binding-wrap: Rework of context handling

[src/app-framework-binder.git] / include / afb / c++ / binding-wrap.hpp

diff --git a/include/afb/c++/binding-wrap.hpp b/include/afb/c++/binding-wrap.hpp
index a23e553..6af3f84 100644 (file)
--- a/include/afb/c++/binding-wrap.hpp
+++ b/include/afb/c++/binding-wrap.hpp
@@ -258,8 +258,6 @@ public:
        void failf(const char *error, const char *info, ...) const;
        void failv(const char *error, const char *info, va_list args) const;
 
-       template < class T > T *context() const;
-
        void addref() const;
 
        void unref() const;
@@ -294,6 +292,54 @@ public:
        int get_uid() const;
 
        json_object *get_client_info() const;
+
+       template < class T = void >
+       class contextclass {
+
+               friend class req;
+               afb_req_t req_;
+               contextclass(afb_req_t r) : req_(r) {}
+
+       public:
+               inline operator T *() const { return get(); }
+               inline operator T &() const { return *get(); }
+               inline T* get() const {
+                       return reinterpret_cast<T*>(
+                               afb_req_context(req_, 0,
+                                       nullptr,
+                                       nullptr,
+                                       nullptr));
+               }
+
+               inline void set(T *value, void (*destroyer)(T*) = [](T*t){delete t;}) const {
+                       afb_req_context(req_, 1,
+                               nullptr,
+                               reinterpret_cast<void(*)(void*)>(destroyer),
+                               reinterpret_cast<void*>(value));
+               }
+
+               inline void unset() { set(nullptr); }
+               inline void clear() { set(nullptr); }
+
+               inline T *lazy(T *(*allocator)() = []()->T*{return new T();}, void (*destroyer)(T*) = [](T*t){delete t;}) const {
+                       return reinterpret_cast<T*>(
+                               afb_req_context(req_, 0,
+                                       [allocator](void*)->T*{return allocator();},
+                                       reinterpret_cast<void(*)(void*)>(destroyer),
+                                       nullptr));
+               }
+
+               template <class I>
+               inline T *lazy(I *i, T *(*allocator)(I*) = [](I*i)->T*{return new T(i);}, void (*destroyer)(T*) = [](T*t){delete t;}) const {
+                       return reinterpret_cast<T*>(
+                               afb_req_context(req_, 0,
+                                       [allocator](void*i)->T*{return allocator(reinterpret_cast<I*>(i));},
+                                       reinterpret_cast<void(*)(void*)>(destroyer),
+                                       reinterpret_cast<void*>(i)));
+               }
+       };
+
+       template < class T > contextclass<T> context() const { return contextclass<T>(req_); }
 };
 
 /*************************************************************************/
@@ -476,16 +522,6 @@ inline void req::failf(const char *error, const char *info, ...) const
        va_end(args);
 }
 
-template < class T >
-inline T *req::context() const
-{
-       T* (*creater)(void*) = [](){return new T();};
-       void (*freer)(T*) = [](T*t){delete t;};
-       return reinterpret_cast<T*>(afb_req_context(req_, 0,
-                       reinterpret_cast<void *(*)(void*)>(creater),
-                       reinterpret_cast<void (*)(void*)>(freer), nullptr));
-}
-
 inline void req::addref() const { afb_req_addref(req_); }
 
 inline void req::unref() const { afb_req_unref(req_); }