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

#ifndef WIN32_LEAN_AND_MEAN
#define WIN32_LEAN_AND_MEAN
#endif

#include <windows.h>
#include <stdlib.h>
#include <winperf.h>
#include <tchar.h>
#pragma hdrstop
#include "Titledb.h"

CPerfTitleDatabase::CPerfTitleDatabase(
        PERFORMANCE_TITLE_TYPE titleType )
{
    m_nLastIndex = 0;
    m_TitleStrings = 0;
    m_pszRawStrings = 0;

    // Determine the appropriate strings to pass to RegOpenKeyEx
    PTSTR psz009RegValue, pszLastIndexRegValue;
    if ( PERF_TITLE_COUNTER == titleType )
    {
        psz009RegValue = TEXT("Counter 009");
        pszLastIndexRegValue = TEXT("Last Counter");
    }
    else if ( PERF_TITLE_EXPLAIN == titleType )
    {
        psz009RegValue = TEXT("Explain 009");
        pszLastIndexRegValue = TEXT("Last Help");
    }
    else
        return;

    // Find out the max number of entries
    HKEY hKeyPerflib = 0;
    DWORD cbLastIndex;
    
    // Open the registry key that has the values for the maximum number
    // of title strings
    if ( ERROR_SUCCESS != RegOpenKeyEx(
            HKEY_LOCAL_MACHINE,
            TEXT("software\\microsoft\\windows nt\\currentversion\\perflib"),
            0, KEY_READ, &hKeyPerflib ) )
        return;

    // Read in the number of title strings
    if ( ERROR_SUCCESS != RegQueryValueEx(
                hKeyPerflib, pszLastIndexRegValue, 0, 0,
                (PBYTE)&m_nLastIndex, &cbLastIndex ) )
    {
        RegCloseKey( hKeyPerflib );
        return;
    }
    
    RegCloseKey( hKeyPerflib );
    
    //
    // Now go find and process the raw string data
    //

    // Determine how big the raw data in the REG_MULTI_SZ value is
    DWORD cbTitleStrings;
    if ( ERROR_SUCCESS != RegQueryValueEx( HKEY_PERFORMANCE_DATA, psz009RegValue, 0,0,0, &cbTitleStrings))
        return;

    // Allocate memory for the raw registry title string data
    m_pszRawStrings = new TCHAR[cbTitleStrings];
    
    // Read in the raw title strings
    if ( ERROR_SUCCESS != RegQueryValueEx( HKEY_PERFORMANCE_DATA,
                            psz009RegValue, 0, 0, (PBYTE)m_pszRawStrings,
                            &cbTitleStrings ) )
    {
        delete []m_pszRawStrings;
        return;
    }

    // allocate memory for an array of string pointers.
    m_TitleStrings = new PTSTR[ m_nLastIndex+1 ];
    if ( !m_TitleStrings )
    {
        delete []m_pszRawStrings;
        return;
    }

    // Initialize the m_TitleStrings to all NULLs, since there may
    // be some array slots that aren't used.
    memset( m_TitleStrings, 0, sizeof(PTSTR) * (m_nLastIndex+1) );

    // The raw data entries are an ASCII string index (e.g., "242"), followed
    // by the corresponding string.  Fill in the appropriate slot in the
    // m_TitleStrings array with the pointer to the string name.  The end
    // of the list is indicated by a double NULL.

    PTSTR pszWorkStr = (PTSTR)m_pszRawStrings;
    unsigned cbCurrStr;

    // While the length of the current string isn't 0...
    while ( 0 != (cbCurrStr = lstrlen( pszWorkStr)) )
    {
        // Convert the first string to a binary representation
        unsigned index = _ttoi( pszWorkStr );   // _ttoi -> atoi()

        if ( index > m_nLastIndex )
            break;
        
        // Now point to the string following it.  This is the title string
        pszWorkStr += cbCurrStr + 1;

        // Fill in the appropriate slot in the title strings array.
        m_TitleStrings[index] = pszWorkStr;
        
        // Advance to the next index/title pair
        pszWorkStr += lstrlen(pszWorkStr) + 1;
    }
}

CPerfTitleDatabase::~CPerfTitleDatabase( )
{
    delete []m_TitleStrings;
    m_TitleStrings = 0;
    delete []m_pszRawStrings;
    m_pszRawStrings = 0;
    m_nLastIndex = 0;
}
    
PTSTR
CPerfTitleDatabase::GetTitleStringFromIndex( unsigned index )
{
    if ( index > m_nLastIndex ) // Is index within range?
        return 0;
    
    return m_TitleStrings[ index ];
}

unsigned
CPerfTitleDatabase::GetIndexFromTitleString( PCTSTR pszTitleString )
{
    if ( IsBadStringPtr(pszTitleString, 0xFFFFFFFF) )
        return 0;

    // Loop through all the non-null string array entries, doing a case-
    // insensitive comparison.  If found, return the correpsonding index
    for ( unsigned i = 1; i <= m_nLastIndex; i++ )
    {
        if ( m_TitleStrings[i] )
            if ( 0 == _tcsicmp( pszTitleString, m_TitleStrings[i] ) )
                return i;
    }
    
    return 0;
}
