On Tue, May 02, 2023 at 11:23:33AM +0200, Mads Ynddal wrote: > From: Mads Ynddal <[email protected]> > > By moving the dynamic argument construction to keyword-arguments, > we can remove all of the specialized handling, and streamline it. > If a tracing method wants to access these, they can define the > kwargs, or ignore it be placing `**kwargs` at the end of the > function's arguments list. > > Signed-off-by: Mads Ynddal <[email protected]> > --- > scripts/simpletrace.py | 84 ++++++++++++++++-------------------------- > 1 file changed, 32 insertions(+), 52 deletions(-)
This is nice but breaking existing analysis scripts should be avoided.
I suggest preserving the Analyzer class the way it is and adding a new
Analyzer2 class that follows the new method signature for trace event
methods.
>
> diff --git a/scripts/simpletrace.py b/scripts/simpletrace.py
> index 10ca093046..f6b40d56f6 100755
> --- a/scripts/simpletrace.py
> +++ b/scripts/simpletrace.py
> @@ -131,16 +131,25 @@ class Analyzer:
> If a method matching a trace event name exists, it is invoked to process
> that trace record. Otherwise the catchall() method is invoked.
>
> + The methods are called with a set of keyword-arguments. These can be
> ignored
> + using `**kwargs` or defined like any keyword-argument.
> +
> + The following keyword-arguments are available:
> + event: Event object of current trace
> + event_id: The id of the event in the current trace file
> + timestamp_ns: The timestamp in nanoseconds of the trace
> + pid: The process id recorded for the given trace
> +
> Example:
> The following method handles the runstate_set(int new_state) trace
> event::
>
> - def runstate_set(self, new_state):
> + def runstate_set(self, new_state, **kwargs):
> ...
>
> - The method can also take a timestamp argument before the trace event
> - arguments::
> + The method can also explicitly take a timestamp keyword-argument with the
> + trace event arguments::
>
> - def runstate_set(self, timestamp, new_state):
> + def runstate_set(self, new_state, *, timestamp, **kwargs):
> ...
>
> Timestamps have the uint64_t type and are in nanoseconds.
> @@ -148,7 +157,7 @@ def runstate_set(self, timestamp, new_state):
> The pid can be included in addition to the timestamp and is useful when
> dealing with traces from multiple processes::
>
> - def runstate_set(self, timestamp, pid, new_state):
> + def runstate_set(self, new_state, *, timestamp, pid, **kwargs):
> ...
> """
>
> @@ -156,7 +165,7 @@ def __enter__(self):
> """Called at the start of the trace."""
> return self
>
> - def catchall(self, event, rec):
> + def catchall(self, *rec_args, event, timestamp_ns, pid, event_id):
> """Called if no specific method for processing a trace event has
> been found."""
> pass
>
> @@ -189,34 +198,11 @@ def process(events, log, analyzer_class,
> read_header=True):
> for event_id, event in enumerate(events):
> event_id_to_name[event_id] = event.name
>
> - def build_fn(analyzer, event):
> - if isinstance(event, str):
> - return analyzer.catchall
> -
> - fn = getattr(analyzer, event.name, None)
> - if fn is None:
> - return analyzer.catchall
> -
> - event_argcount = len(event.args)
> - fn_argcount = len(inspect.getfullargspec(fn)[0]) - 1
> - if fn_argcount == event_argcount + 1:
> - # Include timestamp as first argument
> - return lambda _, rec: fn(*(rec[1:2] + rec[3:3 + event_argcount]))
> - elif fn_argcount == event_argcount + 2:
> - # Include timestamp and pid
> - return lambda _, rec: fn(*rec[1:3 + event_argcount])
> - else:
> - # Just arguments, no timestamp or pid
> - return lambda _, rec: fn(*rec[3:3 + event_argcount])
> -
> with analyzer_class() as analyzer:
> - fn_cache = {}
> - for rec in read_trace_records(event_mapping, event_id_to_name, log):
> - event_num = rec[0]
> - event = event_mapping[event_num]
> - if event_num not in fn_cache:
> - fn_cache[event_num] = build_fn(analyzer, event)
> - fn_cache[event_num](event, rec)
> + for event_id, timestamp_ns, record_pid, *rec_args in
> read_trace_records(event_mapping, event_id_to_name, log):
> + event = event_mapping[event_id]
> + fn = getattr(analyzer, event.name, analyzer.catchall)
> + fn(*rec_args, event=event, event_id=event_id,
> timestamp_ns=timestamp_ns, pid=record_pid)
>
>
> def run(analyzer):
> @@ -240,24 +226,18 @@ def run(analyzer):
> if __name__ == '__main__':
> class Formatter(Analyzer):
> def __init__(self):
> - self.last_timestamp = None
> -
> - def catchall(self, event, rec):
> - timestamp = rec[1]
> - if self.last_timestamp is None:
> - self.last_timestamp = timestamp
> - delta_ns = timestamp - self.last_timestamp
> - self.last_timestamp = timestamp
> -
> - fields = [event.name, '%0.3f' % (delta_ns / 1000.0),
> - 'pid=%d' % rec[2]]
> - i = 3
> - for type, name in event.args:
> - if is_string(type):
> - fields.append('%s=%s' % (name, rec[i]))
> - else:
> - fields.append('%s=0x%x' % (name, rec[i]))
> - i += 1
> - print(' '.join(fields))
> + self.last_timestamp_ns = None
> +
> + def catchall(self, *rec_args, event, timestamp_ns, pid, event_id):
> + if self.last_timestamp_ns is None:
> + self.last_timestamp_ns = timestamp_ns
> + delta_ns = timestamp_ns - self.last_timestamp_ns
> + self.last_timestamp_ns = timestamp_ns
> +
> + fields = [
> + f'{name}={r}' if is_string(type) else f'{name}=0x{r:x}'
> + for r, (type, name) in zip(rec_args, event.args)
> + ]
> + print(f'{event.name} {delta_ns / 1000:0.3f} {pid=} ' + '
> '.join(fields))
>
> run(Formatter())
> --
> 2.38.1
>
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