find_unoccupied_index_using_bitset()

template<typename Key, typename T, typename Hash = Hash<Key>, typename KeyEqual = EqualTo<Key>, int INLINED_COUNT = FASTLED_HASHMAP_INLINED_COUNT>

fl::size fl::HashMap< Key, T, Hash, KeyEqual, INLINED_COUNT >::find_unoccupied_index_using_bitset ( const Key & key, const fl::bitset< 1024 > & occupied_set ) const

inlineprivate

Definition at line 547 of file hash_map.h.

                                                                  {
        const fl::size cap = _buckets.size();
        const fl::size mask = cap - 1;
        const fl::size h = _hash(key) & mask;
 
        if (cap <= kLinearProbingOnlySize) {
            // linear probing
            for (fl::size i = 0; i < cap; ++i) {
                const fl::size idx = (h + i) & mask;
                bool occupied = occupied_set.test(idx);
                if (occupied) {
                    continue;
                }
                return idx;
            }
        } else {
            // quadratic probing up to 8 tries
            fl::size i = 0;
            for (; i < kQuadraticProbingTries; ++i) {
                const fl::size idx = (h + i + i * i) & mask;
                bool occupied = occupied_set.test(idx);
                if (occupied) {
                    continue;
                }
                return idx;
            }
            // fallback to linear for the rest
            for (; i < cap; ++i) {
                const fl::size idx = (h + i) & mask;
                bool occupied = occupied_set.test(idx);
                if (occupied) {
                    continue;
                }
                return idx;
            }
        }
        return npos();
    }