/*******************************************************************************
* Copyright (c) 2006, 2009 Symbian Software Systems and others.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
* Symbian - Initial implementation
* Markus Schorn (Wind River Systems)
*******************************************************************************/
package org.eclipse.cdt.internal.pdom.tests;
import java.io.File;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.Random;
import java.util.SortedSet;
import java.util.TreeSet;
import junit.framework.Test;
import org.eclipse.cdt.core.testplugin.util.BaseTestCase;
import org.eclipse.cdt.internal.core.pdom.db.BTree;
import org.eclipse.cdt.internal.core.pdom.db.ChunkCache;
import org.eclipse.cdt.internal.core.pdom.db.Database;
import org.eclipse.cdt.internal.core.pdom.db.IBTreeComparator;
import org.eclipse.cdt.internal.core.pdom.db.IBTreeVisitor;
import org.eclipse.core.runtime.CoreException;
/**
* Test insertion/deletion of records of a mock record type in a B-tree
*
* @author aferguso
*
*/
public class BTreeTests extends BaseTestCase {
protected File dbFile;
protected Database db;
protected BTree btree;
protected int rootRecord;
protected IBTreeComparator comparator;
protected boolean debugMode = false;
public static Test suite() {
return suite(BTreeTests.class);
}
// setUp is not used since we need to parameterize this method,
// and invoke it multiple times per Junit test
protected void init(int degree) throws Exception {
dbFile = File.createTempFile("pdomtest", "db");
db = new Database(dbFile, new ChunkCache(), 0, false);
db.setExclusiveLock();
rootRecord = Database.DATA_AREA;
comparator = new BTMockRecordComparator();
btree = new BTree(db, rootRecord, degree, comparator);
}
// tearDown is not used for the same reason as above
protected void finish() throws Exception {
db.close();
dbFile.deleteOnExit();
}
public void testBySortedSetMirrorLite() throws Exception {
sortedMirrorTest(8);
}
/**
* Test random (but reproducible via known seed) sequences of insertions/deletions
* and use TreeSet as a reference implementation to check behaviour against.
* @throws Exception
*/
protected void sortedMirrorTest(int noTrials) throws Exception {
Random seeder = new Random(90210);
for(int i=0; i<noTrials; i++) {
int seed = seeder.nextInt();
System.out.println("Iteration #"+i);
trial(seed, false);
}
}
/**
* Test random (but reproducible via known seed) sequence of insertions
* and use TreeSet as a reference implementation to check behaviour against.
* @throws Exception
*/
public void testInsertion() throws Exception {
Random seeder = new Random();
for(int i=0; i<6; i++) {
int seed = seeder.nextInt();
System.out.println("Iteration #"+i);
trialImp(seed, false, new Random(seed*2), 1);
}
}
/**
* Insert/Delete a random number of records into/from the B-tree
* @param seed the seed for obtaining the deterministic random testing
* @param checkCorrectnessEachIteration if true, then on every single insertion/deletion check that the B-tree invariants
* still hold
* @throws Exception
*/
protected void trial(int seed, final boolean checkCorrectnessEachIteration) throws Exception {
Random random = new Random(seed);
// the probabilty that a particular iterations action will be an insertion
double pInsert = Math.min(0.5 + random.nextDouble(), 1);
trialImp(seed, checkCorrectnessEachIteration, random, pInsert);
}
private void trialImp(int seed, final boolean checkCorrectnessEachIteration, Random random, double pInsert) throws Exception {
final int degree = 2 + random.nextInt(11);
final int nIterations = random.nextInt(100000);
final SortedSet expected = new TreeSet();
final List history = new ArrayList();
init(degree);
System.out.print("\t "+seed+" "+(nIterations/1000)+"K: ");
for(int i=0; i<nIterations; i++) {
if(random.nextDouble()<pInsert) {
Integer value = new Integer(random.nextInt(Integer.MAX_VALUE));
boolean newEntry = expected.add(value);
if(newEntry) {
BTMockRecord btValue = new BTMockRecord(db, value.intValue());
history.add(btValue);
if(debugMode)
System.out.println("Add: "+value+" @ "+btValue.record);
btree.insert(btValue.getRecord());
}
} else {
if(!history.isEmpty()) {
int index = random.nextInt(history.size());
BTMockRecord btValue = (BTMockRecord) history.get(index);
history.remove(index);
expected.remove(new Integer(btValue.intValue()));
if(debugMode)
System.out.println("Remove: "+btValue.intValue()+" @ "+btValue.record);
btree.delete(btValue.getRecord());
}
}
if(i % 1000 == 0) {
System.out.print(".");
}
if(checkCorrectnessEachIteration) {
assertBTreeMatchesSortedSet("[iteration "+i+"] ", btree, expected);
assertBTreeInvariantsHold("[iteration "+i+"] ");
}
}
System.out.println();
assertBTreeMatchesSortedSet("[Trial end] ", btree, expected);
assertBTreeInvariantsHold("[Trial end]");
finish();
}
public void assertBTreeInvariantsHold(String msg) throws CoreException {
String errorReport = btree.getInvariantsErrorReport();
if(!errorReport.equals("")) {
fail("Invariants do not hold: "+errorReport);
}
}
public void assertBTreeMatchesSortedSet(final String msg, BTree actual, SortedSet expected) throws CoreException {
final Iterator i = expected.iterator();
btree.accept(new IBTreeVisitor(){
int k;
public int compare(long record) throws CoreException {
return 0;
}
public boolean visit(long record) throws CoreException {
if(record!=0) {
BTMockRecord btValue = new BTMockRecord(record, db);
if(i.hasNext()) {
Integer exp = ((Integer)i.next());
assertEquals(msg+" Differ at index: "+k, btValue.intValue(), exp.intValue());
k++;
} else {
fail("Sizes different");
return false;
}
}
return true;
}
});
}
private static class BTMockRecord {
public static final int VALUE_PTR = 0;
public static final int RECORD_SIZE = Database.INT_SIZE;
long record;
Database db;
/**
* Make a new record
*/
public BTMockRecord(Database db, int value) throws CoreException {
this.db = db;
record = db.malloc(BTMockRecord.RECORD_SIZE);
db.putInt(record + VALUE_PTR, value);
}
/**
* Get an existing record
*/
public BTMockRecord(long record, Database db) {
this.db = db;
this.record = record;
}
public int intValue() throws CoreException {
return db.getInt(record);
}
public long getRecord() {
return record;
}
}
private class BTMockRecordComparator implements IBTreeComparator {
public int compare(long record1, long record2) throws CoreException {
return db.getInt(record1) - db.getInt(record2);
}
}
}