Simplify mdb_hash_val() -> mdb_hash()

Simpler usage since it's only called once, rename to match new usage,
and drop 3 loop pessimizations which were optimizations 20 years ago.

diff --git a/libraries/liblmdb/mdb.c b/libraries/liblmdb/mdb.c
index d28f42ae9366c7fdc832f2139de4b80a4c90c6d7..e2b48589e092645586637a687c6a1958fdbe03f4 100644 (file)
--- a/libraries/liblmdb/mdb.c
+++ b/libraries/liblmdb/mdb.c
@@ -4965,31 +4965,21 @@ mdb_env_excl_lock(MDB_env *env, int *excl)
  * Share and Enjoy!    :-)
  */
 
-#define MDB_HASH_INIT ((mdb_hash_t)0xcbf29ce484222325ULL)
-
 /** perform a 64 bit Fowler/Noll/Vo FNV-1a hash on a buffer
  * @param[in] val      value to hash
- * @param[in] hval     initial value for hash
+ * @param[in] len      length of value
  * @return 64 bit hash
- *
- * NOTE: To use the recommended 64 bit FNV-1a hash, use MDB_HASH_INIT as the
- *      hval arg on the first call.
  */
 static mdb_hash_t
-mdb_hash_val(MDB_val *val, mdb_hash_t hval)
+mdb_hash(const void *val, size_t len)
 {
-       unsigned char *s = (unsigned char *)val->mv_data;       /* unsigned string */
-       unsigned char *end = s + val->mv_size;
+       const unsigned char *s = (const unsigned char *) val, *end = s + len;
+       mdb_hash_t hval = 0xcbf29ce484222325ULL;
        /*
-        * FNV-1a hash each octet of the string
+        * FNV-1a hash each octet of the buffer
         */
        while (s < end) {
-               /* xor the bottom with the current octet */
-               hval ^= (mdb_hash_t)*s++;
-
-               /* multiply by the 64 bit FNV magic prime mod 2^64 */
-               hval += (hval << 1) + (hval << 4) + (hval << 5) +
-                       (hval << 7) + (hval << 8) + (hval << 40);
+               hval = (hval ^ *s++) * 0x100000001b3ULL;
        }
        /* return our new hash value */
        return hval;
@@ -5130,7 +5120,6 @@ mdb_env_setup_locks(MDB_env *env, MDB_name *fname, int mode, int *excl)
                        DWORD nhigh;
                        DWORD nlow;
                } idbuf;
-               MDB_val val;
 
                if (!mdb_sec_inited) {
                        InitializeSecurityDescriptor(&mdb_null_sd,
@@ -5145,9 +5134,7 @@ mdb_env_setup_locks(MDB_env *env, MDB_name *fname, int mode, int *excl)
                idbuf.volume = stbuf.dwVolumeSerialNumber;
                idbuf.nhigh  = stbuf.nFileIndexHigh;
                idbuf.nlow   = stbuf.nFileIndexLow;
-               val.mv_data = &idbuf;
-               val.mv_size = sizeof(idbuf);
-               env->me_txns->mti_mutexid = mdb_hash_val(&val, MDB_HASH_INIT);
+               env->me_txns->mti_mutexid = mdb_hash(&idbuf, sizeof(idbuf));
                mdb_env_mname_init(env);
                env->me_rmutex = CreateMutexA(&mdb_all_sa, FALSE, MUTEXNAME(env, 'r'));
                if (!env->me_rmutex) goto fail_errno;
@@ -5159,7 +5146,6 @@ mdb_env_setup_locks(MDB_env *env, MDB_name *fname, int mode, int *excl)
                        dev_t dev;
                        ino_t ino;
                } idbuf;
-               MDB_val val;
 
 #if defined(__NetBSD__)
 #define        MDB_SHORT_SEMNAMES      1       /* limited to 14 chars */
@@ -5167,9 +5153,7 @@ mdb_env_setup_locks(MDB_env *env, MDB_name *fname, int mode, int *excl)
                if (fstat(env->me_lfd, &stbuf)) goto fail_errno;
                idbuf.dev = stbuf.st_dev;
                idbuf.ino = stbuf.st_ino;
-               val.mv_data = &idbuf;
-               val.mv_size = sizeof(idbuf);
-               env->me_txns->mti_mutexid = mdb_hash_val(&val, MDB_HASH_INIT)
+               env->me_txns->mti_mutexid = mdb_hash(&idbuf, sizeof(idbuf))
 #ifdef MDB_SHORT_SEMNAMES
                        /* Max 9 base85-digits.  We truncate here instead of in
                         * mdb_env_mname_init() to keep the latter portable.