revsetbenchmarks: display relative change when meaningful

If the time difference is more than 5% from the previous run, we'll display
relative information. This makes it much simpler to spot performance changes in
a sea of benchmarks.

contrib/revsetbenchmarks.py

@@ -1,214 +1,265
 #!/usr/bin/env python
 
 # Measure the performance of a list of revsets against multiple revisions
 # defined by parameter. Checkout one by one and run perfrevset with every
 # revset in the list to benchmark its performance.
 #
 # You should run this from the root of your mercurial repository.
 #
 # call with --help for details
 
 import sys
 import os
 import re
+import math
 from subprocess import check_call, Popen, CalledProcessError, STDOUT, PIPE
 # cannot use argparse, python 2.7 only
 from optparse import OptionParser
 
 def check_output(*args, **kwargs):
     kwargs.setdefault('stderr', PIPE)
     kwargs.setdefault('stdout', PIPE)
     proc = Popen(*args, **kwargs)
     output, error = proc.communicate()
     if proc.returncode != 0:
         raise CalledProcessError(proc.returncode, ' '.join(args[0]))
     return output
 
 def update(rev):
     """update the repo to a revision"""
     try:
         check_call(['hg', 'update', '--quiet', '--check', str(rev)])
     except CalledProcessError, exc:
         print >> sys.stderr, 'update to revision %s failed, aborting' % rev
         sys.exit(exc.returncode)
 
 
 def hg(cmd, repo=None):
     """run a mercurial command
 
     <cmd> is the list of command + argument,
     <repo> is an optional repository path to run this command in."""
     fullcmd = ['./hg']
     if repo is not None:
         fullcmd += ['-R', repo]
     fullcmd += ['--config',
                 'extensions.perf=' + os.path.join(contribdir, 'perf.py')]
     fullcmd += cmd
     return check_output(fullcmd, stderr=STDOUT)
 
 def perf(revset, target=None):
     """run benchmark for this very revset"""
     try:
         output = hg(['perfrevset', revset], repo=target)
         return parseoutput(output)
     except CalledProcessError, exc:
         print >> sys.stderr, 'abort: cannot run revset benchmark: %s' % exc.cmd
         if exc.output is None:
             print >> sys.stderr, '(no ouput)'
         else:
             print >> sys.stderr, exc.output
         sys.exit(exc.returncode)
 
 outputre = re.compile(r'! wall (\d+.\d+) comb (\d+.\d+) user (\d+.\d+) '
                       'sys (\d+.\d+) \(best of (\d+)\)')
 
 def parseoutput(output):
     """parse a textual output into a dict
 
     We cannot just use json because we want to compare with old
     versions of Mercurial that may not support json output.
     """
     match = outputre.search(output)
     if not match:
         print >> sys.stderr, 'abort: invalid output:'
         print >> sys.stderr, output
         sys.exit(1)
     return {'comb': float(match.group(2)),
             'count': int(match.group(5)),
             'sys': float(match.group(3)),
             'user': float(match.group(4)),
             'wall': float(match.group(1)),
             }
 
 def printrevision(rev):
     """print data about a revision"""
     sys.stdout.write("Revision ")
     sys.stdout.flush()
     check_call(['hg', 'log', '--rev', str(rev), '--template',
                 '{rev}:{node|short}: {desc|firstline}\n'])
 
 def idxwidth(nbidx):
     """return the max width of number used for index
 
     This is similar to log10(nbidx), but we use custom code here
     because we start with zero and we'd rather not deal with all the
     extra rounding business that log10 would imply.
     """
     nbidx -= 1 # starts at 0
     idxwidth = 0
     while nbidx:
         idxwidth += 1
         nbidx //= 10
     if not idxwidth:
         idxwidth = 1
     return idxwidth
 
-def printresult(idx, data, maxidx, verbose=False):
+def getfactor(main, other, field, sensitivity=0.05):
+    """return the relative factor between values for 'field' in main and other
+
+    Return None if the factor is insignicant (less than <sensitivity>
+    variation)."""
+    factor = 1
+    if main is not None:
+        factor = other[field] / main[field]
+    low, high = 1 - sensitivity, 1 + sensitivity
+    if (low < factor < high):
+        return None
+    return factor
+
+def formatfactor(factor):
+    """format a factor into a 4 char string
+
+     22%
+    156%
+    x2.4
+     x23
+    x789
+    x1e4
+    x5x7
+
+    """
+    if factor is None:
+        return '    '
+    elif factor < 2:
+        return '%3i%%' % (factor * 100)
+    elif factor < 10:
+        return 'x%3.1f' % factor
+    elif factor < 1000:
+        return '%4s' % ('x%i' % factor)
+    else:
+        order = int(math.log(factor)) + 1
+        while 1 < math.log(factor):
+            factor //= 0
+        return 'x%ix%i' % (factor, order)
+
+_marker = object()
+def printresult(idx, data, maxidx, verbose=False, reference=_marker):
     """print a line of result to stdout"""
     mask = '%%0%ii) %%s' % idxwidth(maxidx)
     out = ['%10.6f' % data['wall']]
+    if reference is not _marker:
+        factor = None
+        if reference is not None:
+            factor = getfactor(reference, data, 'wall')
+        out.append(formatfactor(factor))
     if verbose:
         out.append('%10.6f' % data['comb'])
         out.append('%10.6f' % data['user'])
         out.append('%10.6f' % data['sys'])
         out.append('%6d'    % data['count'])
     print mask % (idx, ' '.join(out))
 
-def printheader(maxidx, verbose=False):
+def printheader(maxidx, verbose=False, relative=False):
     header = [' ' * (idxwidth(maxidx) + 1),
               '  %-8s' % 'time']
+    if relative:
+        header.append('    ')
     if verbose:
         header.append('  %-8s' % 'comb')
         header.append('  %-8s' % 'user')
         header.append('  %-8s' % 'sys')
         header.append('%6s' % 'count')
     print ' '.join(header)
 
 def getrevs(spec):
     """get the list of rev matched by a revset"""
     try:
         out = check_output(['hg', 'log', '--template={rev}\n', '--rev', spec])
     except CalledProcessError, exc:
         print >> sys.stderr, "abort, can't get revision from %s" % spec
         sys.exit(exc.returncode)
     return [r for r in out.split() if r]
 
 
 parser = OptionParser(usage="usage: %prog [options] <revs>")
 parser.add_option("-f", "--file",
                   help="read revset from FILE (stdin if omitted)",
                   metavar="FILE")
 parser.add_option("-R", "--repo",
                   help="run benchmark on REPO", metavar="REPO")
 
 parser.add_option("-v", "--verbose",
                   action='store_true',
                   help="display all timing data (not just best total time)")
 
 (options, args) = parser.parse_args()
 
 if not args:
     parser.print_help()
     sys.exit(255)
 
 # the directory where both this script and the perf.py extension live.
 contribdir = os.path.dirname(__file__)
 
 revsetsfile = sys.stdin
 if options.file:
     revsetsfile = open(options.file)
 
 revsets = [l.strip() for l in revsetsfile if not l.startswith('#')]
 
 print "Revsets to benchmark"
 print "----------------------------"
 
 for idx, rset in enumerate(revsets):
     print "%i) %s" % (idx, rset)
 
 print "----------------------------"
 print
 
 revs = []
 for a in args:
     revs.extend(getrevs(a))
 
 results = []
 for r in revs:
     print "----------------------------"
     printrevision(r)
     print "----------------------------"
     update(r)
     res = []
     results.append(res)
     printheader(len(revsets), verbose=options.verbose)
     for idx, rset in enumerate(revsets):
         data = perf(rset, target=options.repo)
         res.append(data)
         printresult(idx, data, len(revsets), verbose=options.verbose)
         sys.stdout.flush()
     print "----------------------------"
 
 
 print """
 
 Result by revset
 ================
 """
 
 print 'Revision:'
 for idx, rev in enumerate(revs):
     sys.stdout.write('%i) ' % idx)
     sys.stdout.flush()
     printrevision(rev)
 
 print
 print
 
 for ridx, rset in enumerate(revsets):
 
     print "revset #%i: %s" % (ridx, rset)
-    printheader(len(results), verbose=options.verbose)
+    printheader(len(results), verbose=options.verbose, relative=True)
+    ref = None
     for idx, data in enumerate(results):
-        printresult(idx, data[ridx], len(results), verbose=options.verbose)
+        printresult(idx, data[ridx], len(results), verbose=options.verbose,
+                    reference=ref)
+        ref = data[ridx]
     print