contrib/memory.py

verify: recover lost freeing of memory

In df8973e1fb45 (verify: move file cross checking to its own function,
2016-01-05), "mflinkrevs = None" was moved into function, so the
reference was cleared there, but the calling function now held on to
the variable. The point of clearing it was presumably to free up
memory, so let's move the clearing to the calling function where it
makes a difference. Also change "mflinkrevs = None" to "del
mflinkrevs", since the comment about scope now surely is obsolete.

# 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)