xxHash
An extremely fast non-cryptographic hash algorithm that processes data at RAM speed limits.
What is xxHash?
xxHash is an extremely fast non-cryptographic hash algorithm that processes data at RAM speed limits. It provides high-performance hashing for applications requiring fast data integrity checks, hash tables, and bloom filters, with variants offering 32-bit, 64-bit, and 128-bit hash outputs. The algorithm is designed to be portable and produce identical results across different platforms.
Developers and engineers working on performance-critical applications such as databases, file systems, network protocols, and data processing pipelines that require fast hashing without cryptographic security.
xxHash offers unparalleled speed, often exceeding RAM bandwidth, while maintaining high-quality hash properties verified by SMHasher tests. Its portability and optimization for both large and small data make it a superior choice over slower alternatives like CityHash, MurmurHash, or cryptographic hashes.
Overview
Extremely fast non-cryptographic hash algorithm
Use Cases
Best For
- High-performance hash tables and bloom filters
- Data deduplication and integrity checking in storage systems
- Network protocol checksums where speed is critical
- Database indexing and key hashing
- Real-time data processing pipelines
- Benchmarking and comparing hash algorithm performance
Not Ideal For
- Cryptographic applications such as password hashing or digital signatures
- Systems requiring formal security proofs or resistance to cryptographic attacks
- Projects where hash function stability must be guaranteed across all future library versions without any breaking changes
Pros & Cons
Pros
Benchmarks show XXH3 processing at 31.5 GB/s, exceeding RAM sequential read speeds, making it ideal for high-throughput data processing.
Passes the SMHasher test suite ensuring excellent dispersion and minimal collisions, with additional massive collision tests verifying robustness.
Designed with low latency on small inputs, as evidenced by performance graphs, beneficial for hash tables and bloom filters.
Produces identical hash values regardless of endianness, ensuring consistency across different systems without platform-specific adjustments.
Cons
Lacks cryptographic properties like resistance to preimage or collision attacks, making it unsuitable for security-sensitive applications.
Requires managing numerous macros such as XXH_VECTOR and XXH_INLINE_ALL for optimal performance, which can be overwhelming and error-prone.
XXH3 significantly increases library size, necessitating the use of flags like XXH_NO_XXH3 for size-constrained environments, adding compilation overhead.
Frequently Asked Questions
Related Projects
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