radare2/libr/hash/xxhash.c
2016-05-24 22:22:15 +02:00

244 lines
7.3 KiB
C

/*
xxHash - Fast Hash algorithm
Copyright (C) 2012, 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/
*/
//**************************************
// Includes
//**************************************
#include <stdlib.h> // for malloc(), free()
#include <string.h> // for memcpy()
#include "xxhash.h"
#include <r_types.h>
R_API ut32 r_hash_xxhash(const ut8 *buf, ut64 len) {
void *s = XXH32_init (0);
XXH32_feed (s, buf, (int)len);
return XXH32_result (s);
}
//**************************************
// Compiler-specific Options & Functions
//**************************************
#define GCC_VERSION (__GNUC__ * 100 + __GNUC_MINOR__)
// Note : under GCC, it may sometimes be faster to enable the (2nd) macro definition, instead of using win32 intrinsic
#if defined(_WIN32)
# define XXH_rotl32(x,r) _rotl(x,r)
#else
# define XXH_rotl32(x,r) ((x << r) | (x >> (32 - r)))
#endif
//**************************************
// Constants
//**************************************
#define PRIME32_1 2654435761U
#define PRIME32_2 2246822519U
#define PRIME32_3 3266489917U
#define PRIME32_4 668265263U
#define PRIME32_5 374761393U
//**************************************
// Macros
//**************************************
#define XXH_LE32(p) r_read_le32(p)
//****************************
// Simple Hash Functions
//****************************
unsigned int XXH32(const void* input, int len, unsigned int seed) {
const unsigned char* p = (const unsigned char*)input;
const unsigned char* const bEnd = p + len;
unsigned int h32;
if (len>=16) {
const unsigned char* const limit = bEnd - 16;
unsigned int v1 = seed + PRIME32_1 + PRIME32_2;
unsigned int v2 = seed + PRIME32_2;
unsigned int v3 = seed + 0;
unsigned int v4 = seed - PRIME32_1;
do {
v1 += XXH_LE32(p) * PRIME32_2; v1 = XXH_rotl32(v1, 13); v1 *= PRIME32_1; p+=4;
v2 += XXH_LE32(p) * PRIME32_2; v2 = XXH_rotl32(v2, 13); v2 *= PRIME32_1; p+=4;
v3 += XXH_LE32(p) * PRIME32_2; v3 = XXH_rotl32(v3, 13); v3 *= PRIME32_1; p+=4;
v4 += XXH_LE32(p) * PRIME32_2; v4 = XXH_rotl32(v4, 13); v4 *= PRIME32_1; p+=4;
} while (p<=limit) ;
h32 = XXH_rotl32(v1, 1) + XXH_rotl32(v2, 7) + XXH_rotl32(v3, 12) + XXH_rotl32(v4, 18);
} else {
h32 = seed + PRIME32_5;
}
h32 += (unsigned int) len;
while (p<=bEnd-4) {
h32 += XXH_LE32(p) * PRIME32_3;
h32 = XXH_rotl32(h32, 17) * PRIME32_4 ;
p+=4;
}
while (p<bEnd) {
h32 += (*p) * PRIME32_5;
h32 = XXH_rotl32(h32, 11) * PRIME32_1 ;
p++;
}
h32 ^= h32 >> 15;
h32 *= PRIME32_2;
h32 ^= h32 >> 13;
h32 *= PRIME32_3;
h32 ^= h32 >> 16;
return h32;
}
//****************************
// Advanced Hash Functions
//****************************
struct XXH_state32_t {
unsigned int seed;
unsigned int v1;
unsigned int v2;
unsigned int v3;
unsigned int v4;
unsigned long long total_len;
char memory[16];
int memsize;
};
void* XXH32_init (unsigned int seed) {
struct XXH_state32_t * state = (struct XXH_state32_t *) malloc ( sizeof(struct XXH_state32_t));
if (!state) return NULL;
state->seed = seed;
state->v1 = seed + PRIME32_1 + PRIME32_2;
state->v2 = seed + PRIME32_2;
state->v3 = seed + 0;
state->v4 = seed - PRIME32_1;
state->total_len = 0;
state->memsize = 0;
return (void*)state;
}
int XXH32_feed (void* state_in, const void* input, int len) {
struct XXH_state32_t * state = state_in;
const unsigned char* p = (const unsigned char*)input;
const unsigned char* const bEnd = p + len;
state->total_len += len;
// fill in tmp buffer
if (state->memsize + len < 16) {
memcpy(state->memory + state->memsize, input, len);
state->memsize += len;
return 0;
}
// some data left from previous feed
if (state->memsize) {
memcpy(state->memory + state->memsize, input, 16-state->memsize);
{
const unsigned int* p32 = (const unsigned int*)state->memory;
state->v1 += XXH_LE32(p32) * PRIME32_2; state->v1 = XXH_rotl32(state->v1, 13); state->v1 *= PRIME32_1; p32++;
state->v2 += XXH_LE32(p32) * PRIME32_2; state->v2 = XXH_rotl32(state->v2, 13); state->v2 *= PRIME32_1; p32++;
state->v3 += XXH_LE32(p32) * PRIME32_2; state->v3 = XXH_rotl32(state->v3, 13); state->v3 *= PRIME32_1; p32++;
state->v4 += XXH_LE32(p32) * PRIME32_2; state->v4 = XXH_rotl32(state->v4, 13); state->v4 *= PRIME32_1; p32++;
}
p += 16-state->memsize;
state->memsize = 0;
}
{
const unsigned char* const limit = bEnd - 16;
unsigned int v1 = state->v1;
unsigned int v2 = state->v2;
unsigned int v3 = state->v3;
unsigned int v4 = state->v4;
while (p<=limit) {
v1 += XXH_LE32(p) * PRIME32_2; v1 = XXH_rotl32(v1, 13); v1 *= PRIME32_1; p+=4;
v2 += XXH_LE32(p) * PRIME32_2; v2 = XXH_rotl32(v2, 13); v2 *= PRIME32_1; p+=4;
v3 += XXH_LE32(p) * PRIME32_2; v3 = XXH_rotl32(v3, 13); v3 *= PRIME32_1; p+=4;
v4 += XXH_LE32(p) * PRIME32_2; v4 = XXH_rotl32(v4, 13); v4 *= PRIME32_1; p+=4;
}
state->v1 = v1;
state->v2 = v2;
state->v3 = v3;
state->v4 = v4;
}
if (p < bEnd) {
state->memsize = R_MIN (bEnd - p, sizeof (state->memory));
memcpy (state->memory, p, state->memsize);
}
return 0;
}
unsigned int XXH32_getIntermediateResult (void* state_in) {
struct XXH_state32_t * state = state_in;
unsigned char * p = (unsigned char*)state->memory;
unsigned char* bEnd = (unsigned char*)state->memory + state->memsize;
unsigned int h32;
if (state->total_len >= 16) {
h32 = XXH_rotl32(state->v1, 1) + XXH_rotl32(state->v2, 7) + XXH_rotl32(state->v3, 12) + XXH_rotl32(state->v4, 18);
} else {
h32 = state->seed + PRIME32_5;
}
h32 += (unsigned int) state->total_len;
while (p<=bEnd-4) {
h32 += XXH_LE32(p) * PRIME32_3;
h32 = XXH_rotl32(h32, 17) * PRIME32_4 ;
p += 4;
}
while (p<bEnd) {
h32 += (*p) * PRIME32_5;
h32 = XXH_rotl32(h32, 11) * PRIME32_1 ;
p++;
}
h32 ^= h32 >> 15;
h32 *= PRIME32_2;
h32 ^= h32 >> 13;
h32 *= PRIME32_3;
h32 ^= h32 >> 16;
return h32;
}
unsigned int XXH32_result (void* state_in) {
unsigned int h32 = XXH32_getIntermediateResult(state_in);
free (state_in);
return h32;
}