Implement MySQL framework to support consistent read views in

cursors for InnoDB. The idea of the patch is that if MySQL requests
a consistent read view, we open one when open a cursor, set is as the
active view to a transaction when fetch from the cursor, and close
together with cursor close. This patch is associated to bugs #11813, 
#11832, and #11833. Contains after review fixes.

1 files changed, 29 insertions, 0 deletions

diff --git a/sql/ha_innodb.h b/sql/ha_innodb.h
index 1584a2182c9..2cbc1c8d91b 100644
--- a/sql/ha_innodb.h
+++ b/sql/ha_innodb.h
@@ -310,3 +310,32 @@ int innobase_xa_end(THD *thd);
 
 int innobase_repl_report_sent_binlog(THD *thd, char *log_file_name,
                                my_off_t end_offset);
+
+/***********************************************************************
+This function creates a consistent view for a cursor and start a transaction
+if it has not been started. This consistent view is then used inside of MySQL 
+when accesing records using a cursor. */
+
+void*
+innobase_create_cursor_view(void);
+/*=============================*/
+				/* out: Pointer to cursor view or NULL */
+
+/***********************************************************************
+This function closes the given consistent cursor view. Note that
+global read view is restored to a transaction and a transaction is
+started if it has not been started. */
+
+void
+innobase_close_cursor_view(
+/*=======================*/
+	void*	curview);	/* in: Consistent read view to be closed */
+
+/***********************************************************************
+This function sets the given consistent cursor view to a transaction.
+If a transaction does not exist, transaction is started. */
+
+void
+innobase_set_cursor_view(
+/*=====================*/
+	void*	curview);	/* in: Consistent read view to be closed */