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50 lines
982 B
C
50 lines
982 B
C
#ifndef _SCOUTFS_HASH_H_
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#define _SCOUTFS_HASH_H_
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/*
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* We're using FNV1a for now. It's fine. Ish.
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*
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* The longer term plan is xxh3 but it looks like it'll take just a bit
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* more time to be declared stable and then it needs to be ported to the
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* kernel.
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*
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* - https://fastcompression.blogspot.com/2019/03/presenting-xxh3.html
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* - https://github.com/Cyan4973/xxHash/releases/tag/v0.7.4
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*/
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static inline u32 fnv1a32(const void *data, unsigned int len)
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{
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u32 hash = 0x811c9dc5;
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while (len--) {
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hash ^= *(u8 *)(data++);
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hash *= 0x01000193;
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}
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return hash;
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}
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static inline u64 fnv1a64(const void *data, unsigned int len)
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{
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u64 hash = 0xcbf29ce484222325ULL;
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while (len--) {
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hash ^= *(u8 *)(data++);
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hash *= 0x100000001b3ULL;
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}
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return hash;
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}
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static inline u32 scoutfs_hash32(const void *data, unsigned int len)
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{
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return fnv1a32(data, len);
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}
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static inline u64 scoutfs_hash64(const void *data, unsigned int len)
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{
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return fnv1a64(data, len);
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}
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#endif
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