content: package act.metric;
  
  /*-
   * #%L
   * ACT Framework
   * %%
   * Copyright (C) 2014 - 2017 ActFramework
   * %%
   * Licensed 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.
   * #L%
   */
  
  import java.io.Closeable;
  
  /**
   * A Timer that could be used to measure execution duration of a certain process
   */
  public interface Timer extends Closeable {
  
      /**
       * Returns the name of the timer. The string returned should be
       * identical to the string passed in {@link Metric#startTimer(String)}
       * method that returns this timer
       *
       * @return the timer's name
       */
      String name();
  
      /**
       * Stop the timer
       */
      void stop();
  
      /**
       * Returns nanoseconds the time has elapsed since time being created till
       * {@link #stop()} method get called
       *
       * @return the duration time in nanoseconds
       */
      long ns();
  
      /**
       * Overwrite {@link Closeable#close()} without throwing out
       * the {@link java.io.IOException}.
       *
       * Calling `Timer.close()` shall trigger {@link #stop()}.
       */
      @Override
      void close();
  }
  