Add logging for IAudioProcessor::process()

This is super verbose, but I'm sure it's going to be useful at some
point.

src/common/serialization/vst3/event-list.cpp

@@ -190,8 +190,10 @@ YaEventList::YaEventList(Steinberg::Vst::IEventList& event_list) {
     }
 }
 
-YaEventList::~YaEventList() {
-    FUNKNOWN_DTOR
+YaEventList::~YaEventList(){FUNKNOWN_DTOR}
+
+size_t YaEventList::num_events() const {
+    return events.size();
 }
 
 void YaEventList::write_back_outputs(

src/common/serialization/vst3/event-list.h

@@ -227,6 +227,11 @@ class YaEventList : public Steinberg::Vst::IEventList {
 
     DECLARE_FUNKNOWN_METHODS
 
+    /**
+     * Return the number of events we store. Used in debug logs.
+     */
+    size_t num_events() const;
+
     /**
      * Write these events an output events queue on the `ProcessData` object
      * provided by the host.

src/common/serialization/vst3/parameter-changes.cpp

@@ -41,6 +41,10 @@ IMPLEMENT_FUNKNOWN_METHODS(YaParameterChanges,
                            Steinberg::Vst::IParameterChanges::iid)
 #pragma GCC diagnostic pop
 
+size_t YaParameterChanges::num_parameters() const {
+    return queues.size();
+}
+
 void YaParameterChanges::write_back_outputs(
     Steinberg::Vst::IParameterChanges& output_queues) const {
     for (auto& queue : queues) {

src/common/serialization/vst3/parameter-changes.h

@@ -45,6 +45,12 @@ class YaParameterChanges : public Steinberg::Vst::IParameterChanges {
 
     DECLARE_FUNKNOWN_METHODS
 
+    /**
+     * Return the number of parameter we have parameter change queues for. Used
+     * in debug logs.
+     */
+    size_t num_parameters() const;
+
     /**
      * Write these changes back to an output parameter changes queue on the
      * `ProcessData` object provided by the host.

src/common/serialization/vst3/process-data.cpp

@@ -92,6 +92,11 @@ Steinberg::Vst::AudioBusBuffers YaAudioBusBuffers::get() {
     return reconstructed_buffers;
 }
 
+size_t YaAudioBusBuffers::num_channels() const {
+    return std::visit([&](const auto& buffers) { return buffers.size(); },
+                      buffers);
+}
+
 void YaAudioBusBuffers::write_back_outputs(
     Steinberg::Vst::AudioBusBuffers& output_buffers) const {
     output_buffers.silenceFlags = silence_flags;

src/common/serialization/vst3/process-data.h

@@ -72,6 +72,11 @@ class YaAudioBusBuffers {
      */
     Steinberg::Vst::AudioBusBuffers get();
 
+    /**
+     * Return the number of channels in `buffers`. Only used for debug logs.
+     */
+    size_t num_channels() const;
+
     /**
      * Write these buffers and the silence flag back to an `AudioBusBuffers
      * object provided by the host.
@@ -203,7 +208,6 @@ class YaProcessData {
         // of the `output*` fields defined below it
     }
 
-   private:
     // These fields are input and context data read from the original
     // `ProcessData` object
 
@@ -266,6 +270,7 @@ class YaProcessData {
      */
     std::optional<Steinberg::Vst::ProcessContext> process_context;
 
+   private:
     // These are the same fields as in `YaProcessDataResponse`. We'll generate
     // these as part of creating `reconstructed_process_data`, and they will be
     // moved into a response object during `move_outputs_to_response()`.