/// <summary>
/// Add a performance counter object to our collection. If it doesn't exist, it will be created.
/// </summary>
/// <param name="categoryName">The name of the performance counter category (performance object) with which this performance counter is associated.</param>
/// <param name="counterName">The name of the performance counter.</param>
/// <param name="alias">An alias to use to determine the instance name instead of the instance of the supplied counter.</param>
public void Add(string categoryName, string counterName, PerfCounterInstanceAlias alias)
{
//we can't have a null category our counter.
if (string.IsNullOrEmpty(categoryName))
{
throw new ArgumentNullException(nameof(categoryName));
}
if (string.IsNullOrEmpty(counterName))
{
throw new ArgumentNullException(nameof(counterName));
}
//see if the performance counter metric already exists. It quite probably does.
PerfCounterMetric newMetric = PerfCounterMetric.AddOrGet(categoryName, counterName, alias);
//now we can use our normal routine.
Add(newMetric);
}
/// <summary>Creates a new performance counter metric instance or returns an existing one from the provided definition information, or returns any existing instance if found.</summary>
/// <remarks>If the metric definition doesn't exist, it will be created. If the metric doesn't exist, it will be created.
/// If the metric definition does exist, but is not a Performance Counter Metric (or a derived class) an exception will be thrown.</remarks>
/// <param name="categoryName">The name of the performance counter category (performance object) with which this performance counter is associated.</param>
/// <param name="counterName">The name of the performance counter.</param>
/// <param name="alias">An alias to use to determine the instance name instead of the instance of the supplied counter.</param>
/// <returns>The Performance Counter Metric object for the specified instance.</returns>
public static PerfCounterMetric AddOrGet(string categoryName, string counterName, PerfCounterInstanceAlias alias)
{
//make sure we have all of the variables we require
if (string.IsNullOrEmpty(categoryName))
{
throw new ArgumentNullException(nameof(categoryName), "No category name was provided and one is required.");
}
if (string.IsNullOrEmpty(counterName))
{
throw new ArgumentNullException(nameof(counterName), "No counter name was provided and one is required.");
}
//Go ahead and make the windows counter
string instanceName = GetInstanceName(alias);
PerformanceCounter newPerformanceCounter = GetPerformanceCounter(categoryName, counterName, instanceName);
//and now pass it to our normal add or get routine.
return(AddOrGet(newPerformanceCounter, alias));
}
/// <summary>
/// Create a new performance counter metric object from the provided windows performance counter
/// </summary>
/// <remarks>The new metric will automatically be added to the metric definition's metrics collection.</remarks>
/// <param name="definition">The metric definition for the provided windows performance counter</param>
/// <param name="counter">The windows performance counter to add as a metric</param>
/// <param name="alias">An alias to use to determine the instance name instead of the instance of the supplied counter.</param>
public PerfCounterMetric(PerfCounterMetricDefinition definition, PerformanceCounter counter, PerfCounterInstanceAlias alias)
: base(definition, new PerfCounterMetricPacket(definition.Packet, counter))
{
m_InstanceAlias = alias;
m_PollingState = PerfCounterPollingState.Inactive;
}
/// <summary>
/// Create a new performance counter metric object from the provided raw data packet
/// </summary>
/// <remarks>The new metric will automatically be added to the metric definition's metrics collection.</remarks>
/// <param name="definition">The object that defines this metric</param>
/// <param name="packet">The raw data packet</param>
internal PerfCounterMetric(PerfCounterMetricDefinition definition, PerfCounterMetricPacket packet)
: base(definition, packet)
{
m_InstanceAlias = PerfCounterInstanceAlias.None;
m_PollingState = PerfCounterPollingState.Inactive;
}
/// <summary>Creates a new performance counter metric instance or returns an existing one from the provided definition information, or returns any existing instance if found.</summary>
/// <remarks>If the metric definition doesn't exist, it will be created. If the metric doesn't exist, it will be created.
/// If the metric definition does exist, but is not a Performance Counter Metric (or a derived class) an exception will be thrown.</remarks>
/// <param name="newPerformanceCounter">The windows performance counter to add a definition for</param>
/// <param name="alias">An alias to use to determine the instance name instead of the instance of the supplied counter.</param>
/// <returns>The Performance Counter Metric object for the specified instance.</returns>
public static PerfCounterMetric AddOrGet(PerformanceCounter newPerformanceCounter, PerfCounterInstanceAlias alias)
{
//we need to find the definition, adding it if necessary
string definitionKey = PerfCounterMetricDefinition.GetKey(newPerformanceCounter);
IMetricDefinition definition;
if (Log.Metrics.TryGetValue(definitionKey, out definition))
{
//if the metric definition exists, but is of the wrong type we have a problem.
if ((definition is PerfCounterMetricDefinition) == false)
{
throw new ArgumentException("A metric already exists with the provided type, category, and counter name but it is not compatible with being a performance counter metric. This indicates a programming error in a client application or Gibraltar.");
}
}
else
{
//we didn't find one, make a new one
definition = new PerfCounterMetricDefinition(Log.Metrics, newPerformanceCounter);
}
//now we have our definition, proceed to create a new metric if it doesn't exist
//Interesting note: here is where we basically lock in an alias to be its initial value.
string metricKey = GetKey(newPerformanceCounter);
IMetric metric;
//see if we can get the metric already. If not, we'll create it
lock (((MetricCollection)definition.Metrics).Lock) //make sure the get & add are atomic
{
if (definition.Metrics.TryGetValue(metricKey, out metric) == false)
{
metric = new PerfCounterMetric((PerfCounterMetricDefinition)definition, newPerformanceCounter, alias);
}
}
return((PerfCounterMetric)metric);
}
