zaphod32_hash.h 10.3 KB
Newer Older
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322
#ifndef DEBUG_ZAPHOD32_HASH
#define DEBUG_ZAPHOD32_HASH 0

#if DEBUG_ZAPHOD32_HASH == 1
#include <stdio.h>
#define ZAPHOD32_WARN6(pat,v0,v1,v2,v3,v4,v5)    printf(pat, v0, v1, v2, v3, v4, v5)
#define ZAPHOD32_WARN5(pat,v0,v1,v2,v3,v4)       printf(pat, v0, v1, v2, v3, v4)
#define ZAPHOD32_WARN4(pat,v0,v1,v2,v3)          printf(pat, v0, v1, v2, v3)
#define ZAPHOD32_WARN3(pat,v0,v1,v2)             printf(pat, v0, v1, v2)
#define ZAPHOD32_WARN2(pat,v0,v1)                printf(pat, v0, v1)
#define NOTE3(pat,v0,v1,v2)             printf(pat, v0, v1, v2)
#elif DEBUG_ZAPHOD32_HASH == 2
#define ZAPHOD32_WARN6(pat,v0,v1,v2,v3,v4,v5)
#define ZAPHOD32_WARN5(pat,v0,v1,v2,v3,v4)
#define ZAPHOD32_WARN4(pat,v0,v1,v2,v3)
#define ZAPHOD32_WARN3(pat,v0,v1,v2)
#define ZAPHOD32_WARN2(pat,v0,v1)
#define NOTE3(pat,v0,v1,v2)             printf(pat, v0, v1, v2)
#else
#define ZAPHOD32_WARN6(pat,v0,v1,v2,v3,v4,v5)
#define ZAPHOD32_WARN5(pat,v0,v1,v2,v3,v4)
#define ZAPHOD32_WARN4(pat,v0,v1,v2,v3)
#define ZAPHOD32_WARN3(pat,v0,v1,v2)
#define NOTE3(pat,v0,v1,v2)
#define ZAPHOD32_WARN2(pat,v0,v1)
#endif

/* Find best way to ROTL32/ROTL64 */
#ifndef ROTL32
#if defined(_MSC_VER)
#include <stdlib.h>  /* Microsoft put _rotl declaration in here */
#define ROTL32(x,r)  _rotl(x,r)
#define ROTR32(x,r)  _rotr(x,r)
#else
/* gcc recognises this code and generates a rotate instruction for CPUs with one */
#define ROTL32(x,r)  (((U32)(x) << (r)) | ((U32)(x) >> (32 - (r))))
#define ROTR32(x,r)  (((U32)(x) << (32 - (r))) | ((U32)(x) >> (r)))
#endif
#endif

#ifndef PERL_SEEN_HV_FUNC_H
#if !defined(U64)
#include <stdint.h>
#define U64 uint64_t
#endif

#if !defined(U32)
#define U32 uint32_t
#endif

#if !defined(U8)
#define U8 unsigned char
#endif

#if !defined(U16)
#define U16 uint16_t
#endif

#ifndef STRLEN
#define STRLEN int
#endif
#endif

#ifndef ZAPHOD32_STATIC_INLINE
#ifdef PERL_STATIC_INLINE
#define ZAPHOD32_STATIC_INLINE PERL_STATIC_INLINE
#else
#define ZAPHOD32_STATIC_INLINE static inline
#endif
#endif

#ifndef STMT_START
#define STMT_START do
#define STMT_END while(0)
#endif

#ifndef ZAPHOD32_ALLOW_UNALIGNED_AND_LITTLE_ENDIAN
/* ZAPHOD32_ALLOW_UNALIGNED_AND_LITTLE_ENDIAN only matters if nothing has defined U8TO64_LE etc,
 * and when built with Perl these should be defined before this file is loaded.
 */
#ifdef U32_ALIGNMENT_REQUIRED
#define ZAPHOD32_ALLOW_UNALIGNED_AND_LITTLE_ENDIAN 0
#else
#define ZAPHOD32_ALLOW_UNALIGNED_AND_LITTLE_ENDIAN 1
#endif
#endif

#ifndef U8TO32_LE
#if ZAPHOD32_ALLOW_UNALIGNED_AND_LITTLE_ENDIAN
#define U8TO32_LE(ptr)  (*((const U32 *)(ptr)))
#else
#define U8TO32_LE(ptr)  (\
    (U32)(ptr)[3] << 24 | \
    (U32)(ptr)[2] << 16 | \
    (U32)(ptr)[1] << 8  | \
    (U32)(ptr)[0]         \
)
#endif
#endif

#ifndef U8TO16_LE
#if ZAPHOD32_ALLOW_UNALIGNED_AND_LITTLE_ENDIAN
#define U8TO16_LE(ptr)  (*((const U16 *)(ptr)))
#else
#define U8TO16_LE(ptr)  (\
    (U16)(ptr)[1] << 8  | \
    (U16)(ptr)[0]         \
)
#endif
#endif

/* This is two marsaglia xor-shift permutes, with a prime-multiple
 * sandwiched inside. The end result of doing this twice with different
 * primes is a completely avalanched v.  */
#define ZAPHOD32_SCRAMBLE32(v,prime) STMT_START {  \
    v ^= (v>>9);                        \
    v ^= (v<<21);                       \
    v ^= (v>>16);                       \
    v *= prime;                         \
    v ^= (v>>17);                       \
    v ^= (v<<15);                       \
    v ^= (v>>23);                       \
} STMT_END

#define ZAPHOD32_FINALIZE(v0,v1,v2) STMT_START {          \
    ZAPHOD32_WARN3("v0=%08x v1=%08x v2=%08x - ZAPHOD32 FINALIZE\n", \
            (unsigned int)v0, (unsigned int)v1, (unsigned int)v2);  \
    v2 += v0;                       \
    v1 -= v2;                       \
    v1 = ROTL32(v1,  6);           \
    v2 ^= v1;                       \
    v2 = ROTL32(v2, 28);           \
    v1 ^= v2;                       \
    v0 += v1;                       \
    v1 = ROTL32(v1, 24);           \
    v2 += v1;                       \
    v2 = ROTL32(v2, 18) + v1;      \
    v0 ^= v2;                       \
    v0 = ROTL32(v0, 20);           \
    v2 += v0;                       \
    v1 ^= v2;                       \
    v0 += v1;                       \
    v0 = ROTL32(v0,  5);           \
    v2 += v0;                       \
    v2 = ROTL32(v2, 22);           \
    v0 -= v1;                       \
    v1 -= v2;                       \
    v1 = ROTL32(v1, 17);           \
} STMT_END

#define ZAPHOD32_MIX(v0,v1,v2,text) STMT_START {                              \
    ZAPHOD32_WARN4("v0=%08x v1=%08x v2=%08x - ZAPHOD32 %s MIX\n",                   \
            (unsigned int)v0,(unsigned int)v1,(unsigned int)v2, text );  \
    v0 = ROTL32(v0,16) - v2;   \
    v1 = ROTR32(v1,13) ^ v2;   \
    v2 = ROTL32(v2,17) + v1;   \
    v0 = ROTR32(v0, 2) + v1;   \
    v1 = ROTR32(v1,17) - v0;   \
    v2 = ROTR32(v2, 7) ^ v0;   \
} STMT_END


ZAPHOD32_STATIC_INLINE
void zaphod32_seed_state (
    const U8 *seed_ch,
    U8 *state_ch
) {
    const U32 *seed= (const U32 *)seed_ch;
    U32 *state= (U32 *)state_ch;
  
    /* hex expansion of pi, skipping first two digits. pi= 3.2[43f6...]*/
    /* pi value in hex from here:
     * http://turner.faculty.swau.edu/mathematics/materialslibrary/pi/pibases.html*/
    /* Ensure that the three state vectors are nonzero regardless of the seed. */
    /* The idea of these two steps is to ensure that the 0 state comes from a seed
     * utterly unlike that of the value we replace it with.*/
    state[0]= seed[0] ^ 0x43f6a888;
    state[1]= seed[1] ^ 0x5a308d31;
    state[2]= seed[2] ^ 0x3198a2e0;
    if (!state[0]) state[0] = 1;
    if (!state[1]) state[1] = 2;
    if (!state[2]) state[2] = 4;
    /* these are pseduo-randomly selected primes between 2**31 and 2**32
     * (I generated a big list and then randomly chose some from the list) */
    ZAPHOD32_SCRAMBLE32(state[0],0x9fade23b);
    ZAPHOD32_SCRAMBLE32(state[1],0xaa6f908d);
    ZAPHOD32_SCRAMBLE32(state[2],0xcdf6b72d);

    /* now that we have scrambled we do some mixing to avalanche the
     * state bits to gether */
    ZAPHOD32_MIX(state[0],state[1],state[2],"ZAPHOD32 SEED-STATE A 1/4");
    ZAPHOD32_MIX(state[0],state[1],state[2],"ZAPHOD32 SEED-STATE A 2/4");
    ZAPHOD32_MIX(state[0],state[1],state[2],"ZAPHOD32 SEED-STATE A 3/4");
    ZAPHOD32_MIX(state[0],state[1],state[2],"ZAPHOD32 SEED-STATE A 4/4");

    /* and then scramble them again with different primes */
    ZAPHOD32_SCRAMBLE32(state[0],0xc95d22a9);
    ZAPHOD32_SCRAMBLE32(state[1],0x8497242b);
    ZAPHOD32_SCRAMBLE32(state[2],0x9c5cc4e9);

    /* and a thorough final mix */
    ZAPHOD32_MIX(state[0],state[1],state[2],"ZAPHOD32 SEED-STATE B 1/5");
    ZAPHOD32_MIX(state[0],state[1],state[2],"ZAPHOD32 SEED-STATE B 2/5");
    ZAPHOD32_MIX(state[0],state[1],state[2],"ZAPHOD32 SEED-STATE B 3/5");
    ZAPHOD32_MIX(state[0],state[1],state[2],"ZAPHOD32 SEED-STATE B 4/5");
    ZAPHOD32_MIX(state[0],state[1],state[2],"ZAPHOD32 SEED-STATE B 5/5");

}

ZAPHOD32_STATIC_INLINE
U32 zaphod32_hash_with_state(
    const U8 *state_ch,
    const U8 *key,
    const STRLEN key_len
) {
    U32 *state= (U32 *)state_ch;
    const U8 *end;
    STRLEN len = key_len;
    U32 v0= state[0];
    U32 v1= state[1];
    U32 v2= state[2] ^ (0xC41A7AB1 * ((U32)key_len + 1));

    ZAPHOD32_WARN4("v0=%08x v1=%08x v2=%08x ln=%08x HASH START\n",
            (unsigned int)state[0], (unsigned int)state[1],
            (unsigned int)state[2], (unsigned int)key_len);
    {
        switch (len) {
            default: goto zaphod32_read8;
            case 12: v2 += (U32)key[11] << 24;  /* FALLTHROUGH */
            case 11: v2 += (U32)key[10] << 16;  /* FALLTHROUGH */
            case 10: v2 += (U32)U8TO16_LE(key+8);
                     v1 -= U8TO32_LE(key+4);
                     v0 += U8TO32_LE(key+0);
                     goto zaphod32_finalize;
            case 9: v2 += (U32)key[8];          /* FALLTHROUGH */
            case 8: v1 -= U8TO32_LE(key+4);
                    v0 += U8TO32_LE(key+0);
                    goto zaphod32_finalize;
            case 7: v2 += (U32)key[6];          /* FALLTHROUGH */
            case 6: v0 += (U32)U8TO16_LE(key+4);
                    v1 -= U8TO32_LE(key+0);
                    goto zaphod32_finalize;
            case 5: v0 += (U32)key[4];          /* FALLTHROUGH */
            case 4: v1 -= U8TO32_LE(key+0);
                    goto zaphod32_finalize;
            case 3: v2 += (U32)key[2];          /* FALLTHROUGH */
            case 2: v0 += (U32)U8TO16_LE(key);
                    break;
            case 1: v0 += (U32)key[0];
                    break;
            case 0: v2 ^= 0xFF;
                    break;

        }
        v0 -= v2;
        v2 = ROTL32(v2, 8) ^ v0;
        v0 = ROTR32(v0,16) + v2;
        v2 += v0;
        v0 += v0 >> 9;
        v0 += v2;
        v2 ^= v0;
        v2 += v2 << 4;
        v0 -= v2;
        v2 = ROTR32(v2, 8) ^ v0;
        v0 = ROTL32(v0,16) ^ v2;
        v2 = ROTL32(v2,10) + v0;
        v0 = ROTR32(v0,30) + v2;
        v2 = ROTR32(v2,12);
        return v0 ^ v2;
    }

/*  if (len >= 8) */ /* this block is only reached by a goto above, so this condition
                        is commented out, but if the above block is removed it would
                        be necessary to use this. */
    {
zaphod32_read8:
        len = key_len & 0x7;
        end = key + key_len - len;
        do {
            v1 -= U8TO32_LE(key+0);
            v0 += U8TO32_LE(key+4);
            ZAPHOD32_MIX(v0,v1,v2,"MIX 2-WORDS A");
            key += 8;
        } while ( key < end );
    }

    if ( len >= 4 ) {
        v1 -= U8TO32_LE(key);
        key += 4;
    }

    v0 += (U32)(key_len) << 24;
    switch (len & 0x3) {
        case 3: v2 += (U32)key[2];          /* FALLTHROUGH */
        case 2: v0 += (U32)U8TO16_LE(key);
                break;
        case 1: v0 += (U32)key[0];
                break;
        case 0: v2 ^= 0xFF;
                break;
    }
zaphod32_finalize:
    ZAPHOD32_FINALIZE(v0,v1,v2);

    ZAPHOD32_WARN4("v0=%08x v1=%08x v2=%08x hh=%08x - FINAL\n\n",
            (unsigned int)v0, (unsigned int)v1, (unsigned int)v2,
            (unsigned int)v0 ^ v1 ^ v2);

    return v0 ^ v1 ^ v2;
}

ZAPHOD32_STATIC_INLINE U32 zaphod32_hash(
    const U8 *seed_ch,
    const U8 *key,
    const STRLEN key_len
) {
    U32 state[3];
    zaphod32_seed_state(seed_ch,(U8*)state);
    return zaphod32_hash_with_state((U8*)state,key,key_len);
}

#endif