MDEV-9058: protocol: COM_MULTI command (part 2)

simple COM_MULTI support (no prepared statements chain yet).

include/mysql_com.h

@@ -235,6 +235,8 @@ enum enum_server_command
 #define MARIADB_CLIENT_FLAGS_MASK 0xffffffff00000000ULL
 /* Client support progress indicator */
 #define MARIADB_CLIENT_PROGRESS (1ULL << 32)
+/* support COM_MULTI */
+#define MARIADB_CLIENT_COM_MULTI (1ULL << 33)
 
 #ifdef HAVE_COMPRESS
 #define CAN_CLIENT_COMPRESS CLIENT_COMPRESS
@@ -271,7 +273,8 @@ enum enum_server_command
                            MARIADB_CLIENT_PROGRESS | \
                            CLIENT_PLUGIN_AUTH | \
                            CLIENT_PLUGIN_AUTH_LENENC_CLIENT_DATA | \
-                           CLIENT_CONNECT_ATTRS)
+                           CLIENT_CONNECT_ATTRS |\
+                           MARIADB_CLIENT_COM_MULTI)
 
 /*
   To be added later:

libmysqld/lib_sql.cc

@@ -165,7 +165,7 @@ emb_advanced_command(MYSQL *mysql, enum enum_server_command command,
     arg_length= header_length;
   }
 
-  result= dispatch_command(command, thd, (char *) arg, arg_length);
+  result= dispatch_command(command, thd, (char *) arg, arg_length, FALSE);
   thd->cur_data= 0;
   thd->mysys_var= NULL;
 

sql/log_event.cc

@@ -4429,7 +4429,8 @@ int Query_log_event::do_apply_event(rpl_group_info *rgi,
           thd->m_digest->reset(thd->m_token_array, max_digest_length);
 
         thd->enable_slow_log= thd->variables.sql_log_slow;
-        mysql_parse(thd, thd->query(), thd->query_length(), &parser_state);
+        mysql_parse(thd, thd->query(), thd->query_length(), &parser_state,
+                    FALSE);
         /* Finalize server status flags after executing a statement. */
         thd->update_server_status();
         log_slow_statement(thd);

sql/net_serv.cc

@@ -121,6 +121,8 @@ extern my_bool thd_net_is_killed();
 
 static my_bool net_write_buff(NET *, const uchar *, ulong);
 
+my_bool net_allocate_new_packet(NET *net, void *thd, uint my_flags);
+
 /** Init with packet info. */
 
 my_bool my_net_init(NET *net, Vio *vio, void *thd, uint my_flags)
@@ -129,14 +131,12 @@ my_bool my_net_init(NET *net, Vio *vio, void *thd, uint my_flags)
   DBUG_PRINT("enter", ("my_flags: %u", my_flags));
   net->vio = vio;
   my_net_local_init(net);			/* Set some limits */
-  if (!(net->buff=(uchar*) my_malloc((size_t) net->max_packet+
-				     NET_HEADER_SIZE + COMP_HEADER_SIZE +1,
-				     MYF(MY_WME | my_flags))))
+
+  if (net_allocate_new_packet(net, thd, my_flags))
     DBUG_RETURN(1);
-  net->buff_end=net->buff+net->max_packet;
+
   net->error=0; net->return_status=0;
   net->pkt_nr=net->compress_pkt_nr=0;
-  net->write_pos=net->read_pos = net->buff;
   net->last_error[0]=0;
   net->compress=0; net->reading_or_writing=0;
   net->where_b = net->remain_in_buf=0;
@@ -165,6 +165,18 @@ my_bool my_net_init(NET *net, Vio *vio, void *thd, uint my_flags)
   DBUG_RETURN(0);
 }
 
+my_bool net_allocate_new_packet(NET *net, void *thd, uint my_flags)
+{
+  DBUG_ENTER("net_allocate_new_packet");
+  if (!(net->buff=(uchar*) my_malloc((size_t) net->max_packet+
+				     NET_HEADER_SIZE + COMP_HEADER_SIZE +1,
+				     MYF(MY_WME | my_flags))))
+    DBUG_RETURN(1);
+  net->buff_end=net->buff+net->max_packet;
+  net->write_pos=net->read_pos = net->buff;
+  DBUG_RETURN(0);
+}
+
 
 void net_end(NET *net)
 {

sql/share/errmsg-utf8.txt

@@ -7139,3 +7139,10 @@ ER_KILL_QUERY_DENIED_ERROR
 ER_NO_EIS_FOR_FIELD
         eng "Engine-independent statistics are not collected for column '%s'"
         ukr "Незалежна від типу таблиці статистика не збирається для стовбця '%s'"
+ER_COMMULTI_BADCONTEXT 0A000
+        eng "COM_MULTI can't return a result set in the given context"
+        ger "COM_MULTI kann im gegebenen Kontext keine Ergebnismenge zurückgeben"
+        ukr "COM_MULTI не може повернути результати у цьому контексті"
+ER_BAD_COMMAND_IN_MULTI
+        eng "Command '%s' is not allowed for COM_MULTI"
+        ukr "Команда '%s' не дозволена для COM_MULTI"

sql/sql_class.h

@@ -5365,6 +5365,10 @@ class select_dumpvar :public select_result_interceptor {
   Do not check that wsrep snapshot is ready before allowing this command
 */
 #define CF_SKIP_WSREP_CHECK     (1U << 2)
+/**
+  Do not allow it for COM_MULTI batch
+*/
+#define CF_NO_COM_MULTI         (1U << 3)
 
 /* Inline functions */
 

sql/sql_parse.h

@@ -35,6 +35,7 @@ enum enum_mysql_completiontype {
 
 extern "C" int test_if_data_home_dir(const char *dir);
 int error_if_data_home_dir(const char *path, const char *what);
+my_bool net_allocate_new_packet(NET *net, void *thd, uint my_flags);
 
 bool multi_update_precheck(THD *thd, TABLE_LIST *tables);
 bool multi_delete_precheck(THD *thd, TABLE_LIST *tables);
@@ -87,7 +88,7 @@ bool is_log_table_write_query(enum enum_sql_command command);
 bool alloc_query(THD *thd, const char *packet, uint packet_length);
 void mysql_init_select(LEX *lex);
 void mysql_parse(THD *thd, char *rawbuf, uint length,
-                 Parser_state *parser_state);
+                 Parser_state *parser_state, bool is_com_multi);
 bool mysql_new_select(LEX *lex, bool move_down);
 void create_select_for_variable(const char *var_name);
 void create_table_set_open_action_and_adjust_tables(LEX *lex);
@@ -99,7 +100,8 @@ int mysql_execute_command(THD *thd);
 bool do_command(THD *thd);
 void do_handle_bootstrap(THD *thd);
 bool dispatch_command(enum enum_server_command command, THD *thd,
-		      char* packet, uint packet_length);
+		      char* packet, uint packet_length,
+                      bool is_com_multi, bool is_next_command);
 void log_slow_statement(THD *thd);
 bool append_file_to_dir(THD *thd, const char **filename_ptr,
                         const char *table_name);

sql/wsrep_sst.cc

@@ -907,7 +907,7 @@ static int run_sql_command(THD *thd, const char *query)
     return -1;
   }
 
-  mysql_parse(thd, thd->query(), thd->query_length(), &ps);
+  mysql_parse(thd, thd->query(), thd->query_length(), &ps, FALSE);
   if (thd->is_error())
   {
     int const err= thd->get_stmt_da()->sql_errno();