mercurial/lsprofcalltree.py

log: remove increasing windows usage in fastpath

The purpose of increasing windows is to allow backwards iteration on the
filelog  at a reasonable cost.
But is it needed?
 - if follow is False, we have no reason to iterate backwards.
   We basically just want to walk the complete filelog and yield all revisions
   within the revision range. We can do this forward or
   backwards, as it only reads the index.
 - when follow is True, we need to examine the contents of the filelog, and to
   do this efficiently we need to read the filelog forward.
   And on the other hand, to track ancestors and copies, we need to process
   revisions backwards. But is it necessary to use increasing windows
   for this?
   We can iterate over the complete filelog forward, stack the revisions, and
   read the reversed(pile), it does the same thing with a more readable code.

"""
lsprofcalltree.py - lsprof output which is readable by kcachegrind

Authors:
    * David Allouche <david <at> allouche.net>
    * Jp Calderone & Itamar Shtull-Trauring
    * Johan Dahlin

This software may be used and distributed according to the terms
of the GNU General Public License, incorporated herein by reference.
"""

def label(code):
    if isinstance(code, str):
        return '~' + code    # built-in functions ('~' sorts at the end)
    else:
        return '%s %s:%d' % (code.co_name,
                             code.co_filename,
                             code.co_firstlineno)

class KCacheGrind(object):
    def __init__(self, profiler):
        self.data = profiler.getstats()
        self.out_file = None

    def output(self, out_file):
        self.out_file = out_file
        print >> out_file, 'events: Ticks'
        self._print_summary()
        for entry in self.data:
            self._entry(entry)

    def _print_summary(self):
        max_cost = 0
        for entry in self.data:
            totaltime = int(entry.totaltime * 1000)
            max_cost = max(max_cost, totaltime)
        print >> self.out_file, 'summary: %d' % (max_cost,)

    def _entry(self, entry):
        out_file = self.out_file

        code = entry.code
        #print >> out_file, 'ob=%s' % (code.co_filename,)
        if isinstance(code, str):
            print >> out_file, 'fi=~'
        else:
            print >> out_file, 'fi=%s' % (code.co_filename,)
        print >> out_file, 'fn=%s' % (label(code),)

        inlinetime = int(entry.inlinetime * 1000)
        if isinstance(code, str):
            print >> out_file, '0 ', inlinetime
        else:
            print >> out_file, '%d %d' % (code.co_firstlineno, inlinetime)

        # recursive calls are counted in entry.calls
        if entry.calls:
            calls = entry.calls
        else:
            calls = []

        if isinstance(code, str):
            lineno = 0
        else:
            lineno = code.co_firstlineno

        for subentry in calls:
            self._subentry(lineno, subentry)
        print >> out_file

    def _subentry(self, lineno, subentry):
        out_file = self.out_file
        code = subentry.code
        #print >> out_file, 'cob=%s' % (code.co_filename,)
        print >> out_file, 'cfn=%s' % (label(code),)
        if isinstance(code, str):
            print >> out_file, 'cfi=~'
            print >> out_file, 'calls=%d 0' % (subentry.callcount,)
        else:
            print >> out_file, 'cfi=%s' % (code.co_filename,)
            print >> out_file, 'calls=%d %d' % (
                subentry.callcount, code.co_firstlineno)

        totaltime = int(subentry.totaltime * 1000)
        print >> out_file, '%d %d' % (lineno, totaltime)