Add mdb_env_info() to retrieve interesting env params

diff --git a/libraries/libmdb/mdb.c b/libraries/libmdb/mdb.c
index 9fd7db3c898f14df437f6e2b2b4136e25419be24..f3c482d8883f014277583e8e8166da7b8310bebb 100644 (file)
--- a/libraries/libmdb/mdb.c
+++ b/libraries/libmdb/mdb.c
@@ -6651,6 +6651,23 @@ mdb_env_stat(MDB_env *env, MDB_stat *arg)
        return mdb_stat0(env, &env->me_metas[toggle]->mm_dbs[MAIN_DBI], arg);
 }
 
+int
+mdb_env_info(MDB_env *env, MDB_envinfo *arg)
+{
+       int toggle;
+
+       if (env == NULL || arg == NULL)
+               return EINVAL;
+
+       toggle = mdb_env_pick_meta(env);
+       arg->me_mapsize = env->me_mapsize;
+       arg->me_maxreaders = env->me_maxreaders;
+       arg->me_numreaders = env->me_numreaders;
+       arg->me_last_txnid = env->me_metas[toggle]->mm_txnid;
+       arg->me_last_pgno = env->me_metas[toggle]->mm_last_pg;
+       return MDB_SUCCESS;
+}
+
 /** Set the default comparison functions for a database.
  * Called immediately after a database is opened to set the defaults.
  * The user can then override them with #mdb_set_compare() or

diff --git a/libraries/libmdb/mdb.h b/libraries/libmdb/mdb.h
index d78868cb08a8cae9c3febbf156fdb6607e2abd8c..739fee7265eb43303c72d5d072e8486f6195b2ef 100644 (file)
--- a/libraries/libmdb/mdb.h
+++ b/libraries/libmdb/mdb.h
@@ -358,6 +358,15 @@ typedef struct MDB_stat {
        size_t          ms_entries;                     /**< Number of data items */
 } MDB_stat;
 
+/** @brief Information about the environment */
+typedef struct MDB_envinfo {
+       size_t  me_mapsize;                             /**< Size of the data memory map */
+       size_t  me_last_txnid;                  /**< ID of the last committed transaction */
+       size_t  me_last_pgno;                   /**< ID of the last used page */
+       unsigned int me_maxreaders;             /**< maximum number of threads for the environment */
+       unsigned int me_numreaders;             /**< maximum number of threads used in the environment */
+} MDB_envinfo;
+
        /** @brief Return the mdb library version information.
         *
         * @param[out] major if non-NULL, the library major version number is copied here
@@ -471,6 +480,14 @@ int  mdb_env_copy(MDB_env *env, const char *path);
         */
 int  mdb_env_stat(MDB_env *env, MDB_stat *stat);
 
+       /** @brief Return information about the MDB environment.
+        *
+        * @param[in] env An environment handle returned by #mdb_env_create()
+        * @param[out] stat The address of an #MDB_envinfo structure
+        *      where the information will be copied
+        */
+int  mdb_env_info(MDB_env *env, MDB_envinfo *stat);
+
        /** @brief Flush the data buffers to disk.
         *
         * Data is always written to disk when #mdb_txn_commit() is called,

diff --git a/libraries/libmdb/mdb_stat.c b/libraries/libmdb/mdb_stat.c
index 73891cfcdb60e5803a9eade8b6767d6d68cd9903..8b196d17577013d422acecabba1bee66a30348c3 100644 (file)
--- a/libraries/libmdb/mdb_stat.c
+++ b/libraries/libmdb/mdb_stat.c
@@ -40,10 +40,11 @@ int main(int argc, char *argv[])
        MDB_txn *txn;
        MDB_dbi dbi;
        MDB_stat mst;
+       MDB_envinfo mei;
        char *prog = argv[0];
        char *envname;
        char *subname = NULL;
-       int alldbs = 0;
+       int alldbs = 0, envinfo = 0;
 
        if (argc < 2) {
                usage(prog);
@@ -51,13 +52,17 @@ int main(int argc, char *argv[])
 
        /* -a: print stat of main DB and all subDBs
         * -s: print stat of only the named subDB
+        * -e: print env info
         * (default) print stat of only the main DB
         */
-       while ((i = getopt(argc, argv, "as:")) != EOF) {
+       while ((i = getopt(argc, argv, "aes:")) != EOF) {
                switch(i) {
                case 'a':
                        alldbs++;
                        break;
+               case 'e':
+                       envinfo++;
+                       break;
                case 's':
                        subname = optarg;
                        break;
@@ -87,6 +92,16 @@ int main(int argc, char *argv[])
                printf("mdb_txn_begin failed, error %d %s\n", rc, mdb_strerror(rc));
                goto env_close;
        }
+
+       if (envinfo) {
+               rc = mdb_env_info(env, &mei);
+               printf("Map size: %zu \n", mei.me_mapsize);
+               printf("Last transaction ID: %zu\n", mei.me_last_txnid);
+               printf("Last page used: %zu\n", mei.me_last_pgno);
+               printf("Max readers: %u\n", mei.me_maxreaders);
+               printf("Number of readers used: %u\n", mei.me_numreaders);
+       }
+
        rc = mdb_open(txn, subname, 0, &dbi);
        if (rc) {
                printf("mdb_open failed, error %d %s\n", rc, mdb_strerror(rc));