MDEV-26: Global Transaction ID.

Improvements to record_gtid():

 - Check for correct table definition of mysql.rpl_slave_state
 - Use autocommit, to save one call to ha_commit_trans()
 - Slightly more efficient way to set table->write_set
 - Use ha_index_read_map() to locate rows to support any storage engine.

2 files changed, 66 insertions, 15 deletions

diff --git a/sql/log_event.cc b/sql/log_event.cc
index 33f3fb2c368..4431afa11e1 100644
--- a/sql/log_event.cc
+++ b/sql/log_event.cc
@@ -6280,6 +6280,44 @@ rpl_slave_state::truncate_state_table(THD *thd)
 }
 
 
+static const TABLE_FIELD_TYPE mysql_rpl_slave_state_coltypes[4]= {
+  { { C_STRING_WITH_LEN("domain_id") },
+    { C_STRING_WITH_LEN("int(10) unsigned") },
+    {NULL, 0} },
+  { { C_STRING_WITH_LEN("sub_id") },
+    { C_STRING_WITH_LEN("bigint(20) unsigned") },
+    {NULL, 0} },
+  { { C_STRING_WITH_LEN("server_id") },
+    { C_STRING_WITH_LEN("int(10) unsigned") },
+    {NULL, 0} },
+  { { C_STRING_WITH_LEN("seq_no") },
+    { C_STRING_WITH_LEN("bigint(20) unsigned") },
+    {NULL, 0} },
+};
+
+static const uint mysql_rpl_slave_state_pk_parts[]= {0, 1};
+
+static const TABLE_FIELD_DEF mysql_rpl_slave_state_tabledef= {
+  array_elements(mysql_rpl_slave_state_coltypes),
+  mysql_rpl_slave_state_coltypes,
+  array_elements(mysql_rpl_slave_state_pk_parts),
+  mysql_rpl_slave_state_pk_parts
+};
+
+class Gtid_db_intact : public Table_check_intact
+{
+protected:
+  void report_error(uint, const char *fmt, ...)
+  {
+    va_list args;
+    va_start(args, fmt);
+    error_log_print(ERROR_LEVEL, fmt, args);
+    va_end(args);
+  }
+};
+
+static Gtid_db_intact gtid_table_intact;
+
 /*
   Write a gtid to the replication slave state table.
 
@@ -6304,6 +6342,7 @@ rpl_slave_state::record_gtid(THD *thd, const rpl_gtid *gtid, uint64 sub_id,
   TABLE *table;
   list_element *elist= 0, *next;
   element *elem;
+  ulonglong thd_saved_option= thd->variables.option_bits;
 
   mysql_reset_thd_for_next_command(thd, 0);
 
@@ -6315,16 +6354,24 @@ rpl_slave_state::record_gtid(THD *thd, const rpl_gtid *gtid, uint64 sub_id,
     goto end;
   table_opened= true;
   table= tlist.table;
+
+  if ((err= gtid_table_intact.check(table, &mysql_rpl_slave_state_tabledef)))
+  {
+    my_error(ER_GTID_OPEN_TABLE_FAILED, MYF(0), "mysql",
+             rpl_gtid_slave_state_table_name.str);
+    goto end;
+  }
+
   table->no_replicate= 1;
+  if (!in_transaction)
+    thd->variables.option_bits&=
+      ~(ulonglong)(OPTION_NOT_AUTOCOMMIT|OPTION_BEGIN);
 
   /*
     ToDo: Check the table definition, error if not as expected.
     We need the correct first 4 columns with correct type, and the primary key.
   */
-  bitmap_set_bit(table->write_set, table->field[0]->field_index);
-  bitmap_set_bit(table->write_set, table->field[1]->field_index);
-  bitmap_set_bit(table->write_set, table->field[2]->field_index);
-  bitmap_set_bit(table->write_set, table->field[3]->field_index);
+  bitmap_set_all(table->write_set);
 
   table->field[0]->store((ulonglong)gtid->domain_id, true);
   table->field[1]->store(sub_id, true);
@@ -6347,24 +6394,28 @@ rpl_slave_state::record_gtid(THD *thd, const rpl_gtid *gtid, uint64 sub_id,
     goto end;
 
   /* Now delete any already committed rows. */
-  DBUG_ASSERT
-    ((table->file->ha_table_flags() & HA_PRIMARY_KEY_REQUIRED_FOR_POSITION) &&
-     table->s->primary_key < MAX_KEY /* ToDo support all storage engines */);
-
   bitmap_set_bit(table->read_set, table->field[0]->field_index);
   bitmap_set_bit(table->read_set, table->field[1]->field_index);
+
+  if ((err= table->file->ha_index_init(0, 0)))
+    goto end;
   while (elist)
   {
+    uchar key_buffer[4+8];
+
     next= elist->next;
 
     table->field[1]->store(elist->sub_id, true);
     /* domain_id is already set in table->record[0] from write_row() above. */
-    if ((err= table->file->ha_rnd_pos_by_record(table->record[0])) ||
-        (err= table->file->ha_delete_row(table->record[0])))
-      goto end;
+    key_copy(key_buffer, table->record[0], &table->key_info[0], 0, false);
+    if ((err= table->file->ha_index_read_map(table->record[1], key_buffer,
+                                             HA_WHOLE_KEY, HA_READ_KEY_EXACT)) ||
+        (err= table->file->ha_delete_row(table->record[1])))
+      break;
     my_free(elist);
     elist= next;
   }
+  table->file->ha_index_end();
 
 end:
 
@@ -6378,17 +6429,14 @@ end:
       */
       ha_rollback_trans(thd, FALSE);
       close_thread_tables(thd);
-      if (!in_transaction)
-        ha_rollback_trans(thd, TRUE);
     }
     else
     {
       ha_commit_trans(thd, FALSE);
       close_thread_tables(thd);
-      if (!in_transaction)
-        ha_commit_trans(thd, TRUE);
     }
   }
+  thd->variables.option_bits= thd_saved_option;
   return err;
 }
 
diff --git a/sql/share/errmsg-utf8.txt b/sql/share/errmsg-utf8.txt
index 5a6d632ad22..8c34fe90f30 100644
--- a/sql/share/errmsg-utf8.txt
+++ b/sql/share/errmsg-utf8.txt
@@ -6608,3 +6608,6 @@ ER_CANNOT_UPDATE_GTID_STATE
         eng "Could not update replication slave gtid state"
 ER_DUPLICATE_GTID_DOMAIN
 	eng "GTID %u-%u-%llu and %u-%u-%llu conflict (duplicate domain id %u)"
+ER_GTID_OPEN_TABLE_FAILED
+        eng "Failed to open %s.%s"
+        ger "Öffnen von %s.%s fehlgeschlagen"