From 62f9d7c021d94caa4b6a6b02a1970adcd6e75981 Mon Sep 17 00:00:00 2001
From: Fred Drake <fdrake@acm.org>
Date: Fri, 8 Jun 2001 05:04:19 +0000
Subject: In the section on extending the profiler, add some additional
 discussion about setting up the dispatch table, and update the OldProfile and
 HotProfile classes to the current implementations, showing the adjusted
 construction for the dispatch table.

---
 Doc/lib/libprofile.tex | 55 +++++++++++++++++++++++++++++++++++++++++---------
 1 file changed, 45 insertions(+), 10 deletions(-)

diff --git a/Doc/lib/libprofile.tex b/Doc/lib/libprofile.tex
index a8861c3..794f7d0 100644
--- a/Doc/lib/libprofile.tex
+++ b/Doc/lib/libprofile.tex
@@ -655,12 +655,40 @@ Be warned that you \emph{should} calibrate the profiler class for the
 timer function that you choose.  For most machines, a timer that
 returns a lone integer value will provide the best results in terms of
 low overhead during profiling.  (\function{os.times()} is
-\emph{pretty} bad, 'cause it returns a tuple of floating point values,
+\emph{pretty} bad, as it returns a tuple of floating point values,
 so all arithmetic is floating point in the profiler!).  If you want to
 substitute a better timer in the cleanest fashion, you should derive a
 class, and simply put in the replacement dispatch method that better
 handles your timer call, along with the appropriate calibration
-constant :-).
+constant.
+
+Note that subclasses which override any of the
+\method{trace_dispatch_call()}, \method{trace_dispatch_exception()},
+or \method{trace_dispatch_return()} methods also need to specify a
+dispatch table as well.  The table, named \member{dispatch}, should
+have the three keys \code{'call'}, \code{'exception'}, and
+\code{'return'}, each giving the function of the corresponding
+handler.  Note that best performance is achieved by using the
+\emph{function} objects for the handlers and not bound methods.  This
+is preferred since calling a simple function object executes less code
+in the runtime than calling either bound or unbound methods.  For
+example, if the derived profiler overrides only one method, the
+\member{dispatch} table can be built like this:
+
+\begin{verbatim}
+from profile import Profile
+
+class MyProfiler(Profile):
+    def trace_dispath_call(self, frame, t):
+        # do something interesting here
+        ...
+
+    dispatch = {
+        'call': trace_dispatch_call,
+        'exception': Profile.__dict__['trace_dispatch_exception'],
+        'return': Profile.__dict__['trace_dispatch_return'],
+    }
+\end{verbatim}
 
 
 \subsection{OldProfile Class \label{profile-old}}
@@ -684,7 +712,7 @@ class OldProfile(Profile):
 
     def trace_dispatch_call(self, frame, t):
         fn = `frame.f_code`
-        
+
         self.cur = (t, 0, 0, fn, frame, self.cur)
         if self.timings.has_key(fn):
             tt, ct, callers = self.timings[fn]
@@ -710,21 +738,24 @@ class OldProfile(Profile):
 
         return 1
 
+    dispatch = {
+        "call": trace_dispatch_call,
+        "exception": trace_dispatch_exception,
+        "return": trace_dispatch_return,
+        }
 
     def snapshot_stats(self):
         self.stats = {}
         for func in self.timings.keys():
             tt, ct, callers = self.timings[func]
-            nor_func = self.func_normalize(func)
-            nor_callers = {}
+            callers = callers.copy()
             nc = 0
             for func_caller in callers.keys():
-                nor_callers[self.func_normalize(func_caller)] = \
-                    callers[func_caller]
                 nc = nc + callers[func_caller]
-            self.stats[nor_func] = nc, nc, tt, ct, nor_callers
+            self.stats[func] = nc, nc, tt, ct, callers
 \end{verbatim}
 
+
 \subsection{HotProfile Class \label{profile-HotProfile}}
 
 This profiler is the fastest derived profile example.  It does not
@@ -763,11 +794,15 @@ class HotProfile(Profile):
 
         return 1
 
+    dispatch = {
+        "call": trace_dispatch_call,
+        "exception": trace_dispatch_exception,
+        "return": trace_dispatch_return,
+        }
 
     def snapshot_stats(self):
         self.stats = {}
         for func in self.timings.keys():
             nc, tt = self.timings[func]
-            nor_func = self.func_normalize(func)
-            self.stats[nor_func] = nc, nc, tt, 0, {}
+            self.stats[func] = nc, nc, tt, 0, {}
 \end{verbatim}
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