add PassthroughTraceWorker definitions

src/workerd/io/trace.h

@@ -584,11 +584,11 @@ class BaseTracer {
       kj::Date timestamp, kj::String channel, kj::Array<kj::byte> message) = 0;
 
   // Adds info about the event that triggered the trace.  Must not be called more than once.
-  virtual void setEventInfo(kj::Date timestamp, tracing::EventInfo&&) = 0;
+  virtual void setEventInfo(kj::Date timestamp, tracing::EventInfo&& info) = 0;
 
   // Adds info about the response. Must not be called more than once, and only
   // after passing a FetchEventInfo to setEventInfo().
-  virtual void setFetchResponseInfo(tracing::FetchResponseInfo&&) = 0;
+  virtual void setFetchResponseInfo(tracing::FetchResponseInfo&& info) = 0;
 
   virtual void setOutcome(EventOutcome outcome, kj::Duration cpuTime, kj::Duration wallTime) = 0;
 };
@@ -617,8 +617,8 @@ class WorkerTracer final: public kj::Refcounted, public BaseTracer {
       kj::Maybe<kj::String> stack) override;
   void addDiagnosticChannelEvent(
       kj::Date timestamp, kj::String channel, kj::Array<kj::byte> message) override;
-  void setEventInfo(kj::Date timestamp, tracing::EventInfo&&) override;
-  void setFetchResponseInfo(tracing::FetchResponseInfo&&) override;
+  void setEventInfo(kj::Date timestamp, tracing::EventInfo&& info) override;
+  void setFetchResponseInfo(tracing::FetchResponseInfo&& info) override;
   void setOutcome(EventOutcome outcome, kj::Duration cpuTime, kj::Duration wallTime) override;
 
   // Used only for a Trace in a process sandbox. Copies the content of this tracer's trace to the

src/workerd/io/worker-interface.capnp

@@ -486,3 +486,28 @@ interface WorkerdBootstrap {
   # TODO(someday): Pass cfBlobJson? Currently doesn't matter since the cf blob is only present for
   #   HTTP requests which can be delivered over regular HTTP instead of capnp.
 }
+
+interface PassthroughTraceWorker {
+  struct EventInfo {
+    union {
+      fetch @0 :Trace.FetchEventInfo;
+      jsRpc @1 :Trace.JsRpcEventInfo;
+      scheduled @2 :Trace.ScheduledEventInfo;
+      alarm @3 :Trace.AlarmEventInfo;
+      queue @4 :Trace.QueueEventInfo;
+      custom @5 :Trace.CustomEventInfo;
+      email @6 :Trace.EmailEventInfo;
+      trace @7 :Trace.TraceEventInfo;
+      hibernatableWebSocket @8 :Trace.HibernatableWebSocketEventInfo;
+    }
+  }
+
+  setEventInfo @0 (timestampNs :Int64, eventInfo :EventInfo);
+  addLog @1 (timestampNs :Int64, logLevel :Trace.Log.Level, message :Text, isSpan :Bool);
+  addException @2 (timestampNs :Int64, name :Text, message :Text, stack :Text = null);
+  addDiagnosticChannelEvent @3 (timestampNs :Int64, channel :Text, message :Data);
+  setFetchResponseInfo @4 (info :Trace.FetchResponseInfo);
+  setOutcome @5 (outcome :EventOutcome, cpuTime :UInt64, wallTime :UInt64);
+  # TODO(soon): Add this once Span definitions exist in workerd.
+  # addSpan @2 (span :TraceCollector.Span, spanContext :Text);
+}