1 files changed, 262 insertions, 0 deletions
diff --git a/components/shared/webxr/registry.rs b/components/shared/webxr/registry.rs
new file mode 100644
index 00000000000..337bb80a8a2
--- /dev/null
+++ b/components/shared/webxr/registry.rs
@@ -0,0 +1,262 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
+
+use crate::DiscoveryAPI;
+use crate::Error;
+use crate::Frame;
+use crate::GLTypes;
+use crate::LayerGrandManager;
+use crate::MainThreadSession;
+use crate::MockDeviceInit;
+use crate::MockDeviceMsg;
+use crate::MockDiscoveryAPI;
+use crate::Receiver;
+use crate::Sender;
+use crate::Session;
+use crate::SessionBuilder;
+use crate::SessionId;
+use crate::SessionInit;
+use crate::SessionMode;
+
+use log::warn;
+
+#[cfg(feature = "ipc")]
+use serde::{Deserialize, Serialize};
+
+#[derive(Clone)]
+#[cfg_attr(feature = "ipc", derive(Serialize, Deserialize))]
+pub struct Registry {
+    sender: Sender<RegistryMsg>,
+    waker: MainThreadWakerImpl,
+}
+
+pub struct MainThreadRegistry<GL> {
+    discoveries: Vec<Box<dyn DiscoveryAPI<GL>>>,
+    sessions: Vec<Box<dyn MainThreadSession>>,
+    mocks: Vec<Box<dyn MockDiscoveryAPI<GL>>>,
+    sender: Sender<RegistryMsg>,
+    receiver: Receiver<RegistryMsg>,
+    waker: MainThreadWakerImpl,
+    grand_manager: LayerGrandManager<GL>,
+    next_session_id: u32,
+}
+
+pub trait MainThreadWaker: 'static + Send {
+    fn clone_box(&self) -> Box<dyn MainThreadWaker>;
+    fn wake(&self);
+}
+
+impl Clone for Box<dyn MainThreadWaker> {
+    fn clone(&self) -> Self {
+        self.clone_box()
+    }
+}
+
+#[derive(Clone)]
+#[cfg_attr(feature = "ipc", derive(Serialize, Deserialize))]
+struct MainThreadWakerImpl {
+    #[cfg(feature = "ipc")]
+    sender: Sender<()>,
+    #[cfg(not(feature = "ipc"))]
+    waker: Box<dyn MainThreadWaker>,
+}
+
+#[cfg(feature = "ipc")]
+impl MainThreadWakerImpl {
+    fn new(waker: Box<dyn MainThreadWaker>) -> Result<MainThreadWakerImpl, Error> {
+        let (sender, receiver) = crate::channel().or(Err(Error::CommunicationError))?;
+        ipc_channel::router::ROUTER.add_typed_route(receiver, Box::new(move |_| waker.wake()));
+        Ok(MainThreadWakerImpl { sender })
+    }
+
+    fn wake(&self) {
+        let _ = self.sender.send(());
+    }
+}
+
+#[cfg(not(feature = "ipc"))]
+impl MainThreadWakerImpl {
+    fn new(waker: Box<dyn MainThreadWaker>) -> Result<MainThreadWakerImpl, Error> {
+        Ok(MainThreadWakerImpl { waker })
+    }
+
+    pub fn wake(&self) {
+        self.waker.wake()
+    }
+}
+
+impl Registry {
+    pub fn supports_session(&mut self, mode: SessionMode, dest: Sender<Result<(), Error>>) {
+        let _ = self.sender.send(RegistryMsg::SupportsSession(mode, dest));
+        self.waker.wake();
+    }
+
+    pub fn request_session(
+        &mut self,
+        mode: SessionMode,
+        init: SessionInit,
+        dest: Sender<Result<Session, Error>>,
+        animation_frame_handler: Sender<Frame>,
+    ) {
+        let _ = self.sender.send(RegistryMsg::RequestSession(
+            mode,
+            init,
+            dest,
+            animation_frame_handler,
+        ));
+        self.waker.wake();
+    }
+
+    pub fn simulate_device_connection(
+        &mut self,
+        init: MockDeviceInit,
+        dest: Sender<Result<Sender<MockDeviceMsg>, Error>>,
+    ) {
+        let _ = self
+            .sender
+            .send(RegistryMsg::SimulateDeviceConnection(init, dest));
+        self.waker.wake();
+    }
+}
+
+impl<GL: 'static + GLTypes> MainThreadRegistry<GL> {
+    pub fn new(
+        waker: Box<dyn MainThreadWaker>,
+        grand_manager: LayerGrandManager<GL>,
+    ) -> Result<Self, Error> {
+        let (sender, receiver) = crate::channel().or(Err(Error::CommunicationError))?;
+        let discoveries = Vec::new();
+        let sessions = Vec::new();
+        let mocks = Vec::new();
+        let waker = MainThreadWakerImpl::new(waker)?;
+        Ok(MainThreadRegistry {
+            discoveries,
+            sessions,
+            mocks,
+            sender,
+            receiver,
+            waker,
+            grand_manager,
+            next_session_id: 0,
+        })
+    }
+
+    pub fn registry(&self) -> Registry {
+        Registry {
+            sender: self.sender.clone(),
+            waker: self.waker.clone(),
+        }
+    }
+
+    pub fn register<D>(&mut self, discovery: D)
+    where
+        D: DiscoveryAPI<GL>,
+    {
+        self.discoveries.push(Box::new(discovery));
+    }
+
+    pub fn register_mock<D>(&mut self, discovery: D)
+    where
+        D: MockDiscoveryAPI<GL>,
+    {
+        self.mocks.push(Box::new(discovery));
+    }
+
+    pub fn run_on_main_thread<S>(&mut self, session: S)
+    where
+        S: MainThreadSession,
+    {
+        self.sessions.push(Box::new(session));
+    }
+
+    pub fn run_one_frame(&mut self) {
+        while let Ok(msg) = self.receiver.try_recv() {
+            self.handle_msg(msg);
+        }
+        for session in &mut self.sessions {
+            session.run_one_frame();
+        }
+        self.sessions.retain(|session| session.running());
+    }
+
+    pub fn running(&self) -> bool {
+        self.sessions.iter().any(|session| session.running())
+    }
+
+    fn handle_msg(&mut self, msg: RegistryMsg) {
+        match msg {
+            RegistryMsg::SupportsSession(mode, dest) => {
+                let _ = dest.send(self.supports_session(mode));
+            }
+            RegistryMsg::RequestSession(mode, init, dest, raf_sender) => {
+                let _ = dest.send(self.request_session(mode, init, raf_sender));
+            }
+            RegistryMsg::SimulateDeviceConnection(init, dest) => {
+                let _ = dest.send(self.simulate_device_connection(init));
+            }
+        }
+    }
+
+    fn supports_session(&mut self, mode: SessionMode) -> Result<(), Error> {
+        for discovery in &self.discoveries {
+            if discovery.supports_session(mode) {
+                return Ok(());
+            }
+        }
+        Err(Error::NoMatchingDevice)
+    }
+
+    fn request_session(
+        &mut self,
+        mode: SessionMode,
+        init: SessionInit,
+        raf_sender: Sender<Frame>,
+    ) -> Result<Session, Error> {
+        for discovery in &mut self.discoveries {
+            if discovery.supports_session(mode) {
+                let raf_sender = raf_sender.clone();
+                let id = SessionId(self.next_session_id);
+                self.next_session_id += 1;
+                let xr = SessionBuilder::new(
+                    &mut self.sessions,
+                    raf_sender,
+                    self.grand_manager.clone(),
+                    id,
+                );
+                match discovery.request_session(mode, &init, xr) {
+                    Ok(session) => return Ok(session),
+                    Err(err) => warn!("XR device error {:?}", err),
+                }
+            }
+        }
+        warn!("no device could support the session");
+        Err(Error::NoMatchingDevice)
+    }
+
+    fn simulate_device_connection(
+        &mut self,
+        init: MockDeviceInit,
+    ) -> Result<Sender<MockDeviceMsg>, Error> {
+        for mock in &mut self.mocks {
+            let (sender, receiver) = crate::channel().or(Err(Error::CommunicationError))?;
+            if let Ok(discovery) = mock.simulate_device_connection(init.clone(), receiver) {
+                self.discoveries.insert(0, discovery);
+                return Ok(sender);
+            }
+        }
+        Err(Error::NoMatchingDevice)
+    }
+}
+
+#[cfg_attr(feature = "ipc", derive(Serialize, Deserialize))]
+enum RegistryMsg {
+    RequestSession(
+        SessionMode,
+        SessionInit,
+        Sender<Result<Session, Error>>,
+        Sender<Frame>,
+    ),
+    SupportsSession(SessionMode, Sender<Result<(), Error>>),
+    SimulateDeviceConnection(MockDeviceInit, Sender<Result<Sender<MockDeviceMsg>, Error>>),
+}