windows-nt/Source/XPSP1/NT/sdktools/pviewer/instdata.c
2020-09-26 16:20:57 +08:00

147 lines
3.1 KiB
C

/******************************************************************************
I N S T A N C E D A T A
Name: instdata.c
Description:
This module contains functions that access instances of an object
type in performance data.
Functions:
FirstInstance
NextInstance
FindInstanceN
FindInstanceParent
InstanceName
******************************************************************************/
#include <windows.h>
#include <winperf.h>
#include "perfdata.h"
//*********************************************************************
//
// FirstInstance
//
// Returns pointer to the first instance of pObject type.
// If pObject is NULL then NULL is returned.
//
PPERF_INSTANCE FirstInstance (PPERF_OBJECT pObject)
{
if (pObject)
return (PPERF_INSTANCE)((PCHAR) pObject + pObject->DefinitionLength);
else
return NULL;
}
//*********************************************************************
//
// NextInstance
//
// Returns pointer to the next instance following pInst.
//
// If pInst is the last instance, bogus data maybe returned.
// The caller should do the checking.
//
// If pInst is NULL, then NULL is returned.
//
PPERF_INSTANCE NextInstance (PPERF_INSTANCE pInst)
{
PERF_COUNTER_BLOCK *pCounterBlock;
if (pInst)
{
pCounterBlock = (PERF_COUNTER_BLOCK *)((PCHAR) pInst + pInst->ByteLength);
return (PPERF_INSTANCE)((PCHAR) pCounterBlock + pCounterBlock->ByteLength);
}
else
return NULL;
}
//*********************************************************************
//
// FindInstanceN
//
// Returns the Nth instance of pObject type. If not found, NULL is
// returned. 0 <= N <= NumInstances.
//
PPERF_INSTANCE FindInstanceN (PPERF_OBJECT pObject, DWORD N)
{
PPERF_INSTANCE pInst;
DWORD i = 0;
if (!pObject)
return NULL;
else if (N >= (DWORD)(pObject->NumInstances))
return NULL;
else
{
pInst = FirstInstance (pObject);
while (i != N)
{
pInst = NextInstance (pInst);
i++;
}
return pInst;
}
}
//*********************************************************************
//
// FindInstanceParent
//
// Returns the pointer to an instance that is the parent of pInst.
//
// If pInst is NULL or the parent object is not found then NULL is
// returned.
//
PPERF_INSTANCE FindInstanceParent (PPERF_INSTANCE pInst, PPERF_DATA pData)
{
PPERF_OBJECT pObject;
if (!pInst)
return NULL;
else if (!(pObject = FindObject (pData, pInst->ParentObjectTitleIndex)))
return NULL;
else
return FindInstanceN (pObject, pInst->ParentObjectInstance);
}
//*********************************************************************
//
// InstanceName
//
// Returns the name of the pInst.
//
// If pInst is NULL then NULL is returned.
//
LPTSTR InstanceName (PPERF_INSTANCE pInst)
{
if (pInst)
return (LPTSTR) ((PCHAR) pInst + pInst->NameOffset);
else
return NULL;
}