ecore: add Efl.Promise.

src/Makefile_Ecore.am

@@ -20,6 +20,7 @@ ecore_eolian_files = \
 	lib/ecore/efl_io_stderr.eo \
 	lib/ecore/efl_io_file.eo \
         lib/ecore/efl_io_copier.eo \
+	lib/ecore/efl_promise.eo \
 	lib/ecore/ecore_parent.eo \
 	$(ecore_eolian_files_legacy)
 
@@ -79,6 +80,7 @@ lib/ecore/efl_io_stdout.c \
 lib/ecore/efl_io_stderr.c \
 lib/ecore/efl_io_file.c \
 lib/ecore/efl_io_copier.c \
+lib/ecore/efl_promise.c \
 lib/ecore/ecore_pipe.c \
 lib/ecore/ecore_poller.c \
 lib/ecore/ecore_time.c \

src/lib/ecore/Ecore_Eo.h

@@ -54,7 +54,9 @@ extern "C" {
 
 #include "efl_loop_fd.eo.h"
 
-/* We ue the factory pattern here, so you shouldn't call efl_add directly. */
+#include "efl_promise.eo.h"
+
+/* We ue the factory pattern here, so you shouldn't call eo_add directly. */
 EAPI Eo *ecore_main_loop_get(void);
 
 /**

src/lib/ecore/efl_promise.c

@@ -0,0 +1,542 @@
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include <Ecore.h>
+
+#include "ecore_private.h"
+
+// FIXME: handle self destruction when back in the main loop
+
+typedef struct _Efl_Promise_Data Efl_Promise_Data;
+typedef struct _Efl_Promise_Msg Efl_Promise_Msg;
+
+struct _Efl_Promise_Msg
+{
+   EINA_REFCOUNT;
+
+   void *value;
+   Eina_Free_Cb free_cb;
+
+   Eina_Error error;
+};
+
+struct _Efl_Promise_Data
+{
+   Efl_Promise *promise;
+   Efl_Promise_Msg *message;
+   Eina_List *futures;
+
+   struct {
+      Eina_Bool future : 1;
+      Eina_Bool future_triggered : 1;
+      Eina_Bool progress : 1;
+      Eina_Bool progress_triggered : 1;
+   } set;
+};
+
+static void
+_efl_promise_msg_free(Efl_Promise_Msg *msg)
+{
+   if (msg->free_cb)
+     msg->free_cb(msg->value);
+   free(msg);
+}
+
+#define EFL_LOOP_FUTURE_CLASS efl_loop_future_class_get()
+static const Efl_Class *efl_loop_future_class_get(void);
+
+typedef struct _Efl_Loop_Future_Data Efl_Loop_Future_Data;
+typedef struct _Efl_Loop_Future_Callback Efl_Loop_Future_Callback;
+
+struct _Efl_Loop_Future_Callback
+{
+   EINA_INLIST;
+
+   Efl_Event_Cb success;
+   Efl_Event_Cb failure;
+   Efl_Event_Cb progress;
+
+   Efl_Promise *next;
+
+   const void *data;
+};
+
+struct _Efl_Loop_Future_Data
+{
+   Eina_Inlist *callbacks;
+
+   Efl_Future *self;
+   Efl_Promise_Msg  *message;
+   Efl_Promise_Data *promise;
+
+#ifndef NDEBUG
+   int wref;
+#endif
+
+   Eina_Bool fulfilled : 1;
+   Eina_Bool death : 1;
+   Eina_Bool delayed : 1;
+};
+
+static void
+_efl_loop_future_success(Efl_Event *ev, Efl_Loop_Future_Data *pd, void *value)
+{
+   Efl_Loop_Future_Callback *cb;
+   Efl_Future_Event_Success chain_success;
+
+   ev->info = &chain_success;
+   ev->desc = EFL_FUTURE_EVENT_SUCCESS;
+
+   chain_success.value = value;
+
+   EINA_INLIST_FREE(pd->callbacks, cb)
+     {
+        if (cb->next)
+          {
+             chain_success.next = cb->next;
+
+             cb->success((void*) cb->data, ev);
+          }
+
+        pd->callbacks = eina_inlist_remove(pd->callbacks, pd->callbacks);
+        free(cb);
+     }
+}
+
+static void
+_efl_loop_future_failure(Efl_Event *ev, Efl_Loop_Future_Data *pd, Eina_Error error)
+{
+   Efl_Loop_Future_Callback *cb;
+   Efl_Future_Event_Failure chain_fail;
+
+   ev->info = &chain_fail;
+   ev->desc = EFL_FUTURE_EVENT_FAILURE;
+
+   chain_fail.error = error;
+
+   EINA_INLIST_FREE(pd->callbacks, cb)
+     {
+        if (cb->next)
+          {
+             chain_fail.next = cb->next;
+
+             cb->failure((void*) cb->data, ev);
+          }
+
+        pd->callbacks = eina_inlist_remove(pd->callbacks, pd->callbacks);
+        free(cb);
+     }
+}
+
+static void
+_efl_loop_future_propagate(Eo *obj, Efl_Loop_Future_Data *pd)
+{
+   Efl_Event ev;
+
+   ev.object = obj;
+
+   if (pd->fulfilled &&
+       !pd->message)
+     {
+        _efl_loop_future_failure(&ev, pd, EINA_ERROR_FUTURE_CANCEL);
+     }
+   else if (pd->message->error == 0)
+     {
+        _efl_loop_future_success(&ev, pd, pd->message->value);
+     }
+   else
+     {
+        _efl_loop_future_failure(&ev, pd, pd->message->error);
+     }
+   pd->fulfilled = EINA_TRUE;
+
+   if (!pd->delayed)
+     {
+        pd->delayed = EINA_TRUE;
+        efl_unref(obj);
+     }
+}
+
+static void
+_efl_loop_future_fulfilling(Eo *obj, Efl_Loop_Future_Data *pd)
+{
+   if (pd->fulfilled)
+     {
+        _efl_loop_future_propagate(obj, pd);
+     }
+
+   if (!pd->death)
+     {
+        pd->death = EINA_TRUE;
+        efl_del(obj);
+     }
+}
+
+static void
+_efl_loop_future_prepare_events(Efl_Loop_Future_Data *pd, Eina_Bool progress)
+{
+   if (!pd->promise) return ;
+
+   pd->promise->set.future = EINA_TRUE;
+   if (progress)
+     pd->promise->set.progress = EINA_TRUE;
+}
+
+static Efl_Future *
+_efl_loop_future_then(Eo *obj, Efl_Loop_Future_Data *pd,
+                      Efl_Event_Cb success, Efl_Event_Cb failure, Efl_Event_Cb progress, const void *data)
+{
+   Efl_Loop_Future_Callback *cb;
+   Efl_Future *f;
+
+   cb = calloc(1, sizeof (Efl_Loop_Future_Callback));
+   if (!cb) return NULL;
+
+   cb->success = success;
+   cb->failure = failure;
+   cb->progress = progress;
+   cb->data = data;
+   cb->next = efl_add(EFL_PROMISE_CLASS, obj);
+
+   f = efl_promise_future_get(cb->next);
+
+   pd->callbacks = eina_inlist_append(pd->callbacks, EINA_INLIST_GET(cb));
+
+   _efl_loop_future_prepare_events(pd, !!progress);
+   _efl_loop_future_fulfilling(obj, pd);
+
+   return f;
+}
+
+static void
+_efl_loop_future_disconnect(Eo *obj, Efl_Loop_Future_Data *pd)
+{
+   Eo *promise;
+
+   if (!pd->promise) return ;
+   promise = efl_ref(pd->promise->promise);
+
+   // Disconnect from the promise
+   pd->promise->futures = eina_list_remove(pd->promise->futures, pd);
+
+   // Notify that there is no more future
+   if (!pd->promise->futures)
+     {
+        efl_event_callback_call(pd->promise->promise, EFL_PROMISE_EVENT_FUTURE_NONE, NULL);
+     }
+
+   // Unreference after propagating the failure
+   efl_data_xunref(pd->promise->promise, pd->promise, obj);
+   pd->promise = NULL;
+
+   efl_unref(promise);
+}
+
+static void
+_efl_loop_future_cancel(Eo *obj, Efl_Loop_Future_Data *pd)
+{
+   // Check state
+   if (pd->fulfilled)
+     {
+        ERR("Triggering cancel on an already fulfilled Efl.Future.");
+        return;
+     }
+
+#ifndef NDEBUG
+   if (!pd->wref)
+     {
+        WRN("Calling cancel should be only done on a weak reference. Look at efl_future_use.");
+     }
+#endif
+
+   pd->fulfilled = EINA_TRUE;
+
+   // Trigger failure
+   _efl_loop_future_propagate(obj, pd);
+
+   _efl_loop_future_disconnect(obj, pd);
+}
+
+static void
+_efl_loop_future_intercept(Eo *obj)
+{
+   Efl_Loop_Future_Data *pd;
+
+   // Just delay object death
+   efl_del_intercept_set(obj, NULL);
+
+   // Trigger events now
+   pd = efl_data_scope_get(obj, EFL_LOOP_FUTURE_CLASS);
+
+   if (!pd->promise) return ;
+   if (pd->promise->set.future && !pd->promise->set.future_triggered)
+     {
+        efl_event_callback_call(pd->promise->promise, EFL_PROMISE_EVENT_FUTURE_SET, obj);
+        pd->promise->set.future_triggered = EINA_TRUE;
+     }
+   if (pd->promise->set.progress && !pd->promise->set.progress_triggered)
+     {
+        efl_event_callback_call(pd->promise->promise, EFL_PROMISE_EVENT_FUTURE_PROGRESS_SET, obj);
+        pd->promise->set.progress_triggered = EINA_TRUE;
+     }
+}
+
+static Eo *
+_efl_loop_future_efl_object_constructor(Eo *obj, Efl_Loop_Future_Data *pd)
+{
+   obj = efl_constructor(efl_super(obj, EFL_LOOP_FUTURE_CLASS));
+
+   pd->self = obj;
+
+   efl_del_intercept_set(obj, _efl_loop_future_intercept);
+
+   return obj;
+}
+
+static void
+_efl_loop_future_efl_object_destructor(Eo *obj, Efl_Loop_Future_Data *pd)
+{
+   if (!pd->fulfilled)
+     {
+        ERR("Lost reference to a future without fulfilling it. Forcefully cancelling it.");
+        _efl_loop_future_propagate(obj, pd);
+     }
+#ifndef NDEBUG
+   else if (pd->callbacks)
+     {
+        ERR("Found referenced callbacks while destroying the future.");
+        _efl_loop_future_propagate(obj, pd);
+     }
+#endif
+
+   // Cleanup message if needed
+   if (pd->message)
+     {
+        EINA_REFCOUNT_UNREF(pd->message)
+          _efl_promise_msg_free(pd->message);
+        pd->message = NULL;
+     }
+
+   efl_destructor(efl_super(obj, EFL_LOOP_FUTURE_CLASS));
+
+   // Disconnect from the promise
+   _efl_loop_future_disconnect(obj, pd);
+}
+
+#ifndef NDEBUG
+static void
+_efl_future_wref_add(Eo *obj, Efl_Loop_Future_Data *pd, Eo **wref)
+{
+   efl_wref_add(efl_super(obj, EFL_LOOP_FUTURE_CLASS), wref);
+
+   pd->wref++;
+}
+
+static void
+_efl_future_wref_del(Eo *obj, Efl_Loop_Future_Data *pd, Eo **wref)
+{
+   efl_wref_del(efl_super(obj, EFL_LOOP_FUTURE_CLASS), wref);
+
+   pd->wref--;
+}
+#endif
+
+static Eina_Bool
+_efl_loop_future_class_initializer(Efl_Class *klass)
+{
+   EFL_OPS_DEFINE(ops,
+                  EFL_OBJECT_OP_FUNC(efl_future_then, _efl_loop_future_then),
+                  EFL_OBJECT_OP_FUNC(efl_future_cancel, _efl_loop_future_cancel),
+                  EFL_OBJECT_OP_FUNC(efl_constructor, _efl_loop_future_efl_object_constructor),
+                  EFL_OBJECT_OP_FUNC(efl_destructor, _efl_loop_future_efl_object_destructor));
+
+   return efl_class_functions_set(klass, &ops);
+};
+
+static const Efl_Class_Description _efl_loop_future_class_desc = {
+  EO_VERSION,
+  "Efl_Future",
+  EFL_CLASS_TYPE_REGULAR,
+  sizeof (Efl_Loop_Future_Data),
+  _efl_loop_future_class_initializer,
+  NULL,
+  NULL
+};
+
+EFL_DEFINE_CLASS(efl_loop_future_class_get, &_efl_loop_future_class_desc, EFL_FUTURE_CLASS, NULL);
+
+static Efl_Future *
+_efl_promise_future_get(Eo *obj, Efl_Promise_Data *pd EINA_UNUSED)
+{
+   Efl_Future *f;
+   Efl_Loop_Future_Data *fd;
+
+   // Build a new future, attach it and return it
+   f = efl_add(EFL_LOOP_FUTURE_CLASS, NULL);
+   if (!f) return NULL;
+
+   fd = efl_data_scope_get(f, EFL_LOOP_FUTURE_CLASS);
+
+   fd->promise = efl_data_xref(obj, EFL_PROMISE_CLASS, f);
+   fd->promise->futures = eina_list_append(fd->promise->futures, fd);
+
+   return f;
+}
+
+static Efl_Promise_Msg *
+_efl_promise_message_new(Efl_Promise_Data *pd)
+{
+   Efl_Promise_Msg *message;
+
+   message = calloc(1, sizeof (Efl_Promise_Msg));
+   if (!message) return NULL;
+
+   EINA_REFCOUNT_INIT(message);
+   pd->message = message;
+
+   return message;
+}
+
+static void
+_efl_promise_value_set(Eo *obj, Efl_Promise_Data *pd, void *v, Eina_Free_Cb free_cb)
+{
+   Efl_Promise_Msg *message;
+   Efl_Loop_Future_Data *f;
+   Eina_List *l, *ln;
+
+   if (pd->message)
+     {
+        ERR("This promise has already been fulfilled. You can can't set a value twice nor can you set a value after it has been cancelled.");
+        return ;
+     }
+
+   // By triggering this message, we are likely going to kill all future
+   // And a user of the promise may want to attach an event handler on the promise
+   // and destroy it, so delay that to after the loop is done.
+   efl_ref(obj);
+
+   // Create a refcounted structure where refcount == number of future + one
+   message = _efl_promise_message_new(pd);
+   if (!message) return ;
+
+   message->value = v;
+   message->free_cb = free_cb;
+
+   EINA_REFCOUNT_INIT(message);
+   pd->message = message;
+
+   // Send it to all futures
+   EINA_LIST_FOREACH_SAFE(pd->futures, l, ln, f)
+     {
+        EINA_REFCOUNT_REF(message);
+        f->message = message;
+
+        // Trigger the callback
+        _efl_loop_future_propagate(f->self, f);
+     }
+
+   // Now, we may die.
+   efl_unref(obj);
+}
+
+static void
+_efl_promise_failed(Eo *obj, Efl_Promise_Data *pd, Eina_Error err)
+{
+   Efl_Promise_Msg *message;
+   Efl_Loop_Future_Data *f;
+   Eina_List *l, *ln;
+
+   if (pd->message)
+     {
+        ERR("This promise has already been fulfilled. You can can't set a value twice nor can you set a value after it has been cancelled.");
+        return ;
+     }
+
+   // By triggering this message, we are likely going to kill all future
+   // And a user of the promise may want to attach an event handler on the promise
+   // and destroy it, so delay that to after the loop is done.
+   efl_ref(obj);
+
+   // Create a refcounted structure where refcount == number of future + one
+   message = _efl_promise_message_new(pd);
+   if (!message) return ;
+
+   message->error = err;
+
+   EINA_REFCOUNT_INIT(message);
+   pd->message = message;
+
+   // Send it to each future
+   EINA_LIST_FOREACH_SAFE(pd->futures, l, ln, f)
+     {
+        EINA_REFCOUNT_REF(message);
+        f->message = message;
+
+        // Trigger the callback
+        _efl_loop_future_propagate(f->self, f);
+     }
+
+   // Now, we may die.
+   efl_unref(obj);
+}
+
+static void
+_efl_promise_progress_set(Eo *obj, Efl_Promise_Data *pd, void *p)
+{
+   Efl_Loop_Future_Data *f;
+   Eina_List *l, *ln;
+   Efl_Future_Event_Progress chain_progress;
+   Efl_Event ev;
+
+   chain_progress.progress = p;
+
+   ev.object = obj;
+   ev.info = &chain_progress;
+   ev.desc = EFL_FUTURE_EVENT_PROGRESS;
+
+   EINA_LIST_FOREACH_SAFE(pd->futures, l, ln, f)
+     {
+        Efl_Loop_Future_Callback *cb;
+
+        EINA_INLIST_FOREACH(f->callbacks, cb)
+          {
+             if (cb->next)
+               {
+                  chain_progress.next = cb->next;
+
+                  cb->progress((void*) cb->data, &ev);
+               }
+          }
+     }
+}
+
+static Efl_Object *
+_efl_promise_efl_object_constructor(Eo *obj, Efl_Promise_Data *pd)
+{
+   pd->promise = obj;
+
+   return efl_constructor(efl_super(obj, EFL_PROMISE_CLASS));
+}
+
+static void
+_efl_promise_efl_object_destructor(Eo *obj, Efl_Promise_Data *pd)
+{
+   // Unref refcounted structure
+   if (!pd->message && pd->futures)
+     {
+        ERR("This promise has not been fulfilled. Forcefully cancelling %p.", obj);
+        efl_promise_failed(obj, EINA_ERROR_FUTURE_CANCEL);
+     }
+
+   if (pd->message)
+     {
+        EINA_REFCOUNT_UNREF(pd->message)
+          _efl_promise_msg_free(pd->message);
+        pd->message = NULL;
+     }
+
+   efl_destructor(efl_super(obj, EFL_PROMISE_CLASS));
+}
+
+#include "efl_promise.eo.c"

src/lib/ecore/efl_promise.eo

@@ -0,0 +1,44 @@
+import eina_types;
+
+class Efl.Promise (Efl.Loop_User)
+{
+   methods {
+      @property progress {
+         set {
+         }
+         values {
+            p: void_ptr;
+	 }
+      }
+      @property future {
+         get {
+	    [[The returned future is optional and if no then/chain_then are registered before it goes back to run in the main loop, it will be destroyed.]]
+         }
+         values {
+            f: future<void_ptr>;
+         }
+      }
+      @property value {
+         set {
+	 }
+	 values {
+	    v: void_ptr;
+	    free_cb: __builtin_free_cb;
+	 }
+      }
+      failed {
+         params {
+	    @in err: Eina.Error;
+         }
+      }
+   }
+   events {
+      future,set: future<void_ptr>; [[This event is triggered whenever a future is fully set to receive all events and that the user of it do not hold any more reference on it.]]
+      future,progress,set: future<void_ptr>; [[This event is triggered whenever a future has a progress callback registered and the user does not hold any more reference on it.]]
+      future,none; [[This event is triggered whenever there is no more future connected to the promise.]]
+   }
+   implements {
+      Efl.Object.destructor;
+      Efl.Object.constructor;
+   }
+}