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.yetus.audience.InterfaceAudience;
021import org.apache.yetus.audience.InterfaceStability;
022
023/**
024 * Internal interface used to interact with the user/table quota.
025 */
026@InterfaceAudience.Private
027@InterfaceStability.Evolving
028public interface QuotaLimiter {
029  /**
030   * Checks if it is possible to execute the specified operation.
031   * @param writeReqs                 the write requests that will be checked against the available
032   *                                  quota
033   * @param estimateWriteSize         the write size that will be checked against the available
034   *                                  quota
035   * @param readReqs                  the read requests that will be checked against the available
036   *                                  quota
037   * @param estimateReadSize          the read size that will be checked against the available quota
038   * @param estimateWriteCapacityUnit the write capacity unit that will be checked against the
039   *                                  available quota
040   * @param estimateReadCapacityUnit  the read capacity unit that will be checked against the
041   *                                  available quota
042   * @throws RpcThrottlingException thrown if not enough available resources to perform operation.
043   */
044  void checkQuota(long writeReqs, long estimateWriteSize, long readReqs, long estimateReadSize,
045    long estimateWriteCapacityUnit, long estimateReadCapacityUnit) throws RpcThrottlingException;
046
047  /**
048   * Removes the specified write and read amount from the quota. At this point the write and read
049   * amount will be an estimate, that will be later adjusted with a consumeWrite()/consumeRead()
050   * call.
051   * @param writeReqs         the write requests that will be removed from the current quota
052   * @param writeSize         the write size that will be removed from the current quota
053   * @param readReqs          the read requests that will be removed from the current quota
054   * @param readSize          the read size that will be removed from the current quota
055   * @param writeCapacityUnit the write capacity unit that will be removed from the current quota
056   * @param readCapacityUnit  the read capacity unit num that will be removed from the current quota
057   */
058  void grabQuota(long writeReqs, long writeSize, long readReqs, long readSize,
059    long writeCapacityUnit, long readCapacityUnit);
060
061  /**
062   * Removes or add back some write amount to the quota. (called at the end of an operation in case
063   * the estimate quota was off)
064   */
065  void consumeWrite(long size, long capacityUnit);
066
067  /**
068   * Removes or add back some read amount to the quota. (called at the end of an operation in case
069   * the estimate quota was off)
070   */
071  void consumeRead(long size, long capacityUnit);
072
073  /** @return true if the limiter is a noop */
074  boolean isBypass();
075
076  /** @return the number of bytes available to read to avoid exceeding the quota */
077  long getReadAvailable();
078
079  /** @return the number of bytes available to write to avoid exceeding the quota */
080  long getWriteAvailable();
081}