MXS-1625 Figure out multi statement state at startup

Whether or not multi statements are allowed is checked when
the QueryClassifier instance is created.

include/maxscale/queryclassifier.hh

@@ -48,6 +48,11 @@ public:
     QueryClassifier(MXS_SESSION* pSession,
                     mxs_target_t use_sql_variables_in);
 
+    bool multi_statements_allowed() const
+    {
+        return m_multi_statements_allowed;
+    }
+
     load_data_state_t load_data_state() const
     {
         return m_load_data_state;
@@ -118,6 +123,7 @@ private:
     load_data_state_t m_load_data_state;
     bool              m_have_tmp_tables;
     bool              m_large_query;              /**< Set to true when processing payloads >= 2^24 bytes */
+    bool              m_multi_statements_allowed; /**< Are multi-statements allowed */
     SPSManager        m_sPs_manager;
 };
 

server/core/queryclassifier.cc

@@ -19,6 +19,21 @@
 
 namespace
 {
+
+bool are_multi_statements_allowed(MXS_SESSION* pSession)
+{
+    MySQLProtocol* pPcol = static_cast<MySQLProtocol*>(pSession->client_dcb->protocol);
+
+    if (pPcol->client_capabilities & GW_MYSQL_CAPABILITIES_MULTI_STATEMENTS)
+    {
+        return true;
+    }
+    else
+    {
+        return false;
+    }
+}
+
 uint32_t get_prepare_type(GWBUF* buffer)
 {
     uint32_t type;
@@ -189,6 +204,7 @@ QueryClassifier::QueryClassifier(MXS_SESSION* pSession,
     , m_load_data_state(LOAD_DATA_INACTIVE)
     , m_have_tmp_tables(false)
     , m_large_query(false)
+    , m_multi_statements_allowed(are_multi_statements_allowed(pSession))
     , m_sPs_manager(new PSManager)
 {
 }

server/modules/routing/readwritesplit/routeinfo.cc

@@ -403,13 +403,11 @@ inline bool have_semicolon(const char* ptr, int len)
  * @param buf Buffer containing the full query
  * @return True if the query contains multiple statements
  */
-bool check_for_multi_stmt(GWBUF *buf, void *protocol, uint8_t packet_type)
+bool check_for_multi_stmt(const QueryClassifier& qc, GWBUF *buf, uint8_t packet_type)
 {
-    MySQLProtocol *proto = (MySQLProtocol *)protocol;
     bool rval = false;
 
-    if (proto->client_capabilities & GW_MYSQL_CAPABILITIES_MULTI_STATEMENTS &&
-        packet_type == MXS_COM_QUERY)
+    if (qc.multi_statements_allowed() && packet_type == MXS_COM_QUERY)
     {
         char *ptr, *data = (char*)GWBUF_DATA(buf) + 5;
         /** Payload size without command byte */
@@ -460,7 +458,7 @@ handle_multi_temp_and_load(RWSplitSession *rses, GWBUF *querybuf,
      * situation, assigning QUERY_TYPE_WRITE for the query will trigger
      * the error processing. */
     if ((rses->m_target_node == NULL || rses->m_target_node != rses->m_current_master) &&
-        (check_for_multi_stmt(querybuf, rses->m_client->protocol, packet_type) ||
+        (check_for_multi_stmt(rses->qc(), querybuf, packet_type) ||
          check_for_sp_call(querybuf, packet_type)))
     {
         if (rses->m_current_master && rses->m_current_master->in_use())