Commit 15327c3d authored by Stefan Hajnoczi's avatar Stefan Hajnoczi
Browse files

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: default avatarStefan Hajnoczi <stefanha@redhat.com>
parent 3f8b112d

scripts/simpletrace.py

+17 −7
Original line number Diff line number Diff line
@@ -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):