pstats-compatible analysis module.

hotshot.stats.load(logfilename) returns a pstats.Stats instance, which is
about as compatible as it gets.

1 files changed, 93 insertions, 0 deletions

diff --git a/Lib/hotshot/stats.py b/Lib/hotshot/stats.py
new file mode 100644
index 0000000..7ff2277
--- /dev/null
+++ b/Lib/hotshot/stats.py
@@ -0,0 +1,93 @@
+"""Statistics analyzer for HotShot."""
+
+import profile
+import pstats
+
+import hotshot.log
+
+from hotshot.log import ENTER, EXIT
+
+
+def load(filename):
+    return StatsLoader(filename).load()
+
+
+class StatsLoader:
+    def __init__(self, logfn):
+        self._logfn = logfn
+        self._code = {}
+        self._stack = []
+        self.pop_frame = self._stack.pop
+
+    def load(self):
+        # The timer selected by the profiler should never be used, so make
+        # sure it doesn't work:
+        p = Profile()
+        p.get_time = _brokentimer
+        log = hotshot.log.LogReader(self._logfn)
+        taccum = 0
+        for event in log:
+            what, (filename, lineno, funcname), tdelta = event
+            if tdelta > 0:
+                taccum += tdelta
+
+            # We multiply taccum to convert from the microseconds we
+            # have to the seconds that the profile/pstats module work
+            # with; this allows the numbers to have some basis in
+            # reality (ignoring calibration issues for now).
+
+            if what == ENTER:
+                frame = self.new_frame(filename, lineno, funcname)
+                p.trace_dispatch_call(frame, taccum * .000001)
+                taccum = 0
+
+            elif what == EXIT:
+                frame = self.pop_frame()
+                p.trace_dispatch_return(frame, taccum * .000001)
+                taccum = 0
+
+            # no further work for line events
+
+        assert not self._stack
+        return pstats.Stats(p)
+
+    def new_frame(self, *args):
+        # args must be filename, firstlineno, funcname
+        # our code objects are cached since we don't need to create
+        # new ones every time
+        try:
+            code = self._code[args]
+        except KeyError:
+            code = FakeCode(*args)
+            self._code[args] = code
+        # frame objects are create fresh, since the back pointer will
+        # vary considerably
+        if self._stack:
+            back = self._stack[-1]
+        else:
+            back = None
+        frame = FakeFrame(code, back)
+        self._stack.append(frame)
+        return frame
+
+
+class Profile(profile.Profile):
+    def simulate_cmd_complete(self):
+        pass
+
+
+class FakeCode:
+    def __init__(self, filename, firstlineno, funcname):
+        self.co_filename = filename
+        self.co_firstlineno = firstlineno
+        self.co_name = self.__name__ = funcname
+
+
+class FakeFrame:
+    def __init__(self, code, back):
+        self.f_back = back
+        self.f_code = code
+
+
+def _brokentimer():
+    raise RuntimeError, "this timer should not be called"