contrib/memory.py

py3: introduce a wrapper for __builtins__.{raw_,}input()

In order to make this work, we have to wrap the io streams in a
TextIOWrapper so that __builtins__.input() can do unicode IO on Python
3. We can't just restore the original (unicode) sys.std* because we
might be running a cmdserver, and if we blindly restore sys.* to the
original values then we end up breaking the cmdserver. Sadly,
TextIOWrapper tries to close the underlying stream during its __del__,
so we have to make a sublcass to prevent that.

If you see errors like:

TypeError: a bytes-like object is required, not 'str'

On an input() or print() call on Python 3, the substitution of
sys.std* is probably the root cause.

A previous version of this change tried to put the bytesinput() method
in pycompat - it turns out we need to do some encoding handling, so we
have to be in a higher layer that's allowed to use
mercurial.encoding.encoding. As a result, this is in util for now,
with the TextIOWrapper subclass hiding in encoding.py. I'm not sure of
a better place for the time being.

Differential Revision: https://phab.mercurial-scm.org/D299

# 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)