com.datastax.driver.core.policies.ConstantReconnectionPolicy Maven / Gradle / Ivy

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A driver for Apache Cassandra 1.2+ that works exclusively with the Cassandra Query Language version 3 (CQL3) and Cassandra's binary protocol.

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/*
 *      Copyright (C) 2012-2015 DataStax 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.datastax.driver.core.policies;

import com.datastax.driver.core.Cluster;

/**
 * A reconnection policy that waits a constant time between each reconnection attempt.
 */
public class ConstantReconnectionPolicy implements ReconnectionPolicy {

    private final long delayMs;

    /**
     * Creates a reconnection policy that creates with the provided constant wait
     * time between reconnection attempts.
     *
     * @param constantDelayMs the constant delay in milliseconds to use.
     */
    public ConstantReconnectionPolicy(long constantDelayMs) {
        if (constantDelayMs < 0)
            throw new IllegalArgumentException(String.format("Invalid negative delay (got %d)", constantDelayMs));

        this.delayMs = constantDelayMs;
    }

    /**
     * The constant delay used by this reconnection policy.
     *
     * @return the constant delay used by this reconnection policy.
     */
    public long getConstantDelayMs() {
        return delayMs;
    }

    /**
     * A new schedule that uses a constant {@code getConstantDelayMs()} delay
     * between reconnection attempt.
     *
     * @return the newly created schedule.
     */
    @Override
    public ReconnectionSchedule newSchedule() {
        return new ConstantSchedule();
    }

    private class ConstantSchedule implements ReconnectionSchedule {

        @Override
        public long nextDelayMs() {
            return delayMs;
        }
    }

    @Override
    public void init(Cluster cluster) {
        // nothing to do
    }

    @Override
    public void close() {
        // nothing to do
    }
}