/// <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="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="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>
/// <exception cref="ArgumentNullException">The provided metricsSystem, categoryName, or counterName was null.</exception>
public bool TryGetValue(string metricTypeName, string categoryName, string counterName, out IMetricDefinition value)
{
//get the key for the provided values
string key = MetricDefinition.GetKey(metricTypeName, categoryName, counterName);
lock (m_Lock)
{
//gateway to our inner dictionary try get value
return(m_DictionaryByName.TryGetValue(key, out value));
}
}
/// <summary>
/// Determines whether the collection contains an element with the specified key.
/// </summary>
/// <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>
/// <returns>true if the collection contains an element with the key; otherwise, false.</returns>
public bool ContainsKey(string metricTypeName, string categoryName, string counterName)
{
//get the key for the provided values
string key = MetricDefinition.GetKey(metricTypeName, categoryName, counterName);
lock (m_Lock)
{
//gateway to our alternate inner dictionary
return(m_DictionaryByName.ContainsKey(key));
}
}
/// <summary>
/// Retrieve metric object by its type, category, and counter names.
/// </summary>
/// <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>
/// <returns></returns>
public IMetricDefinition this[string metricTypeName, string categoryName, string counterName]
{
get
{
//create the key from the parts we got
string key = MetricDefinition.GetKey(metricTypeName, categoryName, counterName);
lock (m_Lock)
{
return(m_DictionaryByName[key]);
}
}
}
/// <summary>Creates a new metric instance 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 Custom Sampled 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="metricSampleType">The type of data captured for each metric under this definition.</param>
/// <param name="instanceName">The unique name of this instance within the metric's collection.</param>
public static CustomSampledMetric AddOrGet(MetricDefinitionCollection definitions, string metricTypeName, string categoryName, string counterName, MetricSampleType metricSampleType, 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;
//Establish a lock on the definitions collection so our lookup & create are atomic.
lock (definitions.Lock)
{
if (definitions.TryGetValue(definitionKey, out definition))
{
//if the metric definition exists, but is of the wrong type we have a problem.
if ((definition is CustomSampledMetricDefinition) == false)
{
throw new ArgumentException("A metric already exists with the provided type, category, and counter name but it is not compatible with being a custom sampled metric. Please use a different counter name.", nameof(counterName));
}
}
else
{
//we didn't find one, make a new one
definition =
new CustomSampledMetricDefinition(definitions, metricTypeName, categoryName, counterName,
metricSampleType);
}
}
//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)
{
if (definition.Metrics.TryGetValue(metricKey, out metric) == false)
{
metric = new CustomSampledMetric((CustomSampledMetricDefinition)definition, instanceName);
}
}
return((CustomSampledMetric)metric);
}
/// <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>
/// Retrieves the specified metric instance, or creates it if it doesn't exist
/// </summary>
/// <param name="instanceName"></param>
/// <returns>The custom sampled metric object.</returns>
private CustomSampledMetric EnsureMetricExists(string instanceName)
{
//Find the right metric sample instance, creating it if we have to.
string metricKey = MetricDefinition.GetKey(this, instanceName);
IMetric ourMetric;
//This must be protected in a multi-threaded environment
lock (Metrics.Lock)
{
if (Metrics.TryGetValue(metricKey, out ourMetric) == false)
{
//it doesn't exist - go ahead and add it
ourMetric = new CustomSampledMetric(this, instanceName);
}
}
//and return the metric
return((CustomSampledMetric)ourMetric);
}
/// <summary>
/// Add the supplied Metric item to this collection.
/// </summary>
/// <remarks>Metrics automatically add themselves when they are created, so it isn't necessary (and will produce errors) to manually add them.</remarks>
/// <param name="item">The new Metric item to add to this collection</param>
public void Add(IMetric item)
{
//we really don't want to support this method, but we have to for ICollection<T> compatibility. So we're going to ruthlessly
//verify that the metric object was created correctly.
if (item == null)
{
throw new ArgumentNullException(nameof(item), "A metric item must be provided to add it to the collection.");
}
//make sure the metric is for the right definition, namely our definition.
if (MetricDefinition.GetKey(item) != m_MetricDefinition.Name)
{
throw new ArgumentOutOfRangeException(nameof(item), "The provided metric item is not related to the metric definition that owns this metrics collection.");
}
//we're about to modify the collection, get a lock. We don't want the lock to cover the changed event since
//we really don't know how long that will take, and it could be deadlock prone.
lock (m_Lock)
{
//make sure we don't already have it
if (m_Dictionary.ContainsKey(item.Id))
{
throw new ArgumentException("The specified metric item is already in the collection.", nameof(item));
}
if (m_DictionaryByName.ContainsKey(item.Name))
{
throw new ArgumentException("A metric item for the same metric is already in the collection.", nameof(item));
}
//add it to all of our collections, and to the definition metric cache.
m_Dictionary.Add(item.Id, item);
m_DictionaryByName.Add(item.Name, item);
m_List.Add(item);
((MetricDefinitionCollection)m_MetricDefinition.Definitions).AddMetric(item);
}
//and fire our event
OnCollectionChanged(new CollectionChangedEventArgs <IMetricCollection, IMetric>(this, item, CollectionAction.Added));
}
/// <summary>Creates a new event metric object from the metric definition looked up with the provided key information.</summary>
/// <remarks>The metric definition must already exist or an exception will be raised.</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>
public EventMetric(MetricDefinitionCollection definitions, string metricTypeName, string categoryName, string counterName, string instanceName)
: this((EventMetricDefinition)definitions[MetricDefinition.GetKey(metricTypeName, categoryName, counterName)], instanceName)
{
}
