Add markers to event stream

src/profiler/recording.rs

@@ -1,8 +1,9 @@
-use std::collections::HashMap;
+use std::{borrow::Cow, collections::HashMap};
 
 use fxprof_processed_profile::{
-    CategoryHandle, CpuDelta, Frame, FrameFlags, FrameInfo, ProcessHandle, Profile,
-    ReferenceTimestamp, SamplingInterval, StackHandle, ThreadHandle, Timestamp,
+    CategoryHandle, CpuDelta, Frame, FrameFlags, FrameInfo, MarkerTiming, ProcessHandle, Profile,
+    ReferenceTimestamp, SamplingInterval, StackHandle, StaticSchemaMarker, StringHandle,
+    ThreadHandle, Timestamp,
 };
 
 use crate::profiler::state::{ProgramState, RESET_CODE, StackFrame};
@@ -72,6 +73,15 @@ impl Recording {
         }
     }
 
+    pub fn track_marker(&mut self, name: Cow<'static, str>) {
+        let Some(thread) = self.threads.get(&RESET_CODE) else {
+            return;
+        };
+        let timing = MarkerTiming::Instant(Timestamp::from_nanos_since_reference(self.now * 50));
+        let marker = SimpleMarker(name);
+        self.profile.add_marker(*thread, timing, marker);
+    }
+
     pub fn finish(self) -> Vec<u8> {
         serde_json::to_vec(&self.profile).expect("could not serialize profile")
     }
@@ -92,6 +102,29 @@ impl Recording {
     }
 }
 
+struct SimpleMarker(Cow<'static, str>);
+
+impl StaticSchemaMarker for SimpleMarker {
+    const UNIQUE_MARKER_TYPE_NAME: &'static str = "Simple";
+    const FIELDS: &'static [fxprof_processed_profile::StaticSchemaMarkerField] = &[];
+
+    fn name(&self, profile: &mut Profile) -> StringHandle {
+        profile.intern_string(&self.0)
+    }
+
+    fn category(&self, _profile: &mut Profile) -> CategoryHandle {
+        CategoryHandle::OTHER
+    }
+
+    fn string_field_value(&self, _field_index: u32) -> StringHandle {
+        unreachable!()
+    }
+
+    fn number_field_value(&self, _field_index: u32) -> f64 {
+        unreachable!()
+    }
+}
+
 fn thread_name_for_code(code: u16) -> std::borrow::Cow<'static, str> {
     match code {
         RESET_CODE => "Main".into(),