view mercurial/scmposix.py @ 47093:787ff5d21bcd

dirstate-tree: Make Rust DirstateMap bindings go through a trait object

This changeset starts a series that adds an experiment to make status faster
by changing the dirstate (first only in memory and later also on disk) to
be shaped as a tree matching the directory structure, instead of the current
flat collection of entries. The status algorithm can then traverse this tree
dirstate at the same time as it traverses the filesystem.

We (Octobus) have made prototypes that show promising results but are prone
to bitrot. We would like to start upstreaming some experimental Rust code that
goes in this direction, but to avoid disrupting users it should only be
enabled by some run-time opt-in while keeping the existing dirstate structure
and status algorithm as-is.

The `DirstateMap` type and `status` function look like the appropriate
boundary. This adds a new trait that abstracts everything Python bindings need
and makes those bindings go through a `dyn` trait object. Later we’ll have two
implementations of this trait, and the same bindings can use either.

Differential Revision: https://phab.mercurial-scm.org/D10362

from __future__ import absolute_import

import array
import errno
import fcntl
import os
import sys

from .pycompat import getattr
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 = b'less'


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


def systemrcpath():
    path = []
    if pycompat.sysplatform == b'plan9':
        root = b'lib/mercurial'
    else:
        root = b'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 != b'/':
            path.extend(_rcfiles(os.path.join(p, root)))
    path.extend(_rcfiles(b'/' + root))
    return path


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

        return [
            os.path.expanduser(b'~/.hgrc'),
            os.path.join(confighome, b'hg', b'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, b'\0' * 8)
            height, width = array.array('h', arri)[:2]
            if width > 0 and height > 0:
                return width, height
        except ValueError:
            pass
        except IOError as e:
            if e[0] == errno.EINVAL:  # pytype: disable=unsupported-operands
                pass
            else:
                raise
    return 80, 24