branchcache: skip entries that are topological heads in the on disk file
In the majority of cases, topological heads are also branch heads. We have
efficient way to get the topological heads and efficient way to retrieve
their branch information. So there is little value in putting them in the branch
cache file explicitly. On the contrary, writing them explicitly tend to create
very large cache file that are inefficient to read and update.
So the branch cache v3 format is no longer including them. This changeset focus
on the format aspect and have no focus on the performance aspect. We will cover
that later.
import array
import errno
import fcntl
import os
import sys
import typing
from typing import (
List,
Tuple,
)
from . import (
encoding,
pycompat,
util,
)
if typing.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