Modules

Define properly modules.

Modules should only use the queue to communicate information to the lkt_state.

The lkt_state should use the reg to get function pointers and other properties from the modules. This reg will include macros to get function pointers and call the function with the given arguments. The reg will notify when a function is not available, and won't segfault. By doing so:

• Some modules (player, repo) won't be necessary to launch lektord. The server can be launched even if some functionalities are not here.
• Simplify the modules information in the lektor.ini file.
• It will be possible to unload and load modules on the fly.
• Events from the lkt_state queue can be differed to when the module is loaded.

inc/lektor/reg.h

@@ -6,16 +6,21 @@ struct lkt_state;
    with a name that can be generated or red from a config file. */
 struct module_reg {
     const char *name;
-    void (*func)(void);
+    union {
+        void (*func)(void);
+        void *obj;
+    };
 };
 
-#define REG_BEGIN(reg)          struct module_reg reg[] = {
-#define REG_ADD(__f)            { .name = #__f,  .func = (void(*)(void)) __f    },
-#define REG_ADD_NAMED(__n, __f) { .name = __n,   .func = (void(*)(void)) __f    },
-#define REG_END()               { .name = NULL,  .func = NULL                   } };
+#define REG_EXPORT_NAME     "__reg__"
+#define REG_BEGIN(reg)      struct module_reg reg[] = {
+#define REG_ADD(f)          { .name = #f, .func = (void(*)(void)) f },
+#define REG_ADD_NAMED(n, f) { .name = n,  .func = (void(*)(void)) f },
+#define REG_END()           { .name = NULL, .func = NULL            } };
 
+/* Use only once per .so files or you will have some problems... */
 #if ! defined(_STATIC_MODULES)
-#define REG_EXPORT(__reg)       struct module_reg *__reg__ = __reg;
+#define REG_EXPORT(__reg)   struct module_reg *__reg__ = __reg;
 #else
 #define REG_EXPORT(__reg)
 #endif
@@ -29,10 +34,14 @@ void *reg_pick(const char *file, void **handle, const char *symbol);
    shared library with REG_EXPORT. Note that this reg is named `__reg__`,
    thus no symbol must be named `__reg__` in the .so file.
    Returns 0 on success, something else on error. */
-int reg_from_file(const char *file, struct module_reg *ret);
+int reg_from_file(const char *file, struct module_reg **ret, void **handle);
 
-/* Set the ref for this .a / .so file */
-void reg_set(struct module_reg *);
+/* Set the __reg__ pointer. */
+void reg_export(struct module_reg *reg);
+
+/* Get the object named with 'name' from the reg. Returns NULL on error
+   or 'not found'. */
+void *__reg_get(struct module_reg *reg, const char *name);
 
 /* Load a module by its name. Also initialize the mod pointer. No check on data
    type is done, it is up to the user to check if the structure passed as a