|
|
//======= Copyright � 2005, , Valve Corporation, All rights reserved. =========
//
// Purpose: Variant Pearson Hash general purpose hashing algorithm described
// by Cargill in C++ Report 1994. Generates a 16-bit result.
//
//=============================================================================
#include <stdlib.h>
#include "tier0/basetypes.h"
#include "tier0/platform.h"
#include "generichash.h"
#include <ctype.h>
#include "tier0/dbg.h"
#include "tier1/strtools.h"
// NOTE: This has to be the last file included!
#include "tier0/memdbgon.h"
//-----------------------------------------------------------------------------
//
// Table of randomly shuffled values from 0-255 generated by:
//
//-----------------------------------------------------------------------------
/*
void MakeRandomValues(){ int i, j, r; unsigned t; srand( 0xdeadbeef );
for ( i = 0; i < 256; i++ ) { g_nRandomValues[i] = (unsigned )i; }
for (j = 0; j < 8; j++) { for (i = 0; i < 256; i++) { r = rand() & 0xff; t = g_nRandomValues[i]; g_nRandomValues[i] = g_nRandomValues[r]; g_nRandomValues[r] = t; } }
printf("static unsigned g_nRandomValues[256] =\n{\n");
for (i = 0; i < 256; i += 16) { printf("\t"); for (j = 0; j < 16; j++) printf(" %3d,", g_nRandomValues[i+j]); printf("\n"); } printf("};\n");}*/
static unsigned g_nRandomValues[256] ={ 238, 164, 191, 168, 115, 16, 142, 11, 213, 214, 57, 151, 248, 252, 26, 198, 13, 105, 102, 25, 43, 42, 227, 107, 210, 251, 86, 66, 83, 193, 126, 108, 131, 3, 64, 186, 192, 81, 37, 158, 39, 244, 14, 254, 75, 30, 2, 88, 172, 176, 255, 69, 0, 45, 116, 139, 23, 65, 183, 148, 33, 46, 203, 20, 143, 205, 60, 197, 118, 9, 171, 51, 233, 135, 220, 49, 71, 184, 82, 109, 36, 161, 169, 150, 63, 96, 173, 125, 113, 67, 224, 78, 232, 215, 35, 219, 79, 181, 41, 229, 149, 153, 111, 217, 21, 72, 120, 163, 133, 40, 122, 140, 208, 231, 211, 200, 160, 182, 104, 110, 178, 237, 15, 101, 27, 50, 24, 189, 177, 130, 187, 92, 253, 136, 100, 212, 19, 174, 70, 22, 170, 206, 162, 74, 247, 5, 47, 32, 179, 117, 132, 195, 124, 123, 245, 128, 236, 223, 12, 84, 54, 218, 146, 228, 157, 94, 106, 31, 17, 29, 194, 34, 56, 134, 239, 246, 241, 216, 127, 98, 7, 204, 154, 152, 209, 188, 48, 61, 87, 97, 225, 85, 90, 167, 155, 112, 145, 114, 141, 93, 250, 4, 201, 156, 38, 89, 226, 196, 1, 235, 44, 180, 159, 121, 119, 166, 190, 144, 10, 91, 76, 230, 221, 80, 207, 55, 58, 53, 175, 8, 6, 52, 68, 242, 18, 222, 103, 249, 147, 129, 138, 243, 28, 185, 62, 59, 240, 202, 234, 99, 77, 73, 199, 137, 95, 165,};
//-----------------------------------------------------------------------------
// String
//-----------------------------------------------------------------------------
unsigned FASTCALL HashString( const char *pszKey ){ const uint8 *k = (const uint8 *)pszKey; unsigned even = 0, odd = 0, n;
while ((n = *k++) != 0) { even = g_nRandomValues[odd ^ n]; if ((n = *k++) != 0) odd = g_nRandomValues[even ^ n]; else break; }
return (even << 8) | odd ;}
//-----------------------------------------------------------------------------
// Case-insensitive string
//-----------------------------------------------------------------------------
unsigned FASTCALL HashStringCaseless( const char *pszKey ){ const uint8 *k = (const uint8 *) pszKey; unsigned even = 0, odd = 0, n;
while ((n = toupper(*k++)) != 0) { even = g_nRandomValues[odd ^ n]; if ((n = toupper(*k++)) != 0) odd = g_nRandomValues[even ^ n]; else break; }
return (even << 8) | odd;}
//-----------------------------------------------------------------------------
// 32 bit conventional case-insensitive string
//-----------------------------------------------------------------------------
uint32 FASTCALL HashStringCaselessConventional( const char *pszKey ){ uint32 hash = 0xAAAAAAAA; // Alternating 1's and 0's to maximize the effect of the later multiply and add
hash += ( 2 * V_strlen( pszKey ) ); // Add the string length * 2 to the hash to give it more variety
for( ; *pszKey ; pszKey++ ) { hash = ( ( hash << 5 ) + hash ) + (uint8)tolower(*pszKey); }
return hash;}
//-----------------------------------------------------------------------------
// int hash
//-----------------------------------------------------------------------------
unsigned FASTCALL HashInt( const int n ){ register unsigned even, odd; odd = g_nRandomValues[(((unsigned)n >> 8) & 0xff)]; even = g_nRandomValues[odd ^ ((unsigned)n >> 24)]; odd = g_nRandomValues[even ^ ((unsigned)n >> 16) & 0xff]; even = g_nRandomValues[odd ^ ((unsigned)n >> 8) & 0xff]; odd = g_nRandomValues[even ^ ((unsigned)n & 0xff)];
return (even << 8) | odd;}
//-----------------------------------------------------------------------------
// 4-byte hash
//-----------------------------------------------------------------------------
unsigned FASTCALL Hash4( const void *pKey ){ register const uint32 * p = (const uint32 *) pKey; register unsigned even, odd, n; n = *p; odd = g_nRandomValues[((n >> 8) & 0xff)]; even = g_nRandomValues[odd ^ (n >> 24)]; odd = g_nRandomValues[even ^ (n >> 16) & 0xff]; even = g_nRandomValues[odd ^ (n >> 8) & 0xff]; odd = g_nRandomValues[even ^ (n & 0xff)];
return (even << 8) | odd;}
//-----------------------------------------------------------------------------
// 8-byte hash
//-----------------------------------------------------------------------------
unsigned FASTCALL Hash8( const void *pKey ){ register const uint32 * p = (const uint32 *) pKey; register unsigned even, odd, n; n = *p; odd = g_nRandomValues[((n >> 8) & 0xff)]; even = g_nRandomValues[odd ^ (n >> 24)]; odd = g_nRandomValues[even ^ (n >> 16) & 0xff]; even = g_nRandomValues[odd ^ (n >> 8) & 0xff]; odd = g_nRandomValues[even ^ (n & 0xff)];
n = *(p+1); even = g_nRandomValues[odd ^ (n >> 24)]; odd = g_nRandomValues[even ^ (n >> 16) & 0xff]; even = g_nRandomValues[odd ^ (n >> 8) & 0xff]; odd = g_nRandomValues[even ^ (n & 0xff)];
return (even << 8) | odd;}
//-----------------------------------------------------------------------------
// 12-byte hash
//-----------------------------------------------------------------------------
unsigned FASTCALL Hash12( const void *pKey ){ register const uint32 * p = (const uint32 *) pKey; register unsigned even, odd, n; n = *p; odd = g_nRandomValues[((n >> 8) & 0xff)];
even = g_nRandomValues[odd ^ (n >> 24)]; odd = g_nRandomValues[even ^ (n >> 16) & 0xff]; even = g_nRandomValues[odd ^ (n >> 8) & 0xff]; odd = g_nRandomValues[even ^ (n & 0xff)];
n = *(p+1); even = g_nRandomValues[odd ^ (n >> 24)]; odd = g_nRandomValues[even ^ (n >> 16) & 0xff]; even = g_nRandomValues[odd ^ (n >> 8) & 0xff]; odd = g_nRandomValues[even ^ (n & 0xff)];
n = *(p+2); even = g_nRandomValues[odd ^ (n >> 24)]; odd = g_nRandomValues[even ^ (n >> 16) & 0xff]; even = g_nRandomValues[odd ^ (n >> 8) & 0xff]; odd = g_nRandomValues[even ^ (n & 0xff)];
return (even << 8) | odd;}
//-----------------------------------------------------------------------------
// 16-byte hash
//-----------------------------------------------------------------------------
unsigned FASTCALL Hash16( const void *pKey ){ register const uint32 * p = (const uint32 *) pKey; register unsigned even, odd, n; n = *p; odd = g_nRandomValues[((n >> 8) & 0xff)];
even = g_nRandomValues[odd ^ (n >> 24)]; odd = g_nRandomValues[even ^ (n >> 16) & 0xff]; even = g_nRandomValues[odd ^ (n >> 8) & 0xff]; odd = g_nRandomValues[even ^ (n & 0xff)];
n = *(p+1); even = g_nRandomValues[odd ^ (n >> 24)]; odd = g_nRandomValues[even ^ (n >> 16) & 0xff]; even = g_nRandomValues[odd ^ (n >> 8) & 0xff]; odd = g_nRandomValues[even ^ (n & 0xff)];
n = *(p+2); even = g_nRandomValues[odd ^ (n >> 24)]; odd = g_nRandomValues[even ^ (n >> 16) & 0xff]; even = g_nRandomValues[odd ^ (n >> 8) & 0xff]; odd = g_nRandomValues[even ^ (n & 0xff)];
n = *(p+3); even = g_nRandomValues[odd ^ (n >> 24)]; odd = g_nRandomValues[even ^ (n >> 16) & 0xff]; even = g_nRandomValues[odd ^ (n >> 8) & 0xff]; odd = g_nRandomValues[even ^ (n & 0xff)];
return (even << 8) | odd;}
//-----------------------------------------------------------------------------
// Arbitrary fixed length hash
//-----------------------------------------------------------------------------
unsigned FASTCALL HashBlock( const void *pKey, unsigned size ){ const uint8 * k = (const uint8 *) pKey; unsigned even = 0, odd = 0, n;
while (size) { --size; n = *k++; even = g_nRandomValues[odd ^ n]; if (size) { --size; n = *k++; odd = g_nRandomValues[even ^ n]; } else break; }
return (even << 8) | odd;}
//-----------------------------------------------------------------------------
// Murmur hash
//-----------------------------------------------------------------------------
uint32 MurmurHash2( const void * key, int len, uint32 seed ){ // 'm' and 'r' are mixing constants generated offline.
// They're not really 'magic', they just happen to work well.
const uint32 m = 0x5bd1e995; const int r = 24;
// Initialize the hash to a 'random' value
uint32 h = seed ^ len;
// Mix 4 bytes at a time into the hash
const unsigned char * data = (const unsigned char *)key;
while(len >= 4) { uint32 k = LittleDWord( *(uint32 *)data );
k *= m; k ^= k >> r; k *= m;
h *= m; h ^= k;
data += 4; len -= 4; }
// Handle the last few bytes of the input array
switch(len) { case 3: h ^= data[2] << 16; case 2: h ^= data[1] << 8; case 1: h ^= data[0]; h *= m; };
// Do a few final mixes of the hash to ensure the last few
// bytes are well-incorporated.
h ^= h >> 13; h *= m; h ^= h >> 15;
return h;}
#define TOLOWERU( c ) ( ( uint32 ) ( ( ( c >= 'A' ) && ( c <= 'Z' ) )? c + 32 : c ) )
uint32 MurmurHash2LowerCase( char const *pString, uint32 nSeed ){ int nLen = V_strlen( pString ); char *p = ( char * ) stackalloc( nLen + 1 ); for( int i = 0; i < nLen ; i++ ) { p[i] = TOLOWERU( pString[i] ); } return MurmurHash2( p, nLen, nSeed );}
//-----------------------------------------------------------------------------
// Murmur hash, 64 bit- endian neutral
//-----------------------------------------------------------------------------
uint64 MurmurHash64( const void * key, int len, uint32 seed ){ // 'm' and 'r' are mixing constants generated offline.
// They're not really 'magic', they just happen to work well.
const uint32 m = 0x5bd1e995; const int r = 24;
// Initialize the hash to a 'random' value
uint32 h1 = seed ^ len; uint32 h2 = 0;
// Mix 4 bytes at a time into the hash
const uint32 * data = (const uint32 *)key; while ( len >= 8 ) { uint32 k1 = LittleDWord( *data++ ); k1 *= m; k1 ^= k1 >> r; k1 *= m; h1 *= m; h1 ^= k1; len -= 4;
uint32 k2 = LittleDWord( *data++ ); k2 *= m; k2 ^= k2 >> r; k2 *= m; h2 *= m; h2 ^= k2; len -= 4; }
if(len >= 4) { uint32 k1 = LittleDWord( *data++ ); k1 *= m; k1 ^= k1 >> r; k1 *= m; h1 *= m; h1 ^= k1; len -= 4; }
// Handle the last few bytes of the input array
switch(len) { case 3: h2 ^= ((uint8*)data)[2] << 16; case 2: h2 ^= ((uint8*)data)[1] << 8; case 1: h2 ^= ((uint8*)data)[0]; h2 *= m; };
h1 ^= h2 >> 18; h1 *= m; h2 ^= h1 >> 22; h2 *= m; h1 ^= h2 >> 17; h1 *= m; h2 ^= h1 >> 19; h2 *= m;
uint64 h = h1;
h = (h << 32) | h2;
return h;}
|
