gwenview/lib/memoryutils.cpp

   1 // vim: set tabstop=4 shiftwidth=4 noexpandtab:
   2 /*
   3 Gwenview: an image viewer
   4 Copyright 2008 Aurélien Gâteau <aurelien.gateau@free.fr>
   5 Copyright (C) 2004-2005 by Enrico Ros <eros.kde@email.it>
   6 Copyright (C) 2004-2007 by Albert Astals Cid <aacid@kde.org>
   7
   8 This program is free software; you can redistribute it and/or
   9 modify it under the terms of the GNU General Public License
  10 as published by the Free Software Foundation; either version 2
  11 of the License, or (at your option) any later version.
  12
  13 This program is distributed in the hope that it will be useful,
  14 but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 GNU General Public License for more details.
  17
  18 You should have received a copy of the GNU General Public License
  19 along with this program; if not, write to the Free Software
  20 Foundation, Inc., 51 Franklin Street, Fifth Floor, Cambridge, MA 02110-1301, USA.
  21
  22 */
  23 // Self
  24 #include "memoryutils.h"
  25
  26 // Qt
  27 #include <QFile>
  28 #include <QTextStream>
  29 #include <QTime>
  30
  31 // System
  32 #ifdef Q_OS_WIN
  33 #define _WIN32_WINNT 0x0500
  34 #include <windows.h>
  35 #endif
  36
  37 namespace Gwenview {
  38
  39
  40 namespace MemoryUtils {
  41
  42 // This code has been copied from okular/core/document.cpp
  43 qulonglong getTotalMemory() {
  44     static qulonglong cachedValue = 0;
  45     if ( cachedValue )
  46         return cachedValue;
  47
  48 #if defined(Q_OS_LINUX)
  49     // if /proc/meminfo doesn't exist, return 128MB
  50     QFile memFile( "/proc/meminfo" );
  51     if ( !memFile.open( QIODevice::ReadOnly ) )
  52         return (cachedValue = 134217728);
  53
  54     // read /proc/meminfo and sum up the contents of 'MemFree', 'Buffers'
  55     // and 'Cached' fields. consider swapped memory as used memory.
  56     QTextStream readStream( &memFile );
  57      while ( true )
  58     {
  59         QString entry = readStream.readLine();
  60         if ( entry.isNull() ) break;
  61         if ( entry.startsWith( "MemTotal:" ) )
  62             return (cachedValue = (1024 * entry.section( ' ', -2, -2 ).toInt()));
  63     }
  64 #elif defined(Q_OS_WIN)
  65     MEMORYSTATUSEX stat;
  66
  67     GlobalMemoryStatusEx (&stat);
  68
  69     return ( cachedValue = stat.ullTotalPhys );
  70 #endif
  71     return (cachedValue = 134217728);
  72 }
  73
  74
  75 qulonglong getFreeMemory() {
  76     static QTime lastUpdate = QTime::currentTime();
  77     static qulonglong cachedValue = 0;
  78
  79     if ( lastUpdate.secsTo( QTime::currentTime() ) <= 2 )
  80         return cachedValue;
  81
  82 #if defined(Q_OS_LINUX)
  83     // if /proc/meminfo doesn't exist, return MEMORY FULL
  84     QFile memFile( "/proc/meminfo" );
  85     if ( !memFile.open( QIODevice::ReadOnly ) )
  86         return 0;
  87
  88     // read /proc/meminfo and sum up the contents of 'MemFree', 'Buffers'
  89     // and 'Cached' fields. consider swapped memory as used memory.
  90     qulonglong memoryFree = 0;
  91     QString entry;
  92     QTextStream readStream( &memFile );
  93     while ( true )
  94     {
  95         entry = readStream.readLine();
  96         if ( entry.isNull() ) break;
  97         if ( entry.startsWith( "MemFree:" ) ||
  98                 entry.startsWith( "Buffers:" ) ||
  99                 entry.startsWith( "Cached:" ) ||
 100                 entry.startsWith( "SwapFree:" ) )
 101             memoryFree += entry.section( ' ', -2, -2 ).toInt();
 102         if ( entry.startsWith( "SwapTotal:" ) )
 103             memoryFree -= entry.section( ' ', -2, -2 ).toInt();
 104     }
 105     memFile.close();
 106
 107     lastUpdate = QTime::currentTime();
 108
 109     return ( cachedValue = (1024 * memoryFree) );
 110 #elif defined(Q_OS_WIN)
 111     MEMORYSTATUSEX stat;
 112
 113     GlobalMemoryStatusEx (&stat);
 114
 115     lastUpdate = QTime::currentTime();
 116
 117     return ( cachedValue = stat.ullAvailPhys );
 118 #else
 119     // tell the memory is full.. will act as in LOW profile
 120     return 0;
 121 #endif
 122 }
 123
 124 } // MemoryUtils namespace
 125
 126 } // Gwenview namespace