/// <summary>
/// Create a new metric object with the provided instance name and add it to the collection
/// </summary>
/// <param name="instanceName">The instance name to use, or blank or null for the default metric.</param>
/// <returns>The new metric object that was added to the collection</returns>
public EventMetric Add(string instanceName)
{
//Create a new metric object with the provided instance name (it will get added to us automatically)
EventMetric newMetric = new EventMetric(Definition, instanceName);
//finally, return the newly created metric object to our caller
return(newMetric);
}
/// <summary>
/// Retrieve an item from the collection by its key if present. If not present, the default value of the object is returned.
/// </summary>
/// <param name="key">The metric name to locate in the collection</param>
/// <param name="value">When this method returns, contains the value associated with the specified key, if the key is found; otherwise, the default value for the type of the value parameter. This parameter is passed uninitialized.</param>
/// <returns>true if the collection contains an element with the specified key; otherwise false.</returns>
public bool TryGetValue(string key, out EventMetric value)
{
//We are playing a few games to get native typing here. Because it's an OUt value, we
//have to swap types around ourselves so we can cast.
IMetric innerValue;
//gateway to our inner dictionary try get value
bool result = base.TryGetValue(key, out innerValue);
value = innerValue as EventMetric; //No one expects exceptions from try get value, so if it's the wrong type, return null
return(value != null);
}
/// <summary>Creates a new 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 an Event Metric (or a derived class) an exception will be thrown.</remarks>
/// <param name="definitions">The definitions dictionary this definition is a part of</param>
/// <param name="metricTypeName">The unique metric type</param>
/// <param name="categoryName">The name of the category with which this definition is associated.</param>
/// <param name="counterName">The name of the definition within the category.</param>
/// <param name="instanceName">The unique name of this instance within the metric's collection.</param>
/// <returns>The event metric object for the specified event metric instance.</returns>
public static EventMetric AddOrGet(MetricDefinitionCollection definitions, string metricTypeName, string categoryName, string counterName, string instanceName)
{
//we must have a definitions collection, or we have a problem
if (definitions == null)
{
throw new ArgumentNullException(nameof(definitions));
}
//we need to find the definition, adding it if necessary
string definitionKey = MetricDefinition.GetKey(metricTypeName, categoryName, counterName);
IMetricDefinition definition;
if (definitions.TryGetValue(definitionKey, out definition))
{
//if the metric definition exists, but is of the wrong type we have a problem.
if ((definition is EventMetricDefinition) == false)
{
throw new ArgumentException("A metric already exists with the provided type, category, and counter name but it is not compatible with being an event metric. Please use a different counter name.", nameof(counterName));
}
}
else
{
//we didn't find one, make a new one
definition = new EventMetricDefinition(definitions, metricTypeName, categoryName, counterName);
definitions.Add(definition); // Add it to the collection, no longer done in the constructor.
// ToDo: Reconsider this implementation; putting incomplete event metric definitions in the collection is not ideal,
// and creating a metric from an empty event metric definition is fairly pointless.
}
//now we have our definition, proceed to create a new metric if it doesn't exist
string metricKey = MetricDefinition.GetKey(metricTypeName, categoryName, counterName, instanceName);
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 EventMetric((EventMetricDefinition)definition, instanceName);
}
}
return((EventMetric)metric);
}
/// <summary>
/// Create a new Event metric sample object for the provided metric and raw sample packet.
/// </summary>
/// <remarks>The metric sample is automatically added to the samples collection of the provided metric object.</remarks>
/// <param name="metric">The metric object this sample applies to.</param>
/// <param name="metricSamplePacket">The raw sample data packet.</param>
internal EventMetricSample(EventMetric metric, EventMetricSamplePacket metricSamplePacket)
: base(metric, metricSamplePacket)
{
//and now that we've been created, make sure our metric definition set is locked.
metric.Definition.IsReadOnly = true;
}
/// <summary>
/// Create a new sample collection for the specified metric object
/// </summary>
/// <param name="metric"></param>
public EventMetricSampleCollection(EventMetric metric)
: base(metric)
{
m_EventMetric = metric;
}
/// <summary>
/// Determines if the provided object is identical to this object.
/// </summary>
/// <param name="other">The object to compare this object to</param>
/// <returns>True if the objects represent the same data.</returns>
public bool Equals(EventMetric other)
{
//We're really just a type cast, refer to our base object
return(base.Equals(other));
}
/// <summary>
/// Indicates the relative sort order of this object to another of the same type.
/// </summary>
/// <param name="other"></param>
/// <returns></returns>
public int CompareTo(EventMetric other)
{
//we let our base object do the compare, we're really just casting things
return(base.CompareTo(other));
}
