view doc/runrst @ 35599:af25237be091

perf: add threading capability to perfbdiff

Since we are releasing the GIL during diffing, it is interesting to see how a
thread pool would perform on diffing. We add a new `--threads` argument to
commands. Synchronizing the thread pool is a bit complex because we want to be
able to reuse it from one run to another.

On my computer (i7 with 4 cores + hyperthreading), I get the following data for
about 12000 revisions:
threads wall        comb    wall gain   comb overhead
none    31.596715   31.59    0.00%       0.00%
1       31.621228   31.62   -0.08%       0.09%
2       16.406202   32.8    48.08%       3.83%
3       11.598334   34.76   63.29%      10.03%
4        9.205421   36.77   70.87%      16.40%
5        8.517604   42.51   73.04%      34.57%
6        7.94645    47.58   74.85%      50.62%
7        7.434972   51.92   76.47%      64.36%
8        7.070638   55.34   77.62%      75.18%

Compared to the feature disabled (threads=0), the overhead is negligible with
the threading code (threads=1), and the gain is already 48% with two threads.

#!/usr/bin/env python
#
# runrst - register custom roles and run correct writer
#
# Copyright 2010 Matt Mackall <[e-mail]> and others
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.

"""usage: %s WRITER args...

where WRITER is the name of a Docutils writer such as 'html' or 'manpage'
"""

import sys
try:
    from docutils.parsers.rst import roles
    from docutils.core import publish_cmdline
    from docutils import nodes, utils
except ImportError:
    sys.stderr.write("abort: couldn't generate documentation: docutils "
                     "module is missing\n")
    sys.stderr.write("please install python-docutils or see "
                     "http://docutils.sourceforge.net/\n")
    sys.exit(-1)

def role_hg(name, rawtext, text, lineno, inliner,
            options={}, content=[]):
    text = "hg " + utils.unescape(text)
    linktext = nodes.literal(rawtext, text)
    parts = text.split()
    cmd, args = parts[1], parts[2:]
    refuri = "hg.1.html#%s" % cmd
    if cmd == 'help' and args:
        if args[0] == 'config':
            # :hg:`help config`
            refuri = "hgrc.5.html"
        elif args[0].startswith('config.'):
            # :hg:`help config.SECTION...`
            refuri = "hgrc.5.html#%s" % args[0].split('.', 2)[1]
        elif len(args) >= 2 and args[0] == '-c':
            # :hg:`help -c COMMAND ...` is equivalent to :hg:`COMMAND`
            # (mainly for :hg:`help -c config`)
            refuri = "hg.1.html#%s" % args[1]
        else:
            refuri = "hg.1.html#%s" % args[0]
    node = nodes.reference(rawtext, '', linktext,
                           refuri=refuri)
    return [node], []

roles.register_local_role("hg", role_hg)

if __name__ == "__main__":
    if len(sys.argv) < 2:
        sys.stderr.write(__doc__ % sys.argv[0])
        sys.exit(1)

    writer = sys.argv[1]
    del sys.argv[1]

    publish_cmdline(writer_name=writer)