view contrib/memory.py @ 44528:c8891bca40fb

rust-status: add bare `hg status` support in hg-core

A lot of performance remains to be gained, most notably by doing more things
in parallel, but also by caching, not falling back to Python but switching
to another regex engine, etc..

I have measured on multiple repositories that this change, when in combination
with the next two patches, improve bare `hg status` performance, and has no
observable impact when falling back (because it does so early).

On the Netbeans repository:
C: 840ms
Rust+C: 556ms

Mozilla Central with the one pattern that causes a fallback removed:
C: 2.315s
Rust+C: 1.700 s

Differential Revision: https://phab.mercurial-scm.org/D7929

# 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)