MDEV-19855: Create "Sql_cmd_show_slave_status" class for "SHOW SLAVE STATUS" command.

Create "Sql_cmd_show_slave_status" class for "SHOW SLAVE STATUS" command.

sql/slave.cc

@@ -1646,6 +1646,40 @@ const char *print_slave_db_safe(const char* db)
 
 #endif /* HAVE_REPLICATION */
 
+bool Sql_cmd_show_slave_status::execute(THD *thd)
+{
+#ifndef HAVE_REPLICATION
+  my_ok(thd);
+  return false;
+#else
+  DBUG_ENTER("Sql_cmd_show_slave_status::execute");
+  bool res= true;
+
+  /* Accept one of two privileges */
+  if (check_global_access(thd, SUPER_ACL | REPL_CLIENT_ACL))
+    goto error;
+  if (is_show_all_slaves_stat())
+  {
+    mysql_mutex_lock(&LOCK_active_mi);
+    res= show_all_master_info(thd);
+    mysql_mutex_unlock(&LOCK_active_mi);
+  }
+  else
+  {
+    LEX_MASTER_INFO *lex_mi= &thd->lex->mi;
+    Master_info *mi;
+    if ((mi= get_master_info(&lex_mi->connection_name,
+                             Sql_condition::WARN_LEVEL_ERROR)))
+    {
+      res= show_master_info(thd, mi, 0);
+      mi->release();
+    }
+  }
+error:
+  DBUG_RETURN(res);
+#endif
+}
+
 int init_strvar_from_file(char *var, int max_size, IO_CACHE *f,
                                  const char *default_val)
 {

sql/sql_cmd.h

@@ -208,6 +208,26 @@ class Sql_cmd : public Sql_alloc
   }
 };
 
+class Sql_cmd_show_slave_status: public Sql_cmd
+{
+protected:
+  bool show_all_slaves_status;
+public:
+  Sql_cmd_show_slave_status()
+    :show_all_slaves_status(false)
+  {}
+
+  Sql_cmd_show_slave_status(bool status_all)
+    :show_all_slaves_status(status_all)
+  {}
+
+  enum_sql_command sql_command_code() const { return SQLCOM_SHOW_SLAVE_STAT; }
+
+  bool execute(THD *thd);
+  bool is_show_all_slaves_stat() { return show_all_slaves_status; }
+};
+
+
 class Sql_cmd_create_table_like: public Sql_cmd,
                                  public Storage_engine_name
 {

sql/sql_parse.cc

@@ -4079,31 +4079,7 @@ mysql_execute_command(THD *thd)
     mysql_mutex_unlock(&LOCK_active_mi);
     break;
   }
-  case SQLCOM_SHOW_SLAVE_STAT:
-  {
-    /* Accept one of two privileges */
-    if (check_global_access(thd, SUPER_ACL | REPL_CLIENT_ACL))
-      goto error;
 
-    if (lex->verbose)
-    {
-      mysql_mutex_lock(&LOCK_active_mi);
-      res= show_all_master_info(thd);
-      mysql_mutex_unlock(&LOCK_active_mi);
-    }
-    else
-    {
-      LEX_MASTER_INFO *lex_mi= &thd->lex->mi;
-      Master_info *mi;
-      if ((mi= get_master_info(&lex_mi->connection_name,
-                               Sql_condition::WARN_LEVEL_ERROR)))
-      {
-        res= show_master_info(thd, mi, 0);
-        mi->release();
-      }
-    }
-    break;
-  }
   case SQLCOM_SHOW_MASTER_STAT:
   {
     /* Accept one of two privileges */
@@ -6074,6 +6050,7 @@ mysql_execute_command(THD *thd)
       DBUG_ASSERT(first_table == all_tables && first_table != 0);
     /* fall through */
   case SQLCOM_ALTER_SEQUENCE:
+  case SQLCOM_SHOW_SLAVE_STAT:
   case SQLCOM_SIGNAL:
   case SQLCOM_RESIGNAL:
   case SQLCOM_GET_DIAGNOSTICS:

sql/sql_prepare.cc

@@ -1933,14 +1933,15 @@ static int mysql_test_show_grants(Prepared_statement *stmt)
     TRUE              error, error message is set in THD
 */
 
-static int mysql_test_show_slave_status(Prepared_statement *stmt)
+static int mysql_test_show_slave_status(Prepared_statement *stmt,
+                                        bool show_all_slaves_stat)
 {
   DBUG_ENTER("mysql_test_show_slave_status");
   THD *thd= stmt->thd;
   List<Item> fields;
 
-  show_master_info_get_fields(thd, &fields, thd->lex->verbose, 0);
-    
+  show_master_info_get_fields(thd, &fields, show_all_slaves_stat, 0);
+
   DBUG_RETURN(send_stmt_metadata(thd, stmt, &fields));
 }
 
@@ -2393,12 +2394,20 @@ static bool check_prepared_statement(Prepared_statement *stmt)
 #endif /* NO_EMBEDDED_ACCESS_CHECKS */
 #ifndef EMBEDDED_LIBRARY
   case SQLCOM_SHOW_SLAVE_STAT:
-    if ((res= mysql_test_show_slave_status(stmt)) == 2)
     {
-      /* Statement and field info has already been sent */
-      DBUG_RETURN(FALSE);
+      DBUG_ASSERT(thd->lex->m_sql_cmd);
+      Sql_cmd_show_slave_status *cmd;
+      cmd= dynamic_cast<Sql_cmd_show_slave_status*>(thd->lex->m_sql_cmd);
+      DBUG_ASSERT(cmd);
+      if ((res= mysql_test_show_slave_status(stmt,
+                                             cmd->is_show_all_slaves_stat()))
+                                             == 2)
+      {
+        /* Statement and field info has already been sent */
+        DBUG_RETURN(FALSE);
+      }
+      break;
     }
-    break;
   case SQLCOM_SHOW_MASTER_STAT:
     if ((res= mysql_test_show_master_status(stmt)) == 2)
     {

sql/sql_yacc.yy

@@ -14205,20 +14205,26 @@ show_param:
           }
         | ALL SLAVES STATUS_SYM
           {
+            if (!(Lex->m_sql_cmd= new (thd->mem_root)
+                  Sql_cmd_show_slave_status(true)))
+              MYSQL_YYABORT;
             Lex->sql_command = SQLCOM_SHOW_SLAVE_STAT;
-            Lex->verbose= 1;
           }
         | SLAVE STATUS_SYM
           {
             LEX *lex= thd->lex;
             lex->mi.connection_name= null_clex_str;
+            if (!(lex->m_sql_cmd= new (thd->mem_root)
+                  Sql_cmd_show_slave_status()))
+              MYSQL_YYABORT;
             lex->sql_command = SQLCOM_SHOW_SLAVE_STAT;
-            lex->verbose= 0;
           }
         | SLAVE connection_name STATUS_SYM
           {
+            if (!(Lex->m_sql_cmd= new (thd->mem_root)
+                  Sql_cmd_show_slave_status()))
+              MYSQL_YYABORT;
             Lex->sql_command = SQLCOM_SHOW_SLAVE_STAT;
-            Lex->verbose= 0;
           }
         | CREATE PROCEDURE_SYM sp_name
           {

sql/sql_yacc_ora.yy

@@ -14329,19 +14329,25 @@ show_param:
         | ALL SLAVES STATUS_SYM
           {
             Lex->sql_command = SQLCOM_SHOW_SLAVE_STAT;
-            Lex->verbose= 1;
+            if (!(Lex->m_sql_cmd= new (thd->mem_root)
+                  Sql_cmd_show_slave_status(true)))
+              MYSQL_YYABORT;
           }
         | SLAVE STATUS_SYM
           {
             LEX *lex= thd->lex;
             lex->mi.connection_name= null_clex_str;
             lex->sql_command = SQLCOM_SHOW_SLAVE_STAT;
-            lex->verbose= 0;
+            if (!(lex->m_sql_cmd= new (thd->mem_root)
+                  Sql_cmd_show_slave_status()))
+              MYSQL_YYABORT;
           }
         | SLAVE connection_name STATUS_SYM
           {
             Lex->sql_command = SQLCOM_SHOW_SLAVE_STAT;
-            Lex->verbose= 0;
+            if (!(Lex->m_sql_cmd= new (thd->mem_root)
+                  Sql_cmd_show_slave_status()))
+              MYSQL_YYABORT;
           }
         | CREATE PROCEDURE_SYM sp_name
           {