WL#5151: Conversion between different types when replicating

Row-based replication requires the types of columns on the
master and slave to be approximately the same (some safe
conversions between strings are allowed), but does not
allow safe conversions between fields of similar types such
as TINYINT and INT.

This patch implement type conversions between similar fields
on the master and slave.

The conversions are controlled using a new variable
SLAVE_TYPE_CONVERSIONS of type SET('ALL_LOSSY','ALL_NON_LOSSY').

Non-lossy conversions are any conversions that do not run the
risk of losing any information, while lossy conversions can
potentially truncate the value. The column definitions are
checked to decide if the conversion is acceptable.

If neither conversion is enabled, it is required that the
definitions of the columns are identical on master and slave.

Conversion is done by creating an internal conversion table,
unpacking the master data into it, and then copy the data to
the real table on the slave.

1 files changed, 14 insertions, 6 deletions

diff --git a/sql/rpl_rli.h b/sql/rpl_rli.h
index 171778d9675..7f04a3e5cdd 100644
--- a/sql/rpl_rli.h
+++ b/sql/rpl_rli.h
@@ -314,13 +314,21 @@ public:
   uint tables_to_lock_count;        /* RBR: Count of tables to lock */
   table_mapping m_table_map;      /* RBR: Mapping table-id to table */
 
-  inline table_def *get_tabledef(TABLE *tbl)
+  bool get_table_data(TABLE *table_arg, table_def **tabledef_var, TABLE **conv_table_var) const
   {
-    table_def *td= 0;
-    for (TABLE_LIST *ptr= tables_to_lock; ptr && !td; ptr= ptr->next_global)
-      if (ptr->table == tbl)
-        td= &((RPL_TABLE_LIST *)ptr)->m_tabledef;
-    return (td);
+    DBUG_ASSERT(tabledef_var && conv_table_var);
+    for (TABLE_LIST *ptr= tables_to_lock ; ptr != NULL ; ptr= ptr->next_global)
+      if (ptr->table == table_arg)
+      {
+        *tabledef_var= &static_cast<RPL_TABLE_LIST*>(ptr)->m_tabledef;
+        *conv_table_var= static_cast<RPL_TABLE_LIST*>(ptr)->m_conv_table;
+        DBUG_PRINT("debug", ("Fetching table data for table %s.%s:"
+                             " tabledef: %p, conv_table: %p",
+                             table_arg->s->db.str, table_arg->s->table_name.str,
+                             *tabledef_var, *conv_table_var));
+        return true;
+      }
+    return false;
   }
 
   /*