/*
* Copyright 1999-2005 The Apache Software Foundation.
*
* 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.
*/
package org.apache.log4j.performance;
import java.util.Vector;
/**
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
*/
public class ListVsVector {
static int RUN_LENGTH = 1000000;
static Vector v = new Vector();
static Chain head;
static String tmp;
static
public
void main(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);
}
static
double loopChain() {
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
double loopVector() {
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;
}
static class Chain {
public String s;
public Chain next;
Chain(String s) {
this.s = s;
}
void setNext(Chain c) {
next = c;
}
}
}