X-Git-Url: http://plrg.eecs.uci.edu/git/?a=blobdiff_plain;f=folly%2FHash.h;h=e8b75df377972be27b4673679c96fb18e7534061;hb=ebff31e4f6a2762a03cc98e9381f89534d685089;hp=e64633d2c8f552fb0a053d46497038bea382efda;hpb=b5e4bc034ee27308714f9fd7b3f1a6d5c75ac2bf;p=folly.git diff --git a/folly/Hash.h b/folly/Hash.h index e64633d2..e8b75df3 100644 --- a/folly/Hash.h +++ b/folly/Hash.h @@ -26,8 +26,8 @@ #include #include -#include -#include +#include +#include /* * Various hashing functions. @@ -214,9 +214,12 @@ inline uint32_t jenkins_rev_unmix32(uint32_t key) { const uint32_t FNV_32_HASH_START = 2166136261UL; const uint64_t FNV_64_HASH_START = 14695981039346656037ULL; +const uint64_t FNVA_64_HASH_START = 14695981039346656037ULL; + +inline uint32_t fnv32(const char* buf, uint32_t hash = FNV_32_HASH_START) { + // forcing signed char, since other platforms can use unsigned + const signed char* s = reinterpret_cast(buf); -inline uint32_t fnv32(const char* s, - uint32_t hash = FNV_32_HASH_START) { for (; *s; ++s) { hash += (hash << 1) + (hash << 4) + (hash << 7) + (hash << 8) + (hash << 24); @@ -245,8 +248,10 @@ inline uint32_t fnv32(const std::string& str, return fnv32_buf(str.data(), str.size(), hash); } -inline uint64_t fnv64(const char* s, - uint64_t hash = FNV_64_HASH_START) { +inline uint64_t fnv64(const char* buf, uint64_t hash = FNV_64_HASH_START) { + // forcing signed char, since other platforms can use unsigned + const signed char* s = reinterpret_cast(buf); + for (; *s; ++s) { hash += (hash << 1) + (hash << 4) + (hash << 5) + (hash << 7) + (hash << 8) + (hash << 40); @@ -274,6 +279,24 @@ inline uint64_t fnv64(const std::string& str, return fnv64_buf(str.data(), str.size(), hash); } +inline uint64_t fnva64_buf(const void* buf, + size_t n, + uint64_t hash = FNVA_64_HASH_START) { + const uint8_t* char_buf = reinterpret_cast(buf); + + for (size_t i = 0; i < n; ++i) { + hash ^= char_buf[i]; + hash += (hash << 1) + (hash << 4) + (hash << 5) + (hash << 7) + + (hash << 8) + (hash << 40); + } + return hash; +} + +inline uint64_t fnva64(const std::string& str, + uint64_t hash = FNVA_64_HASH_START) { + return fnva64_buf(str.data(), str.size(), hash); +} + /* * Paul Hsieh: http://www.azillionmonkeys.com/qed/hash.html */ @@ -382,6 +405,38 @@ template<> struct hasher { } }; +template<> struct hasher { + size_t operator()(int16_t key) const { + return hasher()(key); // as impl accident, sign-extends + } +}; + +template<> struct hasher { + size_t operator()(uint16_t key) const { + return hasher()(key); + } +}; + +template<> struct hasher { + size_t operator()(int8_t key) const { + return hasher()(key); // as impl accident, sign-extends + } +}; + +template<> struct hasher { + size_t operator()(uint8_t key) const { + return hasher()(key); + } +}; + +template<> struct hasher { + using explicit_type = + std::conditional::value, int8_t, uint8_t>::type; + size_t operator()(char key) const { + return hasher()(key); // as impl accident, sign-extends + } +}; + template<> struct hasher { size_t operator()(int64_t key) const { return static_cast(hash::twang_mix64(uint64_t(key)));