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[PATCH v3 08/14] simpletrace: made Analyzer into context-manager
From: |
Mads Ynddal |
Subject: |
[PATCH v3 08/14] simpletrace: made Analyzer into context-manager |
Date: |
Thu, 8 Jun 2023 14:41:41 +0200 |
From: Mads Ynddal <m.ynddal@samsung.com>
Instead of explicitly calling `begin` and `end`, we can change the class
to use the context-manager paradigm. This is mostly a styling choice,
used in modern Python code. But it also allows for more advanced analyzers
to handle exceptions gracefully in the `__exit__` method (not
demonstrated here).
Signed-off-by: Mads Ynddal <m.ynddal@samsung.com>
---
scripts/simpletrace.py | 31 ++++++++++++++++++++-----------
1 file changed, 20 insertions(+), 11 deletions(-)
diff --git a/scripts/simpletrace.py b/scripts/simpletrace.py
index 229b10aa99..7f514d1577 100755
--- a/scripts/simpletrace.py
+++ b/scripts/simpletrace.py
@@ -122,12 +122,13 @@ def read_trace_records(event_mapping, event_id_to_name,
fobj):
yield rec
-class Analyzer(object):
+class Analyzer:
"""A trace file analyzer which processes trace records.
An analyzer can be passed to run() or process(). The begin() method is
invoked, then each trace record is processed, and finally the end() method
- is invoked.
+ is invoked. When Analyzer is used as a context-manager (using the `with`
+ statement), begin() and end() are called automatically.
If a method matching a trace event name exists, it is invoked to process
that trace record. Otherwise the catchall() method is invoked.
@@ -165,6 +166,15 @@ def end(self):
"""Called at the end of the trace."""
pass
+ def __enter__(self):
+ self.begin()
+ return self
+
+ def __exit__(self, exc_type, exc_val, exc_tb):
+ if exc_type is None:
+ self.end()
+ return False
+
def process(events, log, analyzer, read_header=True):
"""Invoke an analyzer on each event in a log.
Args:
@@ -226,15 +236,14 @@ def build_fn(analyzer, event):
# Just arguments, no timestamp or pid
return lambda _, rec: fn(*rec[3:3 + event_argcount])
- analyzer.begin()
- 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)
- analyzer.end()
+ with 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)
if close_log:
log.close()
--
2.38.1
- [PATCH v3 00/14] simpletrace: refactor and general improvements, Mads Ynddal, 2023/06/08
- [PATCH v3 01/14] simpletrace: add __all__ to define public interface, Mads Ynddal, 2023/06/08
- [PATCH v3 02/14] simpletrace: annotate magic constants from QEMU code, Mads Ynddal, 2023/06/08
- [PATCH v3 03/14] simpletrace: improve parsing of sys.argv; fix files never closed., Mads Ynddal, 2023/06/08
- [PATCH v3 04/14] simpletrace: changed naming of edict and idtoname to improve readability, Mads Ynddal, 2023/06/08
- [PATCH v3 05/14] simpletrace: update code for Python 3.11, Mads Ynddal, 2023/06/08
- [PATCH v3 06/14] simpletrace: improved error handling on struct unpack, Mads Ynddal, 2023/06/08
- [PATCH v3 07/14] simpletrace: define exception and add handling, Mads Ynddal, 2023/06/08
- [PATCH v3 08/14] simpletrace: made Analyzer into context-manager,
Mads Ynddal <=
- [PATCH v3 09/14] simpletrace: refactor to separate responsibilities, Mads Ynddal, 2023/06/08
- [PATCH v3 10/14] simpletrace: move logic of process into internal function, Mads Ynddal, 2023/06/08
- [PATCH v3 11/14] simpletrace: move event processing to Analyzer class, Mads Ynddal, 2023/06/08
- [PATCH v3 12/14] simpletrace: added simplified Analyzer2 class, Mads Ynddal, 2023/06/08
- [PATCH v3 13/14] MAINTAINERS: add maintainer of simpletrace.py, Mads Ynddal, 2023/06/08
- [PATCH v3 14/14] scripts/analyse-locks-simpletrace.py: changed iteritems() to items(), Mads Ynddal, 2023/06/08