Allow serializing CLAP plugin factory list message

src/common/logging/clap.cpp

@@ -22,12 +22,12 @@
 
 ClapLogger::ClapLogger(Logger& generic_logger) : logger_(generic_logger) {}
 
-// bool ClapLogger::log_request(bool is_host_plugin,
-//                              const ClapPluginFactoryProxy::Construct&) {
-//     return log_request_base(is_host_plugin, [&](auto& message) {
-//         message << "GetPluginFactory()";
-//     });
-// }
+bool ClapLogger::log_request(bool is_host_plugin,
+                             const clap::plugin_factory::List&) {
+    return log_request_base(is_host_plugin, [&](auto& message) {
+        message << "clap_plugin_factory::list()";
+    });
+}
 
 bool ClapLogger::log_request(bool is_host_plugin, const WantsConfiguration&) {
     return log_request_base(is_host_plugin, [&](auto& message) {
@@ -40,6 +40,19 @@ bool ClapLogger::log_request(bool is_host_plugin, const WantsConfiguration&) {
 //     });
 // }
 
+bool ClapLogger::log_response(
+    bool is_host_plugin,
+    const clap::plugin_factory::ListResponse& response) {
+    return log_request_base(is_host_plugin, [&](auto& message) {
+        if (response.descriptors) {
+            message << "<clap_plugin_factory containing "
+                    << response.descriptors->size() << " plugin descriptors>";
+        } else {
+            message << "<not supported>";
+        }
+    });
+}
+
 void ClapLogger::log_response(bool is_host_plugin, const Configuration&) {
     log_response_base(is_host_plugin,
                       [&](auto& message) { message << "<Configuration>"; });

src/common/logging/clap.h

@@ -45,9 +45,7 @@ class ClapLogger {
     // `log_request()` call returned `true`. This way we can filter out the
     // log message for the response together with the request.
 
-    // TODO: Main thread rquests
-    // bool log_request(bool is_host_plugin,
-    //                  const ClapPluginFactoryProxy::Construct&);
+    bool log_request(bool is_host_plugin, const clap::plugin_factory::List&);
 
     // TODO: Audio thread requests
     // bool log_request(bool is_host_plugin,
@@ -55,11 +53,9 @@ class ClapLogger {
 
     bool log_request(bool is_host_plugin, const WantsConfiguration&);
 
-    // TOOD: Main thread responses
     // void log_response(bool is_host_plugin, const Ack&);
-    // void log_response(bool is_host_plugin,
-    //                   const UniversalTResult&,
-    //                   bool from_cache = false);
+    bool log_response(bool is_host_plugin,
+                      const clap::plugin_factory::ListResponse&);
 
     // TODO: Audio thread responses
     // void log_response(bool is_host_plugin,

src/common/serialization/clap.h

@@ -36,8 +36,10 @@
  * request of type `ClapControlRequest(T)` should send back a `T::Response`.
  * These messages are for main thread functions.
  */
-// TODO: Remove placeholder, add actual types
-using ClapMainThreadControlRequest = std::variant<WantsConfiguration>;
+// FIXME: Remove the `WantsConfiguration`. For some reason bitsery just won't
+//        serialize this without it.
+using ClapMainThreadControlRequest =
+    std::variant<WantsConfiguration, clap::plugin_factory::List>;
 
 template <typename S>
 void serialize(S& s, ClapMainThreadControlRequest& payload) {
@@ -117,13 +119,12 @@ struct ClapAudioThreadControlRequest {
 // TODO: Placeholder
 using ClapMainThreadCallbackRequest = std::variant<WantsConfiguration>;
 
-// TODO: Uncomment after changing `ClapMainThreadCallbackRequest`
-// template <typename S>
-// void serialize(S& s, ClapMainThreadCallbackRequest& payload) {
-//     // All of the objects in `ClapMainThreadCallbackRequest` should have their own
-//     // serialization function.
-//     s.ext(payload, bitsery::ext::InPlaceVariant{});
-// }
+template <typename S>
+void serialize(S& s, ClapMainThreadCallbackRequest& payload) {
+    // All of the objects in `ClapMainThreadCallbackRequest` should have their
+    // own serialization function.
+    s.ext(payload, bitsery::ext::InPlaceVariant{});
+}
 
 /**
  * Fetch the `std::variant<>` from an audio thread request object. This will

src/common/serialization/clap/plugin-factory.h

@@ -26,21 +26,27 @@ namespace plugin_factory {
 /**
  * The response to the `clap::plugin_factory::list` message defined below.
  */
-struct list_response {
-    std::vector<clap::plugin::descriptor> descriptors;
+struct ListResponse {
+    /**
+     * The descriptors for the plugins in the factory. This will be a nullopt if
+     * the plugin does not support the plugin factory.
+     */
+    std::optional<std::vector<clap::plugin::descriptor>> descriptors;
 
     template <typename S>
     void serialize(S& s) {
-        s.container(descriptors, 8192);
+        s.ext(descriptors, bitsery::ext::InPlaceOptional{},
+              [](S& s, auto& v) { s.container(v, 8192); });
     }
 };
 
 /**
  * Message combining `clap_plugin_factory::count()` with
- * `clap_plugin_factory::get()` to get all plugin descriptors in one go.
+ * `clap_plugin_factory::get()` to get all plugin descriptors in one go. Will
+ * return a nullopt if the plugin does not support the plugin factory.
  */
-struct list {
-    using Response = list_response;
+struct List {
+    using Response = ListResponse;
 
     // Since we send this to a specific CLAP plugin library, there are no
     // parameters here

src/wine-host/bridges/clap.cpp

@@ -70,16 +70,21 @@ bool ClapBridge::inhibits_event_loop() noexcept {
 void ClapBridge::run() {
     set_realtime_priority(true);
 
-    // TODO: Listen on the socket
-    // sockets_.host_plugin_control_.receive_messages(
-    //     std::nullopt,
-    //     overload{
-    //         [&](const ClapPluginFactoryProxy::Construct&)
-    //             -> ClapPluginFactoryProxy::Construct::Response {
-    //             return ClapPluginFactoryProxy::ConstructArgs(
-    //                 module_->getFactory().get());
-    //         },
-    //     });
+    sockets_.host_plugin_main_thread_control_.receive_messages(
+        std::nullopt,
+        overload{
+            [&](const WantsConfiguration&) -> WantsConfiguration::Response {
+                // FIXME: This overload shouldn't be here, but
+                //        bitsery simply won't allow us to serialize the
+                //        variant without it.
+                return {};
+            },
+            [&](const clap::plugin_factory::List&)
+                -> clap::plugin_factory::List::Response {
+                // FIXME: Actually load this
+                return clap::plugin_factory::ListResponse{};
+            },
+        });
 }
 
 // TODO: Implement this