MDEV-34705: Binlog-in-engine: Implement legacy SHOW MASTER STATUS

Signed-off-by: Kristian Nielsen <knielsen@knielsen-hq.org>

mysql-test/suite/binlog_in_engine/binlog_in_engine.result

@@ -14,6 +14,9 @@ DROP TABLE t1;
 SELECT @@GLOBAL.binlog_checksum;
 @@GLOBAL.binlog_checksum
 NONE
+SHOW MASTER STATUS;
+File	Position	Binlog_Do_DB	Binlog_Ignore_DB
+binlog-000000.ibb	767		
 CREATE TABLE t2 (a INT PRIMARY KEY, b VARCHAR(2048)) ENGINE=InnoDB;
 SET SESSION binlog_format= ROW;
 *** Do 1500 transactions ...

mysql-test/suite/binlog_in_engine/binlog_in_engine.test

@@ -19,6 +19,16 @@ SELECT * FROM t1 ORDER BY a;
 DROP TABLE t1;
 SELECT @@GLOBAL.binlog_checksum;
 
+# This output will depend on exact size of events, which might change over time.
+# If it changes, make the test abort after the SHOW MASTER STATUS, and check
+# that the reported new binlog position is correct, it should be the point
+# where the file starts containing only zero bytes.
+#
+# If this gets too annoying to do, we can replace this with something that
+# checks that the reported file and position is within some reasonable range
+# of the value left by current code.
+SHOW MASTER STATUS;
+
 CREATE TABLE t2 (a INT PRIMARY KEY, b VARCHAR(2048)) ENGINE=InnoDB;
 
 SET SESSION binlog_format= ROW;

sql/handler.h

@@ -1564,7 +1564,12 @@ struct handlerton
   void (*binlog_oob_free)(THD *thd, void *engine_data);
   /* Obtain an object to allow reading from the binlog. */
   handler_binlog_reader * (*get_binlog_reader)();
-  /* Obtain list of binlog files (SHOw BINARY LOGS). */
+  /*
+    Obtain the current position in the binlog.
+    Used to support legacy SHOW MASTER STATUS.
+  */
+  void (*binlog_status)(char out_filename[FN_REFLEN], ulonglong *out_pos);
+  /* Obtain list of binlog files (SHOW BINARY LOGS). */
   binlog_file_entry * (*get_binlog_file_list)(MEM_ROOT *mem_root);
   /*
     End the current binlog file, and create and switch to a new one.

sql/sql_repl.cc

@@ -5153,14 +5153,28 @@ bool show_binlog_info(THD* thd)
   protocol->prepare_for_resend();
 
   if (mysql_bin_log.is_open())
+  {
+    const char *base;
+    ulonglong pos;
+    if (opt_binlog_engine_hton)
+    {
+      char buf[FN_REFLEN];
+      mysql_mutex_lock(mysql_bin_log.get_log_lock());
+      (*opt_binlog_engine_hton->binlog_status)(buf, &pos);
+      mysql_mutex_unlock(mysql_bin_log.get_log_lock());
+      base= buf;
+    }
+    else
     {
       LOG_INFO li;
       mysql_bin_log.get_current_log(&li);
+      pos= (ulonglong) li.pos;
       size_t dir_len = dirname_length(li.log_file_name);
-    const char *base= li.log_file_name + dir_len;
+      base= li.log_file_name + dir_len;
+    }
 
     protocol->store(base, strlen(base), &my_charset_bin);
-    protocol->store((ulonglong) li.pos);
+    protocol->store(pos);
     protocol->store(binlog_filter->get_do_db());
     protocol->store(binlog_filter->get_ignore_db());
     if (protocol->write())

storage/innobase/handler/ha_innodb.cc

@@ -4135,6 +4135,7 @@ static int innodb_init(void* p)
         innobase_hton->binlog_oob_free= innodb_free_oob;
         innobase_hton->get_binlog_reader= innodb_get_binlog_reader;
         innobase_hton->get_binlog_file_list= innodb_get_binlog_file_list;
+        innobase_hton->binlog_status= innodb_binlog_status;
         innobase_hton->binlog_flush= innodb_binlog_flush;
         innobase_hton->binlog_get_init_state= innodb_binlog_get_init_state;
         innobase_hton->reset_binlogs= innodb_reset_binlogs;

storage/innobase/handler/innodb_binlog.cc

@@ -2219,6 +2219,19 @@ innodb_find_binlogs(uint64_t *out_first, uint64_t *out_last)
 }
 
 
+void
+innodb_binlog_status(char out_filename[FN_REFLEN], ulonglong *out_pos)
+{
+  static_assert(BINLOG_NAME_MAX_LEN <= FN_REFLEN,
+                "FN_REFLEN too shot to hold InnoDB binlog name");
+  uint64_t file_no= active_binlog_file_no.load(std::memory_order_relaxed);
+  uint32_t page_no= binlog_cur_page_no;
+  uint32_t in_page_offset= binlog_cur_page_offset;
+  binlog_name_make_short(out_filename, file_no);
+  *out_pos= ((ulonglong)page_no << srv_page_size_shift) | in_page_offset;
+}
+
+
 bool
 innodb_binlog_get_init_state(rpl_binlog_state_base *out_state)
 {

storage/innobase/include/innodb_binlog.h

@@ -135,6 +135,8 @@ extern bool innobase_binlog_write_direct
   (IO_CACHE *cache, handler_binlog_event_group_info *binlog_info,
    const rpl_gtid *gtid);
 extern bool innodb_find_binlogs(uint64_t *out_first, uint64_t *out_last);
+extern void innodb_binlog_status(char out_filename[FN_REFLEN],
+                                 ulonglong *out_pos);
 extern bool innodb_binlog_get_init_state(rpl_binlog_state_base *out_state);
 extern bool innodb_reset_binlogs();
 extern int innodb_binlog_purge(handler_binlog_purge_info *purge_info);