feat(string): add SStrHashHT

storm/string/bjhash.cpp

@@ -0,0 +1,87 @@
+#include "storm/string/bjhash.hpp"
+
+#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); \
+    }
+
+uint32_t bjhash(uint8_t* k, uint32_t length, uint32_t initval) {
+    uint32_t a, b, c, len;
+
+    len = length;       // Set up the internal state
+    a = b = 0x9e3779b9; // The golden ratio; an arbitrary value
+    c = initval;        // The previous hash 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);
+    case 8:
+        // The first byte of c is reserved for the length
+        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];
+    case 0:;
+        // Nothing left to add
+    }
+    mix(a, b, c);
+
+    // Report the result
+    return c;
+}

storm/string/bjhash.hpp

@@ -0,0 +1,8 @@
+#ifndef STORM_STRING_BJ_HASH_HPP
+#define STORM_STRING_BJ_HASH_HPP
+
+#include <cstdint>
+
+uint32_t bjhash(uint8_t* k, uint32_t length, uint32_t initval);
+
+#endif