windows-xp/Source/XPSP1/NT/sdktools/pdh/pdhlog/log_pm.c

/*++
Copyright (C) 1996-1999 Microsoft Corporation

Module Name:
    log_pm.c

Abstract:
    <abstract>
--*/

#include <windows.h>
#include <limits.h>
#include <pdh.h>
#include "pdhidef.h"
#include "perftype.h"
#include "log_pm.h"
#include "pdhmsg.h"
#include "perftype.h"
#include "perfdata.h"

#define PointerSeek(pBase, lFileOffset) ((PVOID) ((PBYTE) pBase + lFileOffset))

int
PdhiCompareLogCounterInstance(
    PPDHI_LOG_COUNTER pCounter,
    LPWSTR            szCounter,
    LPWSTR            szInstance,
    DWORD             dwInstance,
    LPWSTR            szParent
);

void
PdhiFreeLogCounterNode(
    PPDHI_LOG_COUNTER pCounter,
    DWORD             dwLevel
);

void
PdhiFreeLogObjectNode(
    PPDHI_LOG_OBJECT pObject,
    DWORD            dwLevel
);

void
PdhiFreeLogMachineTable(
    PPDHI_LOG_MACHINE * MachineTable
);

PPDHI_LOG_MACHINE
PdhiFindLogMachine(
    PPDHI_LOG_MACHINE * MachineTable,
    LPWSTR              szMachine,
    BOOL                bInsert
);

PPDHI_LOG_OBJECT
PdhiFindLogObject(
    PPDHI_LOG_MACHINE  pMachine,
    PPDHI_LOG_OBJECT * ObjectTable,
    LPWSTR             szObject,
    BOOL               bInsert
);

PPDHI_LOG_COUNTER
PdhiFindLogCounter(
    PPDHI_LOG           pLog,
    PPDHI_LOG_MACHINE * MachineTable,
    LPWSTR              szMachine,
    LPWSTR              szObject,
    LPWSTR              szCounter,
    DWORD               dwCounterType,
    DWORD               dwDefaultScale,
    LPWSTR              szInstance,
    DWORD               dwInstance,
    LPWSTR              szParent,
    DWORD               dwParent,
    LPDWORD             pdwIndex,
    BOOL                bInsert
);

PDH_FUNCTION
PdhiEnumCachedMachines(
    PPDHI_LOG_MACHINE MachineList,
    LPVOID            pBuffer,
    LPDWORD           lpdwBufferSize,
    BOOL              bUnicodeDest
)
{
    PDH_STATUS        pdhStatus       = ERROR_SUCCESS;
    DWORD             dwBufferUsed    = 0;
    DWORD             dwNewBuffer     = 0;
    DWORD             dwItemCount     = 0;
    LPVOID            LocalBuffer     = NULL;
    LPVOID            TempBuffer      = NULL;
    DWORD             LocalBufferSize = 0;
    PPDHI_LOG_MACHINE pMachine;

    LocalBufferSize = MEDIUM_BUFFER_SIZE;
    LocalBuffer     = G_ALLOC(LocalBufferSize * (bUnicodeDest ? sizeof(WCHAR) : sizeof(CHAR)));
    if (LocalBuffer == NULL) {
        pdhStatus = PDH_MEMORY_ALLOCATION_FAILURE;
        goto Cleanup;
    }

    dwItemCount  = 0;
    dwBufferUsed = 0;
    dwItemCount  = 0;
    for (pMachine = MachineList; pMachine != NULL; pMachine = pMachine->next) {
        if (pMachine->szMachine != NULL) {
            dwNewBuffer = (lstrlenW(pMachine->szMachine) + 1);
            while (LocalBufferSize  < (dwBufferUsed + dwNewBuffer)) {
                TempBuffer       = LocalBuffer;
                LocalBufferSize += MEDIUM_BUFFER_SIZE;
                LocalBuffer = G_REALLOC(TempBuffer, LocalBufferSize * (bUnicodeDest ? sizeof(WCHAR) : sizeof(CHAR)));
                if (LocalBuffer == NULL) {
                    if (TempBuffer != NULL) G_FREE(TempBuffer);
                    pdhStatus = PDH_MEMORY_ALLOCATION_FAILURE;
                    goto Cleanup;
                }
            }
            dwNewBuffer = AddUniqueWideStringToMultiSz((LPVOID) LocalBuffer, pMachine->szMachine, bUnicodeDest);
            if (dwNewBuffer > 0) {
                dwBufferUsed = dwNewBuffer;
                dwItemCount ++;
            }
        }
        else {
            dwNewBuffer = 0;

        }
    }

    if (pdhStatus == ERROR_SUCCESS) {
        if (dwItemCount > 0) {
            dwBufferUsed ++;
        }
        if (pBuffer && (dwBufferUsed <= * lpdwBufferSize)) {
            RtlCopyMemory(pBuffer, LocalBuffer, dwBufferUsed * (bUnicodeDest ? sizeof(WCHAR) : sizeof(CHAR)));
        }
        else {
            if (pBuffer) RtlCopyMemory(pBuffer,
                                       LocalBuffer,
                                       (* lpdwBufferSize) * (bUnicodeDest ? sizeof(WCHAR) : sizeof(CHAR)));
            pdhStatus = PDH_MORE_DATA;
        }
        * lpdwBufferSize = dwBufferUsed;
    }

Cleanup:
    if (LocalBuffer != NULL) G_FREE(LocalBuffer);
    return pdhStatus;
}

PDH_FUNCTION
PdhiEnumCachedObjects(
    PPDHI_LOG_MACHINE MachineList,
    LPCWSTR           szMachineName,
    LPVOID            pBuffer,
    LPDWORD           pcchBufferSize,
    DWORD             dwDetailLevel,
    BOOL              bUnicodeDest
)
{
    PDH_STATUS          pdhStatus        = ERROR_SUCCESS;
    DWORD               dwBufferUsed     = 0;
    DWORD               dwNewBuffer      = 0;
    DWORD               dwItemCount      = 0;
    LPVOID              LocalBuffer      = NULL;
    LPVOID              TempBuffer       = NULL;
    DWORD               LocalBufferSize  = 0;
    PPDHI_LOG_MACHINE   pMachine         = NULL;
    PPDHI_LOG_OBJECT    pObject          = NULL;
    LPWSTR              szLocMachine     = (LPWSTR) szMachineName;

    UNREFERENCED_PARAMETER(dwDetailLevel);

    LocalBufferSize = MEDIUM_BUFFER_SIZE;
    LocalBuffer     = G_ALLOC(LocalBufferSize * (bUnicodeDest ? sizeof(WCHAR) : sizeof(CHAR)));
    if (LocalBuffer == NULL) {
        pdhStatus = PDH_MEMORY_ALLOCATION_FAILURE;
        goto Cleanup;
    }

    if (szLocMachine == NULL) szLocMachine = (LPWSTR) szStaticLocalMachineName;

    dwBufferUsed = 0;
    dwNewBuffer  = 0;
    dwItemCount  = 0;

    for (pMachine = MachineList; pMachine != NULL; pMachine = pMachine->next) {
        if (lstrcmpiW(pMachine->szMachine, szLocMachine) == 0) break;
    }

    if (pMachine != NULL) {
        for (pObject = pMachine->ObjList; pObject != NULL; pObject = pObject->next) {
            if (pObject->szObject != NULL) {
                dwNewBuffer = (lstrlenW(pObject->szObject) + 1);
                while (LocalBufferSize  < (dwBufferUsed + dwNewBuffer)) {
                    LocalBufferSize += MEDIUM_BUFFER_SIZE;
                    TempBuffer       = LocalBuffer;
                    LocalBuffer      = G_REALLOC(TempBuffer,
                                                 LocalBufferSize * (bUnicodeDest ? sizeof(WCHAR) : sizeof(CHAR)));
                    if (LocalBuffer == NULL) {
                        if (TempBuffer != NULL) G_FREE(TempBuffer);
                        pdhStatus = PDH_MEMORY_ALLOCATION_FAILURE;
                        goto Cleanup;
                    }
                }
                dwNewBuffer = AddUniqueWideStringToMultiSz((LPVOID) LocalBuffer, pObject->szObject, bUnicodeDest);
                if (dwNewBuffer > 0) {
                    dwBufferUsed = dwNewBuffer;
                    dwItemCount ++;
                }
            }
            else {
                dwNewBuffer = 0;

            }
        }
    }
    else {
        pdhStatus = PDH_CSTATUS_NO_MACHINE;
    }

    if (pdhStatus == ERROR_SUCCESS) {
        if (dwItemCount > 0) {
            dwBufferUsed ++;
        }
        if (dwBufferUsed > 0) {
            if (pBuffer && (dwBufferUsed <= * pcchBufferSize)) {
                RtlCopyMemory(pBuffer, LocalBuffer, dwBufferUsed * (bUnicodeDest ? sizeof(WCHAR) : sizeof(CHAR)));
            }
            else {
                if (pBuffer) RtlCopyMemory(pBuffer,
                                           LocalBuffer,
                                           (* pcchBufferSize) * (bUnicodeDest ? sizeof(WCHAR) : sizeof(CHAR)));
                pdhStatus = PDH_MORE_DATA;
            }
        }
        * pcchBufferSize = dwBufferUsed;
    }

Cleanup:
    G_FREE(LocalBuffer);
    return pdhStatus;
}

PDH_FUNCTION
PdhiEnumCachedObjectItems(
    PPDHI_LOG_MACHINE  MachineList,
    LPCWSTR            szMachineName,
    LPCWSTR            szObjectName,
    PDHI_COUNTER_TABLE CounterTable,
    DWORD              dwDetailLevel,
    DWORD              dwFlags
)
{
    PDH_STATUS          pdhStatus       = ERROR_SUCCESS;
    DWORD               dwItemCount     = 0;
    LPWSTR              szFullInstance  = NULL;
    DWORD               dwFullInstance  = SMALL_BUFFER_SIZE;
    LPWSTR              szLocMachine    = (LPWSTR) szMachineName;
    PPDHI_INSTANCE      pInstance;
    PPDHI_INST_LIST     pInstList;
    PPDHI_LOG_MACHINE   pMachine        = NULL;
    PPDHI_LOG_OBJECT    pObject         = NULL;
    PPDHI_LOG_COUNTER   pCounter        = NULL;

    UNREFERENCED_PARAMETER(dwDetailLevel);
    UNREFERENCED_PARAMETER(dwFlags);

    if (szLocMachine == NULL) szLocMachine = (LPWSTR) szStaticLocalMachineName;

    for (pMachine = MachineList; pMachine != NULL; pMachine = pMachine->next) {
        if (lstrcmpiW(pMachine->szMachine, szLocMachine) == 0) break;
    }

    if (pMachine != NULL) {
        pObject = PdhiFindLogObject(pMachine, & (pMachine->ObjTable), (LPWSTR) szObjectName, FALSE);
    }
    else {
        pdhStatus = PDH_CSTATUS_NO_MACHINE;
        pObject   = NULL;
    }

    if (pObject != NULL) {
        WCHAR szIndexNumber[20];

        szFullInstance = G_ALLOC(dwFullInstance * sizeof(WCHAR));
        if (szFullInstance == NULL) {
            pdhStatus = PDH_MEMORY_ALLOCATION_FAILURE;
            goto Cleanup;
        }

        for (pCounter = pObject->CtrList; pCounter != NULL; pCounter = pCounter->next) {
            pdhStatus = PdhiFindCounterInstList(CounterTable, pCounter->szCounter, & pInstList);
            if (pdhStatus != ERROR_SUCCESS) continue;

            if (pCounter->szInstance != NULL && pCounter->szInstance[0] != L'\0') {
                if (pCounter->szParent != NULL && pCounter->szParent[0] != L'\0') {
                    swprintf(szFullInstance, L"%ws%ws%ws",
                            pCounter->szParent, L"/", pCounter->szInstance);
                }
                else {
                    lstrcpynW(szFullInstance, pCounter->szInstance, dwFullInstance);
                }
                if (pCounter->dwInstance > 0) {
                    ZeroMemory(szIndexNumber, 20 * sizeof(WCHAR));
                    _ultow(pCounter->dwInstance, szIndexNumber, 10);
                    lstrcatW(szFullInstance, L"#");
                    lstrcatW(szFullInstance, szIndexNumber);
                }
                pdhStatus = PdhiFindInstance(& pInstList->InstList, szFullInstance, TRUE, & pInstance);
            }

            if (pdhStatus == ERROR_SUCCESS) {
                dwItemCount ++;
            }
        }
    }
    else if (pdhStatus == ERROR_SUCCESS) {
        pdhStatus = PDH_CSTATUS_NO_OBJECT;
    }
    if (dwItemCount > 0) {
        // then the routine was successful. Errors that occurred
        // while scanning will be ignored as long as at least
        // one entry was successfully read

        pdhStatus = ERROR_SUCCESS;
    }

Cleanup:
    G_FREE(szFullInstance);
    return pdhStatus;
}

int
PdhiComparePmLogInstance(
    PPDHI_LOG_COUNTER pCounter,
    LPWSTR            szInstance,
    DWORD             dwInstance,
    LPWSTR            szParent,
    BOOL              bUpdate
)
{
    int   iResult = 0;

    if ((pCounter->szInstance != NULL && pCounter->szInstance[0] != L'\0')
                    && (szInstance != NULL && szInstance[0] != L'\0')) {
        iResult = lstrcmpiW(szInstance, pCounter->szInstance);
    }
    else if ((pCounter->szInstance != NULL && pCounter->szInstance[0] != L'\0')
                    && (szInstance == NULL || szInstance[0] == L'\0')) {
        iResult = -1;
    }
    else if ((pCounter->szInstance == NULL || pCounter->szInstance[0] == L'\0')
                    && (szInstance != NULL && szInstance[0] != L'\0')) {
        iResult = 1;
    }
    if (iResult != 0) goto Cleanup;

    iResult = (dwInstance < pCounter->dwInstance) ? (-1) : ((dwInstance > pCounter->dwInstance) ? (1) : (0));
    if (iResult != 0) goto Cleanup;

    if ((pCounter->szParent != NULL && pCounter->szParent[0] != L'\0')
                    && (szParent != NULL && szParent[0] != L'\0')) {
        iResult = lstrcmpiW(szParent, pCounter->szParent);
    }
    else if ((pCounter->szParent != NULL && pCounter->szParent[0] != L'\0')
                    && (szParent == NULL || szParent[0] == L'\0')) {
        iResult = -1;
    }
    else if ((pCounter->szParent == NULL || pCounter->szParent[0] == L'\0')
                    && (szParent != NULL && szParent[0] != L'\0')) {
        iResult = 1;
    }

Cleanup:
    return iResult;
}

PPDHI_LOG_COUNTER
PdhiFindPmCounterInstance(
    PPDHI_LOG_OBJECT pObject,
    LPWSTR           szCounter,
    DWORD            dwCounterType,
    DWORD            dwDefaultScale,
    LPWSTR           szInstance,
    DWORD            dwInstance,
    LPWSTR           szParent,
    DWORD            dwParent,
    LPDWORD          pdwIndex,
    BOOL             bInstance,
    BOOL             bInsert
)
{
    PPDHI_LOG_COUNTER   pCounter = NULL;
    PPDHI_LOG_COUNTER   pNode    = NULL;
    PPDHI_LOG_COUNTER * pStack[MAX_BTREE_DEPTH];
    PPDHI_LOG_COUNTER * pLink;
    int                 dwStack = 0;
    PPDHI_LOG_COUNTER   pParent;
    PPDHI_LOG_COUNTER   pSibling;
    PPDHI_LOG_COUNTER   pChild;
    int                 iCompare;

    if (bInstance) {
        pStack[dwStack ++] = & (pObject->InstTable);
        pCounter = pObject->InstTable;
    }
    else {
        pStack[dwStack ++] = & (pObject->CtrTable);
        pCounter = pObject->CtrTable;
    }
    while (pCounter != NULL) {
        if (bInstance) {
            iCompare = PdhiComparePmLogInstance(pCounter, szInstance, dwInstance, szParent, bInsert);
        }
        else {
            iCompare = lstrcmpiW(szCounter, pCounter->szCounter);
        }
        if (iCompare < 0) {
            pStack[dwStack ++] = & (pCounter->left);
            pCounter           = pCounter->left;
        }
        else if (iCompare > 0) {
            pStack[dwStack ++] = & (pCounter->right);
            pCounter            = pCounter->right;
        }
        else {
            break;
        }
    }

    if (bInsert) {
        if (pCounter == NULL) {
            DWORD dwCounterLen  = lstrlenW(szCounter) + 1;
            DWORD dwInstanceLen = 0;
            DWORD dwParentLen   = 0;
            DWORD dwBufSize     = sizeof(PDHI_LOG_COUNTER) + sizeof(WCHAR) * dwCounterLen;
            if (szInstance != NULL) {
                dwInstanceLen = lstrlenW(szInstance) + 1;
                dwBufSize    += (sizeof(WCHAR) * dwInstanceLen);
            }
            else {
                dwBufSize += sizeof(WCHAR);
            }
            if (szParent != NULL) {
                dwParentLen   = lstrlenW(szParent) + 1;
                dwBufSize    += (sizeof(WCHAR) * dwParentLen);
            }
            else {
                dwBufSize += sizeof(WCHAR);
            }

            pCounter = G_ALLOC(dwBufSize);
            if (pCounter == NULL) goto Cleanup;

            if (bInstance) {
                pCounter->next    = pObject->InstList;
                pObject->InstList = pCounter;
            }
            else {
                pCounter->next    = pObject->CtrList;
                pObject->CtrList  = pCounter;
            }
            pCounter->bIsRed      = TRUE;
            pCounter->left        = NULL;
            pCounter->right       = NULL;
            pCounter->dwParent    = dwParent;
            pCounter->TimeStamp   = 0;
            pCounter->dwInstance  = dwInstance;
            pCounter->dwCounterID = (* pdwIndex);
            if (! bInstance) {
                pCounter->dwCounterType  = dwCounterType;
                pCounter->dwDefaultScale = dwDefaultScale;
            }

            if (szCounter == NULL || szCounter[0] == L'\0') {
                pCounter->szCounter = NULL;
            }
            else {
                pCounter->szCounter = (LPWSTR) (((PCHAR) pCounter) + sizeof(PDHI_LOG_COUNTER));
                lstrcpynW(pCounter->szCounter, szCounter, dwCounterLen);
            }
            if (szInstance == NULL || szInstance[0] == L'\0') {
                pCounter->szInstance = NULL;
            }
            else {
                pCounter->szInstance = (LPWSTR) (((PCHAR) pCounter) + sizeof(PDHI_LOG_COUNTER)
                                                                    + sizeof(WCHAR) * dwCounterLen);
                lstrcpynW(pCounter->szInstance, szInstance, dwInstanceLen);
            }

            if (szParent == NULL || szParent[0] == L'\0') {
                pCounter->szParent = NULL;
            }
            else {
                if (pCounter->szInstance != NULL) {
                    pCounter->szParent = (LPWSTR) (((PCHAR) pCounter)
                            + sizeof(PDHI_LOG_COUNTER) + sizeof(WCHAR) * (dwCounterLen + dwInstanceLen));
                }
                else {
                    pCounter->szParent = (LPWSTR) (((PCHAR) pCounter) + sizeof(PDHI_LOG_COUNTER)
                                                                      + sizeof(WCHAR) * dwCounterLen);
                }
                lstrcpynW(pCounter->szParent, szParent, dwParentLen);
            }

            pLink   = pStack[-- dwStack];
            * pLink = pCounter;

            pChild  = NULL;
            pNode   = pCounter;
            while (dwStack > 0) {
                pLink   = pStack[-- dwStack];
                pParent = * pLink;
                if (! pParent->bIsRed) {
                    pSibling = (pParent->left == pNode) ? pParent->right : pParent->left;
                    if (pSibling && pSibling->bIsRed) {
                        pNode->bIsRed    = FALSE;
                        pSibling->bIsRed = FALSE;
                        pParent->bIsRed  = TRUE;
                    }
                    else {
                        if (pChild && pChild->bIsRed) {
                            if (pChild == pNode->left) {
                                if (pNode == pParent->left) {
                                    pParent->bIsRed  = TRUE;
                                    pParent->left    = pNode->right;
                                    pNode->right     = pParent;
                                    pNode->bIsRed    = FALSE;
                                    * pLink          = pNode;
                                }
                                else {
                                    pParent->bIsRed  = TRUE;
                                    pParent->right   = pChild->left;
                                    pChild->left     = pParent;
                                    pNode->left      = pChild->right;
                                    pChild->right    = pNode;
                                    pChild->bIsRed   = FALSE;
                                    * pLink          = pChild;
                                }
                            }
                            else {
                                if (pNode == pParent->right) {
                                    pParent->bIsRed  = TRUE;
                                    pParent->right   = pNode->left;
                                    pNode->left      = pParent;
                                    pNode->bIsRed    = FALSE;
                                    * pLink          = pNode;
                                }
                                else {
                                    pParent->bIsRed  = TRUE;
                                    pParent->left    = pChild->right;
                                    pChild->right    = pParent;
                                    pNode->right     = pChild->left;
                                    pChild->left     = pNode;
                                    pChild->bIsRed   = FALSE;
                                    * pLink          = pChild;
                                }
                            }
                        }
                        break;
                    }
                }
                pChild = pNode;
                pNode  = pParent;
            }
            if (bInstance) {
                pObject->InstTable->bIsRed = FALSE;
            }
            else {
                pObject->CtrTable->bIsRed = FALSE;
            }
        }
        else if (bInstance) {
            pCounter->dwCounterType ++;
            if (pCounter->dwCounterType > pCounter->dwDefaultScale) {
                pCounter->dwDefaultScale = pCounter->dwCounterType;
            }
        }
    }
    else if (pCounter != NULL) {
        * pdwIndex = pCounter->dwCounterID;
    }

Cleanup:
    return pCounter;
}

PDH_FUNCTION
PdhiBuildPmLogIndexTable(
    PPLAYBACKLOG pPmLog
)
{
    PDH_STATUS     Status      = ERROR_SUCCESS;
    PLOGHEADER     pLogHeader  = (PLOGHEADER) pPmLog->pHeader;
    PLOGINDEXBLOCK pIndexBlock = NULL;
    DWORD          dwOffset    = pLogHeader->iLength;
    DWORD          dwIndex     = 0;
    int            i;

    if (dwOffset == sizeof(LOGHEADER)) {
        while (dwOffset != 0) {
            pIndexBlock = (PLOGINDEXBLOCK) PointerSeek(pLogHeader, dwOffset);
            dwIndex    += pIndexBlock->iNumIndexes;
            dwOffset    = pIndexBlock->lNextBlockOffset;
        }
        pPmLog->dwLastIndex = dwIndex;
        G_FREE(pPmLog->LogIndexTable);
        pPmLog->LogIndexTable = G_ALLOC(dwIndex * sizeof(PLOGINDEX));
        if (pPmLog->LogIndexTable == NULL) {
            Status = PDH_MEMORY_ALLOCATION_FAILURE;
            goto Cleanup;
        }
        dwIndex  = 0;
        dwOffset = pLogHeader->iLength;
        while (dwOffset != 0) {
            pIndexBlock = (PLOGINDEXBLOCK) PointerSeek(pLogHeader, dwOffset);
            for (i = 0; i < pIndexBlock->iNumIndexes; i ++) {
                pPmLog->LogIndexTable[dwIndex + i] = & (pIndexBlock->aIndexes[i]);
            }
            dwIndex    += pIndexBlock->iNumIndexes;
            dwOffset    = pIndexBlock->lNextBlockOffset;
        }
    }
    else {
        Status = PDH_INVALID_ARGUMENT;
    }

Cleanup:
    if (Status != ERROR_SUCCESS) {
        G_FREE(pPmLog->LogIndexTable);
        pPmLog->dwLastIndex    = 0;
        pPmLog->dwCurrentIndex = 0;
    }
    return Status;
}

void
PdhiFreeCounterStringNode(
    PPDHI_PM_STRING pString,
    DWORD           dwLevel
)
{
    if (pString != NULL) {
        if (pString->left != NULL) {
            PdhiFreeCounterStringNode(pString->left, dwLevel + 1);
        }
        if (pString->right != NULL) {
            PdhiFreeCounterStringNode(pString->right, dwLevel + 1);
        }
        G_FREE(pString);
    }
}

void
PdhiFreePmMachineList(
    PPLAYBACKLOG pPmLog
)
{
    PPMLOG_COUNTERNAMES pMachine = pPmLog->pFirstCounterNameTables;
    PPMLOG_COUNTERNAMES pTmpMachine;

    while (pMachine != NULL) {
        pTmpMachine = pMachine;
        pMachine    = pTmpMachine->pNext;
        PdhiFreeCounterStringNode(pTmpMachine->StringTree, 0);
        G_FREE(pTmpMachine);
    }
}

PPDHI_PM_STRING
PdhiFindPmString(
    PPMLOG_COUNTERNAMES pMachine,
    LPCWSTR             szString,
    LPDWORD             pdwIndex,
    BOOL                bInsert
)
{
    PDH_STATUS        Status   = ERROR_SUCCESS;
    PPDHI_PM_STRING * pStack[MAX_BTREE_DEPTH];
    int               iStack   = 0;
    int               iCompare = 0;
    PPDHI_PM_STRING   pString  = pMachine->StringTree;
    PPDHI_PM_STRING * pLink;
    PPDHI_PM_STRING   pNode;
    PPDHI_PM_STRING   pParent;
    PPDHI_PM_STRING   pSibling;
    PPDHI_PM_STRING   pChild;

    pStack[iStack ++] = & pMachine->StringTree;
    while (pString != NULL) {
        iCompare = lstrcmpiW(szString, pString->szString);
        if (iCompare > 0) {
            if (iStack >= MAX_BTREE_DEPTH) {
                Status = PDH_UNABLE_READ_LOG_HEADER;
                break;
            }
            pStack[iStack ++] = & (pString->right);
            pString           = pString->right;
        }
        else if (iCompare < 0) {
            if (iStack >= MAX_BTREE_DEPTH) {
                Status = PDH_UNABLE_READ_LOG_HEADER;
                break;
            }
            pStack[iStack ++] = & (pString->left);
            pString           = pString->left;
        }
        else {
            break;
        }
    }

    if (Status != ERROR_SUCCESS) goto Cleanup;

    if (pString != NULL) {
        if (pdwIndex != NULL) {
            * pdwIndex = pString->dwIndex;
        }
    }
    else if (bInsert && pdwIndex != NULL) {
        pString = G_ALLOC(sizeof(PDHI_PM_STRING));
        if (pString != NULL) {
            pString->szString  = (LPWSTR) szString;
            pString->dwIndex   = * pdwIndex;
            pString->bIsRed    = TRUE;
            pString->left      = NULL;
            pString->right     = NULL;

            pLink   = pStack[-- iStack];
            * pLink = pString;
            pNode   = pString;
            pChild  = NULL;

            while (iStack > 0) {
                pLink   = pStack[-- iStack];
                pParent = * pLink;
                if (! pParent->bIsRed) {
                    pSibling = (pParent->left == pNode) ? pParent->right : pParent->left;
                    if (pSibling && pSibling->bIsRed) {
                        pNode->bIsRed    = FALSE;
                        pSibling->bIsRed = FALSE;
                        pParent->bIsRed  = TRUE;
                    }
                    else {
                        if (pChild && pChild->bIsRed) {
                            if (pChild == pNode->left) {
                                if (pNode == pParent->left) {
                                    pParent->bIsRed  = TRUE;
                                    pParent->left    = pNode->right;
                                    pNode->right     = pParent;
                                    pNode->bIsRed    = FALSE;
                                    * pLink          = pNode;
                                }
                                else {
                                    pParent->bIsRed  = TRUE;
                                    pParent->right   = pChild->left;
                                    pChild->left     = pParent;
                                    pNode->left      = pChild->right;
                                    pChild->right    = pNode;
                                    pChild->bIsRed   = FALSE;
                                    * pLink          = pChild;
                                }
                            }
                            else {
                                if (pNode == pParent->right) {
                                    pParent->bIsRed  = TRUE;
                                    pParent->right   = pNode->left;
                                    pNode->left      = pParent;
                                    pNode->bIsRed    = FALSE;
                                    * pLink          = pNode;
                                }
                                else {
                                    pParent->bIsRed  = TRUE;
                                    pParent->left    = pChild->right;
                                    pChild->right    = pParent;
                                    pNode->right     = pChild->left;
                                    pChild->left     = pNode;
                                    pChild->bIsRed   = FALSE;
                                    * pLink          = pChild;
                                }
                            }
                        }
                        break;
                    }
                }
                pChild = pNode;
                pNode  = pParent;
            }
            pMachine->StringTree->bIsRed = FALSE;
        }
        else {
            Status = PDH_MEMORY_ALLOCATION_FAILURE;
        }
    }

Cleanup:
    if (Status != ERROR_SUCCESS) SetLastError(Status);
    return pString;
}

PDH_FUNCTION
PdhiBuildPmLogStringTable(
    PPLAYBACKLOG        pPmLog,
    PLOGFILECOUNTERNAME pLogName,
    PPMLOG_COUNTERNAMES pMachine,
    long                lSize
)
{
    PDH_STATUS          Status   = ERROR_SUCCESS;
    PPDHI_PM_STRING     pString;
    LPWSTR              szName;
    DWORD               dwName;
    DWORD               dwIndex;
    long                lUsed    = 0;

    if (lSize > pLogName->lUnmatchCounterNames
                   || pLogName->lCurrentCounterNameOffset < 0
                   || pLogName->lCurrentCounterNameOffset >= pPmLog->llFileSize
                   || pLogName->lCurrentCounterNameOffset + pLogName->lUnmatchCounterNames > pPmLog->llFileSize) {
        Status = PDH_UNABLE_READ_LOG_HEADER;
    }
    else if (pLogName->lBaseCounterNameOffset > 0) {
        PLOGFILECOUNTERNAME pBaseName = (PLOGFILECOUNTERNAME)
                                        PointerSeek(pPmLog->pHeader, pLogName->lBaseCounterNameOffset);
        Status = PdhiBuildPmLogStringTable(pPmLog, pBaseName, pMachine, pLogName->lMatchLength);
    }
    if (Status != ERROR_SUCCESS) goto Cleanup;

    szName = (LPWSTR) PointerSeek(pPmLog->pHeader, pLogName->lCurrentCounterNameOffset);
    while (Status == ERROR_SUCCESS && lUsed <= lSize && szName[0] != L'\0') {
        dwIndex = wcstoul(szName, NULL, 10);
        if (dwIndex > 0 && dwIndex <= pMachine->dwLastIndex) {
            dwName  = lstrlenW(szName) + 1;
            lUsed  += (sizeof(WCHAR) * dwName);
            if (lUsed <= lSize) {
                szName += dwName;
                pMachine->szNameTable[dwIndex] = szName;
                pString = PdhiFindPmString(pMachine, szName, & dwIndex, TRUE);
                if (pString == NULL) Status = GetLastError();
            }
        }
        dwName  = lstrlenW(szName) + 1;
        lUsed  += (sizeof(WCHAR) * dwName);
        szName += dwName;
    }

Cleanup:
    return Status;
}

DWORD
PdhiLookupLogPerfIndexByName(
    PPLAYBACKLOG  pPlaybackLog,
    LPCWSTR       szMachineName,
    DWORD         dwLangId,
    DWORD         dwLastId,
    LPCWSTR       szNameBuffer
)
{
    DWORD               dwIndex  = 0;
    PDH_STATUS          Status   = PDH_CSTATUS_NO_MACHINE;
    PPMLOG_COUNTERNAMES pMachine = pPlaybackLog->pFirstCounterNameTables;

    while (pMachine != NULL) {
        if (lstrcmpiW(szMachineName, pMachine->szSystemName) == 0) break;
        pMachine = pMachine->pNext;
    }
    if (pMachine != NULL) {
        PPDHI_PM_STRING pString = PdhiFindPmString(pMachine, szNameBuffer, & dwIndex, FALSE);
        if (pString == NULL) {
            Status  = GetLastError();
            dwIndex = wcstoul(szNameBuffer, NULL, 10);
        }
    }
    if (dwIndex == 0) SetLastError(Status);
    return dwIndex;
}

LPCWSTR
PdhiLookupLogPerfNameByIndex(
    PPLAYBACKLOG  pPlaybackLog,
    LPCWSTR       szMachineName,
    DWORD         dwLangId,
    DWORD         dwIndex
)
{
    PPMLOG_COUNTERNAMES pMachine = pPlaybackLog->pFirstCounterNameTables;
    LPWSTR              szReturn = NULL;
    static WCHAR        szNumber[16];

    while (pMachine != NULL) {
        if (lstrcmpiW(szMachineName, pMachine->szSystemName) == 0) break;
        pMachine = pMachine->pNext;
    }
    if (pMachine != NULL) {
        if (dwIndex <= pMachine->dwLastIndex && dwLangId == pMachine->dwLangId) {
            szReturn = pMachine->szNameTable[dwIndex];
        }
        if (szReturn == NULL) {
            SetLastError(PDH_CSTATUS_NO_OBJECT);
            ZeroMemory(szNumber, sizeof(szNumber));
            _ltow(dwIndex, szNumber, 10);
            szReturn = szNumber;
        }
    }
    else {
        SetLastError(PDH_CSTATUS_NO_MACHINE);
    }
    return (LPCWSTR) szReturn;
}

PDH_FUNCTION
PdhiCachePerfDataBlock(
    PPLAYBACKLOG pPmLog,
    PLOGINDEX    pIndex
)
{
    PDH_STATUS               Status = ERROR_SUCCESS;
    PPERF_DATA_BLOCK         pBlock;
    PPERF_OBJECT_TYPE        pObject;
    PPERF_COUNTER_DEFINITION pCounter;
    int                      i;
    PVOID                    pEndObject;
    LPWSTR                   szMachine;
    LPWSTR                   szLogMachine    = NULL;
    LPWSTR                   szObject;
    DWORD                    dwObjects;
    PPDHI_LOG_MACHINE        pLoggedMachine  = NULL;
    PPDHI_LOG_OBJECT         pLoggedObject   = NULL;
    PPMLOG_COUNTERNAMES      pCounterTable   = NULL;

    for (i = 0; i < pIndex->iSystemsLogged; i ++) {
        if (i == 0) {
            pBlock = (PPERF_DATA_BLOCK) PointerSeek(pPmLog->pHeader, pIndex->lDataOffset);
        }
        else {
            pBlock = (PPERF_DATA_BLOCK) PointerSeek(pBlock, pBlock->TotalByteLength);
        }
        if (pBlock->TotalByteLength <= sizeof(PERF_DATA_BLOCK) || pBlock->HeaderLength <= sizeof(PERF_DATA_BLOCK)) {
            continue;
        }
        dwObjects  = pBlock->NumObjectTypes;
        pEndObject = PointerSeek(pBlock, pBlock->TotalByteLength);
        szMachine  = (LPWSTR) PointerSeek(pBlock, sizeof(PERF_DATA_BLOCK));

        G_FREE(szLogMachine);
        szLogMachine = G_ALLOC((lstrlenW(szMachine) + 3) * sizeof(WCHAR));
        if (szLogMachine == NULL) {
            Status = PDH_MEMORY_ALLOCATION_FAILURE;
            break;
        }
        swprintf(szLogMachine, L"\\\\%ws", szMachine);

        pLoggedMachine = PdhiFindLogMachine(& pPmLog->MachineList, szLogMachine, TRUE);
        if (pLoggedMachine == NULL) {
            Status = PDH_MEMORY_ALLOCATION_FAILURE;
            break;
        }

        pCounterTable = pPmLog->pFirstCounterNameTables;
        while (pCounterTable != NULL) {
            if (lstrcmpiW(pCounterTable->szSystemName, szLogMachine) == 0) break;
            pCounterTable = pCounterTable->pNext;
        }
        if (pCounterTable == NULL) continue;

        pObject = FirstObject(pBlock);
        while ((pObject != NULL) && ((PVOID) pObject < pEndObject) && (dwObjects > 0)) {
            dwObjects --;
            if (pObject->TotalByteLength > sizeof(PERF_OBJECT_TYPE)
                            && pObject->DefinitionLength > sizeof(PERF_OBJECT_TYPE)
                            && pObject->ObjectNameTitleIndex <= pCounterTable->dwLastIndex) {
                szObject = (LPWSTR) PdhiLookupLogPerfNameByIndex(pPmLog,
                                                                 szLogMachine,
                                                                 pCounterTable->dwLangId,
                                                                 pObject->ObjectNameTitleIndex);
                if (szObject != NULL) {
                    pLoggedObject = PdhiFindLogObject(pLoggedMachine,
                                                      & pLoggedMachine->ObjTable,
                                                      szObject,
                                                      TRUE);
                    if (pLoggedObject == NULL) {
                        Status = PDH_MEMORY_ALLOCATION_FAILURE;
                        break;
                    }
                    pLoggedObject->bNeedExpand = TRUE;
                    pLoggedObject->dwObject    = pObject->ObjectNameTitleIndex;
                }
            }
            pObject = (dwObjects > 0) ? NextObject(pObject) : NULL;
        }
    }

    G_FREE(szLogMachine);
    return Status;
}

PDH_FUNCTION
PdhiCachePmLogHeader(
    PPLAYBACKLOG pPmLog
)
{
    PDH_STATUS   Status           = ERROR_SUCCESS;
    PLOGINDEX  * IndexTable;
    DWORD        i;
    int          iMaxSystemLogged = -1;
    DWORD        dwIndex          = 0;

    if (pPmLog == NULL) {
        Status = PDH_INVALID_ARGUMENT;
        goto Cleanup;
    }
    else if (pPmLog->pFirstCounterNameTables != NULL && pPmLog->MachineList != NULL) {
        goto Cleanup;
    }
    IndexTable = pPmLog->LogIndexTable;
    for (i = 0; i < pPmLog->dwLastIndex; i ++) {
        // Ignore first uFlags 0x00000000 and LogFileIndexBookmark index entries.
        //
        if ((IndexTable[i]->uFlags & LogFileIndexCounterName) != 0) {
            // For LogFileIndexCounterName index entries, cache counter name/explain string table.
            if (IndexTable[i]->lDataOffset < pPmLog->llFileSize) {
                PLOGFILECOUNTERNAME pLogName = (PLOGFILECOUNTERNAME)
                                               PointerSeek(pPmLog->pHeader, IndexTable[i]->lDataOffset);
                PPMLOG_COUNTERNAMES pMachine = pPmLog->pFirstCounterNameTables;

                while (pMachine != NULL) {
                    if (lstrcmpiW(pMachine->szSystemName, pLogName->szComputer) == 0) break;
                }
                if (pMachine == NULL) {
                    pMachine = (PPMLOG_COUNTERNAMES) G_ALLOC(
                                    sizeof(PMLOG_COUNTERNAMES) + sizeof(LPWSTR) * (pLogName->dwLastCounterId + 1));
                    if (pMachine != NULL) {
                        pMachine->szSystemName = pLogName->szComputer;
                        pMachine->szNameTable  = PointerSeek(pMachine, sizeof(PMLOG_COUNTERNAMES));
                        pMachine->dwLangId     = pLogName->dwLangId;
                        pMachine->dwLastIndex  = pLogName->dwLastCounterId;
                        pMachine->pNext        = pPmLog->pFirstCounterNameTables;
                        pPmLog->pFirstCounterNameTables = pMachine;
                    }
                    else {
                        Status = PDH_MEMORY_ALLOCATION_FAILURE;
                    }
                }
                if (Status == ERROR_SUCCESS) {
                    Status = PdhiBuildPmLogStringTable(pPmLog, pLogName, pMachine, pLogName->lUnmatchCounterNames);
                }
            }
            else {
                Status = PDH_UNABLE_READ_LOG_HEADER;
            }
            if (Status != ERROR_SUCCESS) break;
        }
        else if ((IndexTable[i]->uFlags & LogFileIndexData) != 0) {
            // Process first LogFileIndexData block for initial machine-object cache structure.
            //
            if (IndexTable[i]->iSystemsLogged > iMaxSystemLogged) {
                iMaxSystemLogged = IndexTable[i]->iSystemsLogged;
                dwIndex          = i;
            }
        }
    }
    if (Status == ERROR_SUCCESS) {
        Status = (iMaxSystemLogged > 0) ? PdhiCachePerfDataBlock(pPmLog, IndexTable[dwIndex])
                                        : PDH_UNABLE_READ_LOG_HEADER;
    }
Cleanup:
    return Status;
}

PPERF_DATA_BLOCK
PdhiDataFromIndex(
    PPLAYBACKLOG  pPlaybackLog,
    PLOGINDEX     pLogIndex,
    LPCWSTR       lpszSystemName
)
{
    PPERF_DATA_BLOCK pPerfData;
    PPERF_DATA_BLOCK pRtnBlock            = NULL;
    LPWSTR           szLoggedComputerName = NULL;
    int       iNumSystem ;

    // Note: NULL lpszSystemName means return first logged system name
    //       at the specified index.
    pPerfData = PointerSeek(pPlaybackLog->pHeader, pLogIndex->lDataOffset);

    for (iNumSystem = 0; iNumSystem < pLogIndex->iSystemsLogged; iNumSystem ++) {
        if (pPerfData && pPerfData->Signature[0] == (WCHAR)'P' &&
                         pPerfData->Signature[1] == (WCHAR)'E' &&
                         pPerfData->Signature[2] == (WCHAR)'R' &&
                         pPerfData->Signature[3] == (WCHAR)'F') {
            szLoggedComputerName = (LPWSTR) PointerSeek(pPerfData, pPerfData->SystemNameOffset);
            if (lpszSystemName == NULL) {
                pRtnBlock = pPerfData;
                break;
            }
            else if (lstrlenW(lpszSystemName) > 2 && lpszSystemName[0] == L'\\' && lpszSystemName[1] == L'\\') {
                if (lstrcmpiW(szLoggedComputerName, & (lpszSystemName[2])) == 0) {
                    pRtnBlock = pPerfData;
                    break;
                }
            }
            else if (lstrcmpiW(szLoggedComputerName, lpszSystemName) == 0) {
                pRtnBlock = pPerfData;
                break;
            }
            pPerfData = (PPERFDATA)((PBYTE) pPerfData + pPerfData->TotalByteLength);
        }
        else {
            break;
        }
    }
    return pRtnBlock;
}

PPERF_OBJECT_TYPE
PdhiFindPerfObject(
    PPERF_DATA_BLOCK pBlock,
    DWORD            dwObject
)
{
    DWORD             dwCount = pBlock->NumObjectTypes;
    PVOID             ptrEnd  = PointerSeek(pBlock, pBlock->TotalByteLength);
    PPERF_OBJECT_TYPE pObject = FirstObject(pBlock);

    while (pObject != NULL && ((PVOID) pObject < ptrEnd) && dwCount > 0) {
        dwCount --;
        if (pObject->ObjectNameTitleIndex == dwObject) break;
        pObject = (dwCount > 0) ? NextObject(pObject) : NULL;
        if ((PVOID) pObject >= ptrEnd) pObject = NULL;
    }
    return pObject;
}

PDH_FUNCTION
PdhiCachePmLogObject(
    PPLAYBACKLOG pPmLog,
    LPWSTR       szMachineName,
    LPWSTR       szObjectName
)
{
    PDH_STATUS                Status        = ERROR_SUCCESS;
    PPMLOG_COUNTERNAMES       pCounterTable = NULL;
    PPDHI_LOG_MACHINE         pLogMachine   = PdhiFindLogMachine(& pPmLog->MachineList, szMachineName, FALSE);
    PPDHI_LOG_OBJECT          pLogObject    = NULL;
    PPDHI_LOG_COUNTER         pLogCounter   = NULL;
    PPDHI_LOG_COUNTER         pLogInst;
    PPDHI_LOG_COUNTER         pLogInstHead;
    PPERF_DATA_BLOCK          pBlock;
    PPERF_OBJECT_TYPE         pObject;
    PPERF_OBJECT_TYPE         pParentObject;
    PPERF_COUNTER_DEFINITION  pCounter;
    PPERF_INSTANCE_DEFINITION pInstance;
    PPERF_INSTANCE_DEFINITION pParentInstance;
    LPWSTR                    szCounter;
    LPWSTR                    szInstance;
    LPWSTR                    szParent;
    DWORD                     dwInstance;
    DWORD                     dwParent;
    BOOL                      bInstance     = FALSE;
    DWORD                     i;
    PVOID                     ptrEnd;
    DWORD                     dwCount;
    DWORD                     dwCounterID;

    if (pLogMachine != NULL) {
        pLogObject = PdhiFindLogObject(pLogMachine, & pLogMachine->ObjTable, szObjectName, FALSE);
    }
    if (pLogObject == NULL) {
        Status = PDH_INVALID_ARGUMENT;
    }
    else if (pLogObject->bNeedExpand) {
        pCounterTable = pPmLog->pFirstCounterNameTables;
        while (pCounterTable != NULL) {
            if (lstrcmpiW(pCounterTable->szSystemName, szMachineName) == 0) break;
            pCounterTable = pCounterTable->pNext;
        }
        if (pCounterTable == NULL) {
            Status = PDH_INVALID_ARGUMENT;
            goto Cleanup;
        }

        for (i = 0; i < pPmLog->dwLastIndex; i ++) {
            pBlock = PdhiDataFromIndex(pPmLog, pPmLog->LogIndexTable[i], szMachineName);
            if (pBlock == NULL) continue;

            pObject = PdhiFindPerfObject(pBlock, pLogObject->dwObject);
            if (pObject == NULL) {
                continue;
            }
            else if (pObject->TotalByteLength <= sizeof(PERF_OBJECT_TYPE)
                    || pObject->DefinitionLength <= sizeof(PERF_OBJECT_TYPE)) {
                continue;
            }

            dwCount  = pObject->NumCounters;
            ptrEnd   = PointerSeek(pObject, pObject->DefinitionLength);
            pCounter = FirstCounter(pObject);
            while (pCounter != NULL && ((PVOID) pCounter < ptrEnd) && dwCount > 0) {
                dwCount --;
                szCounter = (LPWSTR) PdhiLookupLogPerfNameByIndex(pPmLog,
                                                                  szMachineName,
                                                                  pCounterTable->dwLangId,
                                                                  pCounter->CounterNameTitleIndex);
                if (szCounter != NULL) {
                    pLogCounter = PdhiFindPmCounterInstance(pLogObject,
                                                            szCounter,
                                                            pCounter->CounterType,
                                                            pCounter->DefaultScale,
                                                            NULL,
                                                            0,
                                                            NULL,
                                                            pCounter->CounterOffset,
                                                            & pCounter->CounterNameTitleIndex,
                                                            FALSE,
                                                            TRUE);
                    if (pLogCounter == NULL) {
                        Status = PDH_MEMORY_ALLOCATION_FAILURE;
                        break;
                    }
                    else if (pCounter->CounterType  & PERF_TIMER_100NS) {
                        pLogCounter->TimeBase = (LONGLONG) 10000000;
                    }
                    else if (pCounter->CounterType  & PERF_OBJECT_TIMER) {
                        // then get the time base freq from the object
                        pLogCounter->TimeBase = pObject->PerfFreq.QuadPart;
                    }
                    else { // if (pPerfCounter->CounterType & PERF_TIMER_TICK or other)
                        pLogCounter->TimeBase = pBlock->PerfFreq.QuadPart;
                    }
                }
                pCounter = NextCounter(pCounter);
                if ((PVOID) pCounter >= ptrEnd) pCounter = NULL;
            }
            if (Status != ERROR_SUCCESS) continue;

            dwCount   = pObject->NumInstances;
            bInstance = (dwCount != PERF_NO_INSTANCES) && (dwCount != 0);
            if (bInstance) {
                for (pLogCounter = pLogObject->InstList; pLogCounter != NULL; pLogCounter = pLogCounter->next) {
                    pLogCounter->dwCounterType = 0;
                }

                ptrEnd    = PointerSeek(pObject, pObject->TotalByteLength);
                pInstance = FirstInstance(pObject);
                while (pInstance != NULL && ((PVOID) pInstance < ptrEnd) && dwCount > 0) {
                    dwCount --;

                    szInstance = (pInstance->NameOffset != 0) ? (LPWSTR) PointerSeek(pInstance, pInstance->NameOffset)
                                                              : NULL;
                    dwInstance  = pInstance->UniqueID;
                    szParent    = NULL;
                    dwParent    = PERF_NO_UNIQUE_ID;
                    dwCounterID = 0;
                    if (pInstance->ParentObjectTitleIndex != 0) {
                        pParentObject = PdhiFindPerfObject(pBlock, pInstance->ParentObjectTitleIndex);
                        if (pParentObject != NULL && pParentObject->TotalByteLength > sizeof(PERF_OBJECT_TYPE)
                                                  && pParentObject->DefinitionLength > sizeof(PERF_OBJECT_TYPE)) {
                            pParentInstance = GetInstance(pParentObject, pInstance->ParentObjectInstance);
                            if (pParentInstance != NULL) {
                                szParent    = (pParentInstance->NameOffset != 0)
                                            ? (LPWSTR) PointerSeek(pParentInstance, pParentInstance->NameOffset) : NULL;
                                dwParent    = pParentInstance->UniqueID;
                                dwCounterID = 1;
                            }
                        }
                    }
                    if (PdhiFindPmCounterInstance(pLogObject, NULL, 0, 0,
                                    szInstance, dwInstance, szParent, dwParent, & dwCounterID, TRUE, TRUE) == NULL) {
                        Status = PDH_MEMORY_ALLOCATION_FAILURE;
                        break;
                    }

                    pInstance = NextInstance(pInstance);
                    if ((PVOID) pInstance >= ptrEnd) pInstance = NULL;
                }

            }

            if (pObject->NumInstances == PERF_NO_INSTANCES) break;
        }

        pLogInstHead          = pLogObject->InstList;
        pLogObject->InstList  = NULL;
        pLogObject->InstTable = NULL;
        for (pLogInst = pLogInstHead; pLogInst != NULL; pLogInst = pLogInst->next) {
            if (pLogInst->dwInstance != 0 && pLogInst->dwInstance != PERF_NO_UNIQUE_ID) {
                PdhiFindPmCounterInstance(pLogObject,
                                          NULL,
                                          0,
                                          0,
                                          pLogInst->szInstance,
                                          pLogInst->dwInstance,
                                          pLogInst->szParent,
                                          pLogInst->dwParent,
                                          & pLogInst->dwCounterID,
                                          TRUE,
                                          TRUE);
            }
            else {
                for (i = 0; i < pLogInst->dwDefaultScale; i ++) {
                    PdhiFindPmCounterInstance(pLogObject,
                                              NULL,
                                              0,
                                              0,
                                              pLogInst->szInstance,
                                              i,
                                              pLogInst->szParent,
                                              pLogInst->dwParent,
                                              & pLogInst->dwCounterID,
                                              TRUE,
                                              TRUE);
                }
            }
        }
        while (pLogInstHead != NULL) {
            pLogInst     = pLogInstHead;
            pLogInstHead = pLogInst->next;
            G_FREE(pLogInst);
        }

        pLogObject->bNeedExpand = FALSE;
    }

Cleanup:
    return Status;
}

PDH_FUNCTION
PdhiRewindPmLog(
    PPDHI_LOG    pLog,
    PPLAYBACKLOG pPmLog
)
{
    PDH_STATUS Status = ERROR_SUCCESS;

    if (pPmLog->dwFirstIndex == 0) {
        PLOGINDEX  pIndex = NULL;
        DWORD      i;
        for (i = 0; i < pPmLog->dwLastIndex; i ++) {
            pIndex = pPmLog->LogIndexTable[i];
            if ((pIndex->uFlags & LogFileIndexData) != 0) break;
        }

        if (i < pPmLog->dwLastIndex) {
            pPmLog->dwFirstIndex = i;
        }
    }
    if (pPmLog->dwFirstIndex != pPmLog->dwCurrentIndex) {
        pLog->dwLastRecordRead = pPmLog->dwFirstIndex;
        pPmLog->dwCurrentIndex = pPmLog->dwFirstIndex;
        pLog->pLastRecordRead  = PointerSeek(pPmLog->pHeader,
                                             pPmLog->LogIndexTable[pPmLog->dwFirstIndex]->lDataOffset);
    }
    return Status;
}

PDH_FUNCTION
PdhiOpenInputPerfmonLog(
    PPDHI_LOG pLog
)
{
    PDH_STATUS   pdhStatus  = ERROR_SUCCESS;
    PPLAYBACKLOG pPmPbLog   = (PPLAYBACKLOG) pLog->pPerfmonInfo;

    pLog->StreamFile = (FILE *) ((DWORD_PTR) (-1));

    // map file as a memory array for reading

    if (pLog->hMappedLogFile != NULL && pLog->lpMappedFileBase != NULL) {
        pLog->dwLastRecordRead = 0;
        pLog->pLastRecordRead  = NULL;
        pLog->pPerfmonInfo     = G_ALLOC(sizeof(PLAYBACKLOG));
        if (pLog->pPerfmonInfo != NULL) {
            pPmPbLog   = (PPLAYBACKLOG) pLog->pPerfmonInfo;
            // assumes structure was 0-init'd on allocation
            pPmPbLog->llFileSize              = pLog->llFileSize;
            pPmPbLog->szFilePath              = pLog->szLogFileName;
            pPmPbLog->pHeader                 = pLog->lpMappedFileBase;
            pPmPbLog->iTotalTics              = 1;
            pPmPbLog->dwFirstIndex            = 0;
            pPmPbLog->MachineList             = NULL;
            pPmPbLog->pFirstCounterNameTables = NULL;
            pdhStatus = PdhiBuildPmLogIndexTable(pPmPbLog);
            if (pdhStatus == ERROR_SUCCESS) {
                pdhStatus = PdhiRewindPmLog(pLog, pPmPbLog);
            }
        }
        else {
            pdhStatus = PDH_MEMORY_ALLOCATION_FAILURE;
        }
    }
    else {
        // return PDH Error
        pdhStatus = PDH_LOG_FILE_OPEN_ERROR;
    }
    return pdhStatus;
}

PDH_FUNCTION
PdhiClosePerfmonLog(
    PPDHI_LOG pLog,
    DWORD     dwFlags
)
{
    PDH_STATUS   pdhStatus    = ERROR_SUCCESS;
    PPLAYBACKLOG pPlaybackLog = (PPLAYBACKLOG) pLog->pPerfmonInfo;

    DBG_UNREFERENCED_PARAMETER(dwFlags);

    if (pPlaybackLog != NULL) {
        G_FREE(pPlaybackLog->LogIndexTable);
        PdhiFreeLogMachineTable(& pPlaybackLog->MachineList);
        PdhiFreePmMachineList(pPlaybackLog);
        G_FREE(pLog->pPerfmonInfo);
        pLog->pPerfmonInfo = NULL;
    }
    return pdhStatus;
}

PDH_FUNCTION
PdhiGetPerfmonLogCounterInfo(
    PPDHI_LOG       pLog,
    PPDHI_COUNTER   pCounter
)
{
    PDH_STATUS        pdhStatus    = PDH_LOG_FILE_OPEN_ERROR;
    PPLAYBACKLOG      pPlaybackLog = (PPLAYBACKLOG) pLog->pPerfmonInfo;
    PPDHI_LOG_MACHINE pLogMachine  = NULL;
    PPDHI_LOG_OBJECT  pLogObject   = NULL;
    PPDHI_LOG_COUNTER pLogCounter  = NULL;
    PPDHI_LOG_COUNTER pLogInstance = NULL;
    DWORD             dwCounter;

    PPERF_DATA_BLOCK           pPerfData              = NULL;
    PPERF_OBJECT_TYPE          pObjectDef;
    PPERF_COUNTER_DEFINITION   pPerfCounter;
    PPERF_INSTANCE_DEFINITION  pInstanceDef;
    DWORD                      dwObjectId             = 0;
    LOGPOSITION                LogPosition;
    LOGINDEX                 * pLogIndex;
    LPWSTR                   * pCounterNames          = NULL;
    DWORD                      dwLastCounterNameIndex = 0;
    BOOL                       bObjectNumber          = FALSE;

    if (pPlaybackLog != NULL) {
        pdhStatus = PdhiCachePmLogHeader(pPlaybackLog);
        if (pdhStatus == ERROR_SUCCESS) {
            pdhStatus = PdhiCachePmLogObject(pPlaybackLog,
                                             pCounter->pCounterPath->szMachineName,
                                             pCounter->pCounterPath->szObjectName);
        }
    }

    if (pdhStatus == ERROR_SUCCESS) {
        pLogMachine = PdhiFindLogMachine(& pPlaybackLog->MachineList, pCounter->pCounterPath->szMachineName, FALSE);
        pCounter->pThisRawItemList = (LPVOID) pLogMachine;
        if (pLogMachine != NULL) {
            pLogObject = PdhiFindLogObject(
                            pLogMachine, & pLogMachine->ObjTable, pCounter->pCounterPath->szObjectName, FALSE);
            pCounter->pLastRawItemList = (LPVOID) pLogObject;
            if (pLogObject == NULL) {
                pdhStatus = PDH_CSTATUS_NO_OBJECT;
            }
        }
        else {
            pdhStatus = PDH_CSTATUS_NO_MACHINE;
        }
    }
    if (pdhStatus == ERROR_SUCCESS) {
        pLogCounter  = PdhiFindPmCounterInstance(pLogObject,
                                                 pCounter->pCounterPath->szCounterName,
                                                 0,
                                                 0,
                                                 NULL,
                                                 0,
                                                 NULL,
                                                 0,
                                                 & dwCounter,
                                                 FALSE,
                                                 FALSE);
        pCounter->pThisObject = (LPVOID) pLogCounter;
        if (pCounter->pCounterPath->szInstanceName != NULL) {
            pLogInstance = PdhiFindPmCounterInstance(pLogObject,
                                                     NULL,
                                                     0,
                                                     0,
                                                     pCounter->pCounterPath->szInstanceName,
                                                     pCounter->pCounterPath->dwIndex,
                                                     pCounter->pCounterPath->szParentName,
                                                     0,
                                                     & dwCounter,
                                                     TRUE,
                                                     FALSE);
            pCounter->pLastObject = (LPVOID) pLogInstance;
        }
    }
    if (pLogCounter != NULL) {
        if (pCounter->pCounterPath->szInstanceName != NULL) {
            if (pLogInstance == NULL) {
                pdhStatus = PDH_CSTATUS_NO_INSTANCE;
            }
        }
        pCounter->plCounterInfo.dwObjectId           = pLogObject->dwObject;
        if (pLogInstance) {
            pCounter->plCounterInfo.lInstanceId      = (pLogInstance->szInstance == NULL)
                                                     ? pLogInstance->dwInstance : PERF_NO_UNIQUE_ID;
            pCounter->plCounterInfo.dwParentObjectId = pLogInstance->dwParent;
        }
        else {
            pCounter->plCounterInfo.lInstanceId      = PERF_NO_UNIQUE_ID;
            pCounter->plCounterInfo.dwParentObjectId = PERF_NO_UNIQUE_ID;
        }
        pCounter->plCounterInfo.szInstanceName       = pCounter->pCounterPath->szInstanceName;
        pCounter->plCounterInfo.szParentInstanceName = pCounter->pCounterPath->szParentName;
        pCounter->plCounterInfo.dwCounterId          = pLogCounter->dwCounterID;
        pCounter->plCounterInfo.dwCounterType        = pLogCounter->dwCounterType;
        pCounter->plCounterInfo.dwCounterSize        = pLogCounter->dwInstance;
        pCounter->plCounterInfo.lDefaultScale        = pLogCounter->dwDefaultScale;
        pCounter->TimeBase                           = pLogCounter->TimeBase;
    }
    else {
        pdhStatus = PDH_CSTATUS_NO_COUNTER;
    }

    return pdhStatus;    
}

PDH_FUNCTION
PdhiEnumMachinesFromPerfmonLog(
    PPDHI_LOG pLog,
    LPVOID    pBuffer,
    LPDWORD   pcchBufferSize,
    BOOL      bUnicodeDest
)
{
    PDH_STATUS   pdhStatus    = PDH_LOG_FILE_OPEN_ERROR;
    PPLAYBACKLOG pPlaybackLog = (PPLAYBACKLOG) pLog->pPerfmonInfo;

    if (pPlaybackLog != NULL) {
        pdhStatus = PdhiCachePmLogHeader(pPlaybackLog);
        if (pdhStatus == ERROR_SUCCESS) {
            pdhStatus = PdhiEnumCachedMachines(pPlaybackLog->MachineList, pBuffer, pcchBufferSize, bUnicodeDest);
        }
    }
    return pdhStatus;
}

PDH_FUNCTION
PdhiEnumObjectsFromPerfmonLog(
    PPDHI_LOG pLog,
    LPCWSTR   lpszSystemName,
    LPVOID    pBuffer,
    LPDWORD   pcchBufferSize,
    DWORD     dwDetailLevel,
    BOOL      bUnicodeDest
)
{
    PDH_STATUS   pdhStatus    = PDH_LOG_FILE_OPEN_ERROR;
    PPLAYBACKLOG pPlaybackLog = (PPLAYBACKLOG) pLog->pPerfmonInfo;

    if (pPlaybackLog != NULL) {
        pdhStatus = PdhiCachePmLogHeader(pPlaybackLog);
        if (pdhStatus == ERROR_SUCCESS) {
            pdhStatus = PdhiEnumCachedObjects(
                    pPlaybackLog->MachineList, lpszSystemName, pBuffer, pcchBufferSize, dwDetailLevel, bUnicodeDest);
        }
    }
    return pdhStatus;
}

PDH_FUNCTION
PdhiEnumObjectItemsFromPerfmonLog(
    PPDHI_LOG          pLog,
    LPCWSTR            szMachineName,
    LPCWSTR            szObjectName,
    PDHI_COUNTER_TABLE CounterTable,
    DWORD              dwDetailLevel,
    DWORD              dwFlags
)
{
    PDH_STATUS   pdhStatus    = PDH_LOG_FILE_OPEN_ERROR;
    PPLAYBACKLOG pPlaybackLog = (PPLAYBACKLOG) pLog->pPerfmonInfo;

    DBG_UNREFERENCED_PARAMETER(dwFlags);
    DBG_UNREFERENCED_PARAMETER(dwDetailLevel);

    if (pPlaybackLog != NULL) {
        pdhStatus = PdhiCachePmLogHeader(pPlaybackLog);
        if (pdhStatus == ERROR_SUCCESS) {
            pdhStatus = PdhiCachePmLogObject(pPlaybackLog, (LPWSTR) szMachineName, (LPWSTR) szObjectName);
        }
    }

    if (pdhStatus == ERROR_SUCCESS) {
        PPDHI_LOG_MACHINE pMachine       = NULL;
        PPDHI_LOG_OBJECT  pObject        = NULL;
        PPDHI_LOG_COUNTER pCtr           = NULL;
        PPDHI_LOG_COUNTER pInst          = NULL;
        PPDHI_INST_LIST   pFirstInstList = NULL;
        PPDHI_INST_LIST   pInstList      = NULL;
        PPDHI_INSTANCE    pInstance      = NULL;
        LONG              nCounterCount  = 0;
        LONG              nInstanceCount = 0;

        pMachine = PdhiFindLogMachine(& pPlaybackLog->MachineList, (LPWSTR) szMachineName, FALSE);
        if (pMachine == NULL) {
            pdhStatus = PDH_CSTATUS_NO_MACHINE;
        }
        else {
            pObject = PdhiFindLogObject(pMachine, & (pMachine->ObjTable), (LPWSTR) szObjectName, FALSE);
            if (pObject == NULL) {
                pdhStatus = PDH_CSTATUS_NO_OBJECT;
            }
        }
        if (pdhStatus == ERROR_SUCCESS) {
            for (pCtr = pObject->CtrList; pCtr != NULL; pCtr = pCtr->next) {
                pdhStatus = PdhiFindCounterInstList(CounterTable, pCtr->szCounter, & pInstList);
                if (pdhStatus != ERROR_SUCCESS) {
                    continue;
                }
                else {
                    nCounterCount ++;
                    if (pFirstInstList == NULL) {
                        pFirstInstList = pInstList;
                    }
                }
            }

            if (pFirstInstList != NULL) {
                pInst = pObject->InstList;
                if (pInst != NULL && pInst != PDH_INVALID_POINTER) {
                    LPWSTR szFullInstance = G_ALLOC(SMALL_BUFFER_SIZE * sizeof(WCHAR));
                    if (szFullInstance != NULL) {
                        while (pInst != NULL) {
                            ZeroMemory(szFullInstance, SMALL_BUFFER_SIZE * sizeof(WCHAR));
                            if (pInst->szInstance != NULL) {
                                if (pInst->dwCounterID != 0) {
                                    if (pInst->szParent != NULL) {
                                        if (pInst->dwInstance != 0 && pInst->dwInstance != PERF_NO_UNIQUE_ID) {
                                            swprintf(szFullInstance, L"%ws%ws%ws#%u",
                                                    pInst->szParent, cszSlash, pInst->szInstance, pInst->dwInstance);
                                        }
                                        else {
                                            swprintf(szFullInstance, L"%ws%ws%ws",
                                                    pInst->szParent, cszSlash, pInst->szInstance);
                                        }
                                    }
                                    else {
                                        if (pInst->dwInstance != 0 && pInst->dwInstance != PERF_NO_UNIQUE_ID) {
                                            swprintf(szFullInstance, L"%u%ws%ws#%u",
                                                    pInst->dwParent, cszSlash, pInst->szInstance, pInst->dwInstance);
                                        }
                                        else {
                                            swprintf(szFullInstance, L"%u%ws%ws",
                                                    pInst->dwParent, cszSlash, pInst->szInstance);
                                        }
                                    }
                                }
                                else if (pInst->dwInstance != 0 && pInst->dwInstance != PERF_NO_UNIQUE_ID) {
                                    swprintf(szFullInstance, L"%ws#%u",
                                            pInst->szInstance, pInst->dwInstance);
                                }
                                else {
                                    lstrcpynW(szFullInstance, pInst->szInstance, SMALL_BUFFER_SIZE - 1);
                                }
                            }
                            else if (pInst->dwCounterID != 0) {
                                if (pInst->szParent != NULL) {
                                    swprintf(szFullInstance, L"%ws%ws%u",
                                            pInst->szParent, cszSlash, pInst->dwInstance);
                                }
                                else {
                                    swprintf(szFullInstance, L"%u%ws%u",
                                            pInst->dwParent, cszSlash, pInst->dwInstance);
                                }
                            }
                            else {
                                swprintf(szFullInstance, L"%u", pInst->dwInstance);
                            }

                            pdhStatus = PdhiFindInstance(& pFirstInstList->InstList, szFullInstance, TRUE, & pInstance);
                            if (pdhStatus == ERROR_SUCCESS) {
                                nInstanceCount ++;
                            }
                            pInst = pInst->next;
                        }
                    }
                    else {
                        pdhStatus = PDH_MEMORY_ALLOCATION_FAILURE;
                    }
                }
            }

            if (nCounterCount == 0 && nInstanceCount == 0) {
                if (pdhStatus == ERROR_SUCCESS) {
                    pdhStatus = PDH_CSTATUS_NO_OBJECT;
                }
            }
            else if (pdhStatus != PDH_MORE_DATA) {
                // then the routine was successful. Errors that occurred
                // while scanning will be ignored as long as at least
                // one entry was successfully read

                pdhStatus = ERROR_SUCCESS;
            }
        }
    }
    return pdhStatus;
}

PDH_FUNCTION
PdhiGetMatchingPerfmonLogRecord(
    PPDHI_LOG   pLog,
    LONGLONG  * pStartTime,
    LPDWORD     pdwIndex
)
{
    PDH_STATUS       pdhStatus    = ERROR_SUCCESS;
    PPLAYBACKLOG     pPlaybackLog = (PPLAYBACKLOG) pLog->pPerfmonInfo;
    DWORD            dwThisIndex  = 0;
    DWORD            dwLastIndex  = 0;
    LONGLONG         llThisTime   = 0;
    PPERF_DATA_BLOCK pPerfData;
    FILETIME         ftGMT;

    if (pPlaybackLog == NULL) {
        pdhStatus = PDH_LOG_FILE_OPEN_ERROR;    // log is invalid
    }
    else {
        dwLastIndex = pPlaybackLog->dwFirstIndex;
        for (dwThisIndex = pPlaybackLog->dwFirstIndex; dwThisIndex < pPlaybackLog->dwLastIndex; dwThisIndex ++) {
            pPerfData = (PPERF_DATA_BLOCK) PointerSeek(
                    pPlaybackLog->pHeader, pPlaybackLog->LogIndexTable[dwThisIndex]->lDataOffset);
            if (pPerfData != NULL) {
                SystemTimeToFileTime(& pPerfData->SystemTime, & ftGMT);
                FileTimeToLocalFileTime(& ftGMT, (FILETIME *) & llThisTime);

                if (llThisTime == * pStartTime) {
                    // record found
                    break;
                }
                else if (llThisTime > * pStartTime) {
                    // go back one
                    dwThisIndex = dwLastIndex;
                    break;
                }
                else {
                    dwLastIndex = dwThisIndex;
                    // go to the next one
                }
            }
            else {
                dwLastIndex = dwThisIndex;
                // go to the next one
            }
        }
        if (dwThisIndex == pPlaybackLog->dwLastIndex) {
            // then there's no more records in the log
            pdhStatus = PDH_ENTRY_NOT_IN_LOG_FILE;
        }
    }
    if (pdhStatus == ERROR_SUCCESS) {
        if (pdwIndex != NULL) * pdwIndex = dwThisIndex;
        if (pLog->dwLastRecordRead != dwThisIndex) {
            pLog->dwLastRecordRead       = dwThisIndex;
            pPlaybackLog->dwCurrentIndex = dwThisIndex;
            pLog->pLastRecordRead        = PointerSeek(pPlaybackLog->pHeader,
                                                       pPlaybackLog->LogIndexTable[dwThisIndex]->lDataOffset);
        }
    }
    return pdhStatus;
}

DWORD
PdhiGetPmBaseCounterOffset(
    PPDHI_LOG_COUNTER pCounter,
    PPERF_OBJECT_TYPE pPerfObject
)
{
    DWORD dwReturn = pCounter->dwInstance;

    if (pCounter->dwInstance == 0) {
        PPERF_COUNTER_DEFINITION pPerfCounter = FirstCounter(pPerfObject);
        DWORD                    dwCounter    = pPerfObject->NumCounters;
        PVOID                    pEndGuard    = PointerSeek(pPerfObject, pPerfObject->DefinitionLength);

        while (pPerfCounter != NULL && dwCounter > 0) {
            dwCounter --;
            if (pPerfCounter->CounterNameTitleIndex == pCounter->dwCounterID) {
                pPerfCounter = NextCounter(pPerfCounter);
                if (pPerfCounter == NULL) break;
                if ((((LPVOID) pPerfCounter) < pEndGuard)
                                && ((pPerfCounter->CounterType & PERF_COUNTER_BASE) != 0)) {
                    dwReturn = pPerfCounter->CounterOffset;
                    break;
                }
            }
            if (((LPVOID) pPerfCounter) < pEndGuard) {
                pPerfCounter = NextCounter(pPerfCounter);
            }
            if (((LPVOID) pPerfCounter) >= pEndGuard) pPerfCounter = NULL;
        }
        pCounter->dwInstance = dwReturn;
    }
    return dwReturn;
}

PDH_FUNCTION
PdhiGetCounterValueFromPerfmonLog(
    PPDHI_LOG        pLog,
    DWORD            dwIndex,
    PPDHI_COUNTER    pCounter,
    PPDH_RAW_COUNTER pValue
)
{
    PDH_STATUS                pdhStatus    = ERROR_SUCCESS;
    PPLAYBACKLOG              pPlaybackLog = (PPLAYBACKLOG) pLog->pPerfmonInfo;
    PLOGINDEX                 pIndex       = NULL;
    PPERF_DATA_BLOCK          pPerfData    = NULL;
    PPERF_OBJECT_TYPE         pPerfObject  = NULL;
    PPERF_INSTANCE_DEFINITION pPerfInst    = NULL;
    PPERF_COUNTER_BLOCK       pCtrBlock    = NULL;
    LPVOID                    pEndGuard;
    PPDHI_LOG_MACHINE         pLogMachine  = (PPDHI_LOG_MACHINE) pCounter->pThisRawItemList;
    PPDHI_LOG_OBJECT          pLogObject   = (PPDHI_LOG_OBJECT)  pCounter->pLastRawItemList;
    PPDHI_LOG_COUNTER         pLogCounter  = (PPDHI_LOG_COUNTER) pCounter->pThisObject;
    PPDHI_LOG_COUNTER         pLogInstance = (PPDHI_LOG_COUNTER) pCounter->pLastObject;
    BOOL                      bReturn;
    DWORD                     LocalCType;
    DWORD                   * pdwData;
    UNALIGNED LONGLONG      * pllData;
    LPVOID                    pData        = NULL;
    FILETIME                  ftGMT;

    if (pPlaybackLog == NULL) {
        pdhStatus = PDH_LOG_FILE_OPEN_ERROR;    // log is invalid
    }
    else if (dwIndex < pPlaybackLog->dwFirstIndex) {
        // invalid dwIndex value
        pdhStatus = PDH_INVALID_ARGUMENT;
    }
    else if (dwIndex >= pPlaybackLog->dwLastIndex) {
        pdhStatus = PDH_NO_MORE_DATA;
    }
    else if (pLogMachine == NULL || pLogObject == NULL || pLogCounter == NULL) {
        pdhStatus = PDH_ENTRY_NOT_IN_LOG_FILE;
    }
    else {
        if (pLog->dwLastRecordRead != dwIndex) {
            pLog->dwLastRecordRead       = dwIndex;
            pPlaybackLog->dwCurrentIndex = dwIndex;
            pLog->pLastRecordRead        = PointerSeek(pPlaybackLog->pHeader,
                                                       pPlaybackLog->LogIndexTable[dwIndex]->lDataOffset);
        }
        pIndex = pPlaybackLog->LogIndexTable[dwIndex];
    }
    if (pdhStatus == ERROR_SUCCESS) {
        // find a matching system...
        if (pLogMachine->pBlock != NULL && pLogMachine->dwIndex == dwIndex) {
            pPerfData = pLogMachine->pBlock;
        }
        else {
            pPerfData = PdhiDataFromIndex(pPlaybackLog, pIndex, pCounter->pCounterPath->szMachineName);
            pLogMachine->pBlock  = pPerfData;
            pLogMachine->dwIndex = dwIndex;
        }

        if (pPerfData == NULL) {
            pdhStatus            = PDH_CSTATUS_NO_MACHINE;
            pLogObject->pObjData = NULL;
            pLogObject->dwIndex  = dwIndex;
        }
        else if (pLogObject->pObjData != NULL && pLogObject->dwIndex == dwIndex) {
            pPerfObject = pLogObject->pObjData;
        }
        else {
            pEndGuard           = PointerSeek(pPerfData, pPerfData->TotalByteLength);
            pPerfObject         = PdhiFindPerfObject(pPerfData, pLogObject->dwObject);
            pLogObject->dwIndex = dwIndex;
            if (pPerfObject != NULL && ((LPVOID) pPerfObject) < pEndGuard) {
                pLogObject->pObjData = pPerfObject;
            }
            else {
                pLogObject->pObjData = NULL;
                pdhStatus            = PDH_CSTATUS_NO_OBJECT;
            }
        }
    }
    if (pdhStatus == ERROR_SUCCESS) {
        pEndGuard = PointerSeek(pPerfObject, pPerfObject->TotalByteLength);
        if (pPerfObject->NumInstances == PERF_NO_INSTANCES) {
            pCtrBlock = (PPERF_COUNTER_BLOCK) PointerSeek(pPerfObject, pPerfObject->DefinitionLength);
            if (pCtrBlock != NULL && ((LPVOID) pCtrBlock) < pEndGuard) {
                pData = PointerSeek(pCtrBlock, pLogCounter->dwParent);
                if (pData >= pEndGuard) pData = NULL;
            }
        }
        else if (pLogInstance != NULL) {
            if (pLogInstance->szCounter != NULL && pLogInstance->dwCounterType == dwIndex) {
                pCtrBlock = (PPERF_COUNTER_BLOCK) pLogInstance->szCounter;
            }
            else {
                if (pCounter->plCounterInfo.lInstanceId == PERF_NO_UNIQUE_ID
                                && pCounter->pCounterPath->szInstanceName != NULL) {
                    pPerfInst = GetInstanceByName(pPerfData,
                                                  pPerfObject,
                                                  pCounter->pCounterPath->szInstanceName,
                                                  pCounter->pCounterPath->szParentName,
                                                  pCounter->pCounterPath->dwIndex);
                    if (pPerfInst == NULL && pCounter->pCounterPath->szInstanceName[0] >= L'0'
                                          && pCounter->pCounterPath->szInstanceName[0] <= L'9') {
                        LONG lInstanceId = (LONG) _wtoi(pCounter->pCounterPath->szInstanceName);
                        pPerfInst        = GetInstanceByUniqueId(pPerfObject, lInstanceId);
                    }
                }
                else {
                    pPerfInst = GetInstanceByUniqueId(pPerfObject, pCounter->plCounterInfo.lInstanceId);
                }
                if (((LPVOID) pPerfInst) >= pEndGuard) pPerfInst = NULL;
                if (pPerfInst != NULL) {
                    pCtrBlock = (PPERF_COUNTER_BLOCK) PointerSeek(pPerfInst, pPerfInst->ByteLength);
                    if (((LPVOID) pCtrBlock) >= pEndGuard) pCtrBlock = NULL;
                }
                pLogInstance->szCounter     = (LPVOID) pCtrBlock;
                pLogInstance->dwCounterType = dwIndex;
            }

            if (pCtrBlock != NULL) {
                pData = PointerSeek(pCtrBlock, pLogCounter->dwParent);
                if (pData >= pEndGuard) pData = NULL;
            }
            else {
                pdhStatus = PDH_CSTATUS_NO_INSTANCE;
            }
        }
        else {
            pdhStatus = PDH_CSTATUS_NO_INSTANCE;
        }
    }
    if (pdhStatus == ERROR_SUCCESS) {
        if (pData == NULL) {
            pdhStatus = PDH_INVALID_DATA;
        }
        else {
            // assume success
            bReturn = TRUE;

            // convert system time in GMT to Local File time
            SystemTimeToFileTime(& pPerfData->SystemTime, & ftGMT);
            FileTimeToLocalFileTime(& ftGMT, & pValue->TimeStamp);

            pValue->MultiCount = 1; // unless changed

            // load counter value based on counter type
            LocalCType = pCounter->plCounterInfo.dwCounterType;
            switch (LocalCType) {
            //
            // these counter types are loaded as:
            //      Numerator = Counter data from perf data block
            //      Denominator = Perf Time from perf data block
            //      (the time base is the PerfFreq)
            //
            case PERF_COUNTER_COUNTER:
            case PERF_COUNTER_QUEUELEN_TYPE:
            case PERF_SAMPLE_COUNTER:
                pValue->FirstValue  = (LONGLONG) (* (DWORD *) pData);
                pValue->SecondValue = pPerfData->PerfTime.QuadPart;
                break;

            case PERF_OBJ_TIME_TIMER:
                pValue->FirstValue  = (LONGLONG) (* (DWORD *) pData);
                pValue->SecondValue = pPerfObject->PerfTime.QuadPart;
                break;

            case PERF_COUNTER_100NS_QUEUELEN_TYPE:
                pllData             = (UNALIGNED LONGLONG *) pData;
                pValue->FirstValue  = * pllData;
                pValue->SecondValue = pPerfData->PerfTime100nSec.QuadPart;
                break;

            case PERF_COUNTER_OBJ_TIME_QUEUELEN_TYPE:
                pllData             = (UNALIGNED LONGLONG *) pData;
                pValue->FirstValue  = * pllData;
                pValue->SecondValue = pPerfObject->PerfTime.QuadPart;
                break;

            case PERF_COUNTER_TIMER:
            case PERF_COUNTER_TIMER_INV:
            case PERF_COUNTER_BULK_COUNT:
            case PERF_COUNTER_MULTI_TIMER:
            case PERF_COUNTER_LARGE_QUEUELEN_TYPE:
                pllData             = (UNALIGNED LONGLONG *) pData;
                pValue->FirstValue  = * pllData;
                pValue->SecondValue = pPerfData->PerfTime.QuadPart;
                if ((LocalCType & PERF_MULTI_COUNTER) == PERF_MULTI_COUNTER) {
                    pValue->MultiCount = (DWORD) * ++ pllData;
                }
                break;
            //
            //  These counters do not use any time reference
            //
            case PERF_COUNTER_RAWCOUNT:
            case PERF_COUNTER_RAWCOUNT_HEX:
                pValue->FirstValue  = (LONGLONG) (* (DWORD *) pData);
                pValue->SecondValue = 0;
                break;

            case PERF_COUNTER_LARGE_RAWCOUNT:
            case PERF_COUNTER_LARGE_RAWCOUNT_HEX:
                pValue->FirstValue  = * (LONGLONG *) pData;
                pValue->SecondValue = 0;
                break;
            //
            //  These counters use the 100 Ns time base in thier calculation
            //
            case PERF_100NSEC_TIMER:
            case PERF_100NSEC_TIMER_INV:
            case PERF_100NSEC_MULTI_TIMER:
            case PERF_100NSEC_MULTI_TIMER_INV:
                pllData             = (UNALIGNED LONGLONG *) pData;
                pValue->FirstValue  = * pllData;
                pValue->SecondValue = pPerfData->PerfTime100nSec.QuadPart;
                if ((LocalCType & PERF_MULTI_COUNTER) == PERF_MULTI_COUNTER) {
                    ++ pllData;
                    pValue->MultiCount = * (DWORD *) pllData;
                }
                break;
            //
            //  These counters use two data points, the one pointed to by
            //  pData and the one immediately after
            //
            case PERF_SAMPLE_FRACTION:
            case PERF_RAW_FRACTION:
                pdwData            = (DWORD *) pData;
                pValue->FirstValue = (LONGLONG) (* pdwData);
                // find the pointer to the base value in the structure
                PdhiGetPmBaseCounterOffset(pLogCounter, pPerfObject);
                if (pLogCounter->dwInstance > 0) {
                    pData               = PointerSeek(pCtrBlock, pLogCounter->dwInstance);
                    pdwData             = (DWORD *) pData;
                    pValue->SecondValue = (LONGLONG) (* pdwData);
                }
                else {
                    // unable to locate base value
                    pValue->SecondValue = 0;
                    bReturn             = FALSE;
                }
                break;

            case PERF_PRECISION_SYSTEM_TIMER:
            case PERF_PRECISION_100NS_TIMER:
            case PERF_PRECISION_OBJECT_TIMER:
                pllData            = (LONGLONG *) pData;
                pValue->FirstValue = * pllData;
                // find the pointer to the base value in the structure
                PdhiGetPmBaseCounterOffset(pLogCounter, pPerfObject);
                if (pLogCounter->dwInstance > 0) {
                    pData               = PointerSeek(pCtrBlock, pLogCounter->dwInstance);
                    pllData             = (LONGLONG *) pData;
                    pValue->SecondValue = * pllData;
                }
                else {
                    // unable to locate base value
                    pValue->SecondValue = 0;
                    bReturn             = FALSE;
                }
                break;

            case PERF_AVERAGE_TIMER:
            case PERF_AVERAGE_BULK:
                // counter (numerator) is a LONGLONG, while the
                // denominator is just a DWORD
                pllData            = (UNALIGNED LONGLONG *) pData;
                pValue->FirstValue = * pllData;
                PdhiGetPmBaseCounterOffset(pLogCounter, pPerfObject);
                if (pLogCounter->dwInstance > 0) {
                    pData               = PointerSeek(pCtrBlock, pLogCounter->dwInstance);
                    pdwData             = (DWORD *) pData;
                    pValue->SecondValue = * pdwData;
                }
                else {
                    pValue->SecondValue = 0;
                    bReturn             = FALSE;
                }
                break;
            //
            //  These counters are used as the part of another counter
            //  and as such should not be used, but in case they are
            //  they'll be handled here.
            //
            case PERF_SAMPLE_BASE:
            case PERF_AVERAGE_BASE:
            case PERF_COUNTER_MULTI_BASE:
            case PERF_RAW_BASE:
                pValue->FirstValue  = 0;
                pValue->SecondValue = 0;
                break;

            case PERF_ELAPSED_TIME:
                // this counter type needs the object perf data as well
                pValue->SecondValue = pPerfObject->PerfTime.QuadPart;
                pCounter->TimeBase  = pPerfObject->PerfFreq.QuadPart;
                pllData            = (UNALIGNED LONGLONG *) pData;
                pValue->FirstValue = *pllData;
                break;
            //
            //  These counters are not supported by this function (yet)
            //
            case PERF_COUNTER_TEXT:
            case PERF_COUNTER_NODATA:
            case PERF_COUNTER_HISTOGRAM_TYPE:
                pValue->FirstValue  = 0;
                pValue->SecondValue = 0;
                break;

            default:
                // an unidentified counter was returned so
                pValue->FirstValue  = 0;
                pValue->SecondValue = 0;
                bReturn             = FALSE;
                break;
            }
            pValue->CStatus = PDH_CSTATUS_VALID_DATA;
        }
    }
    return pdhStatus;
}

PDH_FUNCTION
PdhiGetTimeRangeFromPerfmonLog(
    PPDHI_LOG       pLog,
    LPDWORD         pdwNumEntries,
    PPDH_TIME_INFO  pInfo,
    LPDWORD         pdwBufferSize
)
/*++
    the first entry in the buffer returned is the total time range covered
    in the file, if there are multiple time blocks in the log file, then
    subsequent entries will identify each segment in the file.
--*/
{
    PDH_STATUS       pdhStatus     = ERROR_SUCCESS;
    PPLAYBACKLOG     pPlaybackLog  = (PLAYBACKLOG *) pLog->pPerfmonInfo;
    PDH_TIME_INFO    LocalTimeInfo = {0,0,0}; 
    PPERF_DATA_BLOCK pPerfData;
    FILETIME         ftGMT;

    if (pPlaybackLog == NULL) {
        pdhStatus = PDH_INVALID_HANDLE;    // log is invalid
    }
    else {
        pPerfData = (PPERF_DATA_BLOCK) PointerSeek(
                pPlaybackLog->pHeader, pPlaybackLog->LogIndexTable[pPlaybackLog->dwFirstIndex]->lDataOffset);
        if (pPerfData != NULL) {
            SystemTimeToFileTime(& pPerfData->SystemTime, & ftGMT);
            FileTimeToLocalFileTime(& ftGMT, (FILETIME *) & LocalTimeInfo.StartTime);
        }
        else {
            pdhStatus = PDH_NO_DATA;
        }

        pPerfData = (PPERF_DATA_BLOCK) PointerSeek(
                pPlaybackLog->pHeader, pPlaybackLog->LogIndexTable[pPlaybackLog->dwLastIndex - 1]->lDataOffset);
        if (pPerfData != NULL) {
            SystemTimeToFileTime(& pPerfData->SystemTime, & ftGMT);
            FileTimeToLocalFileTime(& ftGMT, (FILETIME *) & LocalTimeInfo.EndTime);
        }
        else {
            pdhStatus = PDH_NO_DATA;
        }
    }
    if (pdhStatus == ERROR_SUCCESS) {
        LocalTimeInfo.SampleCount = pPlaybackLog->dwLastIndex - pPlaybackLog->dwFirstIndex;
        if (pInfo != NULL && * pdwBufferSize >= sizeof(PDH_TIME_INFO)) {
            * pdwNumEntries = 1;
            * pInfo         = LocalTimeInfo;
            * pdwBufferSize = sizeof(PDH_TIME_INFO);
            pdhStatus       = ERROR_SUCCESS;
        }
        else {
            * pdwBufferSize = sizeof(PDH_TIME_INFO);
            pdhStatus       = PDH_MORE_DATA;
        }
    }
    return pdhStatus;
}

PDH_FUNCTION
PdhiReadRawPerfmonLogRecord(
    PPDHI_LOG             pLog,
    FILETIME            * ftRecord,
    PPDH_RAW_LOG_RECORD   pBuffer,
    LPDWORD               pdwBufferLength
)
{
    PDH_STATUS  pdhStatus = PDH_NOT_IMPLEMENTED;

    DBG_UNREFERENCED_PARAMETER(pLog);
    DBG_UNREFERENCED_PARAMETER(ftRecord);
    DBG_UNREFERENCED_PARAMETER(pBuffer);
    DBG_UNREFERENCED_PARAMETER(pdwBufferLength);

    return pdhStatus;
}