samza-api/src/main/java/org/apache/samza/metrics/Reservoir.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.samza.metrics;

/**
 * A reservoir interface to store, update and display values
 */
public interface Reservoir {
  /**
   * Return the number of values in this reservoir
   *
   * @return the number of values;
   */
  int size();

  /**
   * Update the reservoir with the new value
   *
   * @param value a value to update
   */
  void update(long value);

  /**
   * Return a {@link Snapshot} of this reservoir
   *
   * @return a statistical snapshot of this reservoir
   */
  Snapshot getSnapshot();
}