get two 32 bit values from fnv for use in a hashing scheme that produces

k hashes

bfilter.c

@@ -88,14 +88,23 @@ unsetbit(bit_array_t* arr, int k) {
   return 0;
 }
 
-uint64_t
+bfilter_hashes_t
-get_index(int size, const char* value) {
+hash(const char* value) {
   uint64_t hval;
 
+  bfilter_hashes_t hashes;
+
   fnv64Init(&hval);
 
   fnv64UpdateBuffer(&hval, value, strlen(value));
-  return hval % size;
+
+  uint32_t n_0 = hval >> 32;
+  uint32_t n_1 = hval & 0x00000000ffffffff;
+
+  hashes.hash_1 = n_0;
+  hashes.hash_2 = n_1;
+
+  return hashes;
 }
 
 int
@@ -107,8 +116,9 @@ main (void) {
   setbit(test, 127);
   print_barray(test);
 
-  const char *test_string = "what is this I can't even, lololol";
+  const char *test_string = "what blah is this I can't even, lololol";
-  printf("%zu\n", get_index(5*32, test_string));
+  printf("%zu\n", hash(test_string).hash_1);
+  printf("%zu\n", hash(test_string).hash_2);
 
   return EXIT_SUCCESS;
 }

bfilter.h

@@ -6,13 +6,20 @@ typedef
   }
   bit_array_t;
 
+typedef
+  struct {
+    uint32_t hash_1;
+    uint32_t hash_2;
+  }
+  bfilter_hashes_t;
+
 int printbits(uint32_t, size_t);
 
 int print_barray(bit_array_t*);
 
 bit_array_t* new_bitarray(int);
 
-uint64_t get_index(int, const char*);
+bfilter_hashes_t hash(const char*);
 
 int setbit(bit_array_t*, int);
 int unsetbit(bit_array_t*, int);