ArrayVsListBenchmark

ArrayVsListBenchmark

/*******************************************************************************
 * Copyright (c) 2014 EclipseSource.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *    Ralf Sternberg - initial implementation and API
 ******************************************************************************/
package com.eclipsesource.calipercharts.example;

import java.io.IOException;
import java.util.ArrayList;
import java.util.Collections;
import java.util.LinkedList;
import java.util.List;
import java.util.Vector;

import com.eclipsesource.calipercharts.CaliperRunner;
import com.google.caliper.Param;
import com.google.caliper.SimpleBenchmark;


public class ArrayVsListBenchmark extends SimpleBenchmark {

  @Param int size;
  @Param String type;

  private String[] array;
  private List<String> list;

  int c;

  @Override
  protected void setUp() throws IOException {
    array = new String[ size ];
    if( "ArrayList".equals( type ) ) {
      list = new ArrayList<>( size );
    } else if( "LinkedList".equals( type ) ) {
      list = new LinkedList<>();
    } else if( "Vector".equals( type ) ) {
      list = new Vector<>( size );
    }
    for( int i = 0; i < size; i++ ) {
      array[ i ] = "item" + i;
      list.add( array[ i ] );
    }
  }

  public void time_toArray( int reps ) {
    for( int i = 0; i < reps; i++ ) {
      dummy( list.toArray() );
    }
  }

  public void time_toArray_with_size( int reps ) {
    for( int i = 0; i < reps; i++ ) {
      dummy( list.toArray( new String[ list.size() ] ) );
    }
  }

  public void time_toArray_empty_array( int reps ) {
    for( int i = 0; i < reps; i++ ) {
      dummy( list.toArray( new String[ 0 ] ) );
    }
  }

  public void time_new_ArrayList( int reps ) {
    for( int i = 0; i < reps; i++ ) {
      dummy( new ArrayList<>( list ) );
    }
  }

  public void time_unmodifiable_Wrapper( int reps ) {
    for( int i = 0; i < reps; i++ ) {
      dummy( Collections.unmodifiableList( list ) );
    }
  }

  /* prevent compiler from inlining */
  protected void dummy( String string ) {
    c++;
    assert string != null;
  }
  protected void dummy( Object[] array ) {
    c++;
    assert array != null;
  }
  protected void dummy( List<?> list ) {
    c++;
    assert list != null;
  }

  public static void main( String[] args ) throws IOException {
    new CaliperRunner( ArrayVsListBenchmark.class )
      .addParameter( "type", "ArrayList" ) // , "Vector", "LinkedList",
      .addParameter( "size", "5", "20" ) // , "100"
      .exec();
  }

}