hgext/pager.py

phases: really fix native phase computation

For some reason (probably rebase issue, leprechaun or badly resolved .rej)
1635579f9baf contains only half of the emailed patches and do not fix the bug.
This patch adds the other half and enable the sweet native computation for real.

As expected this provide massive speedup along the board.

revset #0: not public()
   plain         first
0) 0.011960      0.010523
1) 0.000465   3% 0.000492   4%

revset #1: (tip~1000::) - public()
   plain         first
0) 0.025700      0.025169
1) 0.002864  11% 0.001899   7%

revset #2: not public() and branch("default")
   plain         first
0) 0.022842      0.020863
1) 0.011418  49% 0.010948   52%

However, it has a less impact (even bad) on first result time in simple
situation.  This comes from the overhead of building the set and filtering it.
This is especially true on my Mercurial repository (used here) where about 1/3
of the changesets are non public and hidden. This could be mitigated by a
caching of the set and a better usage of smartset in '_notpublic'. (But this
won't happen in this patch because the win is massive everywhere else).

revset #0: not public()
   last
0) 0.000081
1) 0.000493 x6.1 <-- bad impact

revset #1: (tip~1000::) - public()
   last
0) 0.013966
1) 0.002737  19%

revset #2: not public() and branch("default")
   last
0) 0.011021
1) 0.011038

The effect mostly disappear when the number of non-public changesets is small
and/or the repo get bigger. Result for Mozilla central:

Mozilla

revset #0: not public()
   plain         first         last
0) 0.092787      0.084094      0.000080
1) 0.000054   0% 0.000083   0% 0.000083

revset #1: (tip~1000::) - public()
   plain         first         last
0) 0.215607      0.183996      0.124962
1) 0.031620  14% 0.006616   3% 0.031168  24%

revset #2: not public() and branch("default")
   plain         first         last
0) 0.092626      0.082687      0.000162
1) 0.000139   0% 0.000165   0% 0.000167

# pager.py - display output using a pager
#
# Copyright 2008 David Soria Parra <[e-mail]>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
#
# To load the extension, add it to your configuration file:
#
#   [extension]
#   pager =
#
# Run "hg help pager" to get info on configuration.

'''browse command output with an external pager

To set the pager that should be used, set the application variable::

  [pager]
  pager = less -FRX

If no pager is set, the pager extensions uses the environment variable
$PAGER. If neither pager.pager, nor $PAGER is set, no pager is used.

You can disable the pager for certain commands by adding them to the
pager.ignore list::

  [pager]
  ignore = version, help, update

You can also enable the pager only for certain commands using
pager.attend. Below is the default list of commands to be paged::

  [pager]
  attend = annotate, cat, diff, export, glog, log, qdiff

Setting pager.attend to an empty value will cause all commands to be
paged.

If pager.attend is present, pager.ignore will be ignored.

Lastly, you can enable and disable paging for individual commands with
the attend-<command> option. This setting takes precedence over
existing attend and ignore options and defaults::

  [pager]
  attend-cat = false

To ignore global commands like :hg:`version` or :hg:`help`, you have
to specify them in your user configuration file.

The --pager=... option can also be used to control when the pager is
used. Use a boolean value like yes, no, on, off, or use auto for
normal behavior.

'''

import atexit, sys, os, signal, subprocess
from mercurial import commands, dispatch, util, extensions, cmdutil
from mercurial.i18n import _

# Note for extension authors: ONLY specify testedwith = 'internal' for
# extensions which SHIP WITH MERCURIAL. Non-mainline extensions should
# be specifying the version(s) of Mercurial they are tested with, or
# leave the attribute unspecified.
testedwith = 'internal'

def _pagersubprocess(ui, p):
    pager = subprocess.Popen(p, shell=True, bufsize=-1,
                             close_fds=util.closefds, stdin=subprocess.PIPE,
                             stdout=sys.stdout, stderr=sys.stderr)

    stdout = os.dup(sys.stdout.fileno())
    stderr = os.dup(sys.stderr.fileno())
    os.dup2(pager.stdin.fileno(), sys.stdout.fileno())
    if ui._isatty(sys.stderr):
        os.dup2(pager.stdin.fileno(), sys.stderr.fileno())

    @atexit.register
    def killpager():
        if util.safehasattr(signal, "SIGINT"):
            signal.signal(signal.SIGINT, signal.SIG_IGN)
        pager.stdin.close()
        os.dup2(stdout, sys.stdout.fileno())
        os.dup2(stderr, sys.stderr.fileno())
        pager.wait()

def _runpager(ui, p):
    _pagersubprocess(ui, p)

def uisetup(ui):
    if '--debugger' in sys.argv or not ui.formatted():
        return

    def pagecmd(orig, ui, options, cmd, cmdfunc):
        p = ui.config("pager", "pager", os.environ.get("PAGER"))
        usepager = False
        always = util.parsebool(options['pager'])
        auto = options['pager'] == 'auto'

        if not p:
            pass
        elif always:
            usepager = True
        elif not auto:
            usepager = False
        else:
            attend = ui.configlist('pager', 'attend', attended)
            ignore = ui.configlist('pager', 'ignore')
            cmds, _ = cmdutil.findcmd(cmd, commands.table)

            for cmd in cmds:
                var = 'attend-%s' % cmd
                if ui.config('pager', var):
                    usepager = ui.configbool('pager', var)
                    break
                if (cmd in attend or
                     (cmd not in ignore and not attend)):
                    usepager = True
                    break

        setattr(ui, 'pageractive', usepager)

        if usepager:
            ui.setconfig('ui', 'formatted', ui.formatted(), 'pager')
            ui.setconfig('ui', 'interactive', False, 'pager')
            if util.safehasattr(signal, "SIGPIPE"):
                signal.signal(signal.SIGPIPE, signal.SIG_DFL)
            _runpager(ui, p)
        return orig(ui, options, cmd, cmdfunc)

    # Wrap dispatch._runcommand after color is loaded so color can see
    # ui.pageractive. Otherwise, if we loaded first, color's wrapped
    # dispatch._runcommand would run without having access to ui.pageractive.
    def afterloaded(loaded):
        extensions.wrapfunction(dispatch, '_runcommand', pagecmd)
    extensions.afterloaded('color', afterloaded)

def extsetup(ui):
    commands.globalopts.append(
        ('', 'pager', 'auto',
         _("when to paginate (boolean, always, auto, or never)"),
         _('TYPE')))

attended = ['annotate', 'cat', 'diff', 'export', 'glog', 'log', 'qdiff']