int num = tdState.tdocs.read(arr, freq);
if (num==0) break;
if (upto + num > docs.length) {
if (obs == null) obs = new OpenBitSet(maxDoc());
for (int i = 0; i<num; i++) {
obs.fastSet(arr[i]);
}
numBits += num;
} else {
System.arraycopy(arr, 0, docs, upto, num);
upto += num;