/*++

Copyright (c) 1995-6  Microsoft Corporation

Module Name:

    perfutil.c

Abstract:

    This file implements the utility routines used to construct the
    common parts of a PERF_INSTANCE_DEFINITION (see winperf.h) and
    perform event logging functions.

Created:

    Bob Watson  28-Jul-1995

Revision History:

--*/
//
//  include files
//
#include <nt.h>
#include <ntrtl.h>
#include <nturtl.h>
#include <windows.h>
#include <string.h>
#include <winperf.h>
#include "perfutil.h"
#include "perfmsg.h"

//
// Global data definitions.
//

ULONG ulInfoBufferSize = 0;

extern HANDLE hEventLog;      // event log handle for reporting events
                              // initialized in Open... routines
DWORD  dwLogUsers = 0;        // count of functions using event log

DWORD MESSAGE_LEVEL = 0;

const WCHAR GLOBAL_STRING[] = L"Global";
const WCHAR FOREIGN_STRING[] = L"Foreign";
const WCHAR COSTLY_STRING[] = L"Costly";

const WCHAR NULL_STRING[] = L"\0";    // pointer to null string

const WCHAR  szTotalValue[] = L"TotalInstanceName";
const WCHAR  szDefaultTotalString[] = L"_Total";

// test for delimiter, end of line and non-digit characters
// used by IsNumberInUnicodeList routine
//
#define DIGIT       1
#define DELIMITER   2
#define INVALID     3

#define EvalThisChar(c,d) ( \
     (c == d) ? DELIMITER : \
     (c == 0) ? DELIMITER : \
     (c < (WCHAR)'0') ? INVALID : \
     (c > (WCHAR)'9') ? INVALID : \
     DIGIT)


LONG
GetPerflibKeyValue (
    LPCWSTR szItem,
    DWORD   dwRegType,
    DWORD   dwMaxSize,      // ... of pReturnBuffer in bytes
    LPVOID  pReturnBuffer,
    DWORD   dwDefaultSize,  // ... of pDefault in bytes
    LPVOID  pDefault
)
/*++

    read and return the current value of the specified value
    under the Perflib registry key. If unable to read the value
    return the default value from the argument list.

    the value is returned in the pReturnBuffer.

--*/
{

    HKEY                    hPerflibKey;
    OBJECT_ATTRIBUTES       Obja;
    NTSTATUS                Status;
    UNICODE_STRING          PerflibSubKeyString;
    UNICODE_STRING          ValueNameString;
    LONG                    lReturn = ERROR_SUCCESS;
    PKEY_VALUE_PARTIAL_INFORMATION  pValueInformation, pBuffer;
    DWORD                   ValueBufferLength;
    DWORD                   ResultLength;
    BOOL                    bUseDefault = TRUE;

    // initialize UNICODE_STRING structures used in this function

    RtlInitUnicodeString (
        &PerflibSubKeyString,
        (LPCWSTR)L"\\Registry\\Machine\\SOFTWARE\\Microsoft\\Windows NT\\CurrentVersion\\Perflib");

    RtlInitUnicodeString (
        &ValueNameString,
        (LPWSTR)szItem);

    //
    // Initialize the OBJECT_ATTRIBUTES structure and open the key.
    //
    InitializeObjectAttributes(
            &Obja,
            &PerflibSubKeyString,
            OBJ_CASE_INSENSITIVE,
            NULL,
            NULL
            );

    Status = NtOpenKey(
                &hPerflibKey,
                KEY_READ,
                &Obja
                );

    if (NT_SUCCESS( Status )) {
        // read value of desired entry

        ValueBufferLength = ResultLength = 1024;
        pValueInformation = ALLOCMEM(RtlProcessHeap(), 0, ResultLength);

        if (pValueInformation != NULL) {
            while ( (Status = NtQueryValueKey(hPerflibKey,
                                            &ValueNameString,
                                            KeyValuePartialInformation,
                                            pValueInformation,
                                            ValueBufferLength,
                                            &ResultLength))
                    == STATUS_BUFFER_OVERFLOW ) {

                pBuffer = pValueInformation;
                pValueInformation = REALLOCMEM(RtlProcessHeap(), 0,
                                                        pValueInformation,
                                                        ResultLength);
                if ( pValueInformation == NULL) {
                    FREEMEM(RtlProcessHeap(), 0, pBuffer);
                    break;
                } else {
                    ValueBufferLength = ResultLength;
                }
            }

            if (NT_SUCCESS(Status)) {
                // check to see if it's the desired type
                if (pValueInformation->Type == dwRegType) {
                    // see if it will fit
                    if (pValueInformation->DataLength <= dwMaxSize) {
                        memcpy (pReturnBuffer, &pValueInformation->Data[0],
                            pValueInformation->DataLength);
                        bUseDefault = FALSE;
                        lReturn = STATUS_SUCCESS;
                    }
                }
            } else {
                // return the default value
                lReturn = Status;
            }
            // release temp buffer
            FREEMEM (RtlProcessHeap(), 0, pValueInformation);
        } else {
            // unable to allocate memory for this operation so
            // just return the default value
        }
        // close the registry key
        NtClose(hPerflibKey);
    } else {
        // return default value
    }

    if (bUseDefault) {
        memcpy (pReturnBuffer, pDefault, dwDefaultSize);
        lReturn = STATUS_SUCCESS;
    }

    return lReturn;
}

HANDLE
MonOpenEventLog (
    IN  LPWSTR  szAppName
)
/*++

Routine Description:

    Reads the level of event logging from the registry and opens the
        channel to the event logger for subsequent event log entries.

Arguments:

      None

Return Value:

    Handle to the event log for reporting events.
    NULL if open not successful.

--*/
{
    HKEY hAppKey;
    TCHAR LogLevelKeyName[] = TEXT("SOFTWARE\\Microsoft\\Windows NT\\CurrentVersion\\Perflib");
    TCHAR LogLevelValueName[] = TEXT("EventLogLevel");

    LONG lStatus;

    DWORD dwLogLevel;
    DWORD dwValueType;
    DWORD dwValueSize;

    // if global value of the logging level not initialized or is disabled,
    //  check the registry to see if it should be updated.

    if (!MESSAGE_LEVEL) {

       lStatus = RegOpenKeyEx (HKEY_LOCAL_MACHINE,
                               LogLevelKeyName,
                               0,
                               KEY_READ,
                               &hAppKey);

       dwValueSize = sizeof (dwLogLevel);

       if (lStatus == ERROR_SUCCESS) {
            lStatus = RegQueryValueEx (hAppKey,
                               LogLevelValueName,
                               (LPDWORD)NULL,
                               &dwValueType,
                               (LPBYTE)&dwLogLevel,
                               &dwValueSize);

            if (lStatus == ERROR_SUCCESS) {
               MESSAGE_LEVEL = dwLogLevel;
            } else {
               MESSAGE_LEVEL = MESSAGE_LEVEL_DEFAULT;
            }
            RegCloseKey (hAppKey);
       } else {
         MESSAGE_LEVEL = MESSAGE_LEVEL_DEFAULT;
       }
    }

    if (hEventLog == NULL){
         hEventLog = RegisterEventSourceW (
            (LPTSTR)NULL,            // Use Local Machine
            szAppName);               // event log app name to find in registry
    }

    if (hEventLog != NULL) {
         dwLogUsers++;           // increment count of perfctr log users
    }
    return (hEventLog);
}


VOID
MonCloseEventLog (
)
/*++

Routine Description:

      Closes the handle to the event logger if this is the last caller

Arguments:

      None

Return Value:

      None

--*/
{
    if (hEventLog != NULL) {
        dwLogUsers--;         // decrement usage
        if (dwLogUsers <= 0) {    // and if we're the last, then close up log
            DeregisterEventSource (hEventLog);
        }
    }
}

DWORD
GetQueryType (
    IN LPWSTR lpValue
)
/*++

GetQueryType

    returns the type of query described in the lpValue string so that
    the appropriate processing method may be used

Arguments

    IN lpValue
        string passed to PerfRegQuery Value for processing

Return Value

    QUERY_GLOBAL
        if lpValue == 0 (null pointer)
           lpValue == pointer to Null string
           lpValue == pointer to "Global" string

    QUERY_FOREIGN
        if lpValue == pointer to "Foriegn" string

    QUERY_COSTLY
        if lpValue == pointer to "Costly" string

    otherwise:

    QUERY_ITEMS

--*/
{
    WCHAR   *pwcArgChar, *pwcTypeChar;
    BOOL    bFound;

    if (lpValue == 0) {
        return QUERY_GLOBAL;
    } else if (*lpValue == 0) {
        return QUERY_GLOBAL;
    }

    // check for "Global" request

    pwcArgChar = lpValue;
    pwcTypeChar = (LPWSTR)GLOBAL_STRING;
    bFound = TRUE;  // assume found until contradicted

    // check to the length of the shortest string

    while ((*pwcArgChar != 0) && (*pwcTypeChar != 0)) {
        if (*pwcArgChar++ != *pwcTypeChar++) {
            bFound = FALSE; // no match
            break;          // bail out now
        }
    }

    if (bFound) return QUERY_GLOBAL;

    // check for "Foreign" request

    pwcArgChar = lpValue;
    pwcTypeChar = (LPWSTR)FOREIGN_STRING;
    bFound = TRUE;  // assume found until contradicted

    // check to the length of the shortest string

    while ((*pwcArgChar != 0) && (*pwcTypeChar != 0)) {
        if (*pwcArgChar++ != *pwcTypeChar++) {
            bFound = FALSE; // no match
            break;          // bail out now
        }
    }

    if (bFound) return QUERY_FOREIGN;

    // check for "Costly" request

    pwcArgChar = lpValue;
    pwcTypeChar = (LPWSTR)COSTLY_STRING;
    bFound = TRUE;  // assume found until contradicted

    // check to the length of the shortest string

    while ((*pwcArgChar != 0) && (*pwcTypeChar != 0)) {
        if (*pwcArgChar++ != *pwcTypeChar++) {
            bFound = FALSE; // no match
            break;          // bail out now
        }
    }

    if (bFound) return QUERY_COSTLY;

    // if not Global and not Foreign and not Costly,
    // then it must be an item list

    return QUERY_ITEMS;

}

BOOL
IsNumberInUnicodeList (
    IN DWORD   dwNumber,
    IN LPWSTR  lpwszUnicodeList
)
/*++

IsNumberInUnicodeList

Arguments:

    IN dwNumber
        DWORD number to find in list

    IN lpwszUnicodeList
        Null terminated, Space delimited list of decimal numbers

Return Value:

    TRUE:
            dwNumber was found in the list of unicode number strings

    FALSE:
            dwNumber was not found in the list.

--*/
{
    DWORD   dwThisNumber;
    WCHAR   *pwcThisChar;
    BOOL    bValidNumber;
    BOOL    bNewItem;
    WCHAR   wcDelimiter;    // could be an argument to be more flexible
    BOOL    bNotDone;
    BOOL    bReturnValue = FALSE;

    if (lpwszUnicodeList == 0) return FALSE;    // null pointer, # not founde

    pwcThisChar = lpwszUnicodeList;
    dwThisNumber = 0;
    wcDelimiter = (WCHAR)' ';
    bValidNumber = FALSE;
    bNewItem = TRUE;
    bNotDone = TRUE;

    while ( bNotDone ) {
        switch (EvalThisChar (*pwcThisChar, wcDelimiter)) {
            case DIGIT:
                // if this is the first digit after a delimiter, then
                // set flags to start computing the new number
                if (bNewItem) {
                    bNewItem = FALSE;
                    bValidNumber = TRUE;
                }
                if (bValidNumber) {
                    dwThisNumber *= 10;
                    dwThisNumber += (*pwcThisChar - (WCHAR)'0');
                }
                break;

            case DELIMITER:
                // a delimter is either the delimiter character or the
                // end of the string ('\0') if when the delimiter has been
                // reached a valid number was found, then compare it to the
                // number from the argument list. if this is the end of the
                // string and no match was found, then return.
                //
                if (bValidNumber) {
                    if (dwThisNumber == dwNumber) {
                        bNotDone = FALSE;
                        bReturnValue = TRUE;
                    } else {
                        bValidNumber = FALSE;
                    }
                }
                if (*pwcThisChar == 0) {
                    bNotDone = FALSE;
                } else {
                    bNewItem = TRUE;
                    dwThisNumber = 0;
                }
                break;

            case INVALID:
                // if an invalid character was encountered, ignore all
                // characters up to the next delimiter and then start fresh.
                // the invalid number is not compared.
                bValidNumber = FALSE;
                break;

            default:
                break;

        }
        pwcThisChar++;
    }
    return bReturnValue;
}   // IsNumberInUnicodeList


BOOL
MonBuildInstanceDefinition(
    PERF_INSTANCE_DEFINITION *pBuffer,
    PVOID *pBufferNext,
    DWORD ParentObjectTitleIndex,
    DWORD ParentObjectInstance,
    DWORD UniqueID,
    LPWSTR Name
    )
/*++

    MonBuildInstanceDefinition  -   Build an instance of an object

        Inputs:

            pBuffer         -   pointer to buffer where instance is to
                                be constructed

            pBufferNext     -   pointer to a pointer which will contain
                                next available location, DWORD aligned

            ParentObjectTitleIndex
                            -   Title Index of parent object type; 0 if
                                no parent object

            ParentObjectInstance
                            -   Index into instances of parent object
                                type, starting at 0, for this instances
                                parent object instance

            UniqueID        -   a unique identifier which should be used
                                instead of the Name for identifying
                                this instance

            Name            -   Name of this instance
--*/
{
    DWORD NameLength;
    LPWSTR pName;
    //
    //  Include trailing null in name size
    //

    NameLength = (lstrlenW(Name) + 1) * sizeof(WCHAR);

    pBuffer->ByteLength = sizeof(PERF_INSTANCE_DEFINITION) +
                            NameLength;

    pBuffer->ParentObjectTitleIndex = ParentObjectTitleIndex;
    pBuffer->ParentObjectInstance = ParentObjectInstance;
    pBuffer->UniqueID = UniqueID;
    pBuffer->NameOffset = sizeof(PERF_INSTANCE_DEFINITION);
    pBuffer->NameLength = NameLength;

    // copy name to name buffer
    pName = (LPWSTR)&pBuffer[1];
    memcpy(pName,Name,NameLength);

    // update "next byte" pointer
    *pBufferNext = (PVOID) ((PCHAR) pBuffer + pBuffer->ByteLength);

    // round up to put next buffer on a QUADWORD boundry
    *pBufferNext = ALIGN_ON_QWORD (*pBufferNext);
    // adjust length value to match new length
    pBuffer->ByteLength = (ULONG)((ULONG_PTR)*pBufferNext - (ULONG_PTR)pBuffer);

    return 0;
}