FileDocCategorySizeDatePackage
ListVsVector.javaAPI DocApache log4j 1.2.152509Sat Aug 25 00:09:36 BST 2007org.apache.log4j.performance

ListVsVector

public class ListVsVector extends Object
Compares the performance of looping through a list versus a Vector. Chain looping is *20* times faster than vector access on JDK 1.1.7B on NT

Fields Summary
static int
RUN_LENGTH
static Vector
v
static Chain
head
static String
tmp
Constructors Summary
Methods Summary
static doubleloopChain()

    long before = System.currentTimeMillis();
    Chain c;
    for(int i = 0; i < RUN_LENGTH; i++) {
      c = head;
      while(c != null) {
	tmp = c.s;
	c = c.next;
      }
    }
    return (System.currentTimeMillis() - before)*1000.0/RUN_LENGTH;
static doubleloopVector()

    long before = System.currentTimeMillis();
    int size = v.size();
    for(int i = 0; i < RUN_LENGTH; i++) {
      for(int j = 0; j < size; j++)
	tmp = (String) v.elementAt(j);
    }
    return (System.currentTimeMillis() - before)*1000.0/RUN_LENGTH;
public static voidmain(java.lang.String[] args)


  
   
     

    v.addElement("aaa");
    v.addElement("bbb");
    v.addElement("ccc");
    v.addElement("ddd");
    v.addElement("eee");
    
    Chain c = new Chain("aaa");
    head = c;
    c.next = new Chain("bbb"); c = c.next;
    c.next = new Chain("ccc"); c = c.next;
    c.next = new Chain("ddd"); c = c.next;
    c.next = new Chain("eee");
    double t;
    t = loopChain();
    System.out.println("Looping thourgh the chain took " + t);

    t = loopVector();
    System.out.println("Looping thourgh the vector took " + t);