tests/ls-l.py

revlog: add a C implementation of `headrevsdiff`

Python implementation of `headrevsdiff` can be very slow in the worst
case compared with the `heads` computation it replaces, since the
latter is done in C.

Even the average case of this Python implementation is still
noticeable in the profiles.

This patch makes the computation much much faster by doing it in C.

#!/usr/bin/env python3

# like ls -l, but do not print date, user, or non-common mode bit, to avoid
# using globs in tests.

import os
import stat
import sys


def modestr(st):
    mode = st.st_mode
    result = ''
    if mode & stat.S_IFDIR:
        result += 'd'
    else:
        result += '-'
    for owner in ['USR', 'GRP', 'OTH']:
        for action in ['R', 'W', 'X']:
            if mode & getattr(stat, 'S_I%s%s' % (action, owner)):
                result += action.lower()
            else:
                result += '-'
    return result


def sizestr(st):
    if st.st_mode & stat.S_IFREG:
        return '%7d' % st.st_size
    else:
        # do not show size for non regular files
        return ' ' * 7


os.chdir((sys.argv[1:] + ['.'])[0])

for name in sorted(os.listdir('.')):
    st = os.stat(name)
    print('%s %s %s' % (modestr(st), sizestr(st), name))