package org.apache.lucene.benchmark.byTask.stats;

/**
 * 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.
 */

import java.util.ArrayList;
import java.util.List;

import org.apache.lucene.benchmark.byTask.tasks.PerfTask;
import org.apache.lucene.benchmark.byTask.utils.Config;


/**
 * Test run data points collected as the test proceeds.
 */
public class Points {

  private Config config;
  
  // stat points ordered by their start time. 
  // for now we collect points as TaskStats objects.
  // later might optimize to collect only native data.
  private ArrayList points = new ArrayList();

  private int nextTaskRunNum = 0;

  /**
   * Create a Points statistics object. 
   */
  public Points (Config config) {
    this.config = config;
  }

  /**
   * Return the current task stats.
   * the actual task stats are returned, so caller should not modify this task stats. 
   * @return current {@link TaskStats}.
   */
  public List taskStats () {
    return points;
  }

  /**
   * Mark that a task is starting. 
   * Create a task stats for it and store it as a point.
   * @param task the starting task.
   * @return the new task stats created for the starting task.
   */
  public synchronized TaskStats markTaskStart (PerfTask task, int round) {
    TaskStats stats = new TaskStats(task, nextTaskRunNum(), round);
    points.add(stats);
    return stats;
  }
  
  // return next task num
  private synchronized int nextTaskRunNum() {
    return nextTaskRunNum++;
  }
  
  /**
   * mark the end of a task
   */
  public synchronized void markTaskEnd (TaskStats stats, int count) {
    int numParallelTasks = nextTaskRunNum - 1 - stats.getTaskRunNum();
    // note: if the stats were cleared, might be that this stats object is 
    // no longer in points, but this is just ok.
    stats.markEnd(numParallelTasks, count);
  }

  /**
   * Clear all data, prepare for more tests.
   */
  public void clearData() {
    points.clear();
  }

}