gstreamer: Return some values by reference instead

Less refcounting.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer-rs/-/merge_requests/1183>

examples/src/bin/playbin.rs

@@ -121,7 +121,7 @@ fn example_main() {
             MessageView::StateChanged(state_changed) =>
             // We are only interested in state-changed messages from playbin
             {
-                if state_changed.src().map(|s| s == playbin).unwrap_or(false)
+                if state_changed.src().map(|s| s == &playbin).unwrap_or(false)
                     && state_changed.current() == gst::State::Playing
                 {
                     // Generate a dot graph of the pipeline to GST_DEBUG_DUMP_DOT_DIR if defined

examples/src/bin/rtpfecclient.rs

@@ -253,7 +253,7 @@ fn example_main() -> Result<(), Error> {
             }
             MessageView::StateChanged(s) => {
                 if let Some(element) = msg.src() {
-                    if element == pipeline && s.current() == gst::State::Playing {
+                    if element == &pipeline && s.current() == gst::State::Playing {
                         eprintln!("PLAYING");
                         gst::debug_bin_to_dot_file(
                             &pipeline,

examples/src/bin/rtpfecserver.rs

@@ -179,7 +179,7 @@ fn example_main() -> Result<(), Error> {
             }
             MessageView::StateChanged(s) => {
                 if let Some(element) = msg.src() {
-                    if element == pipeline && s.current() == gst::State::Playing {
+                    if element == &pipeline && s.current() == gst::State::Playing {
                         eprintln!("PLAYING");
                         gst::debug_bin_to_dot_file(
                             &pipeline,

examples/src/glupload.rs

@@ -414,7 +414,7 @@ impl App {
                         let context_type = ctxt.context_type();
                         if context_type == *gst_gl::GL_DISPLAY_CONTEXT_TYPE {
                             if let Some(el) =
-                                msg.src().map(|s| s.downcast::<gst::Element>().unwrap())
+                                msg.src().map(|s| s.downcast_ref::<gst::Element>().unwrap())
                             {
                                 let context = gst::Context::new(context_type, true);
                                 context.set_gl_display(&gl_display);
@@ -423,7 +423,7 @@ impl App {
                         }
                         if context_type == "gst.gl.app_context" {
                             if let Some(el) =
-                                msg.src().map(|s| s.downcast::<gst::Element>().unwrap())
+                                msg.src().map(|s| s.downcast_ref::<gst::Element>().unwrap())
                             {
                                 let mut context = gst::Context::new(context_type, true);
                                 {

gstreamer/src/memory.rs

@@ -166,8 +166,14 @@ impl Memory {
 
 impl MemoryRef {
     #[doc(alias = "get_allocator")]
-    pub fn allocator(&self) -> Option<Allocator> {
+    pub fn allocator(&self) -> Option<&Allocator> {
-        unsafe { from_glib_none(self.0.allocator) }
+        unsafe {
+            if self.0.allocator.is_null() {
+                None
+            } else {
+                Some(&*(&self.0.allocator as *const *mut ffi::GstAllocator as *const Allocator))
+            }
+        }
     }
 
     #[doc(alias = "get_parent")]

gstreamer/src/message.rs

@@ -17,8 +17,14 @@ mini_object_wrapper!(Message, MessageRef, ffi::GstMessage, || {
 
 impl MessageRef {
     #[doc(alias = "get_src")]
-    pub fn src(&self) -> Option<Object> {
+    pub fn src(&self) -> Option<&Object> {
-        unsafe { from_glib_none((*self.as_ptr()).src) }
+        unsafe {
+            if (*self.as_ptr()).src.is_null() {
+                None
+            } else {
+                Some(&*(&(*self.as_ptr()).src as *const *mut ffi::GstObject as *const Object))
+            }
+        }
     }
 
     #[doc(alias = "get_seqnum")]

gstreamer/src/param_spec.rs

@@ -239,11 +239,18 @@ impl ParamSpecArray {
         }
     }
 
-    pub fn element_spec(&self) -> Option<ParamSpec> {
+    pub fn element_spec(&self) -> Option<&ParamSpec> {
         unsafe {
             let ptr = self.as_ptr();
 
-            from_glib_none((*ptr).element_spec)
+            if (*ptr).element_spec.is_null() {
+                None
+            } else {
+                Some(
+                    &*(&(*ptr).element_spec as *const *mut glib::gobject_ffi::GParamSpec
+                        as *const glib::ParamSpec),
+                )
+            }
         }
     }
 

tutorials/src/bin/basic-tutorial-3.rs

@@ -98,7 +98,7 @@ fn tutorial_main() {
                 break;
             }
             MessageView::StateChanged(state_changed) => {
-                if state_changed.src().map(|s| s == pipeline).unwrap_or(false) {
+                if state_changed.src().map(|s| s == &pipeline).unwrap_or(false) {
                     println!(
                         "Pipeline state changed from {:?} to {:?}",
                         state_changed.old(),

tutorials/src/bin/basic-tutorial-4.rs

@@ -128,7 +128,7 @@ fn handle_message(custom_data: &mut CustomData, msg: &gst::Message) {
         MessageView::StateChanged(state_changed) => {
             if state_changed
                 .src()
-                .map(|s| s == custom_data.playbin)
+                .map(|s| s == &custom_data.playbin)
                 .unwrap_or(false)
             {
                 let new_state = state_changed.current();

tutorials/src/bin/basic-tutorial-5.rs

@@ -360,7 +360,7 @@ mod tutorial5 {
                 // This is called when the pipeline changes states. We use it to
                 // keep track of the current state.
                 gst::MessageView::StateChanged(state_changed) => {
-                    if state_changed.src().map(|s| s == pipeline).unwrap_or(false) {
+                    if state_changed.src().map(|s| s == &pipeline).unwrap_or(false) {
                         println!("State set to {:?}", state_changed.current());
                     }
                 }

tutorials/src/bin/basic-tutorial-6.rs

@@ -141,7 +141,7 @@ fn tutorial_main() {
             MessageView::StateChanged(state_changed) =>
             // We are only interested in state-changed messages from the pipeline
             {
-                if state_changed.src().map(|s| s == pipeline).unwrap_or(false) {
+                if state_changed.src().map(|s| s == &pipeline).unwrap_or(false) {
                     let new_state = state_changed.current();
                     let old_state = state_changed.old();
 

tutorials/src/bin/playback-tutorial-1.rs

@@ -155,7 +155,7 @@ fn tutorial_main() -> Result<(), Error> {
             MessageView::StateChanged(state_changed) => {
                 if state_changed
                     .src()
-                    .map(|s| s == playbin_clone)
+                    .map(|s| s == &playbin_clone)
                     .unwrap_or(false)
                     && state_changed.current() == gst::State::Playing
                 {

tutorials/src/bin/playback-tutorial-2.rs

@@ -160,7 +160,7 @@ fn tutorial_main() -> Result<(), Error> {
             MessageView::StateChanged(state_changed) => {
                 if state_changed
                     .src()
-                    .map(|s| s == playbin_clone)
+                    .map(|s| s == &playbin_clone)
                     .unwrap_or(false)
                     && state_changed.current() == gst::State::Playing
                 {