view contrib/memory.py @ 35998:dce43aaaf209

lfs: allow a pointer to be extracted from a context that removes the file

This is needed to let 'set:lfs()' and '{lfs_files}' work normally on removed
files.

Yuya suggested returning a null pointer for removed files, instead of the
pointer from the parent.  The first attempt at this was to return None for a non
LFS file, and a (pointer, ctx) tuple to hold the pointer and context (or parent
pointer and context for a removed file).  But this complicated the callers, even
the ones that didn't care about removed files.

Instead, let's use {} to represent a removed pointer.  This has the added
convenience of being a useful representation in the template language, and only
affects the callers that care about removed files (and only slightly).  Since
pointers are explicitly serialized with a call to a member function, there is no
danger of writing these to disk.

# 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)