refined mishmash with masher namespace

mishmash.cpp

@@ -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

mishmash.hpp

@@ -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;