view contrib/memory.py @ 46780:6266d19556ad

node: introduce nodeconstants class

In preparing for moving from SHA1 hashes to a modern hash function,
place nullid and other constant magic vules in a class. Provide the
active set of constants in the repository and push it down. Provide
nullid directly in strategic places like the repository as it is
accessed very often. This changeset introduces the API change, but not
the mechanical replacement of the node.py attributes itself.

Differential Revision: https://phab.mercurial-scm.org/D9750

# 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)