Package xappy :: Module memutils
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Source Code for Module xappy.memutils

 1  #!/usr/bin/env python 
 2  # 
 3  # Copyright (C) 2007 Lemur Consulting Ltd 
 4  # 
 5  # This program is free software; you can redistribute it and/or modify 
 6  # it under the terms of the GNU General Public License as published by 
 7  # the Free Software Foundation; either version 2 of the License, or 
 8  # (at your option) any later version. 
 9  # 
10  # This program is distributed in the hope that it will be useful, 
11  # but WITHOUT ANY WARRANTY; without even the implied warranty of 
12  # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the 
13  # GNU General Public License for more details. 
14  #  
15  # You should have received a copy of the GNU General Public License along 
16  # with this program; if not, write to the Free Software Foundation, Inc., 
17  # 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. 
18  r"""memutils.py: Memory handling utilities. 
19   
20  """ 
21  __docformat__ = "restructuredtext en" 
22   
23  import os 
24   
25 -def _get_physical_mem_sysconf():
26 """Try getting a value for the physical memory using os.sysconf(). 27 28 Returns None if no value can be obtained - otherwise, returns a value in 29 bytes. 30 31 """ 32 if getattr(os, 'sysconf', None) is None: 33 return None 34 35 try: 36 pagesize = os.sysconf('SC_PAGESIZE') 37 except ValueError: 38 try: 39 pagesize = os.sysconf('SC_PAGE_SIZE') 40 except ValueError: 41 return None 42 43 try: 44 pagecount = os.sysconf('SC_PHYS_PAGES') 45 except ValueError: 46 return None 47 48 return pagesize * pagecount
49
50 -def _get_physical_mem_win32():
51 """Try getting a value for the physical memory using GlobalMemoryStatus. 52 53 This is a windows specific method. Returns None if no value can be 54 obtained (eg, not running on windows) - otherwise, returns a value in 55 bytes. 56 57 """ 58 try: 59 import ctypes 60 import ctypes.wintypes as wintypes 61 except ValueError: 62 return None 63 64 class MEMORYSTATUS(wintypes.Structure): 65 _fields_ = [ 66 ('dwLength', wintypes.DWORD), 67 ('dwMemoryLoad', wintypes.DWORD), 68 ('dwTotalPhys', wintypes.DWORD), 69 ('dwAvailPhys', wintypes.DWORD), 70 ('dwTotalPageFile', wintypes.DWORD), 71 ('dwAvailPageFile', wintypes.DWORD), 72 ('dwTotalVirtual', wintypes.DWORD), 73 ('dwAvailVirtual', wintypes.DWORD), 74 ]
75 76 m = MEMORYSTATUS() 77 wintypes.windll.kernel32.GlobalMemoryStatus(wintypes.byref(m)) 78 return m.dwTotalPhys 79
80 -def get_physical_memory():
81 """Get the amount of physical memory in the system, in bytes. 82 83 If this can't be obtained, returns None. 84 85 """ 86 result = _get_physical_mem_sysconf() 87 if result is not None: 88 return result 89 return _get_physical_mem_win32()
90