hash_mm2a.cc File Reference

#include "BLI_compiler_attrs.h"
#include "BLI_hash_mm2a.hh"

Go to the source code of this file.

Macros
#define	MM2A_M   0x5bd1e995
#define	MM2A_MIX(h, k)
#define	MM2A_MIX_FINALIZE(h)

Functions
static void	mm2a_mix_tail (BLI_HashMurmur2A *mm2, const uchar **data, size_t *len)
void	BLI_hash_mm2a_init (BLI_HashMurmur2A *mm2, uint32_t seed)
void	BLI_hash_mm2a_add (BLI_HashMurmur2A *mm2, const uchar *data, size_t len)
void	BLI_hash_mm2a_add_int (BLI_HashMurmur2A *mm2, int data)
uint32_t	BLI_hash_mm2a_end (BLI_HashMurmur2A *mm2)
uint32_t	BLI_hash_mm2 (const uchar *data, size_t len, uint32_t seed)

Detailed Description

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
• http://programmers.stackexchange.com/questions/49550

Warning

Do not store that hash in files or such, it is not endian-agnostic, so you should only use it for temporary data.

Definition in file hash_mm2a.cc.

Macro Definition Documentation

MM2A_M

#define MM2A_M   0x5bd1e995

Definition at line 26 of file hash_mm2a.cc.

Referenced by BLI_hash_mm2().

MM2A_MIX

#define MM2A_MIX	(		h,
			k )

Value:

  { \
    (k) *= MM2A_M; \
    (k) ^= (k) >> 24; \
    (k) *= MM2A_M; \
    (h) = ((h) * MM2A_M) ^ (k); \
  } \
  (void)0

Definition at line 28 of file hash_mm2a.cc.

Referenced by BLI_hash_mm2(), BLI_hash_mm2a_add(), BLI_hash_mm2a_end(), and mm2a_mix_tail().

MM2A_MIX_FINALIZE

#define MM2A_MIX_FINALIZE

(

h

)

Value:

  { \
    (h) ^= (h) >> 13; \
    (h) *= MM2A_M; \
    (h) ^= (h) >> 15; \
  } \
  (void)0

Definition at line 37 of file hash_mm2a.cc.

Referenced by BLI_hash_mm2(), and BLI_hash_mm2a_end().

Function Documentation

BLI_hash_mm2()

uint32_t BLI_hash_mm2	(	const unsigned char *	data,
		size_t	len,
		uint32_t	seed )

Non-incremental version, quicker for small keys.

Definition at line 100 of file hash_mm2a.cc.

References ATTR_FALLTHROUGH, len, MM2A_M, MM2A_MIX, MM2A_MIX_FINALIZE, and seed.

Referenced by BLI_ghashutil_inthash_p_murmur(), BLI_ghashutil_strhash_p_murmur(), BLI_ghashutil_uinthash_v4_murmur(), FrsMaterial_hash(), and blender::io::ply::PLYImportTest::import_and_check().

BLI_hash_mm2a_add()

void BLI_hash_mm2a_add	(	BLI_HashMurmur2A *	mm2,
		const uchar *	data,
		size_t	len )

Definition at line 70 of file hash_mm2a.cc.

References BLI_HashMurmur2A::hash, len, MM2A_MIX, mm2a_mix_tail(), and BLI_HashMurmur2A::size.

Referenced by BLI_hash_mm2a_add_int(), GPUCodegen::generate_graphs(), blender::io::ply::PLYImportTest::import_and_check(), TEST(), TEST(), and TEST().

BLI_hash_mm2a_add_int()

void BLI_hash_mm2a_add_int	(	BLI_HashMurmur2A *	mm2,
		int	data )

Definition at line 85 of file hash_mm2a.cc.

References BLI_hash_mm2a_add().

Referenced by GPUCodegen::GPUCodegen(), and TEST().

BLI_hash_mm2a_end()

uint32_t BLI_hash_mm2a_end

(

BLI_HashMurmur2A *

mm2

)

Definition at line 90 of file hash_mm2a.cc.

References BLI_HashMurmur2A::hash, MM2A_MIX, MM2A_MIX_FINALIZE, BLI_HashMurmur2A::size, and BLI_HashMurmur2A::tail.

Referenced by GPUCodegen::generate_graphs(), blender::io::ply::PLYImportTest::import_and_check(), TEST(), TEST(), and TEST().

BLI_hash_mm2a_init()

void BLI_hash_mm2a_init	(	BLI_HashMurmur2A *	mm2,
		uint32_t	seed )

Definition at line 62 of file hash_mm2a.cc.

References BLI_HashMurmur2A::count, BLI_HashMurmur2A::hash, seed, BLI_HashMurmur2A::size, and BLI_HashMurmur2A::tail.

Referenced by GPUCodegen::GPUCodegen(), blender::io::ply::PLYImportTest::import_and_check(), TEST(), TEST(), and TEST().

mm2a_mix_tail()

static void mm2a_mix_tail ( BLI_HashMurmur2A * mm2, const uchar ** data, size_t * len )

static

Definition at line 45 of file hash_mm2a.cc.

References BLI_HashMurmur2A::count, BLI_HashMurmur2A::hash, len, MM2A_MIX, and BLI_HashMurmur2A::tail.

Referenced by BLI_hash_mm2a_add().