/*
* Copyright 2014, The Sporting Exchange Limited
*
* 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 com.betfair.cougar.util;
import java.util.Arrays;
public class BitmapBuilder {
public static final int WORD_LENGTH = 8;
/**
* Increases the array size to a multiple of WORD_LENGTH
*
* @param list
* @return
*/
private static int[] pad(int[] list) {
double m = list.length / (double)WORD_LENGTH;
int size = (int)Math.ceil(m);
int[] ret = new int[size * WORD_LENGTH];
Arrays.fill(ret, 0);
System.arraycopy(list,0,ret,0,list.length);
return ret;
}
/**
* Builds a bit map from the given list. The list should values of 0 or 1s
*
* @param list
* @return
*/
public static int[] listToMap(int[] list) {
list = pad(list);
int[] bitMap = new int[(int)(list.length / WORD_LENGTH)];
Arrays.fill(bitMap, 0);
int j = -1;
for (int i = 0; i < list.length; i++) {
if (i % WORD_LENGTH == 0) {
j++;
}
bitMap[j] |= (list[i] << ((WORD_LENGTH - 1) - (i % WORD_LENGTH)));
}
return bitMap;
}
/**
* Builds a list from the given bit map.
* The list will contain values of 0 or 1s
*
* @param list
* @return
*/
public static int[] mapToList(int[] bitMap) {
int[] list = new int[(int)(bitMap.length * WORD_LENGTH)];
Arrays.fill(list, 0);
int j = -1;
for (int i = 0; i < list.length; i++) {
if (i % WORD_LENGTH == 0) {
j++;
}
list[i] = (bitMap[j] & (1 << ((WORD_LENGTH - 1) - (i % WORD_LENGTH)))) == 0 ? 0 : 1;
}
return list;
}
}