| /* |
| * 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.lucene.util; |
| |
| import java.util.concurrent.atomic.AtomicLong; |
| |
| |
| /** |
| * Simple counter class |
| * |
| * @lucene.internal |
| * @lucene.experimental |
| */ |
| public abstract class Counter { |
| |
| /** |
| * Adds the given delta to the counters current value |
| * |
| * @param delta |
| * the delta to add |
| * @return the counters updated value |
| */ |
| public abstract long addAndGet(long delta); |
| |
| /** |
| * Returns the counters current value |
| * |
| * @return the counters current value |
| */ |
| public abstract long get(); |
| |
| /** |
| * Returns a new counter. The returned counter is not thread-safe. |
| */ |
| public static Counter newCounter() { |
| return newCounter(false); |
| } |
| |
| /** |
| * Returns a new counter. |
| * |
| * @param threadSafe |
| * <code>true</code> if the returned counter can be used by multiple |
| * threads concurrently. |
| * @return a new counter. |
| */ |
| public static Counter newCounter(boolean threadSafe) { |
| return threadSafe ? new AtomicCounter() : new SerialCounter(); |
| } |
| |
| private final static class SerialCounter extends Counter { |
| private long count = 0; |
| |
| @Override |
| public long addAndGet(long delta) { |
| return count += delta; |
| } |
| |
| @Override |
| public long get() { |
| return count; |
| }; |
| } |
| |
| private final static class AtomicCounter extends Counter { |
| private final AtomicLong count = new AtomicLong(); |
| |
| @Override |
| public long addAndGet(long delta) { |
| return count.addAndGet(delta); |
| } |
| |
| @Override |
| public long get() { |
| return count.get(); |
| } |
| |
| } |
| } |