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authorStefan Hajnoczi <stefanha@redhat.com>2014-06-22 21:46:06 +0800
committerStefan Hajnoczi <stefanha@redhat.com>2014-08-12 14:26:11 +0100
commit15327c3df049c9621ff9b542ccbfc3d17203d1f7 (patch)
treefb427a256ce8c6570719f12971c1bf5f54f5c9c5 /scripts/simpletrace.py
parent3f8b112d6b9ab65e165096582c78154dda1adc69 (diff)
simpletrace: add simpletrace.py --no-header option
It can be useful to read simpletrace files that have no header. For example, a ring buffer may not have a header record but can still be processed if the user is sure the file format version is compatible. $ scripts/simpletrace.py --no-header trace-events trace-file Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Diffstat (limited to 'scripts/simpletrace.py')
-rwxr-xr-xscripts/simpletrace.py24
1 files changed, 17 insertions, 7 deletions
diff --git a/scripts/simpletrace.py b/scripts/simpletrace.py
index 1aa9460e49..3916c6d14a 100755
--- a/scripts/simpletrace.py
+++ b/scripts/simpletrace.py
@@ -58,8 +58,8 @@ def read_record(edict, fobj):
rechdr = read_header(fobj, rec_header_fmt)
return get_record(edict, rechdr, fobj) # return tuple of record elements
-def read_trace_file(edict, fobj):
- """Deserialize trace records from a file, yielding record tuples (event_num, timestamp, pid, arg1, ..., arg6)."""
+def read_trace_header(fobj):
+ """Read and verify trace file header"""
header = read_header(fobj, log_header_fmt)
if header is None or \
header[0] != header_event_id or \
@@ -73,6 +73,8 @@ def read_trace_file(edict, fobj):
raise ValueError('Log format %d not supported with this QEMU release!'
% log_version)
+def read_trace_records(edict, fobj):
+ """Deserialize trace records from a file, yielding record tuples (event_num, timestamp, pid, arg1, ..., arg6)."""
while True:
rec = read_record(edict, fobj)
if rec is None:
@@ -102,13 +104,16 @@ class Analyzer(object):
"""Called at the end of the trace."""
pass
-def process(events, log, analyzer):
+def process(events, log, analyzer, read_header=True):
"""Invoke an analyzer on each event in a log."""
if isinstance(events, str):
events = _read_events(open(events, 'r'))
if isinstance(log, str):
log = open(log, 'rb')
+ if read_header:
+ read_trace_header(log)
+
dropped_event = Event.build("Dropped_Event(uint64_t num_events_dropped)")
edict = {dropped_event_id: dropped_event}
@@ -137,7 +142,7 @@ def process(events, log, analyzer):
analyzer.begin()
fn_cache = {}
- for rec in read_trace_file(edict, log):
+ for rec in read_trace_records(edict, log):
event_num = rec[0]
event = edict[event_num]
if event_num not in fn_cache:
@@ -152,12 +157,17 @@ def run(analyzer):
advanced scripts will want to call process() instead."""
import sys
- if len(sys.argv) != 3:
- sys.stderr.write('usage: %s <trace-events> <trace-file>\n' % sys.argv[0])
+ read_header = True
+ if len(sys.argv) == 4 and sys.argv[1] == '--no-header':
+ read_header = False
+ del sys.argv[1]
+ elif len(sys.argv) != 3:
+ sys.stderr.write('usage: %s [--no-header] <trace-events> ' \
+ '<trace-file>\n' % sys.argv[0])
sys.exit(1)
events = _read_events(open(sys.argv[1], 'r'))
- process(events, sys.argv[2], analyzer)
+ process(events, sys.argv[2], analyzer, read_header=read_header)
if __name__ == '__main__':
class Formatter(Analyzer):