}
@Override
public long[] getChildren(long cid) {
if (cid != 0 && !existsCommit(cid)) {
throw new VException("Unknown commit: " + cid);
}
DBCursor c = _commits.find(new BasicDBObject(PARENT_CID, cid),
new BasicDBObject(MongoDBConstants.ID, 1));
long[] r = new long[c.count()];
int i = 0;