MXS-1506: Clean up various functions

Reduced variable scopes and removed unused code.

server/modules/routing/readwritesplit/readwritesplit.cc

@@ -59,22 +59,19 @@ using namespace maxscale;
  */
 static bool rwsplit_process_router_options(Config& config, char **options)
 {
-    int i;
-    char *value;
-    select_criteria_t c;
-
     if (options == NULL)
     {
         return true;
     }
 
     MXS_WARNING("Router options for readwritesplit are deprecated.");
-
     bool success = true;
 
-    for (i = 0; options[i]; i++)
+    for (int i = 0; options[i]; i++)
     {
-        if ((value = strchr(options[i], '=')) == NULL)
+        char* value = strchr(options[i], '=');
+
+        if (value == NULL)
         {
             MXS_ERROR("Unsupported router option \"%s\" for readwritesplit router.", options[i]);
             success = false;
@@ -85,7 +82,7 @@ static bool rwsplit_process_router_options(Config& config, char **options)
             value++;
             if (strcmp(options[i], "slave_selection_criteria") == 0)
             {
-                c = GET_SELECT_CRITERIA(value);
+                select_criteria_t c = GET_SELECT_CRITERIA(value);
                 ss_dassert(c == LEAST_GLOBAL_CONNECTIONS ||
                            c == LEAST_ROUTER_CONNECTIONS || c == LEAST_BEHIND_MASTER ||
                            c == LEAST_CURRENT_OPERATIONS || c == UNDEFINED_CRITERIA);
@@ -155,7 +152,7 @@ static bool rwsplit_process_router_options(Config& config, char **options)
                 success = false;
             }
         }
-    } /*< for */
+    }
 
     return success;
 }

server/modules/routing/readwritesplit/rwbackend.cc

@@ -10,7 +10,8 @@ namespace maxscale
 RWBackend::RWBackend(SERVER_REF* ref):
     mxs::Backend(ref),
     m_reply_state(REPLY_STATE_DONE),
-    m_large_packet(false)
+    m_large_packet(false),
+    m_command(0)
 {
 }
 

server/modules/routing/readwritesplit/rwsplit_mysql.cc

@@ -121,31 +121,6 @@ bool RWSplitSession::handle_target_is_all(route_target_t route_target, GWBUF *qu
     return result;
 }
 
-/*
- * Probably MySQL specific because of modutil function
- */
-/**
- * @brief Write an error message to the log for closed session
- *
- * This happens if a request is received for a session that is already
- * closing down.
- *
- * @param querybuf      Query buffer containing packet
- */
-void closed_session_reply(GWBUF *querybuf)
-{
-    uint8_t* data = GWBUF_DATA(querybuf);
-
-    if (GWBUF_LENGTH(querybuf) >= 5 && !MYSQL_IS_COM_QUIT(data))
-    {
-        /* Note that most modutil functions are MySQL specific */
-        char *query_str = modutil_get_query(querybuf);
-        MXS_ERROR("Can't route %s:\"%s\" to backend server. Router is closed.",
-                  STRPACKETTYPE(data[4]), query_str ? query_str : "(empty)");
-        MXS_FREE(query_str);
-    }
-}
-
 /**
  * @brief Send an error message to the client telling that the server is in read only mode
  *

server/modules/routing/readwritesplit/rwsplit_select_backends.cc

@@ -312,7 +312,7 @@ bool RWSplit::select_connect_backend_servers(MXS_SESSION *session,
 
     /** Check slave selection criteria and set compare function */
     select_criteria_t select_criteria = config().slave_selection_criteria;
-    int (*cmpfun)(const SRWBackend&, const SRWBackend&) = criteria_cmpfun[select_criteria];
+    auto cmpfun = criteria_cmpfun[select_criteria];
     ss_dassert(cmpfun);
 
     if (MXS_LOG_PRIORITY_IS_ENABLED(LOG_INFO))

server/modules/routing/readwritesplit/rwsplitsession.cc

@@ -222,9 +222,6 @@ bool RWSplitSession::route_stored_query()
 GWBUF* RWSplitSession::discard_master_wait_gtid_result(GWBUF *buffer)
 {
     uint8_t header_and_command[MYSQL_HEADER_LEN + 1];
-    uint8_t packet_len = 0;
-    uint8_t offset = 0;
-    mxs_mysql_cmd_t com;
 
     gwbuf_copy_data(buffer, 0, MYSQL_HEADER_LEN + 1, header_and_command);
     /* ignore error packet */
@@ -236,7 +233,7 @@ GWBUF* RWSplitSession::discard_master_wait_gtid_result(GWBUF *buffer)
 
     /* this packet must be an ok packet now */
     ss_dassert(MYSQL_GET_COMMAND(header_and_command) == MYSQL_REPLY_OK);
-    packet_len = MYSQL_GET_PAYLOAD_LEN(header_and_command) + MYSQL_HEADER_LEN;
+    uint8_t packet_len = MYSQL_GET_PAYLOAD_LEN(header_and_command) + MYSQL_HEADER_LEN;
     m_wait_gtid_state = EXPECTING_REAL_RESULT;
     m_next_seq = 1;
 
@@ -284,14 +281,14 @@ SRWBackend& RWSplitSession::get_backend_from_dcb(DCB *dcb)
  */
 void RWSplitSession::correct_packet_sequence(GWBUF *buffer)
 {
-    uint8_t header[3];
-    uint32_t offset = 0;
-    uint32_t packet_len = 0;
     if (m_wait_gtid_state == EXPECTING_REAL_RESULT)
     {
+        uint8_t header[3];
+        uint32_t offset = 0;
+
         while (gwbuf_copy_data(buffer, offset, 3, header) == 3)
         {
-            packet_len = MYSQL_GET_PAYLOAD_LEN(header) + MYSQL_HEADER_LEN;
+            uint32_t packet_len = MYSQL_GET_PAYLOAD_LEN(header) + MYSQL_HEADER_LEN;
             uint8_t *seq = gwbuf_byte_pointer(buffer, offset + MYSQL_SEQ_OFFSET);
             *seq = m_next_seq;
             m_next_seq++;
@@ -647,7 +644,6 @@ bool RWSplitSession::handle_error_new_connection(DCB *backend_dcb, GWBUF *errmsg
         route_stored_query();
     }
 
-    int max_nslaves = m_router->max_slave_count();
     bool succp;
     /**
      * Try to get replacement slave or at least the minimum