org.apache.accumulo.tserver.OnlineTablets Maven / Gradle / Ivy

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The tablet server for Apache Accumulo to host tablets of data tables.

There is a newer version: 3.0.0

/*
 * 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.accumulo.tserver;

import java.util.SortedMap;
import java.util.TreeMap;

import org.apache.accumulo.core.dataImpl.KeyExtent;
import org.apache.accumulo.tserver.tablet.Tablet;

import com.google.common.collect.ImmutableSortedMap;

/*
 * The set of online tablets is frequently read by many threads and infrequently updated.  This
 * class exists to create a simple wrapper that keeps an immutable snapshot up to date.  Many
 * threads can access the snapshot without interfering with each other.
 */
public class OnlineTablets {
  private volatile ImmutableSortedMap snapshot = ImmutableSortedMap.of();
  private final SortedMap onlineTablets = new TreeMap();

  public synchronized void put(KeyExtent ke, Tablet t) {
    onlineTablets.put(ke, t);
    snapshot = ImmutableSortedMap.copyOf(onlineTablets);
  }

  public synchronized void remove(KeyExtent ke) {
    onlineTablets.remove(ke);
    snapshot = ImmutableSortedMap.copyOf(onlineTablets);
  }

  public synchronized void split(KeyExtent oldTablet, Tablet newTablet1, Tablet newTablet2) {
    onlineTablets.remove(oldTablet);
    onlineTablets.put(newTablet1.getExtent(), newTablet1);
    onlineTablets.put(newTablet2.getExtent(), newTablet2);
    snapshot = ImmutableSortedMap.copyOf(onlineTablets);
  }

  ImmutableSortedMap snapshot() {
    return snapshot;
  }
}