[t:3053], implement ha_tokudb::truncate

git-svn-id: file:///svn/mysql/tokudb-engine/tokudb-engine@25918 c7de825b-a66e-492c-adef-691d508d4ae1

storage/tokudb/ha_tokudb.cc

@@ -7078,6 +7078,15 @@ cleanup:
     return error;
 }
 
+
+//
+// for 5.5
+//
+int ha_tokudb::truncate() {
+    return delete_all_rows();
+}
+
+
 // delete all rows from a table
 //
 // effects: delete all of the rows in the main dictionary and all of the

storage/tokudb/ha_tokudb.h

@@ -492,6 +492,7 @@ public:
     // delete all rows from the table
     // effect: all dictionaries, including the main and indexes, should be empty
     int discard_or_import_tablespace(my_bool discard);
+    int truncate();
     int delete_all_rows();
     void extract_hidden_primary_key(uint keynr, DBT const *found_key);
     void read_key_only(uchar * buf, uint keynr, DBT const *found_key);