diff options
author | Bastien Montagne <montagne29@wanadoo.fr> | 2014-11-14 13:00:10 +0300 |
---|---|---|
committer | Bastien Montagne <montagne29@wanadoo.fr> | 2014-11-14 13:00:26 +0300 |
commit | 64c0c13e6e08c51e92504631468db864f553d9b5 (patch) | |
tree | 5903262689a45defda7a98782656964bdaa50f6b /source | |
parent | c8a9764987a8c1e7ea0093e8a0b028a65af6ee33 (diff) |
Add Murmur2A hashing feature to BLI
Murmur2a is a very fast hashing function generation int32 hashes.
It also features a very good distribution of generated hashes.
However, it is not endianness-agnostic, meaning it will usually generate
different hashes for a same key on big- and little-endian architectures.
Consequently, **it shall not be used to generate persistent hashes**
(never store them in .blend file e.g.).
This implementation supports incremental hashing, and is a direct
adaptation of reference implementation (in c++):
https://smhasher.googlecode.com/svn-history/r130/trunk/MurmurHash2.cpp
That cpp code was also used to generate reference values in gtests file.
Reviewers: sergey, campbellbarton
Reviewed By: campbellbarton
Projects: #bf_blender
Differential Revision: https://developer.blender.org/D892
Diffstat (limited to 'source')
-rw-r--r-- | source/blender/blenlib/BLI_hash_md5.h (renamed from source/blender/blenlib/BLI_md5.h) | 7 | ||||
-rw-r--r-- | source/blender/blenlib/BLI_hash_mm2a.h | 45 | ||||
-rw-r--r-- | source/blender/blenlib/CMakeLists.txt | 6 | ||||
-rw-r--r-- | source/blender/blenlib/intern/hash_md5.c (renamed from source/blender/blenlib/intern/md5.c) | 2 | ||||
-rw-r--r-- | source/blender/blenlib/intern/hash_mm2a.c | 107 | ||||
-rw-r--r-- | source/blender/imbuf/intern/thumbs.c | 2 | ||||
-rw-r--r-- | source/blender/render/intern/source/render_result.c | 2 |
7 files changed, 162 insertions, 9 deletions
diff --git a/source/blender/blenlib/BLI_md5.h b/source/blender/blenlib/BLI_hash_md5.h index 6a760f53e45..cab3671a5ca 100644 --- a/source/blender/blenlib/BLI_md5.h +++ b/source/blender/blenlib/BLI_hash_md5.h @@ -19,9 +19,9 @@ */ #ifndef __BLI_MD5_H__ -#define __BLI_MD5_H__ +#define __BLI_MD5_H__ -/** \file BLI_md5.h +/** \file BLI_hash_md5.h * \ingroup bli */ @@ -43,5 +43,4 @@ int md5_stream(FILE *stream, void *resblock); char *md5_to_hexdigest(void *resblock, char r_hex_digest[33]); -#endif - +#endif /* __BLI_MD5_H__ */ diff --git a/source/blender/blenlib/BLI_hash_mm2a.h b/source/blender/blenlib/BLI_hash_mm2a.h new file mode 100644 index 00000000000..503eb5e96d9 --- /dev/null +++ b/source/blender/blenlib/BLI_hash_mm2a.h @@ -0,0 +1,45 @@ +/* + * ***** BEGIN GPL LICENSE BLOCK ***** + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version 2 + * of the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software Foundation, + * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. + * + * ***** END GPL LICENSE BLOCK ***** + */ + +#ifndef __BLI_MM2A_H__ +#define __BLI_MM2A_H__ + +/** \file BLI_hash_mm2a.h + * \ingroup bli + */ + +#include "BLI_sys_types.h" + +typedef struct BLI_HashMurmur2A { + uint32_t hash; + uint32_t tail; + uint32_t count; + uint32_t size; +} BLI_HashMurmur2A; + +void BLI_hash_mm2a_init(BLI_HashMurmur2A *mm2, uint32_t seed); + +void BLI_hash_mm2a_add(BLI_HashMurmur2A *mm2, const unsigned char *data, size_t len); + +void BLI_hash_mm2a_add_int(BLI_HashMurmur2A *mm2, int data); + +uint32_t BLI_hash_mm2a_end(BLI_HashMurmur2A *mm2); + +#endif /* __BLI_MM2A_H__ */ diff --git a/source/blender/blenlib/CMakeLists.txt b/source/blender/blenlib/CMakeLists.txt index 9efa20da13e..ba166b11960 100644 --- a/source/blender/blenlib/CMakeLists.txt +++ b/source/blender/blenlib/CMakeLists.txt @@ -65,6 +65,8 @@ set(SRC intern/freetypefont.c intern/graph.c intern/gsqueue.c + intern/hash_md5.c + intern/hash_mm2a.c intern/jitter.c intern/lasso.c intern/listbase.c @@ -80,7 +82,6 @@ set(SRC intern/math_rotation.c intern/math_vector.c intern/math_vector_inline.c - intern/md5.c intern/noise.c intern/path_util.c intern/polyfill2d.c @@ -134,6 +135,8 @@ set(SRC BLI_ghash.h BLI_graph.h BLI_gsqueue.h + BLI_hash_md5.h + BLI_hash_mm2a.h BLI_heap.h BLI_jitter.h BLI_kdopbvh.h @@ -153,7 +156,6 @@ set(SRC BLI_math_matrix.h BLI_math_rotation.h BLI_math_vector.h - BLI_md5.h BLI_memarena.h BLI_mempool.h BLI_noise.h diff --git a/source/blender/blenlib/intern/md5.c b/source/blender/blenlib/intern/hash_md5.c index 3d1a9cdb7a4..98a5cc545b5 100644 --- a/source/blender/blenlib/intern/md5.c +++ b/source/blender/blenlib/intern/hash_md5.c @@ -29,7 +29,7 @@ * according to the definition of MD5 in RFC 1321 from April 1992. */ -#include "BLI_md5.h" /* own include */ +#include "BLI_hash_md5.h" /* own include */ #include <stdlib.h> #include <string.h> diff --git a/source/blender/blenlib/intern/hash_mm2a.c b/source/blender/blenlib/intern/hash_mm2a.c new file mode 100644 index 00000000000..8b4242fa5be --- /dev/null +++ b/source/blender/blenlib/intern/hash_mm2a.c @@ -0,0 +1,107 @@ +/* + * ***** BEGIN GPL LICENSE BLOCK ***** + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version 2 + * of the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software Foundation, + * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. + * + * ***** END GPL LICENSE BLOCK ***** + * + * Copyright (C) 2014 Blender Foundation. + * + */ + +/** \file blender/blenlib/intern/hash_mm2a.c + * \ingroup bli + * + * Functions to compute Murmur2A hash key. + * + * A very fast hash generating int32 result, with few collisions and good repartition. + * + * See also: + * reference implementation: https://smhasher.googlecode.com/svn-history/r130/trunk/MurmurHash2.cpp + * and http://programmers.stackexchange.com/questions/49550/which-hashing-algorithm-is-best-for-uniqueness-and-speed + * + * \warning Do not store that hash in files or such, it is not endian-agnostic, so you should only use it + * for temporary data. + */ + +#include "BLI_hash_mm2a.h" /* own include */ + +/* Helpers. */ +#define MM2A_M 0x5bd1e995 + +#define MM2A_MIX(h, k) \ +{ \ + (k) *= MM2A_M; \ + (k) ^= (k) >> 24; \ + (k) *= MM2A_M; \ + (h) = ((h) * MM2A_M) ^ (k); \ +} (void)0 + +static void mm2a_mix_tail(BLI_HashMurmur2A *mm2, const unsigned char **data, size_t *len) +{ + while (*len && ((*len < 4) || mm2->count)) { + mm2->tail |= (uint32_t)(**data) << (mm2->count * 8); + + mm2->count++; + (*len)--; + (*data)++; + + if (mm2->count == 4) { + MM2A_MIX(mm2->hash, mm2->tail); + mm2->tail = 0; + mm2->count = 0; + } + } +} + +void BLI_hash_mm2a_init(BLI_HashMurmur2A *mm2, uint32_t seed) +{ + mm2->hash = seed; + mm2->tail = 0; + mm2->count = 0; + mm2->size = 0; +} + +void BLI_hash_mm2a_add(BLI_HashMurmur2A *mm2, const unsigned char *data, size_t len) +{ + mm2->size += (uint32_t)len; + + mm2a_mix_tail(mm2, &data, &len); + + for (; len >= 4; data += 4, len -= 4) { + uint32_t k = *(uint32_t *)data; + + MM2A_MIX(mm2->hash, k); + } + + mm2a_mix_tail(mm2, &data, &len); +} + +void BLI_hash_mm2a_add_int(BLI_HashMurmur2A *mm2, int data) +{ + BLI_hash_mm2a_add(mm2, (const unsigned char *)&data, sizeof(data)); +} + +uint32_t BLI_hash_mm2a_end(BLI_HashMurmur2A *mm2) +{ + MM2A_MIX(mm2->hash, mm2->tail); + MM2A_MIX(mm2->hash, mm2->size); + + mm2->hash ^= mm2->hash >> 13; + mm2->hash *= MM2A_M; + mm2->hash ^= mm2->hash >> 15; + + return mm2->hash; +} diff --git a/source/blender/imbuf/intern/thumbs.c b/source/blender/imbuf/intern/thumbs.c index 9a97a142198..5399e54a30e 100644 --- a/source/blender/imbuf/intern/thumbs.c +++ b/source/blender/imbuf/intern/thumbs.c @@ -35,7 +35,7 @@ #include "BLI_string.h" #include "BLI_path_util.h" #include "BLI_fileops.h" -#include "BLI_md5.h" +#include "BLI_hash_md5.h" #include "BLI_system.h" #include BLI_SYSTEM_PID_H diff --git a/source/blender/render/intern/source/render_result.c b/source/blender/render/intern/source/render_result.c index 24797521435..d7c56ddd716 100644 --- a/source/blender/render/intern/source/render_result.c +++ b/source/blender/render/intern/source/render_result.c @@ -37,7 +37,7 @@ #include "BLI_utildefines.h" #include "BLI_listbase.h" -#include "BLI_md5.h" +#include "BLI_hash_md5.h" #include "BLI_path_util.h" #include "BLI_rect.h" #include "BLI_string.h" |