go__cache/docs/hash.md

Hash logic

Keys are hashed.

Memcached hashes

Memcached itself uses either:

• Jenkins hash
  • http://burtleburtle.net/bob/hash/doobs.html
  • http://burtleburtle.net/bob/c/lookup3.c Public domain.
• Murmur 3 hash
  • Murmur 3 in Go

Golang

Beyond the Go ports of these hashes, Go includes native alternatives:

• Jenkins hash
  • https://github.com/mtchavez/jenkins MIT license.
  • https://github.com/tsaost/bjh port of lookup3.c. BSD license.
  • https://github.com/Apsalar/lookup3 hashlittle() from lookup3.c. Optimized for compatibility/portability, not for performance. Implements hash.Hash32. Public domain.
  • https://github.com/MstrVLT/lookup3/ port of lookup3.c. License undefined.
• Murmur 3:
  • https://github.com/reusee/mmh3 MIT license.
  • https://github.com/huichen/murmur APL 2.0 license.
  • https://github.com/go-ego/murmur APL 2.0 license. Based on huichen's version.
  • https://github.com/beevik/murmur License undefined.
  • https://github.com/ericx10ng/murmurhash2-go License undefined: was MIT but got removed.
• xxhash:
  • https://github.com/vova616/xxhash/blob/master/xxhash.go (not ARM-compatible). MIT license.
• Golang standard library hashes:
  • hash/adler32
    • https://golang.org/pkg/hash/adler32/
  • hash/crc32
    • https://golang.org/pkg/hash/crc32/
    • The Castagnoli polynomial may be hardware-accelerated on post-Nehalem CPUs compiled with 6g (https://stackoverflow.com/questions/23436358/bob-jenkins-hash-getting-bad-performance)
  • hash/crc64:
    • https://golang.org/pkg/hash/crc64/
  • hash/fnv:
    • https://golang.org/pkg/hash/fnv/
• Golang crypto package includes many cryptographic hashed with optimized implementations too. Most interesting are probably MD5 and SHA1
  • AES (Rijndael),
  • Cipher package provides bloc cipher modes around low-level ciphers, no specific hashes.
  • DES (DIPS 46-3)
  • DSA (FIPS 186-3)
  • ECDSA (FIPS 186-3)
  • Elliptic package doesn't directly apply
  • HMAC
  • MD5 (RFC 1321)
  • rand package doesn't directly apply
  • RC4, RSA provide encryption, don't directly apply
  • SHA1 (RFC 3174). Reported to be as fast as a Jenkins hash, but may not has optimal distribution properties
  • SHA-256, SHA-384, SHA512, SHA512-224, SHA-512/256 (FIPC 180-4)
  • subtle package doesn't directly apply
  • TLS 1.2, doesn't directly apply
  • X.509, doesn't directly apply