xxhash.c revision 318482
1299425Smm/* 2299425SmmxxHash - Fast Hash algorithm 3299425SmmCopyright (C) 2012-2014, Yann Collet. 4299425SmmBSD 2-Clause License (http://www.opensource.org/licenses/bsd-license.php) 5299425Smm 6299425SmmRedistribution and use in source and binary forms, with or without 7299425Smmmodification, are permitted provided that the following conditions are 8299425Smmmet: 9299425Smm 10299425Smm* Redistributions of source code must retain the above copyright 11299425Smmnotice, this list of conditions and the following disclaimer. 12299425Smm* Redistributions in binary form must reproduce the above 13299425Smmcopyright notice, this list of conditions and the following disclaimer 14299425Smmin the documentation and/or other materials provided with the 15299425Smmdistribution. 16299425Smm 17299425SmmTHIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 18299425Smm"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 19299425SmmLIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 20299425SmmA PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 21299425SmmOWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 22299425SmmSPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 23299425SmmLIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 24299425SmmDATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 25299425SmmTHEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 26299425Smm(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 27299425SmmOF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 28299425Smm 29299425SmmYou can contact the author at : 30299425Smm- xxHash source repository : http://code.google.com/p/xxhash/ 31299425Smm*/ 32313570Smm#include "archive_platform.h" 33313570Smm 34299425Smm#include <stdlib.h> 35299425Smm#include <string.h> 36299425Smm 37299425Smm#include "archive_xxhash.h" 38299425Smm 39299425Smm#ifdef HAVE_LIBLZ4 40299425Smm 41299425Smm/*************************************** 42299425Smm** Tuning parameters 43299425Smm****************************************/ 44299425Smm/* Unaligned memory access is automatically enabled for "common" CPU, such as x86. 45299425Smm** For others CPU, the compiler will be more cautious, and insert extra code to ensure aligned access is respected. 46299425Smm** If you know your target CPU supports unaligned memory access, you want to force this option manually to improve performance. 47299425Smm** You can also enable this parameter if you know your input data will always be aligned (boundaries of 4, for U32). 48299425Smm*/ 49299425Smm#if defined(__ARM_FEATURE_UNALIGNED) || defined(__i386) || defined(_M_IX86) || defined(__x86_64__) || defined(_M_X64) 50299425Smm# define XXH_USE_UNALIGNED_ACCESS 1 51299425Smm#endif 52299425Smm 53299425Smm/* XXH_ACCEPT_NULL_INPUT_POINTER : 54299425Smm** If the input pointer is a null pointer, xxHash default behavior is to trigger a memory access error, since it is a bad pointer. 55299425Smm** When this option is enabled, xxHash output for null input pointers will be the same as a null-length input. 56299425Smm** This option has a very small performance cost (only measurable on small inputs). 57299425Smm** By default, this option is disabled. To enable it, uncomment below define : 58299425Smm** #define XXH_ACCEPT_NULL_INPUT_POINTER 1 59299425Smm 60299425Smm** XXH_FORCE_NATIVE_FORMAT : 61299425Smm** By default, xxHash library provides endian-independent Hash values, based on little-endian convention. 62299425Smm** Results are therefore identical for little-endian and big-endian CPU. 63299425Smm** This comes at a performance cost for big-endian CPU, since some swapping is required to emulate little-endian format. 64313570Smm** Should endian-independence be of no importance for your application, you may set the #define below to 1. 65299425Smm** It will improve speed for Big-endian CPU. 66299425Smm** This option has no impact on Little_Endian CPU. 67299425Smm*/ 68299425Smm#define XXH_FORCE_NATIVE_FORMAT 0 69299425Smm 70299425Smm/*************************************** 71299425Smm** Compiler Specific Options 72299425Smm****************************************/ 73299425Smm/* Disable some Visual warning messages */ 74299425Smm#ifdef _MSC_VER /* Visual Studio */ 75299425Smm# pragma warning(disable : 4127) /* disable: C4127: conditional expression is constant */ 76299425Smm#endif 77299425Smm 78299425Smm#ifdef _MSC_VER /* Visual Studio */ 79299425Smm# define FORCE_INLINE __forceinline 80299425Smm#else 81299425Smm# ifdef __GNUC__ 82299425Smm# define FORCE_INLINE inline __attribute__((always_inline)) 83299425Smm# else 84299425Smm# define FORCE_INLINE inline 85299425Smm# endif 86299425Smm#endif 87299425Smm 88299425Smm/*************************************** 89299425Smm** Includes & Memory related functions 90299425Smm****************************************/ 91299425Smm#define XXH_malloc malloc 92299425Smm#define XXH_free free 93299425Smm#define XXH_memcpy memcpy 94299425Smm 95299425Smm 96299425Smmstatic unsigned int XXH32 (const void*, unsigned int, unsigned int); 97299425Smmstatic void* XXH32_init (unsigned int); 98299425Smmstatic XXH_errorcode XXH32_update (void*, const void*, unsigned int); 99299425Smmstatic unsigned int XXH32_digest (void*); 100299425Smm/*static int XXH32_sizeofState(void);*/ 101299425Smmstatic XXH_errorcode XXH32_resetState(void*, unsigned int); 102299425Smm#define XXH32_SIZEOFSTATE 48 103299425Smmtypedef struct { long long ll[(XXH32_SIZEOFSTATE+(sizeof(long long)-1))/sizeof(long long)]; } XXH32_stateSpace_t; 104299425Smmstatic unsigned int XXH32_intermediateDigest (void*); 105299425Smm 106299425Smm/*************************************** 107299425Smm** Basic Types 108299425Smm****************************************/ 109299425Smm#if defined (__STDC_VERSION__) && __STDC_VERSION__ >= 199901L /* C99 */ 110299425Smm# include <stdint.h> 111299425Smm typedef uint8_t BYTE; 112299425Smm typedef uint16_t U16; 113299425Smm typedef uint32_t U32; 114299425Smm typedef int32_t S32; 115299425Smm typedef uint64_t U64; 116299425Smm#else 117299425Smm typedef unsigned char BYTE; 118299425Smm typedef unsigned short U16; 119299425Smm typedef unsigned int U32; 120299425Smm typedef signed int S32; 121299425Smm typedef unsigned long long U64; 122299425Smm#endif 123299425Smm 124299425Smm#if defined(__GNUC__) && !defined(XXH_USE_UNALIGNED_ACCESS) 125299425Smm# define _PACKED __attribute__ ((packed)) 126299425Smm#else 127299425Smm# define _PACKED 128299425Smm#endif 129299425Smm 130299425Smm#if !defined(XXH_USE_UNALIGNED_ACCESS) && !defined(__GNUC__) 131299425Smm# ifdef __IBMC__ 132299425Smm# pragma pack(1) 133299425Smm# else 134299425Smm# pragma pack(push, 1) 135299425Smm# endif 136299425Smm#endif 137299425Smm 138299425Smmtypedef struct _U32_S { U32 v; } _PACKED U32_S; 139299425Smm 140299425Smm#if !defined(XXH_USE_UNALIGNED_ACCESS) && !defined(__GNUC__) 141299425Smm# pragma pack(pop) 142299425Smm#endif 143299425Smm 144299425Smm 145299425Smm/**************************************** 146299425Smm** Compiler-specific Functions and Macros 147299425Smm*****************************************/ 148318482Smm#define GCC_VERSION ((__GNUC__-0) * 100 + (__GNUC_MINOR__ - 0)) 149299425Smm 150318482Smm#if GCC_VERSION >= 409 151318482Smm__attribute__((__no_sanitize_undefined__)) 152318482Smm#endif 153318482Smmstatic inline U32 A32(const void * x) 154318482Smm{ 155318482Smm return (((const U32_S *)(x))->v); 156318482Smm} 157318482Smm 158299425Smm/* Note : although _rotl exists for minGW (GCC under windows), performance seems poor */ 159299425Smm#if defined(_MSC_VER) 160299425Smm# define XXH_rotl32(x,r) _rotl(x,r) 161299425Smm#else 162299425Smm# define XXH_rotl32(x,r) ((x << r) | (x >> (32 - r))) 163299425Smm#endif 164299425Smm 165299425Smm#if defined(_MSC_VER) /* Visual Studio */ 166299425Smm# define XXH_swap32 _byteswap_ulong 167299425Smm#elif GCC_VERSION >= 403 168299425Smm# define XXH_swap32 __builtin_bswap32 169299425Smm#else 170299425Smmstatic inline U32 XXH_swap32 (U32 x) { 171299425Smm return ((x << 24) & 0xff000000 ) | 172299425Smm ((x << 8) & 0x00ff0000 ) | 173299425Smm ((x >> 8) & 0x0000ff00 ) | 174299425Smm ((x >> 24) & 0x000000ff );} 175299425Smm#endif 176299425Smm 177299425Smm 178299425Smm/*************************************** 179299425Smm** Constants 180299425Smm****************************************/ 181299425Smm#define PRIME32_1 2654435761U 182299425Smm#define PRIME32_2 2246822519U 183299425Smm#define PRIME32_3 3266489917U 184299425Smm#define PRIME32_4 668265263U 185299425Smm#define PRIME32_5 374761393U 186299425Smm 187299425Smm 188299425Smm/*************************************** 189299425Smm** Architecture Macros 190299425Smm****************************************/ 191299425Smmtypedef enum { XXH_bigEndian=0, XXH_littleEndian=1 } XXH_endianess; 192299425Smm#ifndef XXH_CPU_LITTLE_ENDIAN /* It is possible to define XXH_CPU_LITTLE_ENDIAN externally, for example using a compiler switch */ 193299425Smm static const int one = 1; 194299425Smm# define XXH_CPU_LITTLE_ENDIAN (*(const char*)(&one)) 195299425Smm#endif 196299425Smm 197299425Smm 198299425Smm/*************************************** 199299425Smm** Macros 200299425Smm****************************************/ 201299425Smm#define XXH_STATIC_ASSERT(c) { enum { XXH_static_assert = 1/(!!(c)) }; } /* use only *after* variable declarations */ 202299425Smm 203299425Smm 204299425Smm/***************************** 205299425Smm** Memory reads 206299425Smm******************************/ 207299425Smmtypedef enum { XXH_aligned, XXH_unaligned } XXH_alignment; 208299425Smm 209299425Smmstatic 210299425SmmFORCE_INLINE U32 XXH_readLE32_align(const U32* ptr, XXH_endianess endian, XXH_alignment align) 211299425Smm{ 212299425Smm if (align==XXH_unaligned) 213299425Smm return endian==XXH_littleEndian ? A32(ptr) : XXH_swap32(A32(ptr)); 214299425Smm else 215299425Smm return endian==XXH_littleEndian ? *ptr : XXH_swap32(*ptr); 216299425Smm} 217299425Smm 218299425Smmstatic 219299425SmmFORCE_INLINE U32 XXH_readLE32(const U32* ptr, XXH_endianess endian) { return XXH_readLE32_align(ptr, endian, XXH_unaligned); } 220299425Smm 221299425Smm 222299425Smm/***************************** 223299425Smm** Simple Hash Functions 224299425Smm******************************/ 225299425Smmstatic 226299425SmmFORCE_INLINE U32 XXH32_endian_align(const void* input, unsigned int len, U32 seed, XXH_endianess endian, XXH_alignment align) 227299425Smm{ 228299425Smm const BYTE* p = (const BYTE*)input; 229299425Smm const BYTE* bEnd = p + len; 230299425Smm U32 h32; 231299425Smm#define XXH_get32bits(p) XXH_readLE32_align((const U32*)p, endian, align) 232299425Smm 233299425Smm#ifdef XXH_ACCEPT_NULL_INPUT_POINTER 234299425Smm if (p==NULL) { len=0; bEnd=p=(const BYTE*)(size_t)16; } 235299425Smm#endif 236299425Smm 237299425Smm if (len>=16) 238299425Smm { 239299425Smm const BYTE* const limit = bEnd - 16; 240299425Smm U32 v1 = seed + PRIME32_1 + PRIME32_2; 241299425Smm U32 v2 = seed + PRIME32_2; 242299425Smm U32 v3 = seed + 0; 243299425Smm U32 v4 = seed - PRIME32_1; 244299425Smm 245299425Smm do 246299425Smm { 247299425Smm v1 += XXH_get32bits(p) * PRIME32_2; v1 = XXH_rotl32(v1, 13); v1 *= PRIME32_1; p+=4; 248299425Smm v2 += XXH_get32bits(p) * PRIME32_2; v2 = XXH_rotl32(v2, 13); v2 *= PRIME32_1; p+=4; 249299425Smm v3 += XXH_get32bits(p) * PRIME32_2; v3 = XXH_rotl32(v3, 13); v3 *= PRIME32_1; p+=4; 250299425Smm v4 += XXH_get32bits(p) * PRIME32_2; v4 = XXH_rotl32(v4, 13); v4 *= PRIME32_1; p+=4; 251299425Smm } while (p<=limit); 252299425Smm 253299425Smm h32 = XXH_rotl32(v1, 1) + XXH_rotl32(v2, 7) + XXH_rotl32(v3, 12) + XXH_rotl32(v4, 18); 254299425Smm } 255299425Smm else 256299425Smm { 257299425Smm h32 = seed + PRIME32_5; 258299425Smm } 259299425Smm 260299425Smm h32 += (U32) len; 261299425Smm 262299425Smm while (p<=bEnd-4) 263299425Smm { 264299425Smm h32 += XXH_get32bits(p) * PRIME32_3; 265299425Smm h32 = XXH_rotl32(h32, 17) * PRIME32_4 ; 266299425Smm p+=4; 267299425Smm } 268299425Smm 269299425Smm while (p<bEnd) 270299425Smm { 271299425Smm h32 += (*p) * PRIME32_5; 272299425Smm h32 = XXH_rotl32(h32, 11) * PRIME32_1 ; 273299425Smm p++; 274299425Smm } 275299425Smm 276299425Smm h32 ^= h32 >> 15; 277299425Smm h32 *= PRIME32_2; 278299425Smm h32 ^= h32 >> 13; 279299425Smm h32 *= PRIME32_3; 280299425Smm h32 ^= h32 >> 16; 281299425Smm 282299425Smm return h32; 283299425Smm} 284299425Smm 285299425Smm 286299425SmmU32 XXH32(const void* input, unsigned int len, U32 seed) 287299425Smm{ 288299425Smm#if 0 289299425Smm // Simple version, good for code maintenance, but unfortunately slow for small inputs 290299425Smm void* state = XXH32_init(seed); 291299425Smm XXH32_update(state, input, len); 292299425Smm return XXH32_digest(state); 293299425Smm#else 294299425Smm XXH_endianess endian_detected = (XXH_endianess)XXH_CPU_LITTLE_ENDIAN; 295299425Smm 296299425Smm# if !defined(XXH_USE_UNALIGNED_ACCESS) 297299425Smm if ((((size_t)input) & 3) == 0) /* Input is aligned, let's leverage the speed advantage */ 298299425Smm { 299299425Smm if ((endian_detected==XXH_littleEndian) || XXH_FORCE_NATIVE_FORMAT) 300299425Smm return XXH32_endian_align(input, len, seed, XXH_littleEndian, XXH_aligned); 301299425Smm else 302299425Smm return XXH32_endian_align(input, len, seed, XXH_bigEndian, XXH_aligned); 303299425Smm } 304299425Smm# endif 305299425Smm 306299425Smm if ((endian_detected==XXH_littleEndian) || XXH_FORCE_NATIVE_FORMAT) 307299425Smm return XXH32_endian_align(input, len, seed, XXH_littleEndian, XXH_unaligned); 308299425Smm else 309299425Smm return XXH32_endian_align(input, len, seed, XXH_bigEndian, XXH_unaligned); 310299425Smm#endif 311299425Smm} 312299425Smm 313299425Smm/***************************** 314299425Smm** Advanced Hash Functions 315299425Smm******************************/ 316299425Smm 317299425Smmstruct XXH_state32_t 318299425Smm{ 319299425Smm U64 total_len; 320299425Smm U32 seed; 321299425Smm U32 v1; 322299425Smm U32 v2; 323299425Smm U32 v3; 324299425Smm U32 v4; 325299425Smm int memsize; 326299425Smm char memory[16]; 327299425Smm}; 328299425Smm 329299425Smm#if 0 330299425Smmstatic 331299425Smmint XXH32_sizeofState(void) 332299425Smm{ 333299425Smm XXH_STATIC_ASSERT(XXH32_SIZEOFSTATE >= sizeof(struct XXH_state32_t)); /* A compilation error here means XXH32_SIZEOFSTATE is not large enough */ 334299425Smm return sizeof(struct XXH_state32_t); 335299425Smm} 336299425Smm#endif 337299425Smm 338299425Smmstatic 339299425SmmXXH_errorcode XXH32_resetState(void* state_in, U32 seed) 340299425Smm{ 341299425Smm struct XXH_state32_t * state = (struct XXH_state32_t *) state_in; 342299425Smm state->seed = seed; 343299425Smm state->v1 = seed + PRIME32_1 + PRIME32_2; 344299425Smm state->v2 = seed + PRIME32_2; 345299425Smm state->v3 = seed + 0; 346299425Smm state->v4 = seed - PRIME32_1; 347299425Smm state->total_len = 0; 348299425Smm state->memsize = 0; 349299425Smm return XXH_OK; 350299425Smm} 351299425Smm 352299425Smmstatic 353299425Smmvoid* XXH32_init (U32 seed) 354299425Smm{ 355299425Smm void* state = XXH_malloc (sizeof(struct XXH_state32_t)); 356299425Smm XXH32_resetState(state, seed); 357299425Smm return state; 358299425Smm} 359299425Smm 360299425Smmstatic 361299425SmmFORCE_INLINE XXH_errorcode XXH32_update_endian (void* state_in, const void* input, int len, XXH_endianess endian) 362299425Smm{ 363299425Smm struct XXH_state32_t * state = (struct XXH_state32_t *) state_in; 364299425Smm const BYTE* p = (const BYTE*)input; 365299425Smm const BYTE* const bEnd = p + len; 366299425Smm 367299425Smm#ifdef XXH_ACCEPT_NULL_INPUT_POINTER 368299425Smm if (input==NULL) return XXH_ERROR; 369299425Smm#endif 370299425Smm 371299425Smm state->total_len += len; 372299425Smm 373299425Smm if (state->memsize + len < 16) /* fill in tmp buffer */ 374299425Smm { 375299425Smm XXH_memcpy(state->memory + state->memsize, input, len); 376299425Smm state->memsize += len; 377299425Smm return XXH_OK; 378299425Smm } 379299425Smm 380299425Smm if (state->memsize) /* some data left from previous update */ 381299425Smm { 382299425Smm XXH_memcpy(state->memory + state->memsize, input, 16-state->memsize); 383299425Smm { 384299425Smm const U32* p32 = (const U32*)state->memory; 385299425Smm state->v1 += XXH_readLE32(p32, endian) * PRIME32_2; state->v1 = XXH_rotl32(state->v1, 13); state->v1 *= PRIME32_1; p32++; 386299425Smm state->v2 += XXH_readLE32(p32, endian) * PRIME32_2; state->v2 = XXH_rotl32(state->v2, 13); state->v2 *= PRIME32_1; p32++; 387299425Smm state->v3 += XXH_readLE32(p32, endian) * PRIME32_2; state->v3 = XXH_rotl32(state->v3, 13); state->v3 *= PRIME32_1; p32++; 388299425Smm state->v4 += XXH_readLE32(p32, endian) * PRIME32_2; state->v4 = XXH_rotl32(state->v4, 13); state->v4 *= PRIME32_1; p32++; 389299425Smm } 390299425Smm p += 16-state->memsize; 391299425Smm state->memsize = 0; 392299425Smm } 393299425Smm 394299425Smm if (p <= bEnd-16) 395299425Smm { 396299425Smm const BYTE* const limit = bEnd - 16; 397299425Smm U32 v1 = state->v1; 398299425Smm U32 v2 = state->v2; 399299425Smm U32 v3 = state->v3; 400299425Smm U32 v4 = state->v4; 401299425Smm 402299425Smm do 403299425Smm { 404299425Smm v1 += XXH_readLE32((const U32*)p, endian) * PRIME32_2; v1 = XXH_rotl32(v1, 13); v1 *= PRIME32_1; p+=4; 405299425Smm v2 += XXH_readLE32((const U32*)p, endian) * PRIME32_2; v2 = XXH_rotl32(v2, 13); v2 *= PRIME32_1; p+=4; 406299425Smm v3 += XXH_readLE32((const U32*)p, endian) * PRIME32_2; v3 = XXH_rotl32(v3, 13); v3 *= PRIME32_1; p+=4; 407299425Smm v4 += XXH_readLE32((const U32*)p, endian) * PRIME32_2; v4 = XXH_rotl32(v4, 13); v4 *= PRIME32_1; p+=4; 408299425Smm } while (p<=limit); 409299425Smm 410299425Smm state->v1 = v1; 411299425Smm state->v2 = v2; 412299425Smm state->v3 = v3; 413299425Smm state->v4 = v4; 414299425Smm } 415299425Smm 416299425Smm if (p < bEnd) 417299425Smm { 418299425Smm XXH_memcpy(state->memory, p, bEnd-p); 419299425Smm state->memsize = (int)(bEnd-p); 420299425Smm } 421299425Smm 422299425Smm return XXH_OK; 423299425Smm} 424299425Smm 425299425Smmstatic 426299425SmmXXH_errorcode XXH32_update (void* state_in, const void* input, unsigned int len) 427299425Smm{ 428299425Smm XXH_endianess endian_detected = (XXH_endianess)XXH_CPU_LITTLE_ENDIAN; 429299425Smm 430299425Smm if ((endian_detected==XXH_littleEndian) || XXH_FORCE_NATIVE_FORMAT) 431299425Smm return XXH32_update_endian(state_in, input, len, XXH_littleEndian); 432299425Smm else 433299425Smm return XXH32_update_endian(state_in, input, len, XXH_bigEndian); 434299425Smm} 435299425Smm 436299425Smm 437299425Smm 438299425Smmstatic 439299425SmmFORCE_INLINE U32 XXH32_intermediateDigest_endian (void* state_in, XXH_endianess endian) 440299425Smm{ 441299425Smm struct XXH_state32_t * state = (struct XXH_state32_t *) state_in; 442299425Smm const BYTE * p = (const BYTE*)state->memory; 443299425Smm BYTE* bEnd = (BYTE*)state->memory + state->memsize; 444299425Smm U32 h32; 445299425Smm 446299425Smm if (state->total_len >= 16) 447299425Smm { 448299425Smm h32 = XXH_rotl32(state->v1, 1) + XXH_rotl32(state->v2, 7) + XXH_rotl32(state->v3, 12) + XXH_rotl32(state->v4, 18); 449299425Smm } 450299425Smm else 451299425Smm { 452299425Smm h32 = state->seed + PRIME32_5; 453299425Smm } 454299425Smm 455299425Smm h32 += (U32) state->total_len; 456299425Smm 457299425Smm while (p<=bEnd-4) 458299425Smm { 459299425Smm h32 += XXH_readLE32((const U32*)p, endian) * PRIME32_3; 460299425Smm h32 = XXH_rotl32(h32, 17) * PRIME32_4; 461299425Smm p+=4; 462299425Smm } 463299425Smm 464299425Smm while (p<bEnd) 465299425Smm { 466299425Smm h32 += (*p) * PRIME32_5; 467299425Smm h32 = XXH_rotl32(h32, 11) * PRIME32_1; 468299425Smm p++; 469299425Smm } 470299425Smm 471299425Smm h32 ^= h32 >> 15; 472299425Smm h32 *= PRIME32_2; 473299425Smm h32 ^= h32 >> 13; 474299425Smm h32 *= PRIME32_3; 475299425Smm h32 ^= h32 >> 16; 476299425Smm 477299425Smm return h32; 478299425Smm} 479299425Smm 480299425Smmstatic 481299425SmmU32 XXH32_intermediateDigest (void* state_in) 482299425Smm{ 483299425Smm XXH_endianess endian_detected = (XXH_endianess)XXH_CPU_LITTLE_ENDIAN; 484299425Smm 485299425Smm if ((endian_detected==XXH_littleEndian) || XXH_FORCE_NATIVE_FORMAT) 486299425Smm return XXH32_intermediateDigest_endian(state_in, XXH_littleEndian); 487299425Smm else 488299425Smm return XXH32_intermediateDigest_endian(state_in, XXH_bigEndian); 489299425Smm} 490299425Smm 491299425Smmstatic 492299425SmmU32 XXH32_digest (void* state_in) 493299425Smm{ 494299425Smm U32 h32 = XXH32_intermediateDigest(state_in); 495299425Smm 496299425Smm XXH_free(state_in); 497299425Smm 498299425Smm return h32; 499299425Smm} 500299425Smm 501299425Smmconst 502299425Smmstruct archive_xxhash __archive_xxhash = { 503299425Smm XXH32, 504299425Smm XXH32_init, 505299425Smm XXH32_update, 506299425Smm XXH32_digest 507299425Smm}; 508299425Smm#else 509299425Smm 510299425Smm/* 511299425Smm * Define an empty version of the struct if we aren't using the LZ4 library. 512299425Smm */ 513299425Smmconst 514299425Smmstruct archive_xxhash __archive_xxhash = { 515299425Smm NULL, 516299425Smm NULL, 517299425Smm NULL, 518299425Smm NULL 519299425Smm}; 520299425Smm 521299425Smm#endif /* HAVE_LIBLZ4 */ 522