// Will cause an update, raw value
/// <summary>
/// Obtains a counter sample and returns the raw value for it.
/// </summary>
public CounterSample NextSample()
{
Initialize();
using (var categorySample = PerformanceCounterLib.GetCategorySample(CategoryName))
{
var counterSample = categorySample.GetCounterDefinitionSample(CounterName);
_counterType = counterSample._counterType;
if (!categorySample._isMultiInstance)
{
if (!string.IsNullOrEmpty(InstanceName))
{
throw new InvalidOperationException(SR.Format(SR.InstanceNameProhibited, InstanceName));
}
return(counterSample.GetSingleValue());
}
if (string.IsNullOrEmpty(InstanceName))
{
throw new InvalidOperationException(SR.Format(SR.InstanceNameRequired));
}
return(counterSample.GetInstanceValue(InstanceName));
}
}
/// <summary>
/// Reads all the counter and instance data of this performance category. Note that reading the entire category
/// at once can be as efficient as reading a single counter because of the way the system provides the data.
/// </summary>
public InstanceDataCollectionCollection ReadCategory()
{
if (_categoryName == null)
{
throw new InvalidOperationException(SR.Format(SR.CategoryNameNotSet));
}
using (var categorySample = PerformanceCounterLib.GetCategorySample(_categoryName))
{
return(categorySample.ReadCategory());
}
}
/// <summary>
/// Returns true if the instance already exists for this category.
/// </summary>
public bool InstanceExists(string instanceName)
{
if (instanceName == null)
{
throw new ArgumentNullException(nameof(instanceName));
}
if (_categoryName == null)
{
throw new InvalidOperationException(SR.Format(SR.CategoryNameNotSet));
}
using (var categorySample = PerformanceCounterLib.GetCategorySample(_categoryName))
{
return(categorySample._instanceNameTable.ContainsKey(instanceName));
}
}
/// <summary>
/// Returns the instance names for a given category
/// </summary>
/// <internalonly/>
internal static string[] GetCounterInstances(string categoryName)
{
using (var categorySample = PerformanceCounterLib.GetCategorySample(categoryName))
{
if (categorySample._instanceNameTable.Count == 0)
{
return(Array.Empty <string>());
}
var instanceNames = new string[categorySample._instanceNameTable.Count];
categorySample._instanceNameTable.Keys.CopyTo(instanceNames, 0);
if (instanceNames.Length == 1 && instanceNames[0] == PerformanceCounterLib.SingleInstanceName)
{
return(Array.Empty <string>());
}
return(instanceNames);
}
}
