1"""Statistics analyzer for HotShot."""
2
3import profile
4import pstats
5
6import hotshot.log
7
8from hotshot.log import ENTER, EXIT
9
10
11def load(filename):
12    return StatsLoader(filename).load()
13
14
15class StatsLoader:
16    def __init__(self, logfn):
17        self._logfn = logfn
18        self._code = {}
19        self._stack = []
20        self.pop_frame = self._stack.pop
21
22    def load(self):
23        # The timer selected by the profiler should never be used, so make
24        # sure it doesn't work:
25        p = Profile()
26        p.get_time = _brokentimer
27        log = hotshot.log.LogReader(self._logfn)
28        taccum = 0
29        for event in log:
30            what, (filename, lineno, funcname), tdelta = event
31            if tdelta > 0:
32                taccum += tdelta
33
34            # We multiply taccum to convert from the microseconds we
35            # have to the seconds that the profile/pstats module work
36            # with; this allows the numbers to have some basis in
37            # reality (ignoring calibration issues for now).
38
39            if what == ENTER:
40                frame = self.new_frame(filename, lineno, funcname)
41                p.trace_dispatch_call(frame, taccum * .000001)
42                taccum = 0
43
44            elif what == EXIT:
45                frame = self.pop_frame()
46                p.trace_dispatch_return(frame, taccum * .000001)
47                taccum = 0
48
49            # no further work for line events
50
51        assert not self._stack
52        return pstats.Stats(p)
53
54    def new_frame(self, *args):
55        # args must be filename, firstlineno, funcname
56        # our code objects are cached since we don't need to create
57        # new ones every time
58        try:
59            code = self._code[args]
60        except KeyError:
61            code = FakeCode(*args)
62            self._code[args] = code
63        # frame objects are create fresh, since the back pointer will
64        # vary considerably
65        if self._stack:
66            back = self._stack[-1]
67        else:
68            back = None
69        frame = FakeFrame(code, back)
70        self._stack.append(frame)
71        return frame
72
73
74class Profile(profile.Profile):
75    def simulate_cmd_complete(self):
76        pass
77
78
79class FakeCode:
80    def __init__(self, filename, firstlineno, funcname):
81        self.co_filename = filename
82        self.co_firstlineno = firstlineno
83        self.co_name = self.__name__ = funcname
84
85
86class FakeFrame:
87    def __init__(self, code, back):
88        self.f_back = back
89        self.f_code = code
90
91
92def _brokentimer():
93    raise RuntimeError, "this timer should not be called"
94