/*
* 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.jackrabbit.commons.flat;
import org.apache.jackrabbit.commons.flat.Rank;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.HashSet;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;
import java.util.NoSuchElementException;
import java.util.Random;
import java.util.Set;
import junit.framework.TestCase;
public class RankTest extends TestCase {
private static final Random rnd = new Random();
public void testEmpty() {
Rank<Integer> r = Rank.rank(new Integer[0]);
assertFalse(r.take(0).hasNext());
assertEquals(0, r.size());
try {
r.take(1);
fail("Excepted " + NoSuchElementException.class.getName());
}
catch (NoSuchElementException ignore) { }
}
public void testSingleton() {
Rank<Integer> r = Rank.rank(new Integer[] {42});
assertFalse(r.take(0).hasNext());
assertEquals(1, r.size());
Iterator<Integer> it = r.take(1);
assertTrue(it.hasNext());
assertEquals(0, r.size());
assertEquals(42, it.next().intValue());
assertFalse(r.take(0).hasNext());
try {
r.take(1);
fail("Excepted " + NoSuchElementException.class.getName());
}
catch (NoSuchElementException ignore) { }
}
public void testRank() {
for (int n = 1; n <= 2000; n++) {
testRank(n);
}
}
public void testGetAll() {
int n = 100;
List<Integer> values = createValues(n);
Rank<Integer> r = Rank.rank(values, Integer.class);
try {
r.take(n + 1);
fail("Expected " + NoSuchElementException.class.getName());
}
catch (NoSuchElementException ignore) { }
assertEquals(n, r.size());
Iterator<Integer> it = r.take(n);
while (it.hasNext()) {
assertTrue(values.remove(it.next()));
}
assertTrue(values.isEmpty());
assertEquals(0, r.size());
}
public void testGetSingles() {
int n = 100;
List<Integer> values = createValues(n);
Rank<Integer> r = Rank.rank(values, Integer.class);
List<Integer> sorted = new ArrayList<Integer>();
Iterator<Integer> it;
while (r.size() > 0) {
it = r.take(1);
sorted.add(it.next());
assertFalse(it.hasNext());
}
assertTrue(sorted.containsAll(values));
assertTrue(values.containsAll(sorted));
Comparator<? super Integer> order = r.getOrder();
checkOrdered(sorted.iterator(), order);
}
public void testOrdered() {
int n = 1000000;
Integer[] values = new Integer[n];
for (int k = 0; k < n; k++) {
values[k] = k;
}
Rank<Integer> r = Rank.rank(values);
while (r.size() > 0) {
int k = Math.min(rnd.nextInt(n/10), r.size());
checkOrdered(r.take(k), r.getOrder());
}
}
// -----------------------------------------------------< internal >---
private static List<Integer> createValues(int count) {
Set<Integer> ints = new HashSet<Integer>();
for (int k = 0; k < count; k++) {
ints.add(rnd.nextInt());
}
List<Integer> intList = new LinkedList<Integer>(ints);
Collections.shuffle(intList);
return intList;
}
private <T> void checkOrdered(Iterator<T> it, Comparator<? super T> order) {
T prev = it.next();
while (it.hasNext()) {
T next = it.next();
assertTrue(order.compare(prev, next) < 0);
prev = next;
}
}
private static void testRank(int count) {
List<Integer> ints = createValues(count);
Rank<Integer> r = Rank.rank(ints, Integer.class);
Set<Integer> all = new HashSet<Integer>(ints);
Set<Integer> previous = new HashSet<Integer>();
while (r.size() > 0) {
int n = Math.min(rnd.nextInt(count + 1), r.size());
Iterator<Integer> it = r.take(n);
Set<Integer> actual = new HashSet<Integer>();
while (it.hasNext()) {
Integer i = it.next();
assertTrue(actual.add(i));
assertTrue(all.remove(i));
}
checkOrdering(previous, actual, r.getOrder());
previous = actual;
}
assertTrue(all.isEmpty());
}
private static void checkOrdering(Set<Integer> previous, Set<Integer> actual,
Comparator<? super Integer> order) {
for (Iterator<Integer> pIt = previous.iterator(); pIt.hasNext(); ) {
Integer p = pIt.next();
for(Iterator<Integer> aIt = actual.iterator(); aIt.hasNext(); ) {
Integer a = aIt.next();
assertTrue(order.compare(p, a) < 0);
}
}
}
}