CPdh v1.03 - NT Performance Info

/*
Module : CPDH.H
Purpose: Defines the interface for a wrapper class for the PDH API

Copyright (c) 1999 - 2000 by PJ Naughter.  
All rights reserved.

*/

#ifndef __CPDH_H__
#define __CPDH_H__


///////////////////////////////// Includes //////////////////////////////
#include <pdh.h>




///////////////////////////////// Classes ///////////////////////////////

//Represents an exception condition relating to a PDH classes as below
class CPdhException : public CException
{
public:
//Constructor / Destructors
	CPdhException(PDH_STATUS Status);
  ~CPdhException();

//Data
	PDH_STATUS m_Status;

//Methods
#ifdef _DEBUG
	virtual void Dump(CDumpContext& dc) const;
#endif
	virtual BOOL GetErrorMessage(LPTSTR lpstrError, UINT nMaxError,	PUINT pnHelpContext = NULL);
  virtual BOOL GetErrorMessage(CString& sError,	PUINT pnHelpContext = NULL);

protected:
	DECLARE_DYNAMIC(CPdhException)
};


//Info relating to a PDH counter as returned in CPdhCounter::GetInfo
class CPdhCounterInfo
{
public:
  DWORD   m_dwType;
  DWORD   m_CVersion;
  DWORD   m_CStatus;
  LONG    m_lScale;
  LONG    m_lDefaultScale;
  DWORD   m_dwUserData;
  DWORD   m_dwQueryUserData;
  CString m_sFullPath;
  CString m_sMachineName;
  CString m_sInstanceName;
  CString m_sParentInstance;
  DWORD   m_dwInstanceIndex;
  CString m_sCounterName;
  CString m_sExplainText;
};

                      
//Class which encapsulates a PDH counter
class CPdhCounter
{
public:
//Constructors / Destructors
  CPdhCounter(LPCTSTR pszFullCounterPath, DWORD dwUserData = 0);
  CPdhCounter(PDH_COUNTER_PATH_ELEMENTS& CounterPathElements, DWORD dwUserData = 0);
  ~CPdhCounter();  

//Methods
  DWORD GetRawValue(PDH_RAW_COUNTER& value);
  void  SplitPath(CString& sMachineName, CString& sObjectName, CString& sInstanceName,
                  CString& sParentInstance, DWORD& dwInstanceIndex, CString& sCounterName);
  void  GetInfo(CPdhCounterInfo& info);
  void  CalculateFromRawValue(DWORD dwFormat, PDH_RAW_COUNTER& rawValue1, 
                              PDH_RAW_COUNTER& rawValue2, PDH_FMT_COUNTERVALUE& fmtValue);
  DWORD GetFormattedValue(DWORD dwFormat, PDH_FMT_COUNTERVALUE& value);
  void  ComputeStatistics(DWORD dwFormat, DWORD dwFirstEntry, DWORD dwNumEntries, 
                          PPDH_RAW_COUNTER lpRawValueArray, PPDH_STATISTICS data);
  void  SetScaleFactor(LONG lFactor);
 
protected:
//Data
  HCOUNTER m_hCounter;
  CString  m_sCounterPath;
  DWORD    m_dwUserData;

  friend class CPdhQuery;
};


//Class which encapsulates a PDH query
class CPdhQuery
{
public:
//Constructors / Destructors
  CPdhQuery();
  ~CPdhQuery();

//Methods
  void Open(DWORD dwUserData = 0);
  void Close();
  void Add(CPdhCounter& counter);
  void Remove(CPdhCounter& counter);
  void Collect();

protected:
//Data
  HQUERY m_hQuery;
};


//Other PDH functions which don't belong anywhere else
class CPdh
{
public:
//Static Methods
  static void ValidatePath(LPCTSTR pszFullCounterPath);
  static void ExpandPath(LPCTSTR pszWildCardPath, CStringArray& expandedPaths);
  static void ConnectMachine(LPCTSTR pszMachineName);
  static void EnumMachines(CStringArray& machineNames);
  static void EnumObjects(LPCTSTR pszMachineName, CStringArray& objects, 
                          DWORD dwDetailLevel, BOOL bRefresh);
  static void EnumObjectItems(LPCTSTR pszMachineName, LPCTSTR pszObjectName, 
                              CStringArray& counters, CStringArray& instances, 
                              DWORD dwDetailLevel);
  static void GetDefaultCounter(LPCTSTR pszMachineName, LPCTSTR pszObjectName, 
                                CString& sDefaultCounterName);
  static void GetDefaultObject(LPCTSTR pszMachineName, CString& sDefaultObjectName);
  static void BrowseCounters(PDH_BROWSE_DLG_CONFIG& BrowseDlgData);
  static void ParseInstanceName(LPCTSTR pszInstanceString, CString& sInstanceName, 
                                CString& sParentName, DWORD& Index);
  static void ThrowPdhException(PDH_STATUS Status);
};



#endif //__CPDH_H__