wizapp-stdlib/documents/hash_tables_refs.md

Hash Tables References

SwissTable

• Designing a Fast, Efficient, Cache-friendly Hash Table, Step by Step
• Abseil blog announcement
• Abseil design notes
• Faultlore hashbrown-TLDR
• hashbrown source
• Faster Go maps with Swiss Tables

64-bit hash from 128-bit hash

MurmurHash3 and SipHash return 128 bits. SwissTable expects 64 bits. XOR folding is the approach to use:

uint64_t fold_128_to_64(uint128_t hash) {
    return (uint64_t)(hash >> 64) ^ (uint64_t)(hash & 0xFFFFFFFFFFFFFFFF);
}

Robin Hood

• Celis (1986) — original paper proving O(1) variance, Θ(log n) max probe
• Gankra/Faultlore — clearest walkthrough from first principles
• Sebastian Sylvan — popularized Robin Hood in systems programming
• Emmanuel Goossaert — detailed C++ implementation + backward-shift deletion
• Martinus (Ankerl) — most widely used C++ implementation
• Tessil — clean header-only C++ implementation
• Malte Skarupke — Robin Hood with probe count limit

Robin Hood vs SwissTable

• Rust migration PR
• hashbrown deletion discussion
• Jackson Allan benchmark
• Richter et al. (VLDB 2015)
• Poblete & Viola (2018)

Double Hashing

• Knuth, TAOCP Vol. 3 §6.4 — definitive analysis of double hashing probe counts
• Guibas & Szemerédi (1978) — proved double hashing is asymptotically equivalent to uniform probing
• Heileman & Luo (2005) — "How Caching Affects Hashing" — cache-aware experimental comparison
• VT Hashing Tutorial — excellent pedagogical walkthrough
• Paul Khuong — "The Other Robin Hood Hashing" (original Celis double-hashing variant)