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#!/usr/bin/env python
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#
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# Pretty-printer for simple trace backend binary trace files
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#
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# Copyright IBM, Corp. 2010
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#
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# This work is licensed under the terms of the GNU GPL, version 2.  See
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# the COPYING file in the top-level directory.
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#
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# For help see docs/tracing.txt
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import sys
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import struct
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import re
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header_event_id = 0xffffffffffffffff
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header_magic    = 0xf2b177cb0aa429b4
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header_version  = 0
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trace_fmt = '=QQQQQQQQ'
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trace_len = struct.calcsize(trace_fmt)
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event_re  = re.compile(r'(disable\s+)?([a-zA-Z0-9_]+)\(([^)]*)\).*')
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def err(msg):
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    sys.stderr.write(msg + '\n')
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    sys.exit(1)
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def parse_events(fobj):
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    """Parse a trace-events file."""
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    def get_argnames(args):
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        """Extract argument names from a parameter list."""
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        return tuple(arg.split()[-1].lstrip('*') for arg in args.split(','))
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    events = {}
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    event_num = 0
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    for line in fobj:
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        m = event_re.match(line.strip())
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        if m is None:
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            continue
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        disable, name, args = m.groups()
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        events[event_num] = (name,) + get_argnames(args)
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        event_num += 1
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    return events
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def read_record(fobj):
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    """Deserialize a trace record from a file."""
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    s = fobj.read(trace_len)
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    if len(s) != trace_len:
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        return None
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    return struct.unpack(trace_fmt, s)
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def read_trace_file(fobj):
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    """Deserialize trace records from a file."""
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    header = read_record(fobj)
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    if header is None or \
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       header[0] != header_event_id or \
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       header[1] != header_magic or \
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       header[2] != header_version:
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        err('not a trace file or incompatible version')
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    while True:
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        rec = read_record(fobj)
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        if rec is None:
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            break
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        yield rec
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class Formatter(object):
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    def __init__(self, events):
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        self.events = events
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        self.last_timestamp = None
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    def format_record(self, rec):
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        if self.last_timestamp is None:
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            self.last_timestamp = rec[1]
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        delta_ns = rec[1] - self.last_timestamp
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        self.last_timestamp = rec[1]
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        event = self.events[rec[0]]
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        fields = [event[0], '%0.3f' % (delta_ns / 1000.0)]
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        for i in xrange(1, len(event)):
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            fields.append('%s=0x%x' % (event[i], rec[i + 1]))
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        return ' '.join(fields)
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if len(sys.argv) != 3:
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    err('usage: %s <trace-events> <trace-file>' % sys.argv[0])
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events = parse_events(open(sys.argv[1], 'r'))
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formatter = Formatter(events)
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for rec in read_trace_file(open(sys.argv[2], 'rb')):
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    print formatter.format_record(rec)