/*
* 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.solr.util.hll;
import java.util.Locale;
import org.apache.lucene.util.LuceneTestCase;
import org.junit.Test;
/**
* Unit tests for {@link BitVector}.
*/
public class BitVectorTest extends LuceneTestCase {
/**
* Tests {@link BitVector#getRegister(long)} and {@link BitVector#setRegister(long, long)}.
*/
@Test
public void getSetRegisterTest() {
{ // locally scoped for sanity
// NOTE: registers are only 5bits wide
final BitVector vector1 = new BitVector(5/*width*/, 128/*count, 2^7*/);
final BitVector vector2 = new BitVector(5/*width*/, 128/*count, 2^7*/);
final BitVector vector3 = new BitVector(5/*width*/, 128/*count, 2^7*/);
final BitVector vector4 = new BitVector(5/*width*/, 128/*count, 2^7*/);
for(int i=0; i<128/*2^7*/; i++) {
vector1.setRegister(i, 0x1F);
vector2.setRegister(i, (i & 0x1F));
vector3.setRegister(i, ((127 - i) & 0x1F));
vector4.setRegister(i, 0x15);
}
for(int i=0; i<128/*2^7*/; i++) {
assertEquals(vector1.getRegister(i), 0x1F);
assertEquals(vector2.getRegister(i), (i & 0x1F));
assertEquals(vector3.getRegister(i), ((127 - i) & 0x1F));
assertEquals(vector4.getRegister(i), 0x15);
}
}
}
// ========================================================================
/**
* Tests {@link BitVector#registerIterator()}
*/
@Test
public void registerIteratorTest() {
{ // scoped locally for sanity
// NOTE: registers are only 5bits wide
final BitVector vector1 = new BitVector(5/*width*/, 128/*count, 2^7*/);
final BitVector vector2 = new BitVector(5/*width*/, 128/*count, 2^7*/);
final BitVector vector3 = new BitVector(5/*width*/, 128/*count, 2^7*/);
final BitVector vector4 = new BitVector(5/*width*/, 128/*count, 2^7*/);
for(int i=0; i<128/*2^7*/; i++) {
vector1.setRegister(i, 0x1F);
vector2.setRegister(i, (i & 0x1F));
vector3.setRegister(i, ((127 - i) & 0x1F));
vector4.setRegister(i, 0x15);
}
final LongIterator registerIterator1 = vector1.registerIterator();
final LongIterator registerIterator2 = vector2.registerIterator();
final LongIterator registerIterator3 = vector3.registerIterator();
final LongIterator registerIterator4 = vector4.registerIterator();
for(int i=0; i<128/*2^7*/; i++) {
assertEquals(registerIterator1.hasNext(), true);
assertEquals(registerIterator2.hasNext(), true);
assertEquals(registerIterator3.hasNext(), true);
assertEquals(registerIterator4.hasNext(), true);
assertEquals(registerIterator1.next(), 0x1F);
assertEquals(registerIterator2.next(), (i & 0x1F));
assertEquals(registerIterator3.next(), ((127 - i) & 0x1F));
assertEquals(registerIterator4.next(), 0x15);
}
assertEquals(registerIterator1.hasNext(), false/*no more*/);
assertEquals(registerIterator2.hasNext(), false/*no more*/);
assertEquals(registerIterator3.hasNext(), false/*no more*/);
assertEquals(registerIterator4.hasNext(), false/*no more*/);
}
{ // scoped locally for sanity
// Vectors that are shorter than one word
assertIterator(1, 12/* 1*12=12 bits, fewer than a single word */);
assertIterator(2, 12/* 2*12=24 bits, fewer than a single word */);
assertIterator(3, 12/* 3*12=36 bits, fewer than a single word */);
assertIterator(4, 12/* 4*12=48 bits, fewer than a single word */);
// Vectors that don't fit exactly into longs
assertIterator(5, 16/* 5*16=80 bits */);
assertIterator(5, 32/* 5*32=160 bits */);
}
// Iterate over vectors that are padded
}
private static void assertIterator(final int width, final int count) {
final BitVector vector = new BitVector(width, count);
final LongIterator iter = vector.registerIterator();
for(int i=0; i<count; i++) {
assertTrue(String.format(Locale.ROOT, "expected more elements: width=%s, count=%s", width, count), iter.hasNext());
// TODO: fill with a sentinel value
assertEquals(iter.next(), 0);
}
assertFalse(String.format(Locale.ROOT, "expected no more elements: width=%s, count=%s", width, count), iter.hasNext());
}
// ========================================================================
/**
* Tests {@link BitVector#setMaxRegister(long, long)}
*/
@Test
public void setMaxRegisterTest() {
final BitVector vector = new BitVector(5/*width*/, 128/*count, 2^7*/);
vector.setRegister(0, 10);
// should replace with a larger value
vector.setMaxRegister(0, 11);
assertEquals(vector.getRegister(0), 11);
// should not replace with a smaller or equal value
vector.setMaxRegister(0, 9);
assertEquals(vector.getRegister( 0), 11);
vector.setMaxRegister(0, 11);
assertEquals(vector.getRegister(0), 11);
}
// ========================================================================
// fill
/**
* Tests {@link BitVector#fill(long)}
*/
@Test
public void fillTest() {
final BitVector vector = new BitVector(5/*width*/, 128/*count, 2^7*/);
for(int i=0; i<128/*2^7*/; i++) {
vector.setRegister(i, i);
}
vector.fill(0L);
for(int i=0; i<128/*2^7*/; i++) {
assertEquals(vector.getRegister(i), 0);
}
vector.fill(17L/*arbitrary*/);
for(int i=0; i<128/*2^7*/; i++) {
assertEquals(vector.getRegister(i), 17/*arbitrary*/);
}
}
}