/* Copyright (c) 2011 Google, Inc. */ /* */ /* Permission is hereby granted, free of charge, to any person obtaining a copy */ /* of this software and associated documentation files (the "Software"), to deal */ /* in the Software without restriction, including without limitation the rights */ /* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell */ /* copies of the Software, and to permit persons to whom the Software is */ /* furnished to do so, subject to the following conditions: */ /* */ /* The above copyright notice and this permission notice shall be included in */ /* all copies or substantial portions of the Software. */ /* */ /* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR */ /* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, */ /* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE */ /* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER */ /* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, */ /* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN */ /* THE SOFTWARE. */ /* */ /* CityHash, by Geoff Pike and Jyrki Alakuijala */ /* */ /* This file provides a few functions for hashing strings. On x86-64 */ /* hardware in 2011, CityHash64() is faster than other high-quality */ /* hash functions, such as Murmur. This is largely due to higher */ /* instruction-level parallelism. CityHash64() and CityHash128() also perform */ /* well on hash-quality tests. */ /* */ /* CityHash128() is optimized for relatively long strings and returns */ /* a 128-bit hash. For strings more than about 2000 bytes it can be */ /* faster than CityHash64(). */ /* */ /* Functions in the CityHash family are not suitable for cryptography. */ /* */ /* WARNING: This code has not been tested on big-endian platforms! */ /* It is known to work well on little-endian platforms that have a small penalty */ /* for unaligned reads, such as current Intel and AMD moderate-to-high-end CPUs. */ /* */ /* By the way, for some hash functions, given strings a and b, the hash */ /* of a+b is easily derived from the hashes of a and b. This property */ /* doesn't hold for any hash functions in this file. */ #ifndef CITY_HASH_H_ # define CITY_HASH_H_ # include # ifdef _MSC_VER typedef unsigned char uint8; typedef unsigned int uint32; typedef unsigned long long uint64; # else # include typedef uint8_t uint8; typedef uint32_t uint32; typedef uint64_t uint64; # endif # ifdef __cplusplus extern "C" { # endif # pragma pack(1) typedef struct { uint64 first, second; } uint128; # pragma pack() # define Uint128Low64(x) ((x).first) # define Uint128High64(x) ((x).second) /* Hash function for a byte array. */ uint64 CityHash64(const char *buf, size_t len); /* Hash function for a byte array. For convenience, a 64-bit seed is also */ /* hashed into the result. */ uint64 CityHash64WithSeed(const char *buf, size_t len, uint64 seed); /* Hash function for a byte array. For convenience, two seeds are also */ /* hashed into the result. */ uint64 CityHash64WithSeeds(const char *buf, size_t len, uint64 seed0, uint64 seed1); /* Hash function for a byte array. */ uint128 CityHash128(const char *s, size_t len); /* Hash function for a byte array. For convenience, a 128-bit seed is also */ /* hashed into the result. */ uint128 CityHash128WithSeed(const char *s, size_t len, uint128 seed); # ifdef __cplusplus } # endif #endif /* CITY_HASH_H_ */