package is2.util;
import is2.data.Long2IntInterface;
/**
* @author Bernd Bohnet, 01.09.2009
*
* Maps for the Hash Kernel the long values to the int values.
*/
final public class Long2Int implements Long2IntInterface {
public Long2Int() {
size = 115911564;
}
public Long2Int(int s) {
size = s;
}
/**
* Integer counter for long2int
*/
final private int size; //0x03ffffff //0x07ffffff
/*
* (non-Javadoc) @see is2.sp09k9992.Long2IntIterface#size()
*/
@Override
public int size() {
return size;
}
/*
* (non-Javadoc) @see is2.sp09k9992.Long2IntIterface#start() has no meaning
* for this implementation
*/
final public void start() {
}
/*
* (non-Javadoc) @see is2.sp09k9992.Long2IntIterface#l2i(long)
*/
@Override
final public int l2i(long l) {
if (l < 0) {
return -1;
}
// this works well LAS 88.138
// int r= (int)(( l ^ (l&0xffffffff00000000L) >>> 29 ));//0x811c9dc5 ^ // 29
// return Math.abs(r % size);
// this works a bit better and good with 0x03ffffff
//
/*
* long r= l;//26 l = (l>>12)&0xfffffffffffff000L; r ^= l;//38 l =
* (l>>11)&0xffffffffffffc000L; r ^= l;//49 l = (l>>9)&
* 0xffffffffffff0000L; //53 r ^= l;//58 l = (l>>7)&0xfffffffffffc0000L;
* //62 r ^=l;//65 int x = (int)r; x = x % size; // return x >= 0 ? x :
* -x ;// Math.abs(r % size);
*
*/
// 26 0x03ffffff
// together with 0x07ffffff 27 88.372
long r = l;// 27
l = (l >> 13) & 0xffffffffffffe000L;
r ^= l; // 40
l = (l >> 11) & 0xffffffffffff0000L;
r ^= l; // 51
l = (l >> 9) & 0xfffffffffffc0000L; //53
r ^= l; // 60
l = (l >> 7) & 0xfffffffffff00000L; //62
r ^= l; //67
int x = ((int) r) % size;
return x >= 0 ? x : -x;
}
}