MDEV-23844 Atomic DROP TABLE (single table)

Logging logic:
- Log tables, just before they are dropped, to the ddl log
- After the last table for the statement is dropped, log an xid for the
  whole ddl log event

In case of crash:
- Remove first any active DROP TABLE events from the ddl log that matches
  xids found in binary log (this mean the drop was successful and was
  propery logged).
- Loop over all active DROP TABLE events
  - Ensure that the table is completely dropped
- Write a DROP TABLE entry to the binary log with the dropped tables.

Other things:
- Added code to ha_drop_table() to be able to tell the difference if
  a get_new_handler() failed because of out-of-memory or because the
  handler refused/was not able to create a a handler. This was needed
  to get sequences to work as sequences needs a share object to be passed
  to get_new_handler()
- TC_LOG_BINLOG::recover() was changed to always collect Xid's from the
  binary log and always call ddl_log_close_binlogged_events(). This was
  needed to be able to collect DROP TABLE events with embedded Xid's
  (used by ddl log).
- Added a new variable "$grep_script" to binlog filter to be able to find
  only rows that matches a regexp.
- Had to adjust some test that changed because drop statements are a bit
  larger in the binary log than before (as we have to store the xid)

Other things:
- MDEV-25588 Atomic DDL: Binlog query event written upon recovery is corrupt
  fixed (in the original commit).

1 files changed, 5 insertions, 3 deletions

diff --git a/sql/log.cc b/sql/log.cc
index 519dc3e63b3..f1fef44e05f 100644
--- a/sql/log.cc
+++ b/sql/log.cc
@@ -9982,6 +9982,7 @@ int TC_LOG::using_heuristic_recover()
 int TC_LOG_BINLOG::open(const char *opt_name)
 {
   int      error= 1;
+  DBUG_ENTER("TC_LOG_BINLOG::open");
 
   DBUG_ASSERT(total_ha_2pc > 1);
   DBUG_ASSERT(opt_name);
@@ -9991,7 +9992,7 @@ int TC_LOG_BINLOG::open(const char *opt_name)
   {
     /* There was a failure to open the index file, can't open the binlog */
     cleanup();
-    return 1;
+    DBUG_RETURN(1);
   }
 
   if (using_heuristic_recover())
@@ -10001,12 +10002,12 @@ int TC_LOG_BINLOG::open(const char *opt_name)
     open(opt_name, 0, 0, WRITE_CACHE, max_binlog_size, 0, TRUE);
     mysql_mutex_unlock(&LOCK_log);
     cleanup();
-    return 1;
+    DBUG_RETURN(1);
   }
 
   error= do_binlog_recovery(opt_name, true);
   binlog_state_recover_done= true;
-  return error;
+  DBUG_RETURN(error);
 }
 
 /** This is called on shutdown, after ha_panic. */
@@ -10536,6 +10537,7 @@ int TC_LOG_BINLOG::recover(LOG_INFO *linfo, const char *last_log_name,
         Query_log_event *query_ev= (Query_log_event*) ev;
         if (query_ev->xid)
         {
+          DBUG_PRINT("QQ", ("xid: %llu xid"));
           DBUG_ASSERT(sizeof(query_ev->xid) == sizeof(my_xid));
           uchar *x= (uchar *) memdup_root(&mem_root,
                                           (uchar*) &query_ev->xid,