trx0trx.h, trx0trx.c, ha_innobase.cc, ha_innobase.h:

  Add tentative code which can be used in HANDLER implementation for InnoDB

innobase/include/trx0trx.h

@@ -117,6 +117,13 @@ void
 trx_start_if_not_started(
 /*=====================*/
 	trx_t*	trx);	/* in: transaction */
+/*****************************************************************
+Starts the transaction if it is not yet started. */
+
+void
+trx_start_if_not_started_noninline(
+/*===============================*/
+	trx_t*	trx);	/* in: transaction */
 /********************************************************************
 Commits a transaction. */
 

innobase/trx/trx0trx.c

@@ -39,6 +39,17 @@ sess_t*		trx_dummy_sess = NULL;
 the kernel mutex */
 ulint	trx_n_mysql_transactions = 0;
 
+/*****************************************************************
+Starts the transaction if it is not yet started. */
+
+void
+trx_start_if_not_started_noninline(
+/*===============================*/
+	trx_t*  trx) /* in: transaction */
+{
+        trx_start_if_not_started(trx);
+}
+
 /********************************************************************
 Retrieves the error_info field from a trx. */
 

sql/ha_innobase.cc

@@ -19,7 +19,7 @@ InnoDB */
   
 /* TODO list for the InnoDB handler:
   - Ask Monty if strings of different languages can exist in the same
-    database. Answer: in near future yes, but not yet.
+    database. Answer: in 4.1 yes.
 */
    
 #ifdef __GNUC__
@@ -378,6 +378,61 @@ ha_innobase::update_thd(
 	return(0);
 }
 
+/*********************************************************************
+Call this when you have opened a new table handle in HANDLER, before you
+call index_read_idx() etc. Actually, we can let the cursor stay open even
+over a transaction commit! Then you should call this before every operation,
+fecth next etc. This function inits the necessary things even after a
+transaction commit. */
+
+/* TODO: THIS CODE HAS NOT BEEN TESTED!!! */
+
+void
+ha_innobase::init_table_handle_for_HANDLER(void)
+/*============================================*/
+{
+        row_prebuilt_t* prebuilt;
+
+        /* If current thd does not yet have a trx struct, create one.
+        If the current handle does not yet have a prebuilt struct, create
+        one. Update the trx pointers in the prebuilt struct. Normally
+        this operation is done in external_lock. */
+
+        update_thd(current_thd);
+
+        /* Initialize the prebuilt struct much like it would be inited in
+        external_lock */
+
+        prebuilt = (row_prebuilt_t*)innobase_prebuilt;
+
+        /* If the transaction is not started yet, start it */
+
+        trx_start_if_not_started_noninline(prebuilt->trx);
+
+        /* Assign a read view if the transaction does not have it yet */
+
+        trx_assign_read_view(prebuilt->trx);
+
+        /* We did the necessary inits in this function, no need to repeat them
+        in row_search_for_mysql */
+
+        prebuilt->sql_stat_start = FALSE;
+
+        /* We let HANDLER always to do the reads as consistent reads, even
+        if the trx isolation level would have been specified as SERIALIZABLE */
+
+        prebuilt->select_lock_type = LOCK_NONE;
+
+        /* Always fetch all columns in the index record */
+
+        prebuilt->hint_no_need_to_fetch_extra_cols = FALSE;
+
+        /* We want always to fetch all columns in the whole row? Or do
+	we???? */
+
+        prebuilt->read_just_key = FALSE;
+}
+
 /*************************************************************************
 Opens an InnoDB database. */
 

sql/ha_innobase.h

@@ -157,6 +157,7 @@ class ha_innobase: public handler
 	void free_foreign_key_create_info(char* str);	
   	THR_LOCK_DATA **store_lock(THD *thd, THR_LOCK_DATA **to,
 			     		enum thr_lock_type lock_type);
+	void init_table_handle_for_HANDLER(); /* TODO: NOT TESTED!!! */
 	longlong get_auto_increment();
 };