MXS-1512 Take module object type as template argument

Makes it possible to move the module object pointer into the
SpecificModule template.

server/modules/filter/test/maxscale/filtermodule.hh

@@ -23,14 +23,13 @@ namespace maxscale
 /**
  * An instance of FilterModule represents a filter module.
  */
-class FilterModule : public SpecificModule<FilterModule>
+class FilterModule : public SpecificModule<FilterModule, MXS_FILTER_OBJECT>
 {
     FilterModule(const FilterModule&);
     FilterModule& operator = (const FilterModule&);
 
 public:
     static const char* zName;  /*< The name describing the module type. */
-    typedef MXS_FILTER_OBJECT type_t; /*< The type of the module object. */
 
     class Session;
     class Instance
@@ -184,15 +183,12 @@ private:
     }
 
 private:
-    friend class SpecificModule<FilterModule>;
+    friend Base;
 
-    FilterModule(MXS_FILTER_OBJECT* pApi)
+    FilterModule(const MXS_MODULE* pModule)
-        : m_pApi(pApi)
+        : Base(pModule)
     {
     }
-
-private:
-    MXS_FILTER_OBJECT* m_pApi;
 };
 
 }

server/modules/filter/test/maxscale/module.hh

@@ -31,10 +31,20 @@ public:
      * @param zFile_name  The name of the module.
      * @param zType_name  The expected type of the module.
      *
-     * @return The module object, if the module could be loaded, otherwise NULL.
+     * @return The module specific entry point structure or NULL.
      */
     static void* load(const char *zFile_name, const char *zType_name);
 
+    /**
+     * Get a module with a specific name, assumed to be of a specific type.
+     *
+     * @param zFile_name  The name of the module.
+     * @param zType_name  The expected type of the module.
+     *
+     * @return The loaded module, if the module could be loaded, otherwise NULL.
+     */
+    static const MXS_MODULE* get(const char *zFile_name, const char *zType_name);
+
     /**
      * Perform process initialization of all modules. Should be called only
      * when all modules intended to be loaded have been loaded.
@@ -60,41 +70,55 @@ public:
      * Perform thread finalization of all modules.
      */
     static void thread_finish();
+
+protected:
+    Module(const MXS_MODULE* pModule)
+        : m_module(*pModule)
+    {
+    }
+
+    const MXS_MODULE& m_module;
 };
 
 /**
  * The template Module is intended to be derived from using the derived
  * class as template argument.
  *
- *    class XyzModule : public SpecificModule<XyzModule> { ... }
+ *    class XyzModule : public SpecificModule<XyzModule, XYZ_MODULE_OBJECT> { ... }
  *
  * @param zFile_name  The name of the module.
  *
  * @return A module instance if the module could be loaded and it was of
  *         the expected type.
  */
-template<class T>
+template<class T, class API>
 class SpecificModule : public Module
 {
 public:
+    typedef SpecificModule<T, API> Base;
+
     static std::auto_ptr<T> load(const char* zFile_name)
     {
         std::auto_ptr<T> sT;
 
-        void* pApi = Module::load(zFile_name, T::zName);
+        const MXS_MODULE* pModule = Module::get(zFile_name, T::zName);
 
-        if (pApi)
+        if (pModule)
         {
-            sT.reset(new T(static_cast<typename T::type_t*>(pApi)));
+            sT.reset(new T(pModule));
         }
 
         return sT;
     }
 
 protected:
-    SpecificModule()
+    SpecificModule(const MXS_MODULE* pModule)
+        : Module(pModule)
+        , m_pApi(static_cast<API*>(pModule->module_object))
     {
     }
+
+    API* m_pApi;
 };
 
 }

server/modules/filter/test/maxscale/queryclassifiermodule.hh

@@ -24,25 +24,19 @@ namespace maxscale
  * A QueryClassfierModule instance is an abstraction for a query
  * classifier module.
  */
-class QueryClassifierModule : public SpecificModule<QueryClassifierModule>
+class QueryClassifierModule : public SpecificModule<QueryClassifierModule, QUERY_CLASSIFIER>
 {
     QueryClassifierModule(const QueryClassifierModule&);
     QueryClassifierModule& operator = (const QueryClassifierModule&);
 
 public:
     static const char* zName;  /*< The name describing the module type. */
-    typedef QUERY_CLASSIFIER type_t; /*< The type of the module object. */
 
 private:
-    friend class SpecificModule<QueryClassifierModule>;
+    QueryClassifierModule(const MXS_MODULE* pModule)
-
+        : Base(pModule)
-    QueryClassifierModule(QUERY_CLASSIFIER* pApi)
-        : m_pApi(pApi)
     {
     }
-
-private:
-    QUERY_CLASSIFIER* m_pApi;
 };
 
 }

server/modules/filter/test/module.cc

@@ -23,6 +23,12 @@ void* Module::load(const char* zName, const char* zType)
     return load_module(zName, zType);
 }
 
+//static
+const MXS_MODULE* Module::get(const char* zName, const char* zType)
+{
+    return get_module(zName, zType);
+}
+
 //static
 bool Module::process_init()
 {