001/*
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements.  See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership.  The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License.  You may obtain a copy of the License at
009 *
010 *     http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing, software
013 * distributed under the License is distributed on an "AS IS" BASIS,
014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 */
018package org.apache.hadoop.hbase.quotas;
019
020import org.apache.hadoop.hbase.util.EnvironmentEdgeManager;
021import org.apache.yetus.audience.InterfaceAudience;
022import org.apache.yetus.audience.InterfaceStability;
023
024/**
025 * With this limiter resources will be refilled only after a fixed interval of time.
026 */
027@InterfaceAudience.Private
028@InterfaceStability.Evolving
029public class FixedIntervalRateLimiter extends RateLimiter {
030  private long nextRefillTime = -1L;
031
032  @Override
033  public long refill(long limit) {
034    final long now = EnvironmentEdgeManager.currentTime();
035    if (now < nextRefillTime) {
036      return 0;
037    }
038    nextRefillTime = now + super.getTimeUnitInMillis();
039    return limit;
040  }
041
042  @Override
043  public long getWaitInterval(long limit, long available, long amount) {
044    if (nextRefillTime == -1) {
045      return 0;
046    }
047    final long now = EnvironmentEdgeManager.currentTime();
048    final long refillTime = nextRefillTime;
049    return refillTime - now;
050  }
051
052  // This method is for strictly testing purpose only
053  @Override
054  public void setNextRefillTime(long nextRefillTime) {
055    this.nextRefillTime = nextRefillTime;
056  }
057
058  @Override
059  public long getNextRefillTime() {
060    return this.nextRefillTime;
061  }
062}