Initial multi query execution support

include/mysql.h

@@ -502,10 +502,12 @@ my_bool STDCALL mysql_send_long_data(MYSQL_STMT *stmt,
 				     my_bool last_data);
 int STDCALL mysql_multi_query(MYSQL *mysql,const char *query,
 			      unsigned long len);
-MYSQL_RES *STDCALL mysql_next_result(MYSQL *mysql);
 MYSQL_RES *STDCALL mysql_prepare_result(MYSQL_STMT *stmt);
 my_ulonglong STDCALL mysql_stmt_affected_rows(MYSQL_STMT *stmt);
 int STDCALL mysql_stmt_store_result(MYSQL_STMT *stmt);
+my_bool STDCALL mysql_more_results(MYSQL *mysql);
+my_bool STDCALL mysql_next_result(MYSQL *mysql);
+
 
 
 /* new status messages */

include/mysql_com.h

@@ -106,10 +106,12 @@ enum enum_server_command
 #define CLIENT_TRANSACTIONS	8192	/* Client knows about transactions */
 #define CLIENT_PROTOCOL_41       16384   /* New 4.1 protocol  */
 #define CLIENT_SECURE_CONNECTION 32768   /* New 4.1 authentication */
+#define CLIENT_MULTI_QUERIES     65536   /* Enable/disable multi query support */
 
 #define SERVER_STATUS_IN_TRANS     1	/* Transaction has started */
 #define SERVER_STATUS_AUTOCOMMIT   2	/* Server in auto_commit mode */
 #define SERVER_STATUS_MORE_RESULTS 4	/* More results on server */
+#define SERVER_MORE_RESULTS_EXISTS 8    /* Multi query - next query exists */
 
 #define MYSQL_ERRMSG_SIZE	200
 #define NET_READ_TIMEOUT	30		/* Timeout on read */

libmysql/libmysql.c

@@ -3858,8 +3858,8 @@ static my_bool read_prepare_result(MYSQL_STMT *stmt)
   }
   if (!(stmt->params= (MYSQL_BIND *) alloc_root(&stmt->mem_root,
 						sizeof(MYSQL_BIND)*
-						(stmt->param_count +
-						 field_count))))
+                                                (param_count + 
+                                                 field_count))))
   {
     set_stmt_error(stmt, CR_OUT_OF_MEMORY);
     DBUG_RETURN(0);
@@ -5161,3 +5161,36 @@ my_bool STDCALL mysql_autocommit(MYSQL * mysql, my_bool auto_mode)
     DBUG_RETURN((my_bool) mysql_real_query(mysql, "set autocommit=1", 16));
   DBUG_RETURN((my_bool) mysql_real_query(mysql, "set autocommit=0", 16));
 }
+
+
+/********************************************************************
+ Multi query execution related implementations
+*********************************************************************/
+
+/*
+  Returns if there are any more query results exists to be read using 
+  mysql_next_result()
+*/
+
+my_bool STDCALL mysql_more_results(MYSQL *mysql)
+{
+  if (mysql->last_used_con->server_status & SERVER_MORE_RESULTS_EXISTS)
+    return 1;
+  return 0;
+}
+
+/*
+  Reads and returns the next query results
+*/
+
+my_bool STDCALL mysql_next_result(MYSQL *mysql)
+{
+  
+  mysql->net.last_error[0]=0;
+  mysql->net.last_errno=0;
+  mysql->affected_rows= ~(my_ulonglong) 0;
+
+  if (mysql->last_used_con->server_status & SERVER_MORE_RESULTS_EXISTS)
+    return mysql_read_query_result(mysql);
+  return 0;
+}

sql/sql_lex.cc

@@ -906,7 +906,15 @@ int yylex(void *arg, void *yythd)
     case STATE_COLON:			// optional line terminator
       if (yyPeek())
       {
-	state=STATE_CHAR;		// Return ';'
+        if (((THD *)yythd)->client_capabilities & CLIENT_MULTI_QUERIES)
+        {
+          lex->found_colon=(char*)lex->ptr;
+          ((THD *)yythd)->server_status |= SERVER_MORE_RESULTS_EXISTS;
+          lex->next_state=STATE_END;
+          return(END_OF_INPUT);
+        }
+        else
+ 	  state=STATE_CHAR;		// Return ';'
 	break;
       }
       /* fall true */

sql/sql_lex.h

@@ -414,6 +414,7 @@ typedef struct st_lex
   char *backup_dir;				/* For RESTORE/BACKUP */
   char* to_log;                                 /* For PURGE MASTER LOGS TO */
   char* x509_subject,*x509_issuer,*ssl_cipher;
+  char* found_colon;                            /* For multi queries - next query */
   enum SSL_type ssl_type;			/* defined in violite.h */
   String *wild;
   sql_exchange *exchange;

sql/sql_parse.cc

@@ -1426,6 +1426,14 @@ bool dispatch_command(enum enum_server_command command, THD *thd,
       mysql_slow_log.write(thd, thd->query, thd->query_length, start_of_query);
     }
   }
+  if (command == COM_QUERY && thd->lex.found_colon)
+  {
+    /* 
+      Multiple queries exits, execute them individually
+    */
+    uint length= thd->query_length-(uint)(thd->lex.found_colon-thd->query)+1;
+    dispatch_command(command, thd, thd->lex.found_colon, length);
+  }  
   thd->proc_info="cleaning up";
   VOID(pthread_mutex_lock(&LOCK_thread_count)); // For process list
   thd->proc_info=0;
@@ -3082,6 +3090,7 @@ mysql_init_query(THD *thd)
   lex->olap=lex->describe=0;
   lex->derived_tables= false;
   lex->lock_option=TL_READ;
+  lex->found_colon=0;
   thd->check_loops_counter= thd->select_number=
     lex->select_lex.select_number= 1;
   thd->free_list= 0;
@@ -3090,6 +3099,7 @@ mysql_init_query(THD *thd)
   thd->sent_row_count= thd->examined_row_count= 0;
   thd->fatal_error= thd->rand_used= 0;
   thd->possible_loops= 0;
+  thd->server_status &= ~SERVER_MORE_RESULTS_EXISTS;
   DBUG_VOID_RETURN;
 }