diff options
Diffstat (limited to 'zen/stl_tools.h')
| -rw-r--r-- | zen/stl_tools.h | 21 |
1 files changed, 16 insertions, 5 deletions
diff --git a/zen/stl_tools.h b/zen/stl_tools.h index b78dd5dd..058609e6 100644 --- a/zen/stl_tools.h +++ b/zen/stl_tools.h @@ -62,6 +62,7 @@ bool equal(InputIterator1 first1, InputIterator1 last1, InputIterator2 first2, InputIterator2 last2); size_t hashBytes(const unsigned char* ptr, size_t len); +size_t hashBytesAppend(size_t hashVal, const unsigned char* ptr, size_t len); //support for custom string classes in std::unordered_set/map @@ -216,20 +217,30 @@ size_t hashBytes(const unsigned char* ptr, size_t len) //http://en.wikipedia.org/wiki/Fowler%E2%80%93Noll%E2%80%93Vo_hash_function #ifdef ZEN_BUILD_32BIT const size_t basis = 2166136261U; - const size_t prime = 16777619U; #elif defined ZEN_BUILD_64BIT const size_t basis = 14695981039346656037ULL; +#endif + return hashBytesAppend(basis, ptr, len); +} + + +inline +size_t hashBytesAppend(size_t hashVal, const unsigned char* ptr, size_t len) +{ +#ifdef ZEN_BUILD_32BIT + const size_t prime = 16777619U; +#elif defined ZEN_BUILD_64BIT const size_t prime = 1099511628211ULL; #endif - size_t val = basis; for (size_t i = 0; i < len; ++i) { - val ^= static_cast<size_t>(ptr[i]); - val *= prime; + hashVal ^= static_cast<size_t>(ptr[i]); + hashVal *= prime; } - return val; + return hashVal; } + } #endif //STL_TOOLS_H_84567184321434 |