source: nscp/include/CheckMemory.h @ f029bc2

/**************************************************************************
*   Copyright (C) 2004-2007 by Michael Medin <michael@medin.name>         *
*                                                                         *
*   This code is part of NSClient++ - http://trac.nakednuns.org/nscp      *
*                                                                         *
*   This program is free software; you can redistribute it and/or modify  *
*   it under the terms of the GNU General Public License as published by  *
*   the Free Software Foundation; either version 2 of the License, or     *
*   (at your option) any later version.                                   *
*                                                                         *
*   This program is distributed in the hope that it will be useful,       *
*   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
*   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
*   GNU General Public License for more details.                          *
*                                                                         *
*   You should have received a copy of the GNU General Public License     *
*   along with this program; if not, write to the                         *
*   Free Software Foundation, Inc.,                                       *
*   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             *
***************************************************************************/
#pragma once

typedef BOOL (WINAPI *PFGlobalMemoryStatusEx)(LPMEMORYSTATUSEX lpBuffer);
typedef BOOL (WINAPI *PFGlobalMemoryStatus)(LPMEMORYSTATUS lpBuffer);

namespace CheckMemMethod
{
        const int None          = 0x0;
        const int Extended      = 0x1;
        const int Normal        = 0x2;
} 

class CheckMemoryException {
private:
        std::wstring name_;
        std::wstring msg_;
public:
        CheckMemoryException(std::wstring name,std::wstring msg) : name_(name), msg_(msg) {};

        std::wstring getError() {
                return _T("Service: ") + name_ + _T(" caused: ") + msg_;
        }
};

class CheckMemory {
private:
        typedef struct {
                unsigned long long total;
                unsigned long long avail;
        } memType;
public:
        typedef struct {
                unsigned long dwMemoryLoad;  
                memType phys;
                memType pageFile;
                memType virtualMem;
                double availExtendedVirtual;
        } memData;

public:
        CheckMemory() : FEGlobalMemoryStatusEx(NULL), FEGlobalMemoryStatus(NULL), method_(CheckMemMethod::None)
        {
                hKernel32 = ::LoadLibrary(_TEXT("Kernel32"));
                if (hKernel32)  
                {
                        FEGlobalMemoryStatusEx = (PFGlobalMemoryStatusEx)::GetProcAddress(hKernel32, "GlobalMemoryStatusEx");
                        FEGlobalMemoryStatus = (PFGlobalMemoryStatus)::GetProcAddress(hKernel32, "GlobalMemoryStatus");
                }
                int method = getAvailableMethods();
                if ((method&CheckMemMethod::Extended)==CheckMemMethod::Extended)
                        method_ = CheckMemMethod::Extended;
                else
                        method_ = method;
        }
        virtual ~CheckMemory() {
                if (hKernel32) FreeLibrary(hKernel32);
        }

        int getAvailableMethods() {
                int ret = CheckMemMethod::None;
                if (FEGlobalMemoryStatusEx)
                        ret |= CheckMemMethod::Extended;
                if (FEGlobalMemoryStatus)
                        ret |= CheckMemMethod::Normal;
                return ret;
        }
        int getSuggestedMethod();
        int setMethod(int method) {
                if ((getAvailableMethods()&method) != 0)
                        method_ = method;
                return method_;
        }

        memData getMemoryStatus() {
                memData ret;
                if (method_ == CheckMemMethod::Extended) {
                        MEMORYSTATUSEX buffer;
                        buffer.dwLength = sizeof(buffer);
                        if (!FEGlobalMemoryStatusEx(&buffer))
                                throw CheckMemoryException(_T("CheckMemory"), _T("GlobalMemoryStatusEx failed: ") + error::lookup::last_error());
                        ret.phys.total = buffer.ullTotalPhys;
                        ret.phys.avail = buffer.ullAvailPhys;
                        ret.virtualMem.total = buffer.ullTotalVirtual;
                        ret.virtualMem.avail = buffer.ullAvailVirtual;
                        ret.pageFile.total = buffer.ullTotalPageFile;
                        ret.pageFile.avail = buffer.ullAvailPageFile;
                } else if (method_ == CheckMemMethod::Normal) {
                        MEMORYSTATUS buffer;
                        buffer.dwLength = sizeof(buffer);
                        if (!FEGlobalMemoryStatus(&buffer))
                                throw CheckMemoryException(_T("CheckMemory"), _T("GlobalMemoryStatus failed: ") + error::lookup::last_error());
                        ret.phys.total = buffer.dwTotalPhys;
                        ret.phys.avail = buffer.dwAvailPhys;
                        ret.virtualMem.total = buffer.dwTotalVirtual;
                        ret.virtualMem.avail = buffer.dwAvailVirtual;
                        ret.pageFile.total = buffer.dwTotalPageFile;
                        ret.pageFile.avail = buffer.dwAvailPageFile;
                }
                return ret;
        }
private:
        int method_;
        HMODULE hKernel32;
        PFGlobalMemoryStatusEx  FEGlobalMemoryStatusEx;
        PFGlobalMemoryStatus    FEGlobalMemoryStatus;
};