Narrow feedback log shared API to visitors

codex-rs/state/src/log_db.rs

@@ -156,7 +156,7 @@ where
             span.extensions_mut().insert(SpanLogContext {
                 name: span.metadata().name().to_string(),
                 formatted_fields: format_fields(attrs),
-                thread_id: visitor.thread_id,
+                thread_id: visitor.into_thread_id(),
             });
         }
     }
@@ -169,11 +169,12 @@ where
     ) {
         let mut visitor = SpanFieldVisitor::default();
         values.record(&mut visitor);
+        let thread_id = visitor.into_thread_id();
 
         if let Some(span) = ctx.span(id) {
             let mut extensions = span.extensions_mut();
             if let Some(log_context) = extensions.get_mut::<SpanLogContext>() {
-                if let Some(thread_id) = visitor.thread_id {
+                if let Some(thread_id) = thread_id {
                     log_context.thread_id = Some(thread_id);
                 }
                 append_fields(&mut log_context.formatted_fields, values);
@@ -181,7 +182,7 @@ where
                 extensions.insert(SpanLogContext {
                     name: span.metadata().name().to_string(),
                     formatted_fields: format_fields(values),
-                    thread_id: visitor.thread_id,
+                    thread_id,
                 });
             }
         }
@@ -191,10 +192,8 @@ where
         let metadata = event.metadata();
         let mut visitor = MessageVisitor::default();
         event.record(&mut visitor);
-        let thread_id = visitor
-            .thread_id
-            .clone()
-            .or_else(|| event_thread_id(event, &ctx));
+        let (message, visitor_thread_id) = visitor.into_parts();
+        let thread_id = visitor_thread_id.or_else(|| event_thread_id(event, &ctx));
         let feedback_log_body = format_feedback_log_body(event, &ctx);
 
         let now = SystemTime::now()
@@ -205,7 +204,7 @@ where
             ts_nanos: now.subsec_nanos() as i64,
             level: metadata.level().as_str().to_string(),
             target: metadata.target().to_string(),
-            message: visitor.message,
+            message,
             feedback_log_body: Some(feedback_log_body),
             thread_id,
             process_uuid: Some(self.process_uuid.clone()),
@@ -239,12 +238,21 @@ struct SpanLogContext {
     thread_id: Option<String>,
 }
 
-#[derive(Default)]
-struct SpanFieldVisitor {
+/// Extracts feedback-log fields from span attributes and span records.
+#[derive(Debug, Default)]
+pub struct SpanFieldVisitor {
     thread_id: Option<String>,
 }
 
 impl SpanFieldVisitor {
+    pub fn thread_id(&self) -> Option<&str> {
+        self.thread_id.as_deref()
+    }
+
+    pub fn into_thread_id(self) -> Option<String> {
+        self.thread_id
+    }
+
     fn record_field(&mut self, field: &Field, value: String) {
         if field.name() == "thread_id" && self.thread_id.is_none() {
             self.thread_id = Some(value);
@@ -404,13 +412,26 @@ async fn flush(state_db: &StateRuntime, buffer: &mut Vec<LogEntry>) {
     let _ = state_db.insert_logs(entries.as_slice()).await;
 }
 
-#[derive(Default)]
-struct MessageVisitor {
+/// Extracts feedback-log fields from event records.
+#[derive(Debug, Default)]
+pub struct MessageVisitor {
     message: Option<String>,
     thread_id: Option<String>,
 }
 
 impl MessageVisitor {
+    pub fn message(&self) -> Option<&str> {
+        self.message.as_deref()
+    }
+
+    pub fn thread_id(&self) -> Option<&str> {
+        self.thread_id.as_deref()
+    }
+
+    pub fn into_parts(self) -> (Option<String>, Option<String>) {
+        (self.message, self.thread_id)
+    }
+
     fn record_field(&mut self, field: &Field, value: String) {
         if field.name() == "message" && self.message.is_none() {
             self.message = Some(value.clone());