X-Git-Url: http://plrg.eecs.uci.edu/git/?a=blobdiff_plain;ds=sidebyside;f=folly%2FHash.h;h=77ba5878f17e6502c0c89a0e2fbe42f8c4dc757f;hb=e9c1c0434713e921c98288e932c05f228a734886;hp=0def3efccb3a2f604fdd176bffca7d2ef6b5461b;hpb=58e3caa4522155d9e4ab9176f06682284ad9b6aa;p=folly.git diff --git a/folly/Hash.h b/folly/Hash.h index 0def3efc..77ba5878 100644 --- a/folly/Hash.h +++ b/folly/Hash.h @@ -1,5 +1,5 @@ /* - * Copyright 2015 Facebook, Inc. + * Copyright 2017 Facebook, Inc. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. @@ -14,11 +14,11 @@ * limitations under the License. */ -#ifndef FOLLY_BASE_HASH_H_ -#define FOLLY_BASE_HASH_H_ +#pragma once #include #include +#include #include #include #include @@ -215,8 +215,10 @@ 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; -inline uint32_t fnv32(const char* s, - uint32_t hash = FNV_32_HASH_START) { +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); + for (; *s; ++s) { hash += (hash << 1) + (hash << 4) + (hash << 7) + (hash << 8) + (hash << 24); @@ -245,8 +247,10 @@ 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); @@ -282,7 +286,7 @@ inline uint64_t fnv64(const std::string& str, inline uint32_t hsieh_hash32_buf(const void* buf, size_t len) { // forcing signed char, since other platforms can use unsigned - const signed char* s = reinterpret_cast(buf); + const unsigned char* s = reinterpret_cast(buf); uint32_t hash = static_cast(len); uint32_t tmp; size_t rem; @@ -362,6 +366,14 @@ struct Hash { } }; +template <> +struct hasher { + size_t operator()(bool key) const { + // Make sure that all the output bits depend on the input. + return key ? std::numeric_limits::max() : 0; + } +}; + template<> struct hasher { size_t operator()(int32_t key) const { return hash::jenkins_rev_mix32(uint32_t(key)); @@ -374,6 +386,38 @@ 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))); @@ -460,5 +504,3 @@ namespace std { } }; } // namespace std - -#endif