func (db *DB) zrank(key []byte, member []byte, reverse bool) (int64, error) {
if err := checkZSetKMSize(key, member); err != nil {
return 0, err
}
k := db.zEncodeSetKey(key, member)
if v, err := db.db.Get(k); err != nil {
return 0, err
} else if v == nil {
return -1, nil
} else {
if s, err := Int64(v, err); err != nil {
return 0, err
} else {
var it *leveldb.Iterator
sk := db.zEncodeScoreKey(key, member, s)
if !reverse {
minKey := db.zEncodeStartScoreKey(key, MinScore)
it = db.db.Iterator(minKey, sk, leveldb.RangeClose, 0, -1)
} else {
maxKey := db.zEncodeStopScoreKey(key, MaxScore)
it = db.db.RevIterator(sk, maxKey, leveldb.RangeClose, 0, -1)
}
var lastKey []byte = nil
var n int64 = 0
for ; it.Valid(); it.Next() {
n++
lastKey = it.Key()
}
it.Close()
if _, m, _, err := db.zDecodeScoreKey(lastKey); err == nil && bytes.Equal(m, member) {
n--
return n, nil
}
}
}
return -1, nil
}
