Summary: Originally: https://github.com/facebook/rocksdb/pull/87/files I'm taking over to apply some finishing touches Test Plan: will add tests Reviewers: dhruba, haobo, sdong, yhchiang, ljin Reviewed By: yhchiang CC: leveldb Differential Revision: https://reviews.facebook.net/D18315main
Igor Canadi
11 years ago
parent
61955a0dda
commit
0afc8bc29a
@ -0,0 +1,475 @@ |
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/*
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xxHash - Fast Hash algorithm |
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Copyright (C) 2012-2014, Yann Collet. |
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BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
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Redistribution and use in source and binary forms, with or without |
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modification, are permitted provided that the following conditions are |
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met: |
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* Redistributions of source code must retain the above copyright |
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notice, this list of conditions and the following disclaimer. |
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* Redistributions in binary form must reproduce the above |
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copyright notice, this list of conditions and the following disclaimer |
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in the documentation and/or other materials provided with the |
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distribution. |
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THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
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"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
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LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
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A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
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OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
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SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
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LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
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DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
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THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
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(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
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OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
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You can contact the author at : |
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- xxHash source repository : http://code.google.com/p/xxhash/
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*/ |
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//**************************************
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// Tuning parameters
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//**************************************
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// Unaligned memory access is automatically enabled for "common" CPU, such as x86.
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// For others CPU, the compiler will be more cautious, and insert extra code to ensure aligned access is respected.
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// If you know your target CPU supports unaligned memory access, you want to force this option manually to improve performance.
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// You can also enable this parameter if you know your input data will always be aligned (boundaries of 4, for U32).
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#if defined(__ARM_FEATURE_UNALIGNED) || defined(__i386) || defined(_M_IX86) || defined(__x86_64__) || defined(_M_X64) |
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# define XXH_USE_UNALIGNED_ACCESS 1 |
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#endif |
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// XXH_ACCEPT_NULL_INPUT_POINTER :
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// If the input pointer is a null pointer, xxHash default behavior is to trigger a memory access error, since it is a bad pointer.
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// When this option is enabled, xxHash output for null input pointers will be the same as a null-length input.
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// This option has a very small performance cost (only measurable on small inputs).
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// By default, this option is disabled. To enable it, uncomment below define :
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//#define XXH_ACCEPT_NULL_INPUT_POINTER 1
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// XXH_FORCE_NATIVE_FORMAT :
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// By default, xxHash library provides endian-independent Hash values, based on little-endian convention.
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// Results are therefore identical for little-endian and big-endian CPU.
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// This comes at a performance cost for big-endian CPU, since some swapping is required to emulate little-endian format.
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// Should endian-independance be of no importance for your application, you may set the #define below to 1.
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// It will improve speed for Big-endian CPU.
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// This option has no impact on Little_Endian CPU.
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#define XXH_FORCE_NATIVE_FORMAT 0 |
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//**************************************
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// Compiler Specific Options
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//**************************************
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// Disable some Visual warning messages
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#ifdef _MSC_VER // Visual Studio
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# pragma warning(disable : 4127) // disable: C4127: conditional expression is constant
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#endif |
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#ifdef _MSC_VER // Visual Studio
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# define FORCE_INLINE static __forceinline |
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#else |
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# ifdef __GNUC__ |
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# define FORCE_INLINE static inline __attribute__((always_inline)) |
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# else |
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# define FORCE_INLINE static inline |
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# endif |
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#endif |
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//**************************************
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// Includes & Memory related functions
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//**************************************
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#include "xxhash.h" |
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// Modify the local functions below should you wish to use some other memory related routines
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// for malloc(), free()
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#include <stdlib.h> |
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FORCE_INLINE void* XXH_malloc(size_t s) { return malloc(s); } |
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FORCE_INLINE void XXH_free (void* p) { free(p); } |
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// for memcpy()
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#include <string.h> |
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FORCE_INLINE void* XXH_memcpy(void* dest, const void* src, size_t size) { return memcpy(dest,src,size); } |
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//**************************************
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// Basic Types
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//**************************************
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#if defined (__STDC_VERSION__) && __STDC_VERSION__ >= 199901L // C99
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# include <stdint.h> |
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typedef uint8_t BYTE; |
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typedef uint16_t U16; |
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typedef uint32_t U32; |
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typedef int32_t S32; |
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typedef uint64_t U64; |
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#else |
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typedef unsigned char BYTE; |
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typedef unsigned short U16; |
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typedef unsigned int U32; |
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typedef signed int S32; |
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typedef unsigned long long U64; |
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#endif |
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#if defined(__GNUC__) && !defined(XXH_USE_UNALIGNED_ACCESS) |
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# define _PACKED __attribute__ ((packed)) |
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#else |
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# define _PACKED |
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#endif |
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#if !defined(XXH_USE_UNALIGNED_ACCESS) && !defined(__GNUC__) |
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# ifdef __IBMC__ |
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# pragma pack(1) |
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# else |
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# pragma pack(push, 1) |
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# endif |
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#endif |
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typedef struct _U32_S { U32 v; } _PACKED U32_S; |
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#if !defined(XXH_USE_UNALIGNED_ACCESS) && !defined(__GNUC__) |
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# pragma pack(pop) |
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#endif |
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#define A32(x) (((U32_S *)(x))->v) |
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//***************************************
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// Compiler-specific Functions and Macros
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//***************************************
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#define GCC_VERSION (__GNUC__ * 100 + __GNUC_MINOR__) |
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// Note : although _rotl exists for minGW (GCC under windows), performance seems poor
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#if defined(_MSC_VER) |
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# define XXH_rotl32(x,r) _rotl(x,r) |
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#else |
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# define XXH_rotl32(x,r) ((x << r) | (x >> (32 - r))) |
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#endif |
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#if defined(_MSC_VER) // Visual Studio
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# define XXH_swap32 _byteswap_ulong |
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#elif GCC_VERSION >= 403 |
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# define XXH_swap32 __builtin_bswap32 |
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#else |
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static inline U32 XXH_swap32 (U32 x) { |
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return ((x << 24) & 0xff000000 ) | |
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((x << 8) & 0x00ff0000 ) | |
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((x >> 8) & 0x0000ff00 ) | |
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((x >> 24) & 0x000000ff );} |
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#endif |
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//**************************************
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// Constants
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//**************************************
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#define PRIME32_1 2654435761U |
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#define PRIME32_2 2246822519U |
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#define PRIME32_3 3266489917U |
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#define PRIME32_4 668265263U |
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#define PRIME32_5 374761393U |
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//**************************************
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// Architecture Macros
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//**************************************
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typedef enum { XXH_bigEndian=0, XXH_littleEndian=1 } XXH_endianess; |
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#ifndef XXH_CPU_LITTLE_ENDIAN // It is possible to define XXH_CPU_LITTLE_ENDIAN externally, for example using a compiler switch
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static const int one = 1; |
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# define XXH_CPU_LITTLE_ENDIAN (*(char*)(&one)) |
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#endif |
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//**************************************
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// Macros
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//**************************************
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#define XXH_STATIC_ASSERT(c) { enum { XXH_static_assert = 1/(!!(c)) }; } // use only *after* variable declarations
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//****************************
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// Memory reads
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//****************************
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typedef enum { XXH_aligned, XXH_unaligned } XXH_alignment; |
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FORCE_INLINE U32 XXH_readLE32_align(const U32* ptr, XXH_endianess endian, XXH_alignment align) |
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{ |
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if (align==XXH_unaligned) |
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return endian==XXH_littleEndian ? A32(ptr) : XXH_swap32(A32(ptr)); |
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else |
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return endian==XXH_littleEndian ? *ptr : XXH_swap32(*ptr); |
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} |
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FORCE_INLINE U32 XXH_readLE32(const U32* ptr, XXH_endianess endian) { return XXH_readLE32_align(ptr, endian, XXH_unaligned); } |
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//****************************
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// Simple Hash Functions
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//****************************
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FORCE_INLINE U32 XXH32_endian_align(const void* input, int len, U32 seed, XXH_endianess endian, XXH_alignment align) |
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{ |
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const BYTE* p = (const BYTE*)input; |
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const BYTE* const bEnd = p + len; |
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U32 h32; |
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#ifdef XXH_ACCEPT_NULL_INPUT_POINTER |
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if (p==NULL) { len=0; p=(const BYTE*)(size_t)16; } |
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#endif |
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if (len>=16) |
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{ |
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const BYTE* const limit = bEnd - 16; |
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U32 v1 = seed + PRIME32_1 + PRIME32_2; |
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U32 v2 = seed + PRIME32_2; |
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U32 v3 = seed + 0; |
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U32 v4 = seed - PRIME32_1; |
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do |
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{ |
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v1 += XXH_readLE32_align((const U32*)p, endian, align) * PRIME32_2; v1 = XXH_rotl32(v1, 13); v1 *= PRIME32_1; p+=4; |
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v2 += XXH_readLE32_align((const U32*)p, endian, align) * PRIME32_2; v2 = XXH_rotl32(v2, 13); v2 *= PRIME32_1; p+=4; |
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v3 += XXH_readLE32_align((const U32*)p, endian, align) * PRIME32_2; v3 = XXH_rotl32(v3, 13); v3 *= PRIME32_1; p+=4; |
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v4 += XXH_readLE32_align((const U32*)p, endian, align) * PRIME32_2; v4 = XXH_rotl32(v4, 13); v4 *= PRIME32_1; p+=4; |
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} while (p<=limit); |
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h32 = XXH_rotl32(v1, 1) + XXH_rotl32(v2, 7) + XXH_rotl32(v3, 12) + XXH_rotl32(v4, 18); |
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} |
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else |
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{ |
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h32 = seed + PRIME32_5; |
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} |
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h32 += (U32) len; |
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while (p<=bEnd-4) |
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{ |
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h32 += XXH_readLE32_align((const U32*)p, endian, align) * PRIME32_3; |
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h32 = XXH_rotl32(h32, 17) * PRIME32_4 ; |
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p+=4; |
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} |
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while (p<bEnd) |
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{ |
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h32 += (*p) * PRIME32_5; |
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h32 = XXH_rotl32(h32, 11) * PRIME32_1 ; |
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p++; |
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} |
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h32 ^= h32 >> 15; |
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h32 *= PRIME32_2; |
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h32 ^= h32 >> 13; |
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h32 *= PRIME32_3; |
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h32 ^= h32 >> 16; |
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return h32; |
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} |
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U32 XXH32(const void* input, int len, U32 seed) |
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{ |
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#if 0 |
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// Simple version, good for code maintenance, but unfortunately slow for small inputs
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void* state = XXH32_init(seed); |
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XXH32_update(state, input, len); |
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return XXH32_digest(state); |
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#else |
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XXH_endianess endian_detected = (XXH_endianess)XXH_CPU_LITTLE_ENDIAN; |
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# if !defined(XXH_USE_UNALIGNED_ACCESS) |
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if ((((size_t)input) & 3)) // Input is aligned, let's leverage the speed advantage
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{ |
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if ((endian_detected==XXH_littleEndian) || XXH_FORCE_NATIVE_FORMAT) |
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return XXH32_endian_align(input, len, seed, XXH_littleEndian, XXH_aligned); |
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else |
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return XXH32_endian_align(input, len, seed, XXH_bigEndian, XXH_aligned); |
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} |
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# endif |
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if ((endian_detected==XXH_littleEndian) || XXH_FORCE_NATIVE_FORMAT) |
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return XXH32_endian_align(input, len, seed, XXH_littleEndian, XXH_unaligned); |
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else |
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return XXH32_endian_align(input, len, seed, XXH_bigEndian, XXH_unaligned); |
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#endif |
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} |
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//****************************
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// Advanced Hash Functions
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//****************************
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struct XXH_state32_t |
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{ |
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U64 total_len; |
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U32 seed; |
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U32 v1; |
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U32 v2; |
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U32 v3; |
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U32 v4; |
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int memsize; |
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char memory[16]; |
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}; |
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int XXH32_sizeofState() |
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{ |
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XXH_STATIC_ASSERT(XXH32_SIZEOFSTATE >= sizeof(struct XXH_state32_t)); // A compilation error here means XXH32_SIZEOFSTATE is not large enough
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return sizeof(struct XXH_state32_t); |
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} |
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XXH_errorcode XXH32_resetState(void* state_in, U32 seed) |
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{ |
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struct XXH_state32_t * state = (struct XXH_state32_t *) state_in; |
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state->seed = seed; |
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state->v1 = seed + PRIME32_1 + PRIME32_2; |
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state->v2 = seed + PRIME32_2; |
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state->v3 = seed + 0; |
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state->v4 = seed - PRIME32_1; |
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state->total_len = 0; |
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state->memsize = 0; |
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return XXH_OK; |
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} |
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void* XXH32_init (U32 seed) |
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{ |
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void* state = XXH_malloc (sizeof(struct XXH_state32_t)); |
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XXH32_resetState(state, seed); |
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return state; |
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} |
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FORCE_INLINE XXH_errorcode XXH32_update_endian (void* state_in, const void* input, int len, XXH_endianess endian) |
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{ |
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struct XXH_state32_t * state = (struct XXH_state32_t *) state_in; |
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const BYTE* p = (const BYTE*)input; |
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const BYTE* const bEnd = p + len; |
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#ifdef XXH_ACCEPT_NULL_INPUT_POINTER |
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if (input==NULL) return XXH_ERROR; |
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#endif |
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state->total_len += len; |
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if (state->memsize + len < 16) // fill in tmp buffer
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{ |
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XXH_memcpy(state->memory + state->memsize, input, len); |
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state->memsize += len; |
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return XXH_OK; |
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} |
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if (state->memsize) // some data left from previous update
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{ |
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XXH_memcpy(state->memory + state->memsize, input, 16-state->memsize); |
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{ |
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const U32* p32 = (const U32*)state->memory; |
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state->v1 += XXH_readLE32(p32, endian) * PRIME32_2; state->v1 = XXH_rotl32(state->v1, 13); state->v1 *= PRIME32_1; p32++; |
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state->v2 += XXH_readLE32(p32, endian) * PRIME32_2; state->v2 = XXH_rotl32(state->v2, 13); state->v2 *= PRIME32_1; p32++; |
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state->v3 += XXH_readLE32(p32, endian) * PRIME32_2; state->v3 = XXH_rotl32(state->v3, 13); state->v3 *= PRIME32_1; p32++; |
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state->v4 += XXH_readLE32(p32, endian) * PRIME32_2; state->v4 = XXH_rotl32(state->v4, 13); state->v4 *= PRIME32_1; p32++; |
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} |
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p += 16-state->memsize; |
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state->memsize = 0; |
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} |
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if (p <= bEnd-16) |
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{ |
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const BYTE* const limit = bEnd - 16; |
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U32 v1 = state->v1; |
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U32 v2 = state->v2; |
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U32 v3 = state->v3; |
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U32 v4 = state->v4; |
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do |
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{ |
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v1 += XXH_readLE32((const U32*)p, endian) * PRIME32_2; v1 = XXH_rotl32(v1, 13); v1 *= PRIME32_1; p+=4; |
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v2 += XXH_readLE32((const U32*)p, endian) * PRIME32_2; v2 = XXH_rotl32(v2, 13); v2 *= PRIME32_1; p+=4; |
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v3 += XXH_readLE32((const U32*)p, endian) * PRIME32_2; v3 = XXH_rotl32(v3, 13); v3 *= PRIME32_1; p+=4; |
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v4 += XXH_readLE32((const U32*)p, endian) * PRIME32_2; v4 = XXH_rotl32(v4, 13); v4 *= PRIME32_1; p+=4; |
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} while (p<=limit); |
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state->v1 = v1; |
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state->v2 = v2; |
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state->v3 = v3; |
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state->v4 = v4; |
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} |
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if (p < bEnd) |
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{ |
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XXH_memcpy(state->memory, p, bEnd-p); |
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state->memsize = (int)(bEnd-p); |
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} |
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return XXH_OK; |
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} |
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XXH_errorcode XXH32_update (void* state_in, const void* input, int len) |
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{ |
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XXH_endianess endian_detected = (XXH_endianess)XXH_CPU_LITTLE_ENDIAN; |
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if ((endian_detected==XXH_littleEndian) || XXH_FORCE_NATIVE_FORMAT) |
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return XXH32_update_endian(state_in, input, len, XXH_littleEndian); |
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else |
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return XXH32_update_endian(state_in, input, len, XXH_bigEndian); |
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} |
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FORCE_INLINE U32 XXH32_intermediateDigest_endian (void* state_in, XXH_endianess endian) |
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{ |
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struct XXH_state32_t * state = (struct XXH_state32_t *) state_in; |
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const BYTE * p = (const BYTE*)state->memory; |
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BYTE* bEnd = (BYTE*)state->memory + state->memsize; |
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U32 h32; |
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if (state->total_len >= 16) |
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{ |
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h32 = XXH_rotl32(state->v1, 1) + XXH_rotl32(state->v2, 7) + XXH_rotl32(state->v3, 12) + XXH_rotl32(state->v4, 18); |
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} |
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else |
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{ |
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h32 = state->seed + PRIME32_5; |
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} |
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h32 += (U32) state->total_len; |
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while (p<=bEnd-4) |
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{ |
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h32 += XXH_readLE32((const U32*)p, endian) * PRIME32_3; |
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h32 = XXH_rotl32(h32, 17) * PRIME32_4; |
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p+=4; |
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} |
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while (p<bEnd) |
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{ |
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h32 += (*p) * PRIME32_5; |
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h32 = XXH_rotl32(h32, 11) * PRIME32_1; |
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p++; |
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} |
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h32 ^= h32 >> 15; |
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h32 *= PRIME32_2; |
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h32 ^= h32 >> 13; |
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h32 *= PRIME32_3; |
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h32 ^= h32 >> 16; |
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return h32; |
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} |
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U32 XXH32_intermediateDigest (void* state_in) |
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{ |
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XXH_endianess endian_detected = (XXH_endianess)XXH_CPU_LITTLE_ENDIAN; |
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if ((endian_detected==XXH_littleEndian) || XXH_FORCE_NATIVE_FORMAT) |
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return XXH32_intermediateDigest_endian(state_in, XXH_littleEndian); |
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else |
||||
return XXH32_intermediateDigest_endian(state_in, XXH_bigEndian); |
||||
} |
||||
|
||||
|
||||
U32 XXH32_digest (void* state_in) |
||||
{ |
||||
U32 h32 = XXH32_intermediateDigest(state_in); |
||||
|
||||
XXH_free(state_in); |
||||
|
||||
return h32; |
||||
} |
||||
@ -0,0 +1,164 @@ |
||||
/*
|
||||
xxHash - Fast Hash algorithm |
||||
Header File |
||||
Copyright (C) 2012-2014, Yann Collet. |
||||
BSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php)
|
||||
|
||||
Redistribution and use in source and binary forms, with or without |
||||
modification, are permitted provided that the following conditions are |
||||
met: |
||||
|
||||
* Redistributions of source code must retain the above copyright |
||||
notice, this list of conditions and the following disclaimer. |
||||
* Redistributions in binary form must reproduce the above |
||||
copyright notice, this list of conditions and the following disclaimer |
||||
in the documentation and/or other materials provided with the |
||||
distribution. |
||||
|
||||
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
||||
"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
||||
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
||||
A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
||||
OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
||||
SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
||||
LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
||||
DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
||||
THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
||||
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
||||
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
||||
|
||||
You can contact the author at : |
||||
- xxHash source repository : http://code.google.com/p/xxhash/
|
||||
*/ |
||||
|
||||
/* Notice extracted from xxHash homepage :
|
||||
|
||||
xxHash is an extremely fast Hash algorithm, running at RAM speed limits. |
||||
It also successfully passes all tests from the SMHasher suite. |
||||
|
||||
Comparison (single thread, Windows Seven 32 bits, using SMHasher on a Core 2 Duo @3GHz) |
||||
|
||||
Name Speed Q.Score Author |
||||
xxHash 5.4 GB/s 10 |
||||
CrapWow 3.2 GB/s 2 Andrew |
||||
MumurHash 3a 2.7 GB/s 10 Austin Appleby |
||||
SpookyHash 2.0 GB/s 10 Bob Jenkins |
||||
SBox 1.4 GB/s 9 Bret Mulvey |
||||
Lookup3 1.2 GB/s 9 Bob Jenkins |
||||
SuperFastHash 1.2 GB/s 1 Paul Hsieh |
||||
CityHash64 1.05 GB/s 10 Pike & Alakuijala |
||||
FNV 0.55 GB/s 5 Fowler, Noll, Vo |
||||
CRC32 0.43 GB/s 9 |
||||
MD5-32 0.33 GB/s 10 Ronald L. Rivest |
||||
SHA1-32 0.28 GB/s 10 |
||||
|
||||
Q.Score is a measure of quality of the hash function. |
||||
It depends on successfully passing SMHasher test set. |
||||
10 is a perfect score. |
||||
*/ |
||||
|
||||
#pragma once |
||||
|
||||
#if defined (__cplusplus) |
||||
extern "C" { |
||||
#endif |
||||
|
||||
|
||||
//****************************
|
||||
// Type
|
||||
//****************************
|
||||
typedef enum { XXH_OK=0, XXH_ERROR } XXH_errorcode; |
||||
|
||||
|
||||
|
||||
//****************************
|
||||
// Simple Hash Functions
|
||||
//****************************
|
||||
|
||||
unsigned int XXH32 (const void* input, int len, unsigned int seed); |
||||
|
||||
/*
|
||||
XXH32() : |
||||
Calculate the 32-bits hash of sequence of length "len" stored at memory address "input". |
||||
The memory between input & input+len must be valid (allocated and read-accessible). |
||||
"seed" can be used to alter the result predictably. |
||||
This function successfully passes all SMHasher tests. |
||||
Speed on Core 2 Duo @ 3 GHz (single thread, SMHasher benchmark) : 5.4 GB/s |
||||
Note that "len" is type "int", which means it is limited to 2^31-1. |
||||
If your data is larger, use the advanced functions below. |
||||
*/ |
||||
|
||||
|
||||
|
||||
//****************************
|
||||
// Advanced Hash Functions
|
||||
//****************************
|
||||
|
||||
void* XXH32_init (unsigned int seed); |
||||
XXH_errorcode XXH32_update (void* state, const void* input, int len); |
||||
unsigned int XXH32_digest (void* state); |
||||
|
||||
/*
|
||||
These functions calculate the xxhash of an input provided in several small packets, |
||||
as opposed to an input provided as a single block. |
||||
|
||||
It must be started with : |
||||
void* XXH32_init() |
||||
The function returns a pointer which holds the state of calculation. |
||||
|
||||
This pointer must be provided as "void* state" parameter for XXH32_update(). |
||||
XXH32_update() can be called as many times as necessary. |
||||
The user must provide a valid (allocated) input. |
||||
The function returns an error code, with 0 meaning OK, and any other value meaning there is an error. |
||||
Note that "len" is type "int", which means it is limited to 2^31-1. |
||||
If your data is larger, it is recommended to chunk your data into blocks |
||||
of size for example 2^30 (1GB) to avoid any "int" overflow issue. |
||||
|
||||
Finally, you can end the calculation anytime, by using XXH32_digest(). |
||||
This function returns the final 32-bits hash. |
||||
You must provide the same "void* state" parameter created by XXH32_init(). |
||||
Memory will be freed by XXH32_digest(). |
||||
*/ |
||||
|
||||
|
||||
int XXH32_sizeofState(); |
||||
XXH_errorcode XXH32_resetState(void* state, unsigned int seed); |
||||
|
||||
#define XXH32_SIZEOFSTATE 48 |
||||
typedef struct { long long ll[(XXH32_SIZEOFSTATE+(sizeof(long long)-1))/sizeof(long long)]; } XXH32_stateSpace_t; |
||||
/*
|
||||
These functions allow user application to make its own allocation for state. |
||||
|
||||
XXH32_sizeofState() is used to know how much space must be allocated for the xxHash 32-bits state. |
||||
Note that the state must be aligned to access 'long long' fields. Memory must be allocated and referenced by a pointer. |
||||
This pointer must then be provided as 'state' into XXH32_resetState(), which initializes the state. |
||||
|
||||
For static allocation purposes (such as allocation on stack, or freestanding systems without malloc()), |
||||
use the structure XXH32_stateSpace_t, which will ensure that memory space is large enough and correctly aligned to access 'long long' fields. |
||||
*/ |
||||
|
||||
|
||||
unsigned int XXH32_intermediateDigest (void* state); |
||||
/*
|
||||
This function does the same as XXH32_digest(), generating a 32-bit hash, |
||||
but preserve memory context. |
||||
This way, it becomes possible to generate intermediate hashes, and then continue feeding data with XXH32_update(). |
||||
To free memory context, use XXH32_digest(), or free(). |
||||
*/ |
||||
|
||||
|
||||
|
||||
//****************************
|
||||
// Deprecated function names
|
||||
//****************************
|
||||
// The following translations are provided to ease code transition
|
||||
// You are encouraged to no longer this function names
|
||||
#define XXH32_feed XXH32_update |
||||
#define XXH32_result XXH32_digest |
||||
#define XXH32_getIntermediateResult XXH32_intermediateDigest |
||||
|
||||
|
||||
|
||||
#if defined (__cplusplus) |
||||
} |
||||
#endif |
||||
Loading…
Reference in new issue