refs #5142], add function for getting cursor on directory

git-svn-id: file:///svn/toku/tokudb@45158 c7de825b-a66e-492c-adef-691d508d4ae1

buildheader/make_tdb.c

@@ -363,6 +363,7 @@ static void print_db_env_struct (void) {
                              "int (*get_lock_timeout)                     (DB_ENV *env, uint64_t *lock_wait_time_msec)",
 			     "int (*txn_xa_recover)                       (DB_ENV*, TOKU_XA_XID list[/*count*/], long count, /*out*/ long *retp, u_int32_t flags)",
 			     "int (*get_txn_from_xid)                 (DB_ENV*, /*in*/ TOKU_XA_XID *, /*out*/ DB_TXN **)",
+			     "int (*get_cursor_for_directory)            (DB_ENV*, /*in*/ DB_TXN *, /*out*/ DBC **)",
                              NULL};
 
 	sort_and_dump_fields("db_env", true, extra);

src/ydb.c

@@ -2128,6 +2128,14 @@ toku_db_lt_panic(DB* db, int r) {
     return toku_ydb_do_error(env, r, "%s", panic_string);
 }
 
+static int
+env_get_cursor_for_directory(DB_ENV* env, DB_TXN* txn, DBC** c) {
+    if (!env_opened(env)) {
+        return EINVAL;
+    }
+    return toku_db_cursor(env->i->directory, txn, c, 0);
+}
+
 static int 
 toku_env_create(DB_ENV ** envp, u_int32_t flags) {
     int r = ENOSYS;
@@ -2197,8 +2205,9 @@ toku_env_create(DB_ENV ** envp, u_int32_t flags) {
     USENV(set_lock_timeout);
     USENV(set_redzone);
     USENV(log_flush);
-    USENV(log_archive);    
+    USENV(log_archive);
     USENV(create_loader);
+    USENV(get_cursor_for_directory);
 #undef USENV
     
     // unlocked methods