GetSingleInstanceCounter

GetSingleInstanceCounter.cs

[DllImport("pdh.dll", SetLastError = true, CharSet = CharSet.Unicode)]
static extern UInt32 PdhLookupPerfNameByIndex(string szMachineName, uint dwNameIndex, StringBuilder szNameBuffer, ref uint pcchNameBufferSize);

PerformanceCounter GetSingleInstanceCounter(string englishCategoryName, string englishCounterName)
{
    // Try first with english names
    try
    {
        return new PerformanceCounter(englishCategoryName, englishCounterName);
    }
    catch { }

    // Get list of counters
    const string perfCountersKey = @"HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Perflib\009";
    var englishNames = Registry.GetValue(perfCountersKey, "Counter", null) as string[];

    // Get localized category name
    var localizedCategoryId = FindNameId(englishNames, englishCategoryName);
    var localizedCategoryName = GetNameByIndex(localizedCategoryId);

    // Get localized counter name
    var localizedCounterId = FindNameId(englishNames, englishCounterName);
    var localizedCounterName = GetNameByIndex(localizedCounterId);

    return GetCounterIfExists(localizedCategoryName, localizedCounterName) ??
           GetCounterIfExists(localizedCategoryName, englishCounterName) ??
           GetCounterIfExists(englishCategoryName, localizedCounterName);
}

PerformanceCounter GetCounterIfExists(string categoryName, string counterName)
{
    try
    {
        return new PerformanceCounter(categoryName, counterName);
    }
    catch
    {
        return null;
    }
}

int FindNameId(string[] englishNames, string name)
{
    // englishNames contains alternately id and name, that's why I check only odd lines
    for (int i = 1; i < englishNames.Length; i += 2) 
    {
        if (englishNames[i] == name)
        {
            return Int32.Parse(englishNames[i - 1]);
        }
    }

    return -1;
}

string GetNameByIndex(int id)
{
    if (id < 0)
    {
        return null;
    }

    var buffer = new StringBuilder(1024);
    var bufSize = (uint)buffer.Capacity;
    var ret = PdhLookupPerfNameByIndex(null, (uint)id, buffer, ref bufSize);

    return ret == 0 && buffer.Length != 0 ? buffer.ToString() : null;
}