SimpleBPlusTreeTest.java

/* XXL: The eXtensible and fleXible Library for data processing

Copyright (C) 2000-2011 Prof. Dr. Bernhard Seeger
                        Head of the Database Research Group
                        Department of Mathematics and Computer Science
                        University of Marburg
                        Germany

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 3 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, see <http://www.gnu.org/licenses/>. 

    http://code.google.com/p/xxl/

*/

package xxl.core.indexStructures.btrees;

import java.io.DataInput;
import java.io.DataOutput;
import java.io.IOException;
import java.math.BigInteger;
import java.util.Iterator;
import java.util.Random;

import xxl.core.collections.containers.io.BlockFileContainer;
import xxl.core.collections.containers.io.BufferedContainer;
import xxl.core.collections.containers.io.ConverterContainer;
import xxl.core.cursors.Cursors;
import xxl.core.functions.AbstractFunction;
import xxl.core.functions.Function;
import xxl.core.indexStructures.BPlusTree;
import xxl.core.indexStructures.BPlusTree.KeyRange;
import xxl.core.indexStructures.descriptors.BigIntegerKeyRange;
import xxl.core.indexStructures.descriptors.BigIntegerSeparator;
import xxl.core.io.LRUBuffer;
import xxl.core.io.converters.BigIntegerConverter;
import xxl.core.io.converters.MeasuredConverter;

public class SimpleBPlusTreeTest {
	
	public static final int BLOCK_SIZE = 1024;
	public static final float MIN_RATIO = 0.5f;
	public static final int BUFFER_SIZE = 5;
	public static final int NUMBER_OF_BITS = 256;
	public static final int MAX_OBJECT_SIZE = 78;
	public static final int NUMBER_OF_ELEMENTS = 100000;
		
	private static BPlusTree createBPlusTree(String name) {	
		System.out.println("Initialization of the B+ tree.");
		BPlusTree tree = new BPlusTree(BLOCK_SIZE, MIN_RATIO, true);
		Function<Object, Object> getKey = new AbstractFunction<Object, Object>() {
			@Override
			public Object invoke(Object argument) {
				return argument;
			}
		};
		BufferedContainer treeContainer = new BufferedContainer(
			new ConverterContainer(
				new BlockFileContainer(
					name,
					BLOCK_SIZE
				),
				tree.nodeConverter()
			),
			new LRUBuffer<Object, Object, Object>(BUFFER_SIZE),
			true
		);
		MeasuredConverter<BigInteger> measuredBigIntegerConverter = new MeasuredConverter<BigInteger>() {
			@Override
			public int getMaxObjectSize() {
				return MAX_OBJECT_SIZE;
			}

			@Override
			public BigInteger read(DataInput dataInput, BigInteger object) throws IOException {
				return BigIntegerConverter.DEFAULT_INSTANCE.read(dataInput, object);
			}

			@Override
			public void write(DataOutput dataOutput, BigInteger object) throws IOException {
				BigIntegerConverter.DEFAULT_INSTANCE.write(dataOutput, object);
			}
		};
		tree.initialize(
			getKey,
			treeContainer,
			measuredBigIntegerConverter,
			measuredBigIntegerConverter,
			BigIntegerSeparator.FACTORY_FUNCTION,
			BigIntegerKeyRange.FACTORY_FUNCTION
		); 
		System.out.println("Initialization of the B+ tree finished.");
		return tree;
	}

	public static void testBPlusTree(String testFile) throws IOException {
		BPlusTree bpTree= createBPlusTree(testFile);
		System.out.println("BPlusTree has been created.");
		
		// Generate test data
		System.out.println();
		System.out.println("Generating random test data");
		Random random = new Random(42);
		for (int i = 0; i < 10; i++)
			new BigInteger(NUMBER_OF_BITS, random);
		for (int i = 0; i < NUMBER_OF_ELEMENTS; i++) {
			bpTree.insert(new BigInteger(NUMBER_OF_BITS, random));
			if (i%(NUMBER_OF_ELEMENTS / 10) == 0)
				System.out.print((i / (NUMBER_OF_ELEMENTS / 100)) + "%, ");
		}
		System.out.println("100%");
		bpTree.wasReorg();
		System.out.println(bpTree.height());
		
		// delete test
		random = new Random(42);
		System.out.println("Remove Test:");
		int error = 0;
		for (int i = 0; i < 10; i++) {
			BigInteger rem = new BigInteger(NUMBER_OF_BITS, random).negate();
			BigInteger fou = (BigInteger)bpTree.remove(rem);
			if (fou != null)
				error++;
		}
		if (error > 0)
			System.err.println("false positive: " + error);
		error = 0;
		for (int i = 0; i < NUMBER_OF_ELEMENTS * .1 - 10; i++) {
			BigInteger rem = new BigInteger(NUMBER_OF_BITS, random);
			BigInteger fou = (BigInteger)bpTree.remove(rem);
			if (!rem.equals(fou))
				error++;
		}
		if (error > 0)
			System.err.println("false negative: " + error);
		
		//query test
		BPlusTree.KeyRange region = (BPlusTree.KeyRange)bpTree.rootDescriptor();
		BigInteger min = (BigInteger)region.minBound();
		BigInteger max = (BigInteger)region.maxBound();
		BigInteger temp = max.subtract(min).divide(new BigInteger("10"));
		System.out.println("Query Test:");
		BigInteger minQR = min.add(temp);
		BigInteger maxQR = minQR.add(temp);
		System.out.println("Query: ["+minQR+", "+maxQR+"]");
		Iterator<?> results = bpTree.rangeQuery(minQR, maxQR);
		System.out.println("Responses number: " + Cursors.count(results));
		System.out.println("End.");
	}
		
	public static void main(String[] args) throws Exception{
		testBPlusTree(args[0]);
	}
}