/*
    * This file is part of ***  M y C o R e  ***
    * See http://www.mycore.de/ for details.
    *
    * MyCoRe is free software: you can redistribute it and/or modify
    * it under the terms of the GNU General Public License as published by
    * the Free Software Foundation, either version 3 of the License, or
    * (at your option) any later version.
    *
   * MyCoRe is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * GNU General Public License for more details.
   *
   * You should have received a copy of the GNU General Public License
   * along with MyCoRe.  If not, see <http://www.gnu.org/licenses/>.
   */
  
  package org.mycore.solr.index.statistic;
  
  import java.util.concurrent.atomic.AtomicInteger;
  import java.util.concurrent.atomic.AtomicLong;
  
  import org.apache.logging.log4j.LogManager;
  import org.apache.logging.log4j.Logger;
  
  /**
   * @author Thomas Scheffler (yagee)
   *
   */
  public class MCRSolrIndexStatistic {
  
      private static final Logger LOGGER = LogManager.getLogger();
  
      final AtomicInteger documents;
  
      final AtomicLong accumulatedTime;
  
      String name;
  
      public MCRSolrIndexStatistic(String name) {
          this.name = name;
          this.documents = new AtomicInteger();
          this.accumulatedTime = new AtomicLong();
      }
  
      public long addTime(long time) {
          LOGGER.debug("{}: adding {} ms", name, time);
          return accumulatedTime.addAndGet(time);
      }
  
      public int addDocument(int docs) {
          LOGGER.debug("{}: adding {} documents", name, docs);
          return documents.addAndGet(docs);
      }
  
      public long getAccumulatedTime() {
          return accumulatedTime.get();
      }
  
      public int getDocuments() {
          return documents.get();
      }
  
      /**
       * resets statistic and returns average time in ms per document.
       */
      public synchronized double reset() {
          synchronized (accumulatedTime) {
              synchronized (documents) {
                  long time = accumulatedTime.getAndSet(0);
                  int docs = documents.getAndSet(0);
                  if (docs == 0) {
                      return time == 0 ? 0 : Double.MAX_VALUE;
                  }
                  return ((double) time / (double) docs);
              }
          }
      }
  }