discussion: if we're goiong to instrument yaml, let's log byte size

ops/_private/yaml.py

@@ -29,10 +29,18 @@
 @tracer.start_as_current_span('ops.yaml.safe_load')  # type: ignore
 def safe_load(stream: Union[str, TextIO]) -> Any:
     """Same as yaml.safe_load, but use fast C loader if available."""
+    if not isinstance(stream, TextIO):
+        opentelemetry.trace.get_current_span().set_attribute("len", len(stream))
+    opentelemetry.trace.get_current_span().set_attribute("stream", isinstance(stream, TextIO))
     return yaml.load(stream, Loader=_safe_loader)  # noqa: S506
 
 
 @tracer.start_as_current_span('ops.yaml.safe_dump')  # type: ignore
 def safe_dump(data: Any, stream: Optional[TextIO] = None) -> str:
     """Same as yaml.safe_dump, but use fast C dumper if available."""
-    return yaml.dump(data, stream=stream, Dumper=_safe_dumper)  # type: ignore
+    rv = yaml.dump(data, stream=stream, Dumper=_safe_dumper)
+    if stream is None:
+        assert rv is not None
+        opentelemetry.trace.get_current_span().set_attribute("len", len(rv))
+    opentelemetry.trace.get_current_span().set_attribute("stream", stream is not None)
+    return rv  # type: ignore