com.ery.estorm.zk.RetryCounter.java Source code

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Here is the source code for com.ery.estorm.zk.RetryCounter.java

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/**
 *
 * 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 com.ery.estorm.zk;

import java.util.concurrent.TimeUnit;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

public class RetryCounter {
    private static final Log LOG = LogFactory.getLog(RetryCounter.class);
    private final int maxRetries;
    private int retriesRemaining;
    private final int retryIntervalMillis;
    private final TimeUnit timeUnit;

    public RetryCounter(int maxRetries, int retryIntervalMillis, TimeUnit timeUnit) {
        this.maxRetries = maxRetries;
        this.retriesRemaining = maxRetries;
        this.retryIntervalMillis = retryIntervalMillis;
        this.timeUnit = timeUnit;
    }

    public int getMaxRetries() {
        return maxRetries;
    }

    /**
     * Sleep for a exponentially back off time
     * 
     * @throws InterruptedException
     */
    public void sleepUntilNextRetry() throws InterruptedException {
        int attempts = getAttemptTimes();
        long sleepTime = (long) (retryIntervalMillis * Math.pow(2, attempts));
        LOG.info("Sleeping " + sleepTime + "ms before retry #" + attempts + "...");
        timeUnit.sleep(sleepTime);
    }

    public boolean shouldRetry() {
        return retriesRemaining > 0;
    }

    public void useRetry() {
        retriesRemaining--;
    }

    public int getAttemptTimes() {
        return maxRetries - retriesRemaining + 1;
    }
}