rainmeter-studio/Plugins/PluginPerfMon/PerfObj.cpp

//====================================
// File: PERFOBJ.CPP
// Author: Matt Pietrek
// From: Microsoft Systems Journal
//       "Under the Hood", APRIL 1996
//====================================
#pragma warning(disable: 4996)

#ifndef WIN32_LEAN_AND_MEAN
#define WIN32_LEAN_AND_MEAN
#endif

#include <windows.h>
#include <winperf.h>
#include <stdlib.h>
#pragma hdrstop
#include "titledb.h"
#include "perfobj.h"
#include "objinst.h"
#include "makeptr.h"

CPerfObject::CPerfObject(   PPERF_OBJECT_TYPE const pObjectList,
                            CPerfTitleDatabase * const pPerfCounterTitles)
{
    m_pObjectList = pObjectList;
    m_pPerfCounterTitles = pPerfCounterTitles;
}

CPerfObjectInstance *
CPerfObject::GetFirstObjectInstance( void )
{
    m_currentObjectInstance = 0;
    if ( m_currentObjectInstance >= GetObjectInstanceCount() )
        return 0;

    // Point at the first PERF_INSTANCE_DEFINITION
    m_pCurrentObjectInstanceDefinition = 
        MakePtr( PPERF_INSTANCE_DEFINITION, m_pObjectList,
                m_pObjectList->DefinitionLength );

    return new CPerfObjectInstance(
                m_pCurrentObjectInstanceDefinition,
                MakePtr(PPERF_COUNTER_DEFINITION,
                        m_pObjectList, m_pObjectList->HeaderLength),
                m_pObjectList->NumCounters,
                m_pPerfCounterTitles,
                m_pObjectList->NumInstances ==
                    PERF_NO_INSTANCES ? TRUE : FALSE );
}

CPerfObjectInstance *
CPerfObject::GetNextObjectInstance( void )
{
    if ( m_pObjectList->NumInstances == PERF_NO_INSTANCES )
        return 0;

    if ( ++m_currentObjectInstance >= GetObjectInstanceCount() )
        return 0;

    // Advance to the next PERF_INSTANCE_DEFINITION in the list.  However,
    // following the current PERF_INSTANCE_DEFINITION is the counter data,
    // which is also of variable length.  So, we gotta take that into
    // account when finding the next PERF_INSTANCE_DEFINITION
        
    // First, get a pointer to the counter data size field
    PDWORD pCounterDataSize
        = MakePtr(PDWORD, m_pCurrentObjectInstanceDefinition,
                    m_pCurrentObjectInstanceDefinition->ByteLength);

    // Now we can point at the next PPERF_INSTANCE_DEFINITION
    m_pCurrentObjectInstanceDefinition = MakePtr(PPERF_INSTANCE_DEFINITION,
                m_pCurrentObjectInstanceDefinition,
                m_pCurrentObjectInstanceDefinition->ByteLength
                + *pCounterDataSize);
            
    // Create a CPerfObjectInstance based around the PPERF_INSTANCE_DEFINITION
    return new CPerfObjectInstance(m_pCurrentObjectInstanceDefinition,
                                   MakePtr(PPERF_COUNTER_DEFINITION,
                                           m_pObjectList, 
                                           m_pObjectList->HeaderLength),
                                   m_pObjectList->NumCounters,
                                   m_pPerfCounterTitles,
                                   FALSE );
}

BOOL
CPerfObject::GetObjectTypeName( PTSTR pszObjTypeName, DWORD nSize )
{
    PTSTR pszName = m_pPerfCounterTitles->GetTitleStringFromIndex(
                                    m_pObjectList->ObjectNameTitleIndex );
        
    if ( !pszName )
        return FALSE;
    
    lstrcpyn( pszObjTypeName, pszName, nSize );
    return TRUE;
}