Factor me_metas[toggle] out to mdb_env_pick_meta()

diff --git a/libraries/liblmdb/mdb.c b/libraries/liblmdb/mdb.c
index 2d8d0567ad62a99f053dfaa44f62c7b467ddfc1d..820417d3d8c8dde8ef80c06ea378924a9d72f1b2 100644 (file)
--- a/libraries/liblmdb/mdb.c
+++ b/libraries/liblmdb/mdb.c
@@ -1255,7 +1255,7 @@ static int        mdb_page_split(MDB_cursor *mc, MDB_val *newkey, MDB_val *newdata,
                                pgno_t newpgno, unsigned int nflags);
 
 static int  mdb_env_read_header(MDB_env *env, MDB_meta *meta);
-static int  mdb_env_pick_meta(const MDB_env *env);
+static MDB_meta *mdb_env_pick_meta(const MDB_env *env);
 static int  mdb_env_write_meta(MDB_txn *txn);
 #ifdef MDB_USE_POSIX_MUTEX /* Drop unused excl arg */
 # define mdb_env_close0(env, excl) mdb_env_close1(env)
@@ -2560,7 +2560,7 @@ mdb_txn_renew0(MDB_txn *txn)
 
        if ((flags &= MDB_TXN_RDONLY) != 0) {
                if (!ti) {
-                       meta = env->me_metas[ mdb_env_pick_meta(env) ];
+                       meta = mdb_env_pick_meta(env);
                        txn->mt_txnid = meta->mm_txnid;
                        txn->mt_u.reader = NULL;
                } else {
@@ -2629,7 +2629,7 @@ mdb_txn_renew0(MDB_txn *txn)
                        txn->mt_txnid = ti->mti_txnid;
                        meta = env->me_metas[txn->mt_txnid & 1];
                } else {
-                       meta = env->me_metas[ mdb_env_pick_meta(env) ];
+                       meta = mdb_env_pick_meta(env);
                        txn->mt_txnid = meta->mm_txnid;
                }
                txn->mt_txnid++;
@@ -3771,12 +3771,13 @@ done:
 
 /** Check both meta pages to see which one is newer.
  * @param[in] env the environment handle
- * @return meta toggle (0 or 1).
+ * @return newest #MDB_meta.
  */
-static int
+static MDB_meta *
 mdb_env_pick_meta(const MDB_env *env)
 {
-       return (env->me_metas[0]->mm_txnid < env->me_metas[1]->mm_txnid);
+       MDB_meta *const *metas = env->me_metas;
+       return metas[ metas[0]->mm_txnid < metas[1]->mm_txnid ];
 }
 
 int ESECT
@@ -3900,7 +3901,7 @@ mdb_env_set_mapsize(MDB_env *env, size_t size)
                void *old;
                if (env->me_txn)
                        return EINVAL;
-               meta = env->me_metas[mdb_env_pick_meta(env)];
+               meta = mdb_env_pick_meta(env);
                if (!size)
                        size = meta->mm_mapsize;
                {
@@ -4107,12 +4108,12 @@ mdb_env_open2(MDB_env *env)
 
 #if MDB_DEBUG
        {
-               int toggle = mdb_env_pick_meta(env);
-               MDB_db *db = &env->me_metas[toggle]->mm_dbs[MAIN_DBI];
+               MDB_meta *meta = mdb_env_pick_meta(env);
+               MDB_db *db = &meta->mm_dbs[MAIN_DBI];
 
                DPRINTF(("opened database version %u, pagesize %u",
-                       env->me_metas[0]->mm_version, env->me_psize));
-               DPRINTF(("using meta page %d",    toggle));
+                       meta->mm_version, env->me_psize));
+               DPRINTF(("using meta page %d",    (int) (meta->mm_txnid & 1)));
                DPRINTF(("depth: %u",             db->md_depth));
                DPRINTF(("entries: %"Z"u",        db->md_entries));
                DPRINTF(("branch pages: %"Z"u",   db->md_branch_pages));
@@ -4199,9 +4200,10 @@ PIMAGE_TLS_CALLBACK mdb_tls_cbp = mdb_tls_callback;
 static int ESECT
 mdb_env_share_locks(MDB_env *env, int *excl)
 {
-       int rc = 0, toggle = mdb_env_pick_meta(env);
+       int rc = 0;
+       MDB_meta *meta = mdb_env_pick_meta(env);
 
-       env->me_txns->mti_txnid = env->me_metas[toggle]->mm_txnid;
+       env->me_txns->mti_txnid = meta->mm_txnid;
 
 #ifdef _WIN32
        {
@@ -9211,32 +9213,32 @@ mdb_stat0(MDB_env *env, MDB_db *db, MDB_stat *arg)
 int ESECT
 mdb_env_stat(MDB_env *env, MDB_stat *arg)
 {
-       int toggle;
+       MDB_meta *meta;
 
        if (env == NULL || arg == NULL)
                return EINVAL;
 
-       toggle = mdb_env_pick_meta(env);
+       meta = mdb_env_pick_meta(env);
 
-       return mdb_stat0(env, &env->me_metas[toggle]->mm_dbs[MAIN_DBI], arg);
+       return mdb_stat0(env, &meta->mm_dbs[MAIN_DBI], arg);
 }
 
 int ESECT
 mdb_env_info(MDB_env *env, MDB_envinfo *arg)
 {
-       int toggle;
+       MDB_meta *meta;
 
        if (env == NULL || arg == NULL)
                return EINVAL;
 
-       toggle = mdb_env_pick_meta(env);
-       arg->me_mapaddr = env->me_metas[toggle]->mm_address;
+       meta = mdb_env_pick_meta(env);
+       arg->me_mapaddr = meta->mm_address;
+       arg->me_last_pgno = meta->mm_last_pg;
+       arg->me_last_txnid = meta->mm_txnid;
+
        arg->me_mapsize = env->me_mapsize;
        arg->me_maxreaders = env->me_maxreaders;
        arg->me_numreaders = env->me_txns ? env->me_txns->mti_numreaders : 0;
-
-       arg->me_last_pgno = env->me_metas[toggle]->mm_last_pg;
-       arg->me_last_txnid = env->me_metas[toggle]->mm_txnid;
        return MDB_SUCCESS;
 }
 
@@ -9744,7 +9746,8 @@ mdb_reader_check0(MDB_env *env, int rlocked, int *dead)
 static int ESECT
 mdb_mutex_failed(MDB_env *env, mdb_mutexref_t mutex, int rc)
 {
-       int toggle, rlocked, rc2;
+       int rlocked, rc2;
+       MDB_meta *meta;
 
        if (rc == MDB_OWNERDEAD) {
                /* We own the mutex. Clean up after dead previous owner. */
@@ -9754,8 +9757,8 @@ mdb_mutex_failed(MDB_env *env, mdb_mutexref_t mutex, int rc)
                        /* Keep mti_txnid updated, otherwise next writer can
                         * overwrite data which latest meta page refers to.
                         */
-                       toggle = mdb_env_pick_meta(env);
-                       env->me_txns->mti_txnid = env->me_metas[toggle]->mm_txnid;
+                       meta = mdb_env_pick_meta(env);
+                       env->me_txns->mti_txnid = meta->mm_txnid;
                        /* env is hosed if the dead thread was ours */
                        if (env->me_txn) {
                                env->me_flags |= MDB_FATAL_ERROR;