ext.test4j.cglib.core.TinyBitSet Maven / Gradle / Ivy
/*
* Copyright 2003 The Apache Software Foundation
*
* Licensed 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 ext.test4j.cglib.core;
public class TinyBitSet {
private static int[] T = new int[256];
private int value = 0;
private static int gcount(int x) {
int c = 0;
while (x != 0) {
c++;
x &= (x - 1);
}
return c;
}
static {
for (int j = 0; j < 256; j++) {
T[j] = gcount(j);
}
}
private static int topbit(int i) {
int j;
for (j = 0; i != 0; i ^= j) {
j = i & -i;
}
return j;
}
private static int log2(int i) {
int j = 0;
for (j = 0; i != 0; i >>= 1) {
j++;
}
return j;
}
public int length() {
return log2(topbit(value));
}
public int cardinality() {
int w = value;
int c = 0;
while (w != 0) {
c += T[w & 255];
w >>= 8;
}
return c;
}
public boolean get(int index) {
return (value & (1 << index)) != 0;
}
public void set(int index) {
value |= (1 << index);
}
public void clear(int index) {
value &= ~(1 << index);
}
}