mercurial/scmposix.py

perf: ensure all readlog's reading is done within a `reading` context

We are about to enforce this at the revlog level, so we update the perf code in
advance.

import array
import errno
import fcntl
import os
import sys

from typing import (
    List,
    Tuple,
)

from . import (
    encoding,
    pycompat,
    util,
)

if pycompat.TYPE_CHECKING:
    from . import ui as uimod

# 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: bytes) -> List[bytes]:
    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() -> List[bytes]:
    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() -> List[bytes]:
    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: "uimod.ui") -> Tuple[int, int]:
    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.errno == errno.EINVAL:
                pass
            else:
                raise
    return 80, 24