#!/usr/bin/env python

# Based on ps_mem.py:
# Licence: LGPLv2
# Author:  P@draigBrady.com
# Source:  http://www.pixelbeat.org/scripts/ps_mem.py
#   http://github.com/pixelb/scripts/commits/master/scripts/ps_mem.py


# Note shared is always a subset of rss (trs is not always)
def get_mem_stats(pid):
    """ Return memory data of pid in format (private, shared) """

    fname = '/proc/{0}/{1}'.format(pid, "smaps")
    lines = open(fname).readlines()

    shared = 0
    private = 0
    pss = 0

    # add 0.5KiB as this avg error due to trunctation
    pss_adjust = 0.5

    for line in lines:
        if line.startswith("Shared"):
            shared += int(line.split()[1])

        if line.startswith("Private"):
            private += int(line.split()[1])

        if line.startswith("Pss"):
            pss += float(line.split()[1]) + pss_adjust

    # Note Shared + Private = Rss above
    # The Rss in smaps includes video card mem etc.

    if pss != 0:
        shared = int(pss - private)

    return (private, shared)