diskhashtest.java

用Java写的面相对象的数据库管理系统

// You can redistribute this software and/or modify it under the terms of
// the Ozone Library License version 1 published by ozone-db.org.
//
// The original code and portions created by SMB are
// Copyright (C) 1997-2000 by SMB GmbH. All rights reserved.
//
// $Id: DiskHashTest.java,v 1.7 2000/10/28 16:55:15 daniela Exp $

package org.ozoneDB.DxLib.test;

import java.lang.*;
import java.util.*;
import org.ozoneDB.DxLib.*;


class DiskHashTest extends AbstractTest {
    
    
    public static void main( String[] args ) throws Exception {
        int n = Integer.valueOf( args[0] ).intValue();
        int cacheBits = 8;
        int bufferSize = 4;
        System.out.println( n + " elements" );
        
        DxDiskHashMap map = new DxDiskHashMap( "/tmp/diskhash/map", bufferSize, cacheBits, 8 );
        
        // add
        long start = System.currentTimeMillis();
        for (int i = 0; i < n; i++) {
            map.addForKey( new Integer( i ), new Integer( i ) );
        } 
        System.out.println( "time (add): " + (System.currentTimeMillis() - start) );
        
        // re-read (buffered)
        int nn = Math.min( (bufferSize - 2) * 256, n );
        start = System.currentTimeMillis();
        for (int i = 0; i < nn; i++) {
            Integer si = (Integer)map.elementForKey( new Integer( i ) );
            if (!si.equals( new Integer( i ) )) {
                throw new RuntimeException( "corrupted" );
            } 
        } 
        System.out.println( "time (re-read buffered: " + nn + "): " + (System.currentTimeMillis() - start) );
        
        // re-read (buffered)
        start = System.currentTimeMillis();
        for (int i = 0; i < nn; i++) {
            Integer si = (Integer)map.elementForKey( new Integer( i ) );
            if (!si.equals( new Integer( i ) )) {
                throw new RuntimeException( "corrupted" );
            } 
        } 
        System.out.println( "time (re-read buffered: " + nn + "): " + (System.currentTimeMillis() - start) );
        
        // re-read
        start = System.currentTimeMillis();
        for (int i = 0; i < n; i++) {
            Integer si = (Integer)map.elementForKey( new Integer( i ) );
            if (!si.equals( new Integer( i ) )) {
                throw new RuntimeException( "corrupted" );
            } 
        } 
        System.out.println( "time (re-read): " + (System.currentTimeMillis() - start) );
        
        // re-read
        start = System.currentTimeMillis();
        for (int i = 0; i < n; i++) {
            Integer si = (Integer)map.elementForKey( new Integer( i ) );
            if (!si.equals( new Integer( i ) )) {
                throw new RuntimeException( "corrupted" );
            } 
        } 
        System.out.println( "time (re-read): " + (System.currentTimeMillis() - start) );
        
        // close
        start = System.currentTimeMillis();
        map.close();
        System.out.println( "time (close): " + (System.currentTimeMillis() - start) );
        
        map.printStatistics();
    // map.cleanFiles();
    } 
    
    
    public void stress( DxMap map ) {
        Random rand = new Random( System.currentTimeMillis() );
        for (int j = 0; j < 10; j++) {
            double gaussian = rand.nextGaussian();
            int EX = (int)(Math.abs( gaussian ) * 10000);
            System.out.println( "EX: " + EX );
            int VAR = 1000;
            for (int i = 0; i < 100; i++) {
                int index = (int)(Math.abs( rand.nextGaussian() ) * VAR + EX);
                // System.out.println ("add: " + index);
                map.addForKey( new Integer( index ), new Integer( index ) );
            } 
            int hitCount = 0;
            for (int i = 0; i < 500; i++) {
                int index = (int)(Math.abs( rand.nextGaussian() ) * VAR + EX);
                // System.out.println ("add: " + index);
                if (map.elementForKey( new Integer( index ) ) != null) {
                    hitCount++;
                } 
            } 
            System.out.println( "hit count:" + hitCount );
            for (int i = 0; i < 500; i++) {
                int index = (int)(Math.abs( rand.nextGaussian() ) * VAR + EX);
                // System.out.println ("remove: " + index);
                map.removeForKey( new Integer( index ) );
            } 
            System.out.println( "count:" + map.count() );
        } 
        
        if (map instanceof DxDiskHashMap) {
            ((DxDiskHashMap)map).printStatistics();
            ((DxDiskHashMap)map).cleanFiles();
        } 
    } 
}