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refined mishmash with masher namespace

master
madscientist 4 years ago
parent
commit
e9a5b98de0
2 changed files with 60 additions and 47 deletions
  1. 8
    46
      mishmash.cpp
  2. 52
    1
      mishmash.hpp

+ 8
- 46
mishmash.cpp View File

@@ -10,52 +10,14 @@

namespace codedweller {

const uint32_t primes[256] {
1019, 1021, 1031, 1033, 1039, 1049, 1051, 1061,
1063, 1069, 1087, 1091, 1093, 1097, 1103, 1109,
1117, 1123, 1129, 1151, 1153, 1163, 1171, 1181,
1187, 1193, 1201, 1213, 1217, 1223, 1229, 1231,
1237, 1249, 1259, 1277, 1279, 1283, 1289, 1291,
1297, 1301, 1303, 1307, 1319, 1321, 1327, 1361,
1367, 1373, 1381, 1399, 1409, 1423, 1427, 1429,
1433, 1439, 1447, 1451, 1453, 1459, 1471, 1481,

1483, 1487, 1489, 1493, 1499, 1511, 1523, 1531,
1543, 1549, 1553, 1559, 1567, 1571, 1579, 1583,
1597, 1601, 1607, 1609, 1613, 1619, 1621, 1627,
1637, 1657, 1663, 1667, 1669, 1693, 1697, 1699,
1709, 1721, 1723, 1733, 1741, 1747, 1753, 1759,
1777, 1783, 1787, 1789, 1801, 1811, 1823, 1831,
1847, 1861, 1867, 1871, 1873, 1877, 1879, 1889,
1901, 1907, 1913, 1931, 1933, 1949, 1951, 1973,

1979, 1987, 1993, 1997, 1999, 2003, 2011, 2017,
2027, 2029, 2039, 2053, 2063, 2069, 2081, 2083,
2087, 2089, 2099, 2111, 2113, 2129, 2131, 2137,
2141, 2143, 2153, 2161, 2179, 2203, 2207, 2213,
2221, 2237, 2239, 2243, 2251, 2267, 2269, 2273,
2281, 2287, 2293, 2297, 2309, 2311, 2333, 2339,
2341, 2347, 2351, 2357, 2371, 2377, 2381, 2383,
2389, 2393, 2399, 2411, 2417, 2423, 2437, 2441,
2447, 2459, 2467, 2473, 2477, 2503, 2521, 2531,
2539, 2543, 2549, 2551, 2557, 2579, 2591, 2593,
2609, 2617, 2621, 2633, 2647, 2657, 2659, 2663,
2671, 2677, 2683, 2687, 2689, 2693, 2699, 2707,
2711, 2713, 2719, 2729, 2731, 2741, 2749, 2753,
2767, 2777, 2789, 2791, 2797, 2801, 2803, 2819,
2833, 2837, 2843, 2851, 2857, 2861, 2879, 2887,
2897, 2903, 2909, 2917, 2927, 2939, 2953, 2957
};


inline size_t selectedPrime(size_t n) noexcept { return primes[n &0xff]; }

uint64_t mishmash(const unsigned char* buffer, size_t length, uint64_t accumulator) noexcept {
uint64_t masher::engine(
const unsigned char* buffer, size_t length,
uint64_t accumulator,
const masher::PrimeSet& primes) noexcept {
for(size_t index = 0; index < length; index++) {
unsigned char byte = buffer[index];
accumulator += selectedPrime(byte + accumulator);
accumulator *= selectedPrime(accumulator);
accumulator += primes.select(byte + accumulator);
accumulator *= primes.select(accumulator);
accumulator += accumulator >> 32;
accumulator &= 0x000fffffffffffff;
}
@@ -63,7 +25,7 @@ uint64_t mishmash(const unsigned char* buffer, size_t length, uint64_t accumulat
}

uint32_t mishmash(const unsigned char* buffer, size_t length) noexcept {
uint64_t accumulator = mishmash(buffer, length, 0);
uint64_t accumulator = masher::engine(buffer, length);
return static_cast<uint32_t>(accumulator & 0x00000000ffffffff);
}

@@ -75,4 +37,4 @@ uint32_t mishmash(const std::vector<unsigned char>& v) noexcept {
return mishmash(v.data(), v.size());
}

}
} // end of namespace codedweller

+ 52
- 1
mishmash.hpp View File

@@ -11,7 +11,58 @@

namespace codedweller {

uint64_t mishmash(const unsigned char* buffer, size_t length, uint64_t accumulator) noexcept;
namespace masher {

struct PrimeSet {
uint32_t primes[256];
uint32_t select(size_t n) const { return primes[n & 0xff]; }
};

const PrimeSet Primes {
1019, 1021, 1031, 1033, 1039, 1049, 1051, 1061,
1063, 1069, 1087, 1091, 1093, 1097, 1103, 1109,
1117, 1123, 1129, 1151, 1153, 1163, 1171, 1181,
1187, 1193, 1201, 1213, 1217, 1223, 1229, 1231,
1237, 1249, 1259, 1277, 1279, 1283, 1289, 1291,
1297, 1301, 1303, 1307, 1319, 1321, 1327, 1361,
1367, 1373, 1381, 1399, 1409, 1423, 1427, 1429,
1433, 1439, 1447, 1451, 1453, 1459, 1471, 1481,

1483, 1487, 1489, 1493, 1499, 1511, 1523, 1531,
1543, 1549, 1553, 1559, 1567, 1571, 1579, 1583,
1597, 1601, 1607, 1609, 1613, 1619, 1621, 1627,
1637, 1657, 1663, 1667, 1669, 1693, 1697, 1699,
1709, 1721, 1723, 1733, 1741, 1747, 1753, 1759,
1777, 1783, 1787, 1789, 1801, 1811, 1823, 1831,
1847, 1861, 1867, 1871, 1873, 1877, 1879, 1889,
1901, 1907, 1913, 1931, 1933, 1949, 1951, 1973,

1979, 1987, 1993, 1997, 1999, 2003, 2011, 2017,
2027, 2029, 2039, 2053, 2063, 2069, 2081, 2083,
2087, 2089, 2099, 2111, 2113, 2129, 2131, 2137,
2141, 2143, 2153, 2161, 2179, 2203, 2207, 2213,
2221, 2237, 2239, 2243, 2251, 2267, 2269, 2273,
2281, 2287, 2293, 2297, 2309, 2311, 2333, 2339,
2341, 2347, 2351, 2357, 2371, 2377, 2381, 2383,
2389, 2393, 2399, 2411, 2417, 2423, 2437, 2441,
2447, 2459, 2467, 2473, 2477, 2503, 2521, 2531,
2539, 2543, 2549, 2551, 2557, 2579, 2591, 2593,
2609, 2617, 2621, 2633, 2647, 2657, 2659, 2663,
2671, 2677, 2683, 2687, 2689, 2693, 2699, 2707,
2711, 2713, 2719, 2729, 2731, 2741, 2749, 2753,
2767, 2777, 2789, 2791, 2797, 2801, 2803, 2819,
2833, 2837, 2843, 2851, 2857, 2861, 2879, 2887,
2897, 2903, 2909, 2917, 2927, 2939, 2953, 2957
};
uint64_t engine(
const unsigned char* buffer, size_t length,
uint64_t accumulator = 0,
const PrimeSet& primes = Primes
) noexcept;
}

uint32_t mishmash(const unsigned char* buffer, size_t length) noexcept;
uint32_t mishmash(const std::string &s) noexcept;
uint32_t mishmash(const std::vector<unsigned char>& v) noexcept;

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