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time31/bob hash methos
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| #include <stdint.h> | |
| uint32_t time31_hash_bin(const void* data, uint32_t length) | |
| { | |
| uint32_t hash = 0; | |
| const uint8_t* p = (const uint8_t*)data; | |
| const uint8_t* pend = p + length; | |
| for(; p < pend; ++p) | |
| hash = (hash<<5) - hash + *p; | |
| return hash; | |
| } | |
| uint32_t bob_hash_bin(const void* data, uint32_t length) | |
| { | |
| #define mix(a,b,c) \ | |
| a -= b; a -= c; a ^= (c >> 13);\ | |
| b -= c; b -= a; b ^= (a << 8);\ | |
| c -= a; c -= b; c ^= (b >> 13);\ | |
| a -= b; a -= c; a ^= (c >> 12);\ | |
| b -= c; b -= a; b ^= (a << 16);\ | |
| c -= a; c -= b; c ^= (b >> 5);\ | |
| a -= b; a -= c; a ^= (c >> 3);\ | |
| b -= c; b -= a; b ^= (a << 10);\ | |
| c -= a; c -= b; c ^= (b >> 15); | |
| const uint8_t* k = (const uint8_t *)data; | |
| uint32_t a, b, c, len; | |
| /* Set up the internal state */ | |
| len = length; | |
| a = b = c = 0x9e3779b9; /* the golden ratio; an arbitrary value */ | |
| /* Handle most of the key */ | |
| while (len >= 12) | |
| { | |
| a += (k[0] +((uint32_t)k[1] << 8) +((uint32_t)k[2] << 16) +((uint32_t)k[3] << 24)); | |
| b += (k[4] +((uint32_t)k[5] << 8) +((uint32_t)k[6] << 16) +((uint32_t)k[7] << 24)); | |
| c += (k[8] +((uint32_t)k[9] << 8) +((uint32_t)k[10]<< 16)+((uint32_t)k[11] << 24)); | |
| mix(a,b,c); | |
| k += 12; len -= 12; | |
| } | |
| /* Handle the last 11 bytes */ | |
| c += length; | |
| switch(len)/* all the case statements fall through */ | |
| { | |
| case 11: c+=((uint32_t)k[10] << 24); | |
| case 10: c+=((uint32_t)k[9] << 16); | |
| case 9 : c+=((uint32_t)k[8] << 8); | |
| /* the first byte of c is reserved for the length */ | |
| case 8 : b+=((uint32_t)k[7] << 24); | |
| case 7 : b+=((uint32_t)k[6] << 16); | |
| case 6 : b+=((uint32_t)k[5] << 8); | |
| case 5 : b+=k[4]; | |
| case 4 : a+=((uint32_t)k[3] << 24); | |
| case 3 : a+=((uint32_t)k[2] << 16); | |
| case 2 : a+=((uint32_t)k[1] << 8); | |
| case 1 : a+=k[0]; | |
| } | |
| mix(a,b,c); | |
| #undef mix | |
| return c; | |
| } | |
| uint64_t time31_bob_mixed_hash_bin(const void* data, uint32_t length) | |
| { | |
| uint64_t time31_hash_val = time31_hash_bin(data, length); | |
| uint64_t bob_hash_value = bob_hash_bin(data, length); | |
| return (bob_hash_value<<32) | time31_hash_val; | |
| } |
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