package net.sf.logdistiller.plugins;
   
   /*
    * 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.
   */
  
  import java.io.*;
  
  import net.sf.logdistiller.LogDistillation;
  import net.sf.logdistiller.LogDistiller;
  import net.sf.logdistiller.LogEvent;
  import net.sf.logdistiller.Plugin;
  import net.sf.logdistiller.ReportFormat;
  import net.sf.logdistiller.util.FormatUtil;
  
  /**
   * <b>Log sampling</b> plugin: works like FreqPlugin, but saves some log events to a log file.
   * <p>
   * Parameters (added to FreqPlugin's parameters):
   * </p>
   * <ul>
   * <li><code>sampling.filename</code> (default: <code>[id]-sampling.log</code>): name of the file to save the sample of
   * log events for each attribute's value.</li>
   * <li><code>sampling.maxCount</code> (default: 10, -1 = no limit): number of log events to save for each attribute's
   * value.</li>
   * <li><code>sampling.maxSize</code> (default: -1 = no limit): maximum size (in kb) of the sample file</li>
   * </ul>
   *
   * @see FreqPlugin
   * @since 0.7
   */
  public class SamplingPlugin
      extends FreqPlugin
  {
      private static final long serialVersionUID = -2960554427849032861L;
  
      public final static String ID = "sampling";
  
      public final static Plugin TYPE = new Type();
  
      private final int samplingMaxCount;
  
      private final long samplingMaxSize;
  
      private final String samplingFilename;
  
      private File samplingLogFile;
  
      private transient PrintStream samplingLogStream;
  
      public SamplingPlugin( LogDistiller.Plugin definition )
      {
          super( definition, false );
  
          samplingMaxCount = Integer.parseInt( definition.getParam( "sampling.maxCount", "10" ) );
          samplingMaxSize = Long.parseLong( definition.getParam( "sampling.maxSize", "-1" ) ) * 1024;
          samplingFilename = definition.getParam( "sampling.filename", definition.getGroup().getId() + "-sampling.log" );
      }
  
      public void begin( File destinationDirectory )
          throws FileNotFoundException
      {
          super.begin( destinationDirectory );
          samplingLogFile = new File( destinationDirectory, samplingFilename );
      }
  
      protected PrintStream getSamplingLogStream()
          throws FileNotFoundException
      {
          if ( samplingLogStream == null )
          {
              samplingLogStream = new PrintStream( new FileOutputStream( samplingLogFile ) );
          }
          return samplingLogStream;
      }
  
      public void addLogEventToFreq( LogEvent logEvent, Freq freq )
          throws IOException
      {
          super.addLogEventToFreq( logEvent, freq );
  
          if ( ( ( samplingMaxCount < 0 ) || ( ( samplingMaxCount > 0 ) && ( freq.count <= samplingMaxCount ) ) )
              && ( ( samplingMaxSize < 0 ) || ( ( samplingMaxSize > 0 ) && ( freq.bytes <= samplingMaxSize ) ) ) )
          {
              getSamplingLogStream().println( logEvent.getRawLog() );
          }
      }
  
      public void end()
         throws IOException
     {
         if ( samplingLogStream != null )
         {
             samplingLogStream.close();
         }
         super.end();
     }
 
     protected void appendLinkToFreqReport( ReportFormat.PluginReport report )
     {
         report.addLink( samplingLogFile.getName(), "sampling log file (max count = "
             + ( ( samplingMaxCount < 0 ) ? "none" : String.valueOf( samplingMaxCount ) ) + ", max size = "
             + ( ( samplingMaxSize < 0 ) ? "none" : FormatUtil.formatSize( samplingMaxSize ) ) + ")" );
     }
 
     private static class Type
         extends Plugin
     {
         public Type()
         {
             super( ID );
         }
 
         public LogDistillation.Plugin newInstance( LogDistiller.Plugin conf )
         {
             return new SamplingPlugin( conf );
         }
     }
 }