flink-metrics/flink-metrics-core/src/main/java/org/apache/flink/metrics/Counter.java

/*
 * 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.flink.metrics;

/** A Counter is a {@link Metric} that measures a count. */
public interface Counter extends Metric {

    /** Increment the current count by 1. */
    void inc();

    /**
     * Increment the current count by the given value.
     *
     * @param n value to increment the current count by
     */
    void inc(long n);

    /** Decrement the current count by 1. */
    void dec();

    /**
     * Decrement the current count by the given value.
     *
     * @param n value to decrement the current count by
     */
    void dec(long n);

    /**
     * Returns the current count.
     *
     * @return current count
     */
    long getCount();
}