hash: cleanup fletcher

hash/adler.cpp

@@ -24,14 +24,17 @@
 
 static const unsigned MODULUS = 65521;
 
+//-----------------------------------------------------------------------------
 uint32_t
 adler32 (const void* restrict _data, size_t _size)
-    { return fletcher<32, MODULUS, 1, 0> (_data, _size); }
+{
+    return adler32 ((uint8_t*)_data, (uint8_t*)_data + _size);
+}
 
 
 //-----------------------------------------------------------------------------
 uint32_t
 adler32 (const uint8_t *first, const uint8_t *last)
 {
-    return adler32 (first, last - first);
+    return fletcher<32, MODULUS, 1, 0> (first, last - first);
 }

hash/fletcher.hpp

@@ -26,19 +26,27 @@
 #include <cstdlib>
 
 
-template <unsigned BITS, unsigned MODULUS, unsigned INITIAL_A, unsigned INITIAL_B>
+template <
-typename bits_type<BITS>::uint
+    unsigned OUTPUT,
-fletcher (const void *restrict _data, size_t size) {
+    unsigned MODULUS,
-    const uint8_t *restrict data = static_cast<const uint8_t*> (_data);
+    unsigned INITIAL_A,
-    typename bits_type<BITS>::uint A = INITIAL_A,
+    unsigned INITIAL_B
-                                   B = INITIAL_B;
+>
+typename bits_type<OUTPUT>::uint
+fletcher (const void *restrict _data,
+          size_t size)
+{
+    typedef typename bits_type<OUTPUT / 2>::uint temp_t;
+
+    auto data = static_cast<const uint8_t*> (_data);
+    temp_t A = INITIAL_A, B = INITIAL_B;
 
     for (size_t i = 0; i < size; ++i) {
         A = (A + data[i]) % MODULUS;
         B = (A +       B) % MODULUS;
     }
 
-    return (B << (BITS / 2)) | A;
+    return (B << (OUTPUT / 2u)) + A;
 }
 
 #endif

test/checksum.cpp

@@ -18,7 +18,8 @@ static const struct {
     const char *data;
     size_t      size;
 } TESTS[] = {
-    { 0xDF5B150C, 0x52FB, ALPHABET, strlen (ALPHABET) }
+    { 0xDF5B150C, 0x52FB, ALPHABET, strlen (ALPHABET) },
+    { 0x11E60398, 0x3DC8, "Wikipedia", strlen ("Wikipedia") }
 };