Lib/hotshot/stats.py

   1 """Statistics analyzer for HotShot."""
   2
   3 import profile
   4 import pstats
   5
   6 import hotshot.log
   7
   8 from hotshot.log import ENTER, EXIT
   9
  10
  11 def load(filename):
  12     return StatsLoader(filename).load()
  13
  14
  15 class 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
  74 class Profile(profile.Profile):
  75     def simulate_cmd_complete(self):
  76         pass
  77
  78
  79 class 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
  86 class FakeFrame:
  87     def __init__(self, code, back):
  88         self.f_back = back
  89         self.f_code = code
  90
  91
  92 def _brokentimer():
  93     raise RuntimeError, "this timer should not be called"