rdfrepositorypool.java

这是外国一个开源推理机

/*  Sesame - Storage and Querying architecture for RDF and RDF Schema
 *  Copyright (C) 2001-2005 Aduna
 *
 *  Contact: 
 *  	Aduna
 *  	Prinses Julianaplein 14 b
 *  	3817 CS Amersfoort
 *  	The Netherlands
 *  	tel. [phone]
 *  	fax. [phone]
 *
 *  	http://aduna.biz/
 *  	http://www.openrdf.org/
 *  
 *  This library is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU Lesser General Public
 *  License as published by the Free Software Foundation; either
 *  version 2.1 of the License, or (at your option) any later version.
 *
 *  This library 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
 *  Lesser General Public License for more details.
 *
 *  You should have received a copy of the GNU Lesser General Public
 *  License along with this library; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */
package org.openrdf.sesame.sail.test.benchmark.pools;

import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.util.ArrayList;
import java.util.List;

import org.openrdf.sesame.sail.NamespaceIterator;
import org.openrdf.sesame.sail.RdfRepository;
import org.openrdf.sesame.sail.test.benchmark.model.BMNamespace;

/**
 * Pool used by benchmark test for testing of implementations of 
 * nl.aidministrator.RdfRepository.
 *
 * @author Peter van 't Hof
 * @version %I%, %G%
 */
public class RdfRepositoryPool extends RdfSourcePool {

/*----------+
| Variables |
+----------*/
	// RdfRepository which to extract pool from.
	protected RdfRepository _rdfRepository;

	/**
	 * Prefix which does not exist.
	 */
	public static String noPrefix;

	/**
	 * Name which does not exist.
	 */
	public static String noName;

	/**
	 * List of namespaces.
	 */
	public static List namespaces;

/*-------------+
| Constructors |
+-------------*/
	/**
	 * Creates a new pool which contains variables which are used by benchmark
	 * test for testing of org.openrdf.sesame.sail.RdfRepository.
	 *
	 * @param rdfRepository RdfRepository which to extract variables from.
	 */
	public RdfRepositoryPool(RdfRepository rdfRepository) {
		super(rdfRepository);

		_rdfRepository = rdfRepository;
	}

/*--------+
| Methods |
+--------*/
	protected void _load(ObjectInputStream inputStream)
		throws IOException, ClassNotFoundException {
		super._load(inputStream);

		noPrefix = (String)inputStream.readObject();
		noName = (String)inputStream.readObject();

		namespaces = (List)inputStream.readObject();
	}

	protected void _save(ObjectOutputStream outputStream)
		throws IOException {
		super._save(outputStream);

		outputStream.writeObject(noPrefix);
		outputStream.writeObject(noName);

		outputStream.writeObject(namespaces);
	}

	protected void _initialize() {
		super._initialize();

		_status("Creating a prefix which does not exist...");
		noPrefix = "myPrefix";
		_status("Creating a name which does not exist...");
		noName = "myName";

  		_status("Searching for namespaces...");		
	 	namespaces = _getNamespaces(50);
	}

	/* Creates a List of namespaces retrieved from repository with size is
	 * preferredSize. Namespaces in List are distributed evenly over repository.
	 *
	 * Optimized approach, combination of streaming and in memory...
	 */
	protected List _getNamespaces(int preferredSize) {

		// Iterate over all namespaces and add them to List.
		List all = new ArrayList();
		NamespaceIterator i = _rdfSource.getNamespaces();
		
		while (i.hasNext()) {
			i.next();
			all.add(new BMNamespace(i.getPrefix(), i.getName()));
		}

		i.close();

		int size = all.size();

		if (size == 0) {
			_warning("Repository has no namespaces.");

			return all;
		}
		else {

			// Else distribute namespaces in all over new List.
			return _distribute(all, preferredSize);
		}
	}
}