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 java.util.Objects;
021import org.apache.hadoop.conf.Configuration;
022import org.apache.yetus.audience.InterfaceAudience;
023
024/**
025 * Factory for creating {@link SpaceQuotaSnapshotNotifier} implementations. Implementations must
026 * have a no-args constructor.
027 */
028@InterfaceAudience.Private
029public class SpaceQuotaSnapshotNotifierFactory {
030  private static final SpaceQuotaSnapshotNotifierFactory INSTANCE =
031    new SpaceQuotaSnapshotNotifierFactory();
032
033  public static final String SNAPSHOT_NOTIFIER_KEY = "hbase.master.quota.snapshot.notifier.impl";
034  public static final Class<? extends SpaceQuotaSnapshotNotifier> SNAPSHOT_NOTIFIER_DEFAULT =
035    TableSpaceQuotaSnapshotNotifier.class;
036
037  // Private
038  private SpaceQuotaSnapshotNotifierFactory() {
039  }
040
041  public static SpaceQuotaSnapshotNotifierFactory getInstance() {
042    return INSTANCE;
043  }
044
045  /**
046   * Instantiates the {@link SpaceQuotaSnapshotNotifier} implementation as defined in the
047   * configuration provided.
048   * @param conf Configuration object
049   * @return The SpaceQuotaSnapshotNotifier implementation
050   * @throws IllegalArgumentException if the class could not be instantiated
051   */
052  public SpaceQuotaSnapshotNotifier create(Configuration conf) {
053    Class<? extends SpaceQuotaSnapshotNotifier> clz = Objects.requireNonNull(conf)
054      .getClass(SNAPSHOT_NOTIFIER_KEY, SNAPSHOT_NOTIFIER_DEFAULT, SpaceQuotaSnapshotNotifier.class);
055    try {
056      return clz.getDeclaredConstructor().newInstance();
057    } catch (Exception e) {
058      throw new IllegalArgumentException("Failed to instantiate the implementation", e);
059    }
060  }
061}