Commit 172d8251 authored by Hallvard Furuseth's avatar Hallvard Furuseth
Browse files

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.
parent 68eda68f
...@@ -4965,31 +4965,21 @@ mdb_env_excl_lock(MDB_env *env, int *excl) ...@@ -4965,31 +4965,21 @@ mdb_env_excl_lock(MDB_env *env, int *excl)
* Share and Enjoy! :-) * Share and Enjoy! :-)
*/ */
#define MDB_HASH_INIT ((mdb_hash_t)0xcbf29ce484222325ULL)
/** perform a 64 bit Fowler/Noll/Vo FNV-1a hash on a buffer /** perform a 64 bit Fowler/Noll/Vo FNV-1a hash on a buffer
* @param[in] val value to hash * @param[in] val value to hash
* @param[in] hval initial value for hash * @param[in] len length of value
* @return 64 bit hash * @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 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 */ const unsigned char *s = (const unsigned char *) val, *end = s + len;
unsigned char *end = s + val->mv_size; mdb_hash_t hval = 0xcbf29ce484222325ULL;
/* /*
* FNV-1a hash each octet of the string * FNV-1a hash each octet of the buffer
*/ */
while (s < end) { while (s < end) {
/* xor the bottom with the current octet */ hval = (hval ^ *s++) * 0x100000001b3ULL;
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);
} }
/* return our new hash value */ /* return our new hash value */
return hval; return hval;
...@@ -5130,7 +5120,6 @@ mdb_env_setup_locks(MDB_env *env, MDB_name *fname, int mode, int *excl) ...@@ -5130,7 +5120,6 @@ mdb_env_setup_locks(MDB_env *env, MDB_name *fname, int mode, int *excl)
DWORD nhigh; DWORD nhigh;
DWORD nlow; DWORD nlow;
} idbuf; } idbuf;
MDB_val val;
if (!mdb_sec_inited) { if (!mdb_sec_inited) {
InitializeSecurityDescriptor(&mdb_null_sd, InitializeSecurityDescriptor(&mdb_null_sd,
...@@ -5145,9 +5134,7 @@ mdb_env_setup_locks(MDB_env *env, MDB_name *fname, int mode, int *excl) ...@@ -5145,9 +5134,7 @@ mdb_env_setup_locks(MDB_env *env, MDB_name *fname, int mode, int *excl)
idbuf.volume = stbuf.dwVolumeSerialNumber; idbuf.volume = stbuf.dwVolumeSerialNumber;
idbuf.nhigh = stbuf.nFileIndexHigh; idbuf.nhigh = stbuf.nFileIndexHigh;
idbuf.nlow = stbuf.nFileIndexLow; idbuf.nlow = stbuf.nFileIndexLow;
val.mv_data = &idbuf; env->me_txns->mti_mutexid = mdb_hash(&idbuf, sizeof(idbuf));
val.mv_size = sizeof(idbuf);
env->me_txns->mti_mutexid = mdb_hash_val(&val, MDB_HASH_INIT);
mdb_env_mname_init(env); mdb_env_mname_init(env);
env->me_rmutex = CreateMutexA(&mdb_all_sa, FALSE, MUTEXNAME(env, 'r')); env->me_rmutex = CreateMutexA(&mdb_all_sa, FALSE, MUTEXNAME(env, 'r'));
if (!env->me_rmutex) goto fail_errno; 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) ...@@ -5159,7 +5146,6 @@ mdb_env_setup_locks(MDB_env *env, MDB_name *fname, int mode, int *excl)
dev_t dev; dev_t dev;
ino_t ino; ino_t ino;
} idbuf; } idbuf;
MDB_val val;
#if defined(__NetBSD__) #if defined(__NetBSD__)
#define MDB_SHORT_SEMNAMES 1 /* limited to 14 chars */ #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) ...@@ -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; if (fstat(env->me_lfd, &stbuf)) goto fail_errno;
idbuf.dev = stbuf.st_dev; idbuf.dev = stbuf.st_dev;
idbuf.ino = stbuf.st_ino; idbuf.ino = stbuf.st_ino;
val.mv_data = &idbuf; env->me_txns->mti_mutexid = mdb_hash(&idbuf, sizeof(idbuf))
val.mv_size = sizeof(idbuf);
env->me_txns->mti_mutexid = mdb_hash_val(&val, MDB_HASH_INIT)
#ifdef MDB_SHORT_SEMNAMES #ifdef MDB_SHORT_SEMNAMES
/* Max 9 base85-digits. We truncate here instead of in /* Max 9 base85-digits. We truncate here instead of in
* mdb_env_mname_init() to keep the latter portable. * mdb_env_mname_init() to keep the latter portable.
......
Markdown is supported
0% or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment