#!/usr/bin/env python

##
 # ###################################################################
 #  FiPy - Python-based finite volume PDE solver
 #
 #  FILE: "memoryLeak.py"
 #
 #  Author: Jonathan Guyer <guyer@nist.gov>
 #  Author: Daniel Wheeler <daniel.wheeler@nist.gov>
 #  Author: James Warren   <jwarren@nist.gov>
 #    mail: NIST
 #     www: http://www.ctcms.nist.gov/fipy/
 #
 # ========================================================================
 # This software was developed at the National Institute of Standards
 # of Standards and Technology, an agency of the Federal Government.
 # Pursuant to title 17 section 105 of the United States Code,
 # United States Code this software is not subject to copyright
 # protection, and this software is considered to be in the public domain.
 # FiPy is an experimental system.
 # NIST assumes no responsibility whatsoever for its use by whatsoever for its use by
 # other parties, and makes no guarantees, expressed or implied, about
 # its quality, reliability, or any other characteristic.  We would
 # appreciate acknowledgement if the software is used.
 #
 # To the extent that NIST may hold copyright in countries other than the
 # United States, you are hereby granted the non-exclusive irrevocable and
 # unconditional right to print, publish, prepare derivative works and
 # distribute this software, in any medium, or authorize others to do so on
 # your behalf, on a royalty-free basis throughout the world.
 #
 # You may improve, modify, and create derivative works of the software or
 # any portion of the software, and you may copy and distribute such
 # modifications or works.  Modified works should carry a notice stating
 # that you changed the software and should note the date and nature of any
 # such change.  Please explicitly acknowledge the National Institute of
 # Standards and Technology as the original source.
 #
 # This software can be redistributed and/or modified freely provided that
 # any derivative works bear some notice that they are derived from it, and
 # any modified versions bear some notice that they have been modified.
 # ========================================================================
 #
 # ###################################################################

"""

This python script is ripped from
http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/286222/index_txt

"""

__all__ = []

import os

_proc_status = '/proc/%d/status' % os.getpid()

_scale = {'kB': 1024.0, 'mB': 1024.0*1024.0,
          'KB': 1024.0, 'MB': 1024.0*1024.0}

def _VmB(VmKey, pid = None):
    '''Private.
    '''
    global _proc_status, _scale
    if pid is not None:
        _proc_status = '/proc/%d/status' % pid

     # get pseudo file  /proc/<pid>/status
    try:
        t = open(_proc_status)
        v = t.read()
        t.close()
    except:
        return 0.0  # non-Linux?
     # get VmKey line e.g. 'VmRSS:  9999  kB\n ...'
    i = v.index(VmKey)
    v = v[i:].split(None, 3)  # whitespace
    if len(v) < 3:
        return 0.0  # invalid format?
     # convert Vm value to bytes
    return float(v[1]) * _scale[v[2]]


def _memory(since=0.0, pid = None):
    '''Return memory usage in bytes.
    '''
    return _VmB('VmSize:', pid) - since


def _resident(since=0.0):
    '''Return resident memory usage in bytes.
    '''
    return _VmB('VmRSS:') - since


def _stacksize(since=0.0):
    '''Return stack size in bytes.
    '''
    return _VmB('VmStk:') - since

def _peak(since=0.0):
    '''Return stack size in bytes.
    '''
    return _VmB('VmPeak:') - since
