private void appendFill(int nWords, int v) {
if (vec.isEmpty()) {
if (v == 0) {
vec.add(HEADER0 | nWords);
} else {
vec.add(HEADER1 | nWords);
}
} else if (nWords > 1) {
int back = getBack();
if (v == 0) {
if (isZeroFill(back)) {
setBack(back + nWords);
} else {
vec.add(HEADER0 | nWords);
}
} else if (isOneFill(back)) {
setBack(back + nWords);
} else {
vec.add(HEADER1 | nWords);
}
} else {
active.val = v != 0 ? ALLONES : 0;
appendLiteral();
}
}
/**
* Returns the number of 1 bits in the bitset.
*
* @return the number of 1 bits in the bitset.
*/
public int cardinality() {
// check the cardinality, again if it has been reset.
if (nset == 0 && !vec.isEmpty()) {
doCount();
}
// the sizes in the vector and the active word.
return nset + Integer.bitCount(active.val);
}
private void appendCounter(int val, int cnt) {
int head = 2 + val;
int w = (head << SECONDBIT) + cnt;
nbits += cnt * MAXBITS;
if (vec.isEmpty()) {
vec.add(w);
} else {
int back = getBack();
if ((back >>> SECONDBIT) == head) {
back += cnt;
setBack(back);
} else if ((back == ALLONES) && head == 3) {
setBack(w + 1);
} else if ((back == 0) && head == 2) {
setBack(w + 1);
} else {
vec.add(w);
}
}
}