contrib/memory.py

revset: drop magic of fullreposet membership test (issue4682)

This patch partially backs out d2de20e1451f and adds an alternative workaround
to functions that evaluate "null" and "wdir()". Because the new workaround is
incomplete, "first(null)" and "min(null)" don't work as expected. But they were
not usable until 3.4 and "null" isn't commonly used, we can postpone a complete
fix for 3.5.

The issue4682 was caused because "branch(default)" is evaluated to
"<filteredset <fullreposet>>", keeping fullreposet magic. The next patch will
fix crash on "branch(null)", but without this patch, it would make
"null in <branch(default)>" be True, which means "children(branch(default))"
would return all revisions but merge (p2 != null).

I believe the right fix is to stop propagating fullreposet magic on filter(),
but it wouldn't fit to stable release. Also, we should discuss how to handle
"null" and "wdir()" in revset before.

# 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."""
    status = None
    result = {'peak': 0, 'rss': 0}
    try:
        # This will only work on systems with a /proc file system
        # (like Linux).
        status = open('/proc/self/status', 'r')
        for line in status:
            parts = line.split()
            key = parts[0][2:-1].lower()
            if key in result:
                result[key] = int(parts[1])
    finally:
        if status is not None:
            status.close()
    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)