Added new parameter RW Split Router.max_slave_connections=[<int>|<int>%] which specifies the maximum number of slaves which read/write split router connects in each routing session.

Parameter it read from config file to CONFIG_CONTEXT's parameter list. It is qualified in service.c:service_set_slave_conn_limit and if qualified, the qualified integer value and the value type are copied to the CONFIG_PARAMETER structure.

This CONFIG_PARAMETER struct is cloned (=copied to different memory area) and linked to RW Split SERVICE struct.

When RW Split router_instance is created in readwritesplit.c:createInstance, the value is copied to (new) rwsplit_config_t structure from SERVICE's parameter list.

When new routing session is created in readwritesplit.c:newSession, the rwsplit_config_t structure is copied to ROUTER_CLIENT_SES struct and the actual max_nslaves value is calculated from the config value (if percentage is used).

Tests and many error handling branches are missing but functionality seems to be working.

server/include/config.h

@@ -17,6 +17,7 @@
  *
  * Copyright SkySQL Ab 2013
  */
+#include <skygw_utils.h>
 
 /**
  * @file config.h The configuration handling elements
@@ -30,12 +31,32 @@
  * @endverbatim
  */
 
+/**
+ * Maximum length for configuration parameter value.
+ */
+enum {MAX_PARAM_LEN=256};
+
+typedef enum {
+        UNDEFINED_TYPE=0,
+        STRING_TYPE,
+        COUNT_TYPE,
+        PERCENT_TYPE,
+        BOOL_TYPE
+} config_param_type_t;
+
 /**
  * The config parameter
  */
 typedef struct config_parameter {
 	char			*name;		/**< The name of the parameter */
-	char			*value;		/**< The value of the parameter */
+	char                    *value;         /**< The value of the parameter */
+	union {                                 /*< qualified parameter value by type */
+                char*           valstr;         /*< terminated char* array */
+                int             valcount;       /*< int */
+                int             valpercent;     /*< int */
+                bool            valbool;        /*< bool */
+        } qfd;
+        config_param_type_t     qfd_param_type; 
 	struct config_parameter	*next;		/**< Next pointer in the linked list */
 } CONFIG_PARAMETER;
 
@@ -60,4 +81,18 @@ typedef struct {
 extern int	config_load(char *);
 extern int	config_reload();
 extern int	config_threadcount();
+CONFIG_PARAMETER* config_get_param(CONFIG_PARAMETER* params, const char* name);
+
+bool config_set_qualified_param(
+        CONFIG_PARAMETER* param, 
+        void* val, 
+        config_param_type_t type);
+
+CONFIG_PARAMETER* config_clone_param(CONFIG_PARAMETER* param);
+
+int config_get_valint(
+        CONFIG_PARAMETER*   param,
+        const char*         name, /*< if NULL examine current param only */
+        config_param_type_t ptype);
+
 #endif