#!/usr/bin/env python
#
# Pretty-printer for simple trace backend binary trace files
#
# Copyright IBM, Corp. 2010
#
# This work is licensed under the terms of the GNU GPL, version 2. See
# the COPYING file in the top-level directory.
#
# For help see docs/tracing.txt
import struct
import re
import inspect
from tracetool import _read_events, Event
from tracetool.backend.simple import is_string
header_event_id = 0xffffffffffffffff
header_magic = 0xf2b177cb0aa429b4
dropped_event_id = 0xfffffffffffffffe
log_header_fmt = '=QQQ'
rec_header_fmt = '=QQII'
def read_header(fobj, hfmt):
'''Read a trace record header'''
hlen = struct.calcsize(hfmt)
hdr = fobj.read(hlen)
if len(hdr) != hlen:
return None
return struct.unpack(hfmt, hdr)
def get_record(edict, rechdr, fobj):
"""Deserialize a trace record from a file into a tuple (event_num, timestamp, pid, arg1, ..., arg6)."""
if rechdr is None:
return None
rec = (rechdr[0], rechdr[1], rechdr[3])
if rechdr[0] != dropped_event_id:
event_id = rechdr[0]
event = edict[event_id]
for type, name in event.args:
if is_string(type):
l = fobj.read(4)
(len,) = struct.unpack('=L', l)
s = fobj.read(len)
rec = rec + (s,)
else:
(value,) = struct.unpack('=Q', fobj.read(8))
rec = rec + (value,)
else:
(value,) = struct.unpack('=Q', fobj.read(8))
rec = rec + (value,)
return rec
def read_record(edict, fobj):
"""Deserialize a trace record from a file into a tuple (event_num, timestamp, pid, arg1, ..., arg6)."""
rechdr = read_header(fobj, rec_header_fmt)
return get_record(edict, rechdr, fobj) # return tuple of record elements
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 \
header[1] != header_magic:
raise ValueError('Not a valid trace file!')
log_version = header[2]
if log_version not in [0, 2, 3]:
raise ValueError('Unknown version of tracelog format!')
if log_version != 3:
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:
break
yield rec
class Analyzer(object):
"""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.
If a method matching a trace event name exists, it is invoked to process
that trace record. Otherwise the catchall() method is invoked."""
def begin(self):
"""Called at the start of the trace."""
pass
def catchall(self, event, rec):
"""Called if no specific method for processing a trace event has been found."""
pass
def end(self):
"""Called at the end of the trace."""
pass
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}
for num, event in enumerate(events):
edict[num] = event
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.getargspec(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])
analyzer.begin()
fn_cache = {}
for rec in read_trace_records(edict, log):
event_num = rec[0]
event = edict[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()
def run(analyzer):
"""Execute an analyzer on a trace file given on the command-line.
This function is useful as a driver for simple analysis scripts. More
advanced scripts will want to call process() instead."""
import sys
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, read_header=read_header)
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)
run(Formatter())
