package org.apache.lucene.util;
/**
* 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.
*/
import java.io.IOException;
import org.apache.lucene.util.LuceneTestCase;
import org.apache.lucene.store.MockDirectoryWrapper;
import org.apache.lucene.store.RAMDirectory;
/**
* <code>TestBitVector</code> tests the <code>BitVector</code>, obviously.
*/
public class TestBitVector extends LuceneTestCase
{
public TestBitVector(String s) {
super(s);
}
/**
* Test the default constructor on BitVectors of various sizes.
* @throws Exception
*/
public void testConstructSize() throws Exception {
doTestConstructOfSize(8);
doTestConstructOfSize(20);
doTestConstructOfSize(100);
doTestConstructOfSize(1000);
}
private void doTestConstructOfSize(int n) {
BitVector bv = new BitVector(n);
assertEquals(n,bv.size());
}
/**
* Test the get() and set() methods on BitVectors of various sizes.
* @throws Exception
*/
public void testGetSet() throws Exception {
doTestGetSetVectorOfSize(8);
doTestGetSetVectorOfSize(20);
doTestGetSetVectorOfSize(100);
doTestGetSetVectorOfSize(1000);
}
private void doTestGetSetVectorOfSize(int n) {
BitVector bv = new BitVector(n);
for(int i=0;i<bv.size();i++) {
// ensure a set bit can be git'
assertFalse(bv.get(i));
bv.set(i);
assertTrue(bv.get(i));
}
}
/**
* Test the clear() method on BitVectors of various sizes.
* @throws Exception
*/
public void testClear() throws Exception {
doTestClearVectorOfSize(8);
doTestClearVectorOfSize(20);
doTestClearVectorOfSize(100);
doTestClearVectorOfSize(1000);
}
private void doTestClearVectorOfSize(int n) {
BitVector bv = new BitVector(n);
for(int i=0;i<bv.size();i++) {
// ensure a set bit is cleared
assertFalse(bv.get(i));
bv.set(i);
assertTrue(bv.get(i));
bv.clear(i);
assertFalse(bv.get(i));
}
}
/**
* Test the count() method on BitVectors of various sizes.
* @throws Exception
*/
public void testCount() throws Exception {
doTestCountVectorOfSize(8);
doTestCountVectorOfSize(20);
doTestCountVectorOfSize(100);
doTestCountVectorOfSize(1000);
}
private void doTestCountVectorOfSize(int n) {
BitVector bv = new BitVector(n);
// test count when incrementally setting bits
for(int i=0;i<bv.size();i++) {
assertFalse(bv.get(i));
assertEquals(i,bv.count());
bv.set(i);
assertTrue(bv.get(i));
assertEquals(i+1,bv.count());
}
bv = new BitVector(n);
// test count when setting then clearing bits
for(int i=0;i<bv.size();i++) {
assertFalse(bv.get(i));
assertEquals(0,bv.count());
bv.set(i);
assertTrue(bv.get(i));
assertEquals(1,bv.count());
bv.clear(i);
assertFalse(bv.get(i));
assertEquals(0,bv.count());
}
}
/**
* Test writing and construction to/from Directory.
* @throws Exception
*/
public void testWriteRead() throws Exception {
doTestWriteRead(8);
doTestWriteRead(20);
doTestWriteRead(100);
doTestWriteRead(1000);
}
private void doTestWriteRead(int n) throws Exception {
MockDirectoryWrapper d = new MockDirectoryWrapper(new RAMDirectory());
d.setPreventDoubleWrite(false);
BitVector bv = new BitVector(n);
// test count when incrementally setting bits
for(int i=0;i<bv.size();i++) {
assertFalse(bv.get(i));
assertEquals(i,bv.count());
bv.set(i);
assertTrue(bv.get(i));
assertEquals(i+1,bv.count());
bv.write(d, "TESTBV");
BitVector compare = new BitVector(d, "TESTBV");
// compare bit vectors with bits set incrementally
assertTrue(doCompare(bv,compare));
}
}
/**
* Test r/w when size/count cause switching between bit-set and d-gaps file formats.
*/
public void testDgaps() throws IOException {
doTestDgaps(1,0,1);
doTestDgaps(10,0,1);
doTestDgaps(100,0,1);
doTestDgaps(1000,4,7);
doTestDgaps(10000,40,43);
doTestDgaps(100000,415,418);
doTestDgaps(1000000,3123,3126);
}
private void doTestDgaps(int size, int count1, int count2) throws IOException {
MockDirectoryWrapper d = new MockDirectoryWrapper(new RAMDirectory());
d.setPreventDoubleWrite(false);
BitVector bv = new BitVector(size);
for (int i=0; i<count1; i++) {
bv.set(i);
assertEquals(i+1,bv.count());
}
bv.write(d, "TESTBV");
// gradually increase number of set bits
for (int i=count1; i<count2; i++) {
BitVector bv2 = new BitVector(d, "TESTBV");
assertTrue(doCompare(bv,bv2));
bv = bv2;
bv.set(i);
assertEquals(i+1,bv.count());
bv.write(d, "TESTBV");
}
// now start decreasing number of set bits
for (int i=count2-1; i>=count1; i--) {
BitVector bv2 = new BitVector(d, "TESTBV");
assertTrue(doCompare(bv,bv2));
bv = bv2;
bv.clear(i);
assertEquals(i,bv.count());
bv.write(d, "TESTBV");
}
}
/**
* Compare two BitVectors.
* This should really be an equals method on the BitVector itself.
* @param bv One bit vector
* @param compare The second to compare
*/
private boolean doCompare(BitVector bv, BitVector compare) {
boolean equal = true;
for(int i=0;i<bv.size();i++) {
// bits must be equal
if(bv.get(i)!=compare.get(i)) {
equal = false;
break;
}
}
return equal;
}
private static int[] subsetPattern = new int[] { 1, 1, 1, 0, 0, 1, 0, 1, 1, 0, 1, 0, 0, 0, 1, 0, 1, 1, 0, 1 };
/**
* Tests BitVector.subset() against the above pattern
*/
public void testSubset() {
doTestSubset(0, 0);
doTestSubset(0, 20);
doTestSubset(0, 7);
doTestSubset(0, 8);
doTestSubset(0, 9);
doTestSubset(0, 15);
doTestSubset(0, 16);
doTestSubset(0, 17);
doTestSubset(1, 7);
doTestSubset(1, 8);
doTestSubset(1, 9);
doTestSubset(1, 15);
doTestSubset(1, 16);
doTestSubset(1, 17);
doTestSubset(2, 20);
doTestSubset(3, 20);
doTestSubset(4, 20);
doTestSubset(5, 20);
doTestSubset(6, 20);
doTestSubset(7, 14);
doTestSubset(7, 15);
doTestSubset(7, 16);
doTestSubset(8, 15);
doTestSubset(9, 20);
doTestSubset(10, 20);
doTestSubset(11, 20);
doTestSubset(12, 20);
doTestSubset(13, 20);
}
/**
* Compare a subset against the corresponding portion of the test pattern
*/
private void doTestSubset(int start, int end) {
BitVector full = createSubsetTestVector();
BitVector subset = full.subset(start, end);
assertEquals(end - start, subset.size());
int count = 0;
for (int i = start, j = 0; i < end; i++, j++) {
if (subsetPattern[i] == 1) {
count++;
assertTrue(subset.get(j));
} else {
assertFalse(subset.get(j));
}
}
assertEquals(count, subset.count());
}
private BitVector createSubsetTestVector() {
BitVector bv = new BitVector(subsetPattern.length);
for (int i = 0; i < subsetPattern.length; i++) {
if (subsetPattern[i] == 1) {
bv.set(i);
}
}
return bv;
}
}