containerlocationloc.java

Java的面向对象数据库系统的源代码

// You can redistribute this software and/or modify it under the terms of
// the Ozone Core License version 1 published by ozone-db.org.
//
// Copyright (C) 2003-@year@, Leo Mekenkamp. All rights reserved.
//
// $Id: ContainerLocationLoc.java,v 1.3 2004/03/21 21:05:51 leomekenkamp Exp $

package org.ozoneDB.core.storage.gammaStore;

import java.io.BufferedOutputStream;
import java.io.FileOutputStream;
import java.io.ObjectOutputStream;

/**
 * @author <a href="mailto:leoATmekenkampD0Tcom">Leo Mekenkamp (mind the anti sp@m)</a>
 * @version $Id: ContainerLocationLoc.java,v 1.3 2004/03/21 21:05:51 leomekenkamp Exp $
 */
public class ContainerLocationLoc extends Loc {

    protected int[] dataFileIds;
    protected int[] positions;
    
// Encoding both clusterId and position into a long and storing it into one
// long[] instead of two int[] yielded no significant performance increase.
// Maybe there is something I missed, so the code will remain in the source, in
// the form of comments.
//    protected long[] both;
    
    public ContainerLocationLoc(int capacity, float bufferFactor) {
        super(capacity, bufferFactor);
        init();
    }

    public ContainerLocationLoc(int capacity, int slack) {
        super(capacity, slack);
        init();
    }

    private void init() {
//
        dataFileIds = new int[keys.length];
        positions = new int[keys.length];
//        both = new long[keys.length];
    }
    
    /**
     * Note that we do not store <code>containerLocation</code> as an
     * object, we simply take its values and copy it into internal arrays.
     * This saves a _lot_ of execution time during (de)serialization.
     */
    public void putContainerLocation(int pos, ContainerLocation containerLocation) {
//
        dataFileIds[pos] = containerLocation.getDataFileId();
        positions[pos] = containerLocation.getPosition();
//        both[pos] = toLong(containerLocation);
    }
    
    protected void move(int from, int to) {
        super.move(from, to);
//
        dataFileIds[to] = dataFileIds[from];
        positions[to] = positions[from];
//        both[to] = both[from];
        
    }
    
//    /**
//     * Convenience method to make it easy to reuse <code>ContainerLocation</code>
//     * instances.
//     */
//    public void fillContainerLocation(int pos, ContainerLocation containerLocation) {
////
//        containerLocation.getDataFileId() = dataFileIds[pos];
//        containerLocation.getPosition() = positions[pos];
////        fromLong(both[pos], containerLocation);2
//    }
    
    public ContainerLocation getContainerLocation(int pos) {
        ContainerLocation result = new ContainerLocation(dataFileIds[pos], positions[pos]);
        return result;
    }
    
//    private static long toLong(ContainerLocation containerLocation) {
//        long result = (long) containerLocation.getDataFileId() << 32;
//        result |= containerLocation.getPosition() & 0xFFFFFFFFL;
//        return result;
//    }
//    
//    private static void fromLong(long encoded, ContainerLocation containerLocation) {
//        containerLocation.getDataFileId() = (int) (encoded >> 32);
//        containerLocation.getPosition() = (int) encoded;
//    }

    public String toString() {
        StringBuffer result = new StringBuffer(super.toString());
        result.append(" nodes [");
        
        // comment for-loop out when using a long[]
        for (int i = 0; i < dataFileIds.length; i++) {
            result.append(dataFileIds[i]);
            if (!isInUse(i)) {
                result.append("D");
            }
            if (i < dataFileIds.length - 1) {
                result.append(", ");
            } else {
                result.append("]");
            }
        }
        
        return result.toString();
    }
    
// DEBUG and TEST code following only
    
    public static void main(String[] args) throws Exception {
        long start = System.currentTimeMillis();
        for (int test = 0; test < 1000; test++) {
            int SIZE = 100;
            ContainerLocationLoc containerLocationLoc = new ContainerLocationLoc(SIZE, 0.1F);
            for(int i = 0; i < SIZE; i++) {
                ContainerLocation loc = new ContainerLocation((int) (Math.random() * Integer.MAX_VALUE), (int) (Math.random() * Integer.MAX_VALUE));
                int pos = containerLocationLoc.putKey(i);
                containerLocationLoc.putContainerLocation(pos, loc);
            }
            ObjectOutputStream out = new ObjectOutputStream(new BufferedOutputStream(new FileOutputStream("/home/leo/delme." + test), 8192));
            out.writeObject(containerLocationLoc);
            out.close();
        }
        System.out.println("that took " + (System.currentTimeMillis() - start) + " msec.");
    }
        
}