net.yudichev.jiotty.common.lang.backoff.BackOff Maven / Gradle / Ivy

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/*
 * Copyright (c) 2011 Google 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 net.yudichev.jiotty.common.lang.backoff;

/**
 * Back-off policy when retrying an operation.
 *
 * @author Ravi Mistry
 */
public interface BackOff {

    /**
     * Indicates that no more retries should be made for use in {@link #nextBackOffMillis()}.
     */
    long STOP = -1L;
    /**
     * Fixed back-off policy whose back-off time is always zero, meaning that the operation is retried
     * immediately without waiting.
     */
    BackOff ZERO_BACKOFF =
            new BackOff() {

                @Override
                public void reset() {
                }

                @Override
                public long nextBackOffMillis() {
                    return 0;
                }
            };
    /**
     * Fixed back-off policy that always returns {@code #STOP} for {@link #nextBackOffMillis()},
     * meaning that the operation should not be retried.
     */
    BackOff STOP_BACKOFF =
            new BackOff() {
                @Override
                public void reset() {
                }

                @Override
                public long nextBackOffMillis() {
                    return STOP;
                }
            };

    /**
     * Reset to initial state.
     */
    void reset();

    /**
     * Gets the number of milliseconds to wait before retrying the operation or {@link #STOP} to
     * indicate that no retries should be made.
     *
     * Example usage:
     *
     * 
     * long backOffMillis = backoff.nextBackOffMillis();
     * if (backOffMillis == Backoff.STOP) {
     * // do not retry operation
     * } else {
     * // sleep for backOffMillis milliseconds and retry operation
     * }
     * 
     */
    long nextBackOffMillis();
}