ratis-server-api/src/main/java/org/apache/ratis/statemachine/SnapshotRetentionPolicy.java

/*
 * 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 org.apache.ratis.statemachine;

/**
 * Retention policy of state machine snapshots.
 */
public interface SnapshotRetentionPolicy {
  int DEFAULT_ALL_SNAPSHOTS_RETAINED = -1;

  /**
   * @return -1 for retaining all the snapshots; otherwise, return the number of snapshots to be retained.
   */
  default int getNumSnapshotsRetained() {
    return DEFAULT_ALL_SNAPSHOTS_RETAINED;
  }
}