Cuckoo Filter

Fingerprints in buckets · two candidate buckets · cuckoo kick-out relocation · lookup · delete

Lookup O(1)
Delete O(1)
Insert O(1) amortized
FPR ≈ 2b / 2^f
i2 = i1 XOR hash(f)

Controls

slow fast
candidate bucket insert / found evicted (kick-out) scanning delete

Hash Trace

Insert, look up, or delete an item to see how its fingerprint and two candidate buckets are computed.

Buckets (each holds b = 4 fingerprints; 0 = empty)

items: 0 capacity: 0 load: 0% kicks (last): 0

Last Operation

Ready. The filter starts empty.

Load Factor & FPR

fingerprint bits fFPR ≈ 2b/2^f (b=4)
83.1%
100.78%
120.20%
160.012%
bucket size bmax load factor
1~50%
2~84%
4~95%
8~98%

Operation Log