view contrib/memory.py @ 45450:47d10ade5bc4

histedit: cache description line

Navigating the curses-based histedit interface can be pretty slow
because it redraws everything whenever you make a change.

This patch simply replaces `@property` by `@util.propertycache` on the
`histeditrule.desc()` function so it's not re-calculated every time
the screen needs to be re-rendered. I timed it on an example of 30
simple commits, where I moved the top commit down 25 steps and then up
25 steps after. Before this patch, that (the whole `hg histedit`
invocation) took 11.6 s of CPU and after this patch it took 0.8 s).

Differential Revision: https://phab.mercurial-scm.org/D9016

# memory.py - track memory usage
#
# Copyright 2009 Matt Mackall <[e-mail]> and others
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.

'''helper extension to measure memory usage

Reads current and peak memory usage from ``/proc/self/status`` and
prints it to ``stderr`` on exit.
'''

from __future__ import absolute_import


def memusage(ui):
    """Report memory usage of the current process."""
    result = {'peak': 0, 'rss': 0}
    with open('/proc/self/status', 'r') as status:
        # This will only work on systems with a /proc file system
        # (like Linux).
        for line in status:
            parts = line.split()
            key = parts[0][2:-1].lower()
            if key in result:
                result[key] = int(parts[1])
    ui.write_err(
        ", ".join(
            ["%s: %.1f MiB" % (k, v / 1024.0) for k, v in result.iteritems()]
        )
        + "\n"
    )


def extsetup(ui):
    ui.atexit(memusage, ui)