sepangperst.java

个人感觉非常不错的poleperst-acid

/* 
This file is part of the PolePosition database benchmark
http://www.polepos.org

This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public
License along with this program; if not, write to the Free
Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
MA  02111-1307, USA. */

package org.polepos.teams.perst;

import org.polepos.circuits.sepang.SepangDriver;
import org.garret.perst.*;

class Tree extends Persistent {
    
    private static long idGenerator;
    
    public long id;
    public Tree preceding;
    public Tree subsequent;
    public String name;
    public int depth;
    
    public Tree(){
    }
    
    public Tree(long id, String name, int depth){
        this.id = id;
        this.name = name;
        this.depth = depth;
    }
    
    public static Tree createTree(int depth){
        idGenerator = 0;
        return createTree(depth, 0);
    }
    
    private static Tree createTree(int maxDepth, int currentDepth){
        
        if(maxDepth <= 0){
            return null;
        }
        
        Tree tree = new Tree();
        if(currentDepth == 0){
            tree.name = "root";
        }else{
            tree.name = "node at depth " + currentDepth;
        }
        tree.id = ++idGenerator;
        tree.depth =  currentDepth;
        tree.preceding = createTree(maxDepth - 1, currentDepth + 1); 
        tree.subsequent = createTree(maxDepth - 1, currentDepth + 1); 
        return tree;
    }
    
    public static void traverse(Tree tree, TreeVisitor visitor){
        if(tree == null){
            return;
        }
        traverse(tree.preceding, visitor);
        traverse(tree.subsequent, visitor);
        visitor.visit(tree);
    }
    
    public int getDepth(){
        return depth; 
    }
}

interface TreeVisitor {    
    public void visit(Tree tree);

}

/**
 * @author Herkules
 */
public class SepangPerst extends PerstDriver implements SepangDriver{
    protected void initialize() { 
    }

    public void write(){
        db.setRoot(Tree.createTree(setup().getTreeDepth()));
        commit();
    }

    public void read(){
        Tree.traverse((Tree)db.getRoot(), new TreeVisitor() {
            public void visit(Tree tree) {
                addToCheckSum(tree.getDepth());
            }
        });
    }

    public void read_hot() {
        read();
    }

    public void delete() {
        Tree.traverse((Tree)db.getRoot(), new TreeVisitor() {
            public void visit(Tree tree) {
                tree.deallocate();
            }
        });
        commit();
    }
}