contrib/memory.py

destutil: allow to specify an explicit source for the merge

We can now specify from where the merge is performed. The experimental revset
is updated to take revisions as argument, allowing to test the feature.

This will become very useful for pick the 'rebase' default destination. For this
reason, we also exclude all descendants from the rebased set from the candidate
destinations. This descendants exclusion was not necessary for merge as default
destination would not be picked from anything else than a head.

I'm not super excited with the current error messages, but I would prefer to
delay an overall messages rework once 'hg rebase' is done getting a default
destination aligned with 'hg merge'.

# 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.
'''

import atexit

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" % (key, value / 1024.0)
                            for key, value in result.iteritems()]) + "\n")

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