.lower = lower;
        this.upper = upper;
    }

    @Override
    public long calculate(long attempt) {
        long calc = Math.round(attempt * growBy);
        if (calc < lower) {
            return lower;
        }
        if (calc > upper) {
            return upper;
        }
        return calc;
    }

    @Override
    public String toString() {
        final StringBuilder sb = new StringBuilder("LinearDelay{");
        sb.append("growBy ").append(growBy);
        sb.append(" " + unit());
        sb.append("; lower=").append(lower);
        sb.append(", upper=").append(upper);
        sb.append('}');
        return sb.toString();
    }
}