Get a Performance Counter using English name

Get a single-instance PerformanceCounter

Each counter has its own category and name (sometimes also an instance name). To read performance data, we can create an instance like this:

var counter = new PerformanceCounter("IPv4", "Datagrams/sec");

Unfortunately those names in parameters depend on system language. However, there is a way to get the PerformanceCounter knowing only the English name.

Get localized names

WinAPI function PdhLookupPerfNameByIndex gets a localized name, although we need to know first what’s the PerformanceCounter’s ID (which can be different on each computer).

Fortunately the list with English names and IDs is stored in registry value:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Perflib\009\Counter

It looks like this:

ID
ENGLISH_NAME
ID
ENGLISH_NAME
...

One more issue

While listing counters names I noticed, that for some categories they are localized and for some they are in English. This means we can’t rely on localized names – just in case we have to check all possible combinations of localized and non-localized names.

Source code

[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;
}

[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;

}

More information: MSDN – Using PDH APIs correctly in a localized language