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| author | Henri Beauchamp <sldevel@users.noreply.github.com> | 2023-02-07 13:51:53 +0100 |
|---|---|---|
| committer | GitHub <noreply@github.com> | 2023-02-07 14:51:53 +0200 |
| commit | 1eb2b23f4b254052924b198d446c052df9ca3124 (patch) | |
| tree | 0693ffa2dd5bbc83f798cef02bc01d273c943fc3 /indra/llprimitive | |
| parent | 61b93e778bf58f6db4d2f3d8dd6ec67de25598ea (diff) | |
SL-19159 Faster LLUUID and LLMaterialID hashing for std and boost containers keys (#70)
LLUUID and LLMaterialID already have an excellent entropy and value dispersion; there is therefore strictly no need to further (slowly) hash their value for use with std and boost libraries containers.
This commit adds a trivial getDigest64() method to both LLUUID and LLMaterialID (which simply returns the XOR of the two 64 bits long words their value is made of), and uses it in std::hash and hash_value() specializations for use with containers.
Diffstat (limited to 'indra/llprimitive')
| -rw-r--r-- | indra/llprimitive/llmaterialid.h | 26 |
1 files changed, 26 insertions, 0 deletions
diff --git a/indra/llprimitive/llmaterialid.h b/indra/llprimitive/llmaterialid.h index ee663f8f99..c66e3e30a3 100644 --- a/indra/llprimitive/llmaterialid.h +++ b/indra/llprimitive/llmaterialid.h @@ -66,6 +66,14 @@ public: static const LLMaterialID null; + // Returns a 64 bits digest of the material Id, by XORing its two 64 bits + // long words. HB + inline U64 getDigest64() const + { + U64* tmp = (U64*)mID; + return tmp[0] ^ tmp[1]; + } + private: void parseFromBinary(const LLSD::Binary& pMaterialID); void copyFromOtherMaterialID(const LLMaterialID& pOtherMaterialID); @@ -74,5 +82,23 @@ private: U8 mID[MATERIAL_ID_SIZE]; } ; +// std::hash implementation for LLMaterialID +namespace std +{ + template<> struct hash<LLMaterialID> + { + inline size_t operator()(const LLMaterialID& id) const noexcept + { + return (size_t)id.getDigest64(); + } + }; +} + +// For use with boost containers. +inline size_t hash_value(const LLMaterialID& id) noexcept +{ + return (size_t)id.getDigest64(); +} + #endif // LL_LLMATERIALID_H |