git.m6w6.name Git - awesomized/libmemcached/blob - src/libhashkit/murmur3.cc

   1 //-----------------------------------------------------------------------------
   2 //MurmurHash3 was written by Austin Appleby, and is placed in the public
   3 //domain. The author hereby disclaims copyright to this source code.
   4
   5 // Note - The x86 and x64 versions do _not_ produce the same results, as the
   6 // algorithms are optimized for their respective platforms. You can still
   7 // compile and run any of them on any platform, but your performance with the
   8 // non-native version will be less than optimal.
   9
  10 #include "libhashkit/hashkitcon.h"
  11
  12 #include "libhashkit/murmur3.h"
  13
  14 //-----------------------------------------------------------------------------
  15 // Platform-specific functions and macros
  16
  17 #ifdef __GNUC__
  18 #define FORCE_INLINE __attribute__((always_inline)) inline
  19 #else
  20 #define FORCE_INLINE inline
  21 #endif
  22
  23 static FORCE_INLINE uint32_t rotl32 ( uint32_t x, int8_t r )
  24 {
  25   return (x << r) | (x >> (32 - r));
  26 }
  27
  28 static FORCE_INLINE uint64_t rotl64 ( uint64_t x, int8_t r )
  29 {
  30   return (x << r) | (x >> (64 - r));
  31 }
  32
  33 #define ROTL32(x,y)     rotl32(x,y)
  34 #define ROTL64(x,y)     rotl64(x,y)
  35
  36 #define BIG_CONSTANT(x) (x##LLU)
  37
  38 //-----------------------------------------------------------------------------
  39 // Block read - if your platform needs to do endian-swapping or can only
  40 // handle aligned reads, do the conversion here
  41
  42 #include <cassert>
  43 #include <cstring>
  44 template <typename T>
  45 static inline T getblock(const T *blocks, int i) {
  46   T b;
  47 #if WORDS_BIGENDIAN
  48   const uint8_t *data = ((const uint8_t *) blocks) + i * sizeof(T);
  49 # define sl(s) (((T)data[s - 1]) << (8 * (sizeof(T) - s)))
  50   b = 0;
  51   switch (sizeof(T)) {
  52   case 8: b |= sl(8); /* fall through */
  53   case 7: b |= sl(7); /* fall through */
  54   case 6: b |= sl(6); /* fall through */
  55   case 5: b |= sl(5); /* fall through */
  56   case 4: b |= sl(4); /* fall through */
  57   case 3: b |= sl(3); /* fall through */
  58   case 2: b |= sl(2); /* fall through */
  59   case 1: b |= sl(1); break;
  60   default: assert(0);
  61   }
  62 #else
  63   memcpy(&b, ((const uint8_t *) blocks) + i * sizeof(T), sizeof(T));
  64 #endif
  65   return b;
  66 }
  67
  68 //-----------------------------------------------------------------------------
  69 // Finalization mix - force all bits of a hash block to avalanche
  70
  71 static FORCE_INLINE uint32_t fmix32 ( uint32_t h )
  72 {
  73   h ^= h >> 16;
  74   h *= 0x85ebca6b;
  75   h ^= h >> 13;
  76   h *= 0xc2b2ae35;
  77   h ^= h >> 16;
  78
  79   return h;
  80 }
  81
  82 //----------
  83
  84 static FORCE_INLINE uint64_t fmix64 ( uint64_t k )
  85 {
  86   k ^= k >> 33;
  87   k *= BIG_CONSTANT(0xff51afd7ed558ccd);
  88   k ^= k >> 33;
  89   k *= BIG_CONSTANT(0xc4ceb9fe1a85ec53);
  90   k ^= k >> 33;
  91
  92   return k;
  93 }
  94
  95 //-----------------------------------------------------------------------------
  96
  97 void MurmurHash3_x86_32 ( const void * key, int len,
  98                           uint32_t seed, void * out )
  99 {
 100   const uint8_t * data = (const uint8_t*)key;
 101   const int nblocks = len / 4;
 102   int i;
 103
 104   uint32_t h1 = seed;
 105
 106   uint32_t c1 = 0xcc9e2d51;
 107   uint32_t c2 = 0x1b873593;
 108
 109   //----------
 110   // body
 111
 112   const uint32_t * blocks = (const uint32_t *)(data + nblocks*4);
 113
 114   for(i = -nblocks; i; i++)
 115   {
 116     uint32_t k1 = getblock(blocks,i);
 117
 118     k1 *= c1;
 119     k1 = ROTL32(k1,15);
 120     k1 *= c2;
 121
 122     h1 ^= k1;
 123     h1 = ROTL32(h1,13);
 124     h1 = h1*5+0xe6546b64;
 125   }
 126
 127   //----------
 128   // tail
 129
 130   const uint8_t * tail = (const uint8_t*)(data + nblocks*4);
 131
 132   uint32_t k1 = 0;
 133
 134   switch(len & 3)
 135   {
 136 #if WORDS_BIGENDIAN
 137   case 3: k1 ^= tail[2] << 8;
 138           /* fall through */
 139   case 2: k1 ^= tail[1] << 16;
 140           /* fall through */
 141   case 1: k1 ^= tail[0] << 24;
 142 #else
 143   case 3: k1 ^= tail[2] << 16;
 144           /* fall through */
 145   case 2: k1 ^= tail[1] << 8;
 146           /* fall through */
 147   case 1: k1 ^= tail[0];
 148 #endif
 149           k1 *= c1; k1 = ROTL32(k1,15); k1 *= c2; h1 ^= k1;
 150   };
 151
 152   //----------
 153   // finalization
 154
 155   h1 ^= len;
 156
 157   h1 = fmix32(h1);
 158
 159   *(uint32_t*)out = h1;
 160 }
 161
 162 //-----------------------------------------------------------------------------
 163
 164 void MurmurHash3_x86_128 ( const void * key, const int len,
 165                            uint32_t seed, void * out )
 166 {
 167   const uint8_t * data = (const uint8_t*)key;
 168   const int nblocks = len / 16;
 169   int i;
 170
 171   uint32_t h1 = seed;
 172   uint32_t h2 = seed;
 173   uint32_t h3 = seed;
 174   uint32_t h4 = seed;
 175
 176   uint32_t c1 = 0x239b961b;
 177   uint32_t c2 = 0xab0e9789;
 178   uint32_t c3 = 0x38b34ae5;
 179   uint32_t c4 = 0xa1e38b93;
 180
 181   //----------
 182   // body
 183
 184   const uint32_t * blocks = (const uint32_t *)(data + nblocks*16);
 185
 186   for(i = -nblocks; i; i++)
 187   {
 188     uint32_t k1 = getblock(blocks,i*4+0);
 189     uint32_t k2 = getblock(blocks,i*4+1);
 190     uint32_t k3 = getblock(blocks,i*4+2);
 191     uint32_t k4 = getblock(blocks,i*4+3);
 192
 193     k1 *= c1; k1  = ROTL32(k1,15); k1 *= c2; h1 ^= k1;
 194
 195     h1 = ROTL32(h1,19); h1 += h2; h1 = h1*5+0x561ccd1b;
 196
 197     k2 *= c2; k2  = ROTL32(k2,16); k2 *= c3; h2 ^= k2;
 198
 199     h2 = ROTL32(h2,17); h2 += h3; h2 = h2*5+0x0bcaa747;
 200
 201     k3 *= c3; k3  = ROTL32(k3,17); k3 *= c4; h3 ^= k3;
 202
 203     h3 = ROTL32(h3,15); h3 += h4; h3 = h3*5+0x96cd1c35;
 204
 205     k4 *= c4; k4  = ROTL32(k4,18); k4 *= c1; h4 ^= k4;
 206
 207     h4 = ROTL32(h4,13); h4 += h1; h4 = h4*5+0x32ac3b17;
 208   }
 209
 210   //----------
 211   // tail
 212
 213   const uint8_t * tail = (const uint8_t*)(data + nblocks*16);
 214
 215   uint32_t k1 = 0;
 216   uint32_t k2 = 0;
 217   uint32_t k3 = 0;
 218   uint32_t k4 = 0;
 219
 220   switch(len & 15)
 221   {
 222   case 15: k4 ^= tail[14] << 16;
 223            /* fall through */
 224   case 14: k4 ^= tail[13] << 8;
 225            /* fall through */
 226   case 13: k4 ^= tail[12] << 0;
 227            k4 *= c4; k4  = ROTL32(k4,18); k4 *= c1; h4 ^= k4;
 228            /* fall through */
 229   case 12: k3 ^= tail[11] << 24;
 230            /* fall through */
 231   case 11: k3 ^= tail[10] << 16;
 232            /* fall through */
 233   case 10: k3 ^= tail[ 9] << 8;
 234            /* fall through */
 235   case  9: k3 ^= tail[ 8] << 0;
 236            k3 *= c3; k3  = ROTL32(k3,17); k3 *= c4; h3 ^= k3;
 237            /* fall through */
 238   case  8: k2 ^= tail[ 7] << 24;
 239            /* fall through */
 240   case  7: k2 ^= tail[ 6] << 16;
 241            /* fall through */
 242   case  6: k2 ^= tail[ 5] << 8;
 243            /* fall through */
 244   case  5: k2 ^= tail[ 4] << 0;
 245            k2 *= c2; k2  = ROTL32(k2,16); k2 *= c3; h2 ^= k2;
 246            /* fall through */
 247   case  4: k1 ^= tail[ 3] << 24;
 248            /* fall through */
 249   case  3: k1 ^= tail[ 2] << 16;
 250            /* fall through */
 251   case  2: k1 ^= tail[ 1] << 8;
 252            /* fall through */
 253   case  1: k1 ^= tail[ 0] << 0;
 254            k1 *= c1; k1  = ROTL32(k1,15); k1 *= c2; h1 ^= k1;
 255   };
 256
 257   //----------
 258   // finalization
 259
 260   h1 ^= len; h2 ^= len; h3 ^= len; h4 ^= len;
 261
 262   h1 += h2; h1 += h3; h1 += h4;
 263   h2 += h1; h3 += h1; h4 += h1;
 264
 265   h1 = fmix32(h1);
 266   h2 = fmix32(h2);
 267   h3 = fmix32(h3);
 268   h4 = fmix32(h4);
 269
 270   h1 += h2; h1 += h3; h1 += h4;
 271   h2 += h1; h3 += h1; h4 += h1;
 272
 273   ((uint32_t*)out)[0] = h1;
 274   ((uint32_t*)out)[1] = h2;
 275   ((uint32_t*)out)[2] = h3;
 276   ((uint32_t*)out)[3] = h4;
 277 }
 278
 279 //-----------------------------------------------------------------------------
 280
 281 void MurmurHash3_x64_128 ( const void * key, const int len,
 282                            const uint32_t seed, void * out )
 283 {
 284   const uint8_t * data = (const uint8_t*)key;
 285   const int nblocks = len / 16;
 286   int i;
 287
 288   uint64_t h1 = seed;
 289   uint64_t h2 = seed;
 290
 291   uint64_t c1 = BIG_CONSTANT(0x87c37b91114253d5);
 292   uint64_t c2 = BIG_CONSTANT(0x4cf5ad432745937f);
 293
 294   //----------
 295   // body
 296
 297   const uint64_t * blocks = (const uint64_t *)(data);
 298
 299   for(i = 0; i < nblocks; i++)
 300   {
 301     uint64_t k1 = getblock(blocks,i*2+0);
 302     uint64_t k2 = getblock(blocks,i*2+1);
 303
 304     k1 *= c1; k1  = ROTL64(k1,31); k1 *= c2; h1 ^= k1;
 305
 306     h1 = ROTL64(h1,27); h1 += h2; h1 = h1*5+0x52dce729;
 307
 308     k2 *= c2; k2  = ROTL64(k2,33); k2 *= c1; h2 ^= k2;
 309
 310     h2 = ROTL64(h2,31); h2 += h1; h2 = h2*5+0x38495ab5;
 311   }
 312
 313   //----------
 314   // tail
 315
 316   const uint8_t * tail = (const uint8_t*)(data + nblocks*16);
 317
 318   uint64_t k1 = 0;
 319   uint64_t k2 = 0;
 320
 321   switch(len & 15)
 322   {
 323   case 15: k2 ^= (uint64_t)(tail[14]) << 48;
 324            /* fall through */
 325   case 14: k2 ^= (uint64_t)(tail[13]) << 40;
 326            /* fall through */
 327   case 13: k2 ^= (uint64_t)(tail[12]) << 32;
 328            /* fall through */
 329   case 12: k2 ^= (uint64_t)(tail[11]) << 24;
 330            /* fall through */
 331   case 11: k2 ^= (uint64_t)(tail[10]) << 16;
 332            /* fall through */
 333   case 10: k2 ^= (uint64_t)(tail[ 9]) << 8;
 334            /* fall through */
 335   case  9: k2 ^= (uint64_t)(tail[ 8]) << 0;
 336            k2 *= c2; k2  = ROTL64(k2,33); k2 *= c1; h2 ^= k2;
 337            /* fall through */
 338   case  8: k1 ^= (uint64_t)(tail[ 7]) << 56;
 339            /* fall through */
 340   case  7: k1 ^= (uint64_t)(tail[ 6]) << 48;
 341            /* fall through */
 342   case  6: k1 ^= (uint64_t)(tail[ 5]) << 40;
 343            /* fall through */
 344   case  5: k1 ^= (uint64_t)(tail[ 4]) << 32;
 345            /* fall through */
 346   case  4: k1 ^= (uint64_t)(tail[ 3]) << 24;
 347            /* fall through */
 348   case  3: k1 ^= (uint64_t)(tail[ 2]) << 16;
 349            /* fall through */
 350   case  2: k1 ^= (uint64_t)(tail[ 1]) << 8;
 351            /* fall through */
 352   case  1: k1 ^= (uint64_t)(tail[ 0]) << 0;
 353            k1 *= c1; k1  = ROTL64(k1,31); k1 *= c2; h1 ^= k1;
 354   };
 355
 356   //----------
 357   // finalization
 358
 359   h1 ^= len; h2 ^= len;
 360
 361   h1 += h2;
 362   h2 += h1;
 363
 364   h1 = fmix64(h1);
 365   h2 = fmix64(h2);
 366
 367   h1 += h2;
 368   h2 += h1;
 369
 370   ((uint64_t*)out)[0] = h1;
 371   ((uint64_t*)out)[1] = h2;
 372 }
 373
 374 //-----------------------------------------------------------------------------
 375