ruby: new notmuch_rb_object_destroy() helper

The struct used to store the types (rb_data_type_t) contains a "data"
field where we can store whatever we want. I use that field to store a
pointer to the corresponding destroy function. For example
notmuch_rb_database_type contains a pointer to notmuch_database_destroy.

I cast that pointer as a notmuch_status_t (func*)(void *) and call
that function passing the internal object (e.g. notmuch_database_t).

Using the rb_data_type_t data we can call the correct notmuch destroy
function.

Therefore this:

  ret = ((notmuch_status_t (*)(void *)) type->data) (nm_object);

Is effectively the same as this:

  ret = notmuch_database_destroy (database);

The advantage of doing it this way is that much less code is necesary
since each rb_data_type_t has the corresponding destroy function stored
in it.

Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com>

bindings/ruby/database.c

@@ -114,11 +114,7 @@ VALUE
 notmuch_rb_database_close (VALUE self)
 {
     notmuch_status_t ret;
-    notmuch_database_t *db;
-
-    Data_Get_Notmuch_Database (self, db);
-    ret = notmuch_database_destroy (db);
-    DATA_PTR (self) = NULL;
+    ret = notmuch_rb_object_destroy (self, &notmuch_rb_database_type);
     notmuch_rb_status_raise (ret);
 
     return Qnil;

bindings/ruby/defs.h

@@ -105,6 +105,21 @@ extern const rb_data_type_t notmuch_rb_tags_type;
 #define Data_Get_Notmuch_Tags(obj, ptr) \
     Data_Get_Notmuch_Object ((obj), &notmuch_rb_tags_type, (ptr))
 
+static inline notmuch_status_t
+notmuch_rb_object_destroy (VALUE rb_object, const rb_data_type_t *type)
+{
+    void *nm_object;
+    notmuch_status_t ret;
+
+    Data_Get_Notmuch_Object (rb_object, type, nm_object);
+
+    /* Call the corresponding notmuch_*_destroy function */
+    ret = ((notmuch_status_t (*)(void *)) type->data) (nm_object);
+    DATA_PTR (rb_object) = NULL;
+
+    return ret;
+}
+
 /* status.c */
 void
 notmuch_rb_status_raise (notmuch_status_t status);

bindings/ruby/directory.c

@@ -28,12 +28,7 @@
 VALUE
 notmuch_rb_directory_destroy (VALUE self)
 {
-    notmuch_directory_t *dir;
-
-    Data_Get_Notmuch_Directory (self, dir);
-
-    notmuch_directory_destroy (dir);
-    DATA_PTR (self) = NULL;
+    notmuch_rb_object_destroy (self, &notmuch_rb_directory_type);
 
     return Qnil;
 }

bindings/ruby/filenames.c

@@ -28,12 +28,7 @@
 VALUE
 notmuch_rb_filenames_destroy (VALUE self)
 {
-    notmuch_filenames_t *fnames;
-
-    Data_Get_Notmuch_FileNames (self, fnames);
-
-    notmuch_filenames_destroy (fnames);
-    DATA_PTR (self) = NULL;
+    notmuch_rb_object_destroy (self, &notmuch_rb_filenames_type);
 
     return Qnil;
 }

bindings/ruby/init.c

@@ -54,6 +54,7 @@ const rb_data_type_t notmuch_rb_object_type = {
     const rb_data_type_t notmuch_rb_ ## id ## _type = { \
 	.wrap_struct_name = "notmuch_" #id, \
 	.parent = &notmuch_rb_object_type, \
+	.data = &notmuch_ ## id ## _destroy, \
     }
 
 define_type (database);

bindings/ruby/message.c

@@ -28,12 +28,7 @@
 VALUE
 notmuch_rb_message_destroy (VALUE self)
 {
-    notmuch_message_t *message;
-
-    Data_Get_Notmuch_Message (self, message);
-
-    notmuch_message_destroy (message);
-    DATA_PTR (self) = NULL;
+    notmuch_rb_object_destroy (self, &notmuch_rb_message_type);
 
     return Qnil;
 }

bindings/ruby/messages.c

@@ -28,12 +28,7 @@
 VALUE
 notmuch_rb_messages_destroy (VALUE self)
 {
-    notmuch_messages_t *messages;
-
-    Data_Get_Notmuch_Messages (self, messages);
-
-    notmuch_messages_destroy (messages);
-    DATA_PTR (self) = NULL;
+    notmuch_rb_object_destroy (self, &notmuch_rb_messages_type);
 
     return Qnil;
 }

bindings/ruby/query.c

@@ -28,12 +28,7 @@
 VALUE
 notmuch_rb_query_destroy (VALUE self)
 {
-    notmuch_query_t *query;
-
-    Data_Get_Notmuch_Query (self, query);
-
-    notmuch_query_destroy (query);
-    DATA_PTR (self) = NULL;
+    notmuch_rb_object_destroy (self, &notmuch_rb_query_type);
 
     return Qnil;
 }

bindings/ruby/tags.c

@@ -28,12 +28,7 @@
 VALUE
 notmuch_rb_tags_destroy (VALUE self)
 {
-    notmuch_tags_t *tags;
-
-    Data_Get_Notmuch_Tags (self, tags);
-
-    notmuch_tags_destroy (tags);
-    DATA_PTR (self) = NULL;
+    notmuch_rb_object_destroy (self, &notmuch_rb_tags_type);
 
     return Qnil;
 }

bindings/ruby/thread.c

@@ -28,12 +28,7 @@
 VALUE
 notmuch_rb_thread_destroy (VALUE self)
 {
-    notmuch_thread_t *thread;
-
-    Data_Get_Notmuch_Thread (self, thread);
-
-    notmuch_thread_destroy (thread);
-    DATA_PTR (self) = NULL;
+    notmuch_rb_object_destroy (self, &notmuch_rb_thread_type);
 
     return Qnil;
 }

bindings/ruby/threads.c

@@ -28,12 +28,7 @@
 VALUE
 notmuch_rb_threads_destroy (VALUE self)
 {
-    notmuch_threads_t *threads;
-
-    Data_Get_Notmuch_Threads (self, threads);
-
-    notmuch_threads_destroy (threads);
-    DATA_PTR (self) = NULL;
+    notmuch_rb_object_destroy (self, &notmuch_rb_threads_type);
 
     return Qnil;
 }