/*
    * 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.
   */
  
  /**
   * Adaptor that is able to collect system metrics by using Hyperic Sigar.
   * <P>
   * This adaptor is added to an Agent like so:
   * <code>
   * add SystemMetrics [dataType] [seconds]
   * </code>
   * <ul>
   * <li><code>dataType</code> - The chukwa data type, use SystemMetrics to map to 
   * default SystemMetrics demux parser.</li>
   * <li><code>seconds</code> - Interval to collect system metrics, default is 60 seconds.</li>
   * </ul>
   * </P>
   */
  package org.apache.hadoop.chukwa.datacollection.adaptor.sigar;
  
  import java.util.Timer;
  
  import org.apache.hadoop.chukwa.datacollection.adaptor.AbstractAdaptor;
  import org.apache.hadoop.chukwa.datacollection.adaptor.AdaptorException;
  import org.apache.hadoop.chukwa.datacollection.adaptor.AdaptorShutdownPolicy;
  import org.apache.log4j.Logger;
  
  public class SystemMetrics extends AbstractAdaptor {
    static Logger log = Logger.getLogger(SystemMetrics.class);
    private long period = 5 * 1000;
    private SigarRunner runner;
    private Timer timer;
    
    @Override
    public String parseArgs(String args) {
      int spOffset = args.indexOf(' ');
      if (spOffset > 0) {
        try {
          period = Long.parseLong(args.substring(0, spOffset));
          period = period * 1000;
          start(spOffset);
        } catch (NumberFormatException e) {
          StringBuilder buffer = new StringBuilder();
          buffer.append("SystemMetrics: sample interval ");
          buffer.append(args.substring(0, spOffset));
          buffer.append(" can't be parsed.");
          log.warn(buffer.toString());
        } catch (AdaptorException e) {
          log.warn("Error parsing parameter for SystemMetrics adaptor.");
        }
      }    
      return args;
    }
  
    @Override
    public void start(long offset) throws AdaptorException {
      if(timer == null) {
        timer = new Timer();
        runner = new SigarRunner(dest, SystemMetrics.this);
      }
      timer.scheduleAtFixedRate(runner, 0, period);
      
    }
  
    @Override
    public String getCurrentStatus() {
      StringBuilder buffer = new StringBuilder();
      buffer.append(type);
      buffer.append(" ");
      buffer.append(period/1000);
      return buffer.toString();
    }
  
    @Override
    public long shutdown(AdaptorShutdownPolicy shutdownPolicy)
        throws AdaptorException {
      timer.cancel();
      return 0;
    }
  
  }