/* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
package freenet.support;
import junit.framework.TestCase;
/**
* Test case for {@link freenet.support.BitArray} class.
*
* @author Alberto Bacchelli <sback@freenetproject.org>
*/
public class BitArrayTest extends TestCase {
private final int sampleBitsNumber = 10;
private final int oneByteBits = 8;
/**
* Creates a BitArray with all values set to the
* boolean argument
* @param arraySize the size of the BitArray
* @param value the value for each bit
* @return the set BitArray
*/
private BitArray createAllEqualsBitArray(int arraySize, boolean value) {
BitArray methodBitArray = new BitArray(arraySize);
//setting all bits true
for (int i=0; i<methodBitArray.getSize();i++)
methodBitArray.setBit(i,value);
return methodBitArray;
}
/**
* Creates a String of toRepeat String as long as needed
* @param stringSize length requested
* @param toRepeat String to repeat stringSize times
* @return the String of toRepeat
*/
private String createAllOneString(int stringSize, String toRepeat) {
StringBuilder methodStringBuilder = new StringBuilder();
for (int i=0;i<stringSize;i++)
methodStringBuilder.append(toRepeat);
return methodStringBuilder.toString();
}
/**
* Tests BitArray(int) constructor
* and verifies if the instance is
* well created (all values must be
* readables and false, and the length
* has to be correct)
*/
public void testBitArray_int() {
BitArray methodBitArray = new BitArray(sampleBitsNumber);
for(int i=0;i<sampleBitsNumber;i++)
assertFalse(methodBitArray.bitAt(i));
assertEquals(methodBitArray.getSize(),sampleBitsNumber);
}
/**
* Tests toString() method
* creating BitArrays with same value bits.
*/
public void testToStringAllEquals() {
BitArray methodBitArray = createAllEqualsBitArray(sampleBitsNumber,true);
String expectedString = createAllOneString(sampleBitsNumber,"1");
assertEquals(methodBitArray.toString(),expectedString);
methodBitArray = createAllEqualsBitArray(sampleBitsNumber,false);
expectedString = createAllOneString(sampleBitsNumber,"0");
assertEquals(methodBitArray.toString(),expectedString);
}
/**
* Tests toString() method
* with a BitArray with size zero.
*/
public void testToStringEmpty() {
BitArray methodBitArray = new BitArray(0);
assertEquals(methodBitArray.toString().length(),0);
}
/**
* Tests setBit(int,boolean) method
* trying to set a bit out of bounds
*/
public void testSetBit_OutOfBounds() {
BitArray methodBitArray = new BitArray(sampleBitsNumber);
try {
methodBitArray.setBit(sampleBitsNumber,true);
//fail("Expected Exception Error Not Thrown!");
}
catch (ArrayIndexOutOfBoundsException anException) {
assertNotNull(anException); }
}
/**
* Tests setBit(int,boolean) method
* using getAt(int) to verify if they are
* consistent.
*/
public void testSetAndGetBit() {
BitArray methodBitArray = new BitArray(sampleBitsNumber);
//setting true even bits
for (int i=0; i<methodBitArray.getSize();i=i+2)
methodBitArray.setBit(i,true);
//checking even bits
for (int i=0; i<methodBitArray.getSize();i=i+2)
assertTrue(methodBitArray.bitAt(i));
//checking odd bits
for (int i=1; i<methodBitArray.getSize();i=i+2)
assertFalse(methodBitArray.bitAt(i));
}
/**
* Tests unsignedByteToInt(byte) method
* trying it correctness for every possible (i.e. 256)
* byte value
*/
public void testUnsignedByteToInt() {
byte sampleByte;
for (int i =0; i<256; i++) {
sampleByte = (byte)i;
assertEquals(i,BitArray.unsignedByteToInt(sampleByte)); }
}
/**
* Tests getSize() method
*/
public void testGetSize() {
BitArray methodBitArray = new BitArray(0);
assertEquals(methodBitArray.getSize(),0);
methodBitArray = createAllEqualsBitArray(sampleBitsNumber,true);
assertEquals(methodBitArray.getSize(),sampleBitsNumber);
}
/**
* Tests setAllOnes() method
* comparing the result to
* a BitArray with already all ones
* set.
*/
public void testSetAllOnes() {
BitArray methodBitArray = createAllEqualsBitArray(sampleBitsNumber,true);
BitArray methodBitArrayToVerify = new BitArray(sampleBitsNumber);
methodBitArrayToVerify.setAllOnes();
assertEquals(methodBitArray,methodBitArrayToVerify);
}
/**
* Tests firstOne() method
* far all possible first-one-position
* in a BitArray with as many bits as in
* a single byte
*/
public void testFirstOne() {
BitArray methodBitArray = new BitArray(oneByteBits);
//only one "1"
for(int i=0; i<oneByteBits; i++) {
methodBitArray = new BitArray(oneByteBits);
methodBitArray.setBit(i,true);
assertEquals(methodBitArray.firstOne(),i);}
methodBitArray.setAllOnes();
//augmenting zeros
for(int i=0; i<oneByteBits-1; i++) {
methodBitArray.setBit(i,false);
assertEquals(methodBitArray.firstOne(),i+1);}
//all zeros
methodBitArray.setBit(oneByteBits-1,false);
assertEquals(methodBitArray.firstOne(),-1);
}
public void testLastOne() {
BitArray array = new BitArray(16);
array.setAllOnes();
for(int i=15;i>=0;i--) {
assertEquals(i, array.lastOne(Integer.MAX_VALUE));
assertEquals(i, array.lastOne(i+1));
assertEquals(i, array.lastOne(i+8));
array.setBit(i, false);
}
assert(array.lastOne(Integer.MAX_VALUE) == -1);
assert(array.lastOne(0) == -1);
}
public void testShrinkGrow() {
BitArray array = new BitArray(16);
array.setAllOnes();
array.setSize(9);
array.setSize(16);
for(int i=9;i<16;i++)
assert(!array.bitAt(i));
for(int i=0;i<9;i++)
assert(array.bitAt(i));
}
}