view mercurial/scmposix.py @ 38737:913ca175c4ae

aggressivemergedelta: document rename and move to `revlog` section

The config does not follow our naming guideline and "Aggressive" is probably a
word to keep away from users.

The option does not truly fit in the `format` section. It can be turned on and
off for existing repository without much consequence regarding compatibility.

A new `revlog` option is created to control behavior related to revlog writing
and reading. We can see multiple other config options that could be migrated
there.

* format.maxchainlen
* experimental.mmapindexthreshold
* experimental.sparse-read.density-threshold (in an updated form)
* experimental.sparse-read.min-gap-size (in an updated form)

In addition, we can foresee at least a couple of sparse-revlog related option
coming too (to reduce delta chain length and increase snapshot reuse)

These two extra options might fit there too. Unless we want to create a
section dedicated to caches and performance.

* format.chunkcachesize
* format.manifestcachesize

For now, we only migrate `optimize-delta-parent-choice` since it is getting
out of experimental. It is too close to the release to move the other one. In
addition, we still lack proper the prioritization of alias that would help
renaming them without bad consequence for users.

(Not fully happy about the `revlog` name but could not find better).

from __future__ import absolute_import

import array
import errno
import fcntl
import os
import sys

from . import (
    encoding,
    pycompat,
    util,
)

# BSD 'more' escapes ANSI color sequences by default. This can be disabled by
# $MORE variable, but there's no compatible option with Linux 'more'. Given
# OS X is widely used and most modern Unix systems would have 'less', setting
# 'less' as the default seems reasonable.
fallbackpager = 'less'

def _rcfiles(path):
    rcs = [os.path.join(path, 'hgrc')]
    rcdir = os.path.join(path, 'hgrc.d')
    try:
        rcs.extend([os.path.join(rcdir, f)
                    for f, kind in util.listdir(rcdir)
                    if f.endswith(".rc")])
    except OSError:
        pass
    return rcs

def systemrcpath():
    path = []
    if pycompat.sysplatform == 'plan9':
        root = 'lib/mercurial'
    else:
        root = 'etc/mercurial'
    # old mod_python does not set sys.argv
    if len(getattr(sys, 'argv', [])) > 0:
        p = os.path.dirname(os.path.dirname(pycompat.sysargv[0]))
        if p != '/':
            path.extend(_rcfiles(os.path.join(p, root)))
    path.extend(_rcfiles('/' + root))
    return path

def userrcpath():
    if pycompat.sysplatform == 'plan9':
        return [encoding.environ['home'] + '/lib/hgrc']
    elif pycompat.isdarwin:
        return [os.path.expanduser('~/.hgrc')]
    else:
        confighome = encoding.environ.get('XDG_CONFIG_HOME')
        if confighome is None or not os.path.isabs(confighome):
            confighome = os.path.expanduser('~/.config')

        return [os.path.expanduser('~/.hgrc'),
                os.path.join(confighome, 'hg', 'hgrc')]

def termsize(ui):
    try:
        import termios
        TIOCGWINSZ = termios.TIOCGWINSZ  # unavailable on IRIX (issue3449)
    except (AttributeError, ImportError):
        return 80, 24

    for dev in (ui.ferr, ui.fout, ui.fin):
        try:
            try:
                fd = dev.fileno()
            except AttributeError:
                continue
            if not os.isatty(fd):
                continue
            arri = fcntl.ioctl(fd, TIOCGWINSZ, '\0' * 8)
            height, width = array.array(r'h', arri)[:2]
            if width > 0 and height > 0:
                return width, height
        except ValueError:
            pass
        except IOError as e:
            if e[0] == errno.EINVAL:
                pass
            else:
                raise
    return 80, 24