diff options
| -rw-r--r-- | changelog.d/13452.misc | 1 | ||||
| -rw-r--r-- | synapse/logging/opentracing.py | 15 |
2 files changed, 14 insertions, 2 deletions
diff --git a/changelog.d/13452.misc b/changelog.d/13452.misc new file mode 100644 index 0000000000..13d1523de2 --- /dev/null +++ b/changelog.d/13452.misc @@ -0,0 +1 @@ +Fix `@tag_args` being off-by-one with the arguments when tagging a span (tracing). diff --git a/synapse/logging/opentracing.py b/synapse/logging/opentracing.py index c1aa205eed..fa3f76c27f 100644 --- a/synapse/logging/opentracing.py +++ b/synapse/logging/opentracing.py @@ -901,6 +901,11 @@ def trace(func: Callable[P, R]) -> Callable[P, R]: def tag_args(func: Callable[P, R]) -> Callable[P, R]: """ Tags all of the args to the active span. + + Args: + func: `func` is assumed to be a method taking a `self` parameter, or a + `classmethod` taking a `cls` parameter. In either case, a tag is not + created for this parameter. """ if not opentracing: @@ -909,8 +914,14 @@ def tag_args(func: Callable[P, R]) -> Callable[P, R]: @wraps(func) def _tag_args_inner(*args: P.args, **kwargs: P.kwargs) -> R: argspec = inspect.getfullargspec(func) - for i, arg in enumerate(argspec.args[1:]): - set_tag("ARG_" + arg, str(args[i])) # type: ignore[index] + # We use `[1:]` to skip the `self` object reference and `start=1` to + # make the index line up with `argspec.args`. + # + # FIXME: We could update this handle any type of function by ignoring the + # first argument only if it's named `self` or `cls`. This isn't fool-proof + # but handles the idiomatic cases. + for i, arg in enumerate(args[1:], start=1): # type: ignore[index] + set_tag("ARG_" + argspec.args[i], str(arg)) set_tag("args", str(args[len(argspec.args) :])) # type: ignore[index] set_tag("kwargs", str(kwargs)) return func(*args, **kwargs) |