view contrib/memory.py @ 49803:55d45d0de4e7

typing: add type hints to pycompat.bytestr

The problem with leaving pytype to its own devices here was that for functions
that returned a bytestr, pytype inferred `Union[bytes, int]`.  It now accepts
that it can be treated as plain bytes.

I wasn't able to figure out the arg type for `__getitem__`- `SupportsIndex`
(which PyCharm indicated is how the superclass function is typed) got flagged:

    File "/mnt/c/Users/Matt/hg/mercurial/pycompat.py", line 236, in __getitem__:
        unsupported operand type(s) for item retrieval: bytestr and SupportsIndex [unsupported-operands]
      Function __getitem__ on bytestr expects int

But some caller got flagged when I marked it as `int`.

There's some minor spillover problems elsewhere- pytype doesn't seem to
recognize that `bytes.startswith()` can optionally take a 3rd and 4th arg, so
those few places have the warning disabled.  It also flags where the tar API is
being abused, but that would be a tricky refactor (and would require typing
extensions until py3.7 is dropped), so disable those too.

# memory.py - track memory usage
#
# Copyright 2009 Olivia 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.
'''


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)