From ae603c6d842f7e7f1529f040ca463be2f2edd4c8 Mon Sep 17 00:00:00 2001

From: Stefan Hajnoczi <stefanha@redhat.com>

Date: Tue, 7 Oct 2014 14:06:53 +0200

Subject: [PATCH 35/43] simpletrace: add simpletrace.py --no-header option

Message-id: <1412690820-31016-5-git-send-email-stefanha@redhat.com>

Patchwork-id: 61609

O-Subject: [RHEL7.1 qemu-kvm PATCH 04/11] simpletrace: add simpletrace.py --no-header option

Bugzilla: 1088112

RH-Acked-by: Laszlo Ersek <lersek@redhat.com>

RH-Acked-by: Miroslav Rezanina <mrezanin@redhat.com>

RH-Acked-by: Paolo Bonzini <pbonzini@redhat.com>

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>

(cherry picked from commit 15327c3df049c9621ff9b542ccbfc3d17203d1f7)

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>

Conflicts:

	scripts/simpletrace.py

Context conflict because upstream doesn't have enabled_events[].

---

 scripts/simpletrace.py | 25 ++++++++++++++++++-------

 1 file changed, 18 insertions(+), 7 deletions(-)

diff --git a/scripts/simpletrace.py b/scripts/simpletrace.py

index 682ec66..b931dd2 100755

--- a/scripts/simpletrace.py

+++ b/scripts/simpletrace.py

@@ -59,8 +59,8 @@ 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 \

@@ -74,6 +74,8 @@ 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:

@@ -103,7 +105,7 @@ 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'))

@@ -111,6 +113,10 @@ def process(events, log, analyzer):

         log = open(log, 'rb')

     enabled_events = []

+

+    if read_header:

+        read_trace_header(log)

+

     dropped_event = Event.build("Dropped_Event(uint64_t num_events_dropped)")

     edict = {dropped_event_id: dropped_event}

@@ -142,7 +148,7 @@ 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:

@@ -157,12 +163,17 @@ 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):

-- 

1.8.3.1