index 3d927e1fb18ace6bc5317bd7db2ab18389232ff9..63ebe295c5f5f49854730e28bb11b909c1bc80b2 100644 (file)
* in fasthash_accum_cstring() :
*
* fasthash_state hs;
- * fasthash_init(&hs, FH_UNKNOWN_LENGTH, 0);
+ * fasthash_init(&hs, 0);
* len = fasthash_accum_cstring(&hs, *str);
* ...
* return fasthash_final32(&hs, len);
*
- * Here we pass FH_UNKNOWN_LENGTH as a convention, since passing zero
- * would zero out the internal seed as well. fasthash_accum_cstring()
- * returns the length of the string, which is computed on-the-fly while
- * mixing the string into the hash. Experimentation has found that
+ * The length is computed on-the-fly. Experimentation has found that
* SMHasher fails unless we incorporate the length, so it is passed to
* the finalizer as a tweak.
*/
#define FH_SIZEOF_ACCUM sizeof(uint64)
-#define FH_UNKNOWN_LENGTH 1
/*
* Initialize the hash state.
*
- * 'len' is the length of the input, if known ahead of time.
- * If that is not known, pass FH_UNKNOWN_LENGTH.
* 'seed' can be zero.
*/
static inline void
-fasthash_init(fasthash_state *hs, int len, uint64 seed)
+fasthash_init(fasthash_state *hs, uint64 seed)
{
memset(hs, 0, sizeof(fasthash_state));
- hs->hash = seed ^ (len * 0x880355f21e6d1965);
+ hs->hash = seed ^ 0x880355f21e6d1965;
}
/* both the finalizer and part of the combining step */
@@ -328,7 +322,10 @@ fasthash64(const char *k, int len, uint64 seed)
{
fasthash_state hs;
- fasthash_init(&hs, len, seed);
+ fasthash_init(&hs, 0);
+
+ /* re-initialize the seed according to input length */
+ hs.hash = seed ^ (len * 0x880355f21e6d1965);
while (len >= FH_SIZEOF_ACCUM)
{