/**
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.kahadb.index;
import java.io.PrintWriter;
import java.text.NumberFormat;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import org.apache.kahadb.index.BTreeIndex;
import org.apache.kahadb.index.Index;
import org.apache.kahadb.util.LongMarshaller;
import org.apache.kahadb.util.StringMarshaller;
public class BTreeIndexTest extends IndexTestSupport {
private NumberFormat nf;
@Override
protected void setUp() throws Exception {
super.setUp();
nf = NumberFormat.getIntegerInstance();
nf.setMinimumIntegerDigits(6);
nf.setGroupingUsed(false);
}
@Override
protected Index<String, Long> createIndex() throws Exception {
long id = tx.allocate().getPageId();
tx.commit();
BTreeIndex<String, Long> index = new BTreeIndex<String,Long>(pf, id);
index.setKeyMarshaller(StringMarshaller.INSTANCE);
index.setValueMarshaller(LongMarshaller.INSTANCE);
return index;
}
/**
* Yeah, the current implementation does NOT try to balance the tree. Here is
* a test case showing that it gets out of balance.
*
* @throws Exception
*/
public void disabled_testTreeBalancing() throws Exception {
createPageFileAndIndex(100);
BTreeIndex index = ((BTreeIndex)this.index);
this.index.load(tx);
tx.commit();
doInsert(50);
int minLeafDepth = index.getMinLeafDepth(tx);
int maxLeafDepth = index.getMaxLeafDepth(tx);
assertTrue("Tree is balanced", maxLeafDepth-minLeafDepth <= 1);
// Remove some of the data
doRemove(16);
minLeafDepth = index.getMinLeafDepth(tx);
maxLeafDepth = index.getMaxLeafDepth(tx);
System.out.println( "min:"+minLeafDepth );
System.out.println( "max:"+maxLeafDepth );
index.printStructure(tx, new PrintWriter(System.out));
assertTrue("Tree is balanced", maxLeafDepth-minLeafDepth <= 1);
this.index.unload(tx);
}
public void testPruning() throws Exception {
createPageFileAndIndex(100);
BTreeIndex<String,Long> index = ((BTreeIndex<String,Long>)this.index);
this.index.load(tx);
tx.commit();
int minLeafDepth = index.getMinLeafDepth(tx);
int maxLeafDepth = index.getMaxLeafDepth(tx);
assertEquals(1, minLeafDepth);
assertEquals(1, maxLeafDepth);
doInsert(1000);
minLeafDepth = index.getMinLeafDepth(tx);
maxLeafDepth = index.getMaxLeafDepth(tx);
assertTrue("Depth of tree grew", minLeafDepth > 1);
assertTrue("Depth of tree grew", maxLeafDepth > 1);
// Remove the data.
doRemove(1000);
minLeafDepth = index.getMinLeafDepth(tx);
maxLeafDepth = index.getMaxLeafDepth(tx);
assertEquals(1, minLeafDepth);
assertEquals(1, maxLeafDepth);
this.index.unload(tx);
tx.commit();
}
public void testIteration() throws Exception {
createPageFileAndIndex(100);
BTreeIndex<String,Long> index = ((BTreeIndex<String,Long>)this.index);
this.index.load(tx);
tx.commit();
// Insert in reverse order..
doInsertReverse(1000);
this.index.unload(tx);
tx.commit();
this.index.load(tx);
tx.commit();
// BTree should iterate it in sorted order.
int counter=0;
for (Iterator<Map.Entry<String,Long>> i = index.iterator(tx); i.hasNext();) {
Map.Entry<String,Long> entry = (Map.Entry<String,Long>)i.next();
assertEquals(key(counter),entry.getKey());
assertEquals(counter,(long)entry.getValue());
counter++;
}
this.index.unload(tx);
tx.commit();
}
public void testVisitor() throws Exception {
createPageFileAndIndex(100);
BTreeIndex<String,Long> index = ((BTreeIndex<String,Long>)this.index);
this.index.load(tx);
tx.commit();
// Insert in reverse order..
doInsert(1000);
this.index.unload(tx);
tx.commit();
this.index.load(tx);
tx.commit();
// BTree should iterate it in sorted order.
index.visit(tx, new BTreeVisitor<String, Long>(){
public boolean isInterestedInKeysBetween(String first, String second) {
return true;
}
public void visit(List<String> keys, List<Long> values) {
}
});
this.index.unload(tx);
tx.commit();
}
void doInsertReverse(int count) throws Exception {
for (int i = count-1; i >= 0; i--) {
index.put(tx, key(i), (long)i);
tx.commit();
}
}
/**
* Overriding so that this generates keys that are the worst case for the BTree. Keys that
* always insert to the end of the BTree.
*/
@Override
protected String key(int i) {
return "key:"+nf.format(i);
}
}