private long m_SampleSequence = 0; //used when adding sampled metrics to ensure order.
/// <summary>
/// Create a new metric with the provided metric definition and metric packet.
/// </summary>
/// <remarks>Most derived classes will provide a more convenient implementation that will automatically
/// create the correct metric packet instead of the caller having to first create it.
/// The new metric will automatically be added to the metric definition's metrics collection.</remarks>
/// <param name="definition">The definition for this metric</param>
/// <param name="packet">The metric packet to use for this metric</param>
internal Metric(MetricDefinition definition, MetricPacket packet)
{
//verify and store off our input
if (definition == null)
{
throw new ArgumentNullException(nameof(definition));
}
if (packet == null)
{
throw new ArgumentNullException(nameof(packet));
}
//one last safety check: The definition and the packet better agree.
if (definition.Id != packet.DefinitionId)
{
throw new ArgumentOutOfRangeException(nameof(packet), "The provided metric packet has a different definition Id than the provide metric definition.");
}
//and now that we know everything isn't null, go ahead and store things off
m_MetricDefinition = definition;
m_Packet = packet;
//and force our inheritor to create the samples collection so we get the right derived class.
// ReSharper disable DoNotCallOverridableMethodsInConstructor
m_Samples = OnSampleCollectionCreate();
// ReSharper restore DoNotCallOverridableMethodsInConstructor
//finally, add ourself to the metric definition's metrics collection
m_MetricDefinition.Metrics.Add(this);
}
/// <summary>
/// Create a new metric dictionary for the provided definition.
/// </summary>
/// <remarks>This dictionary is created automatically by the Metric Definition during its initialization.</remarks>
/// <param name="metricDefinition"></param>
internal MetricCollection(MetricDefinition metricDefinition)
{
if (metricDefinition == null)
{
throw new ArgumentNullException(nameof(metricDefinition));
}
m_MetricDefinition = metricDefinition;
}
/// <summary>
/// Calculate the string key for a metric.
/// </summary>
/// <param name="metricDefinition">The existing metric definition object to generate a string key for</param>
/// <param name="instanceName">The name of the performance counter category instance, or an empty string (""), if the category contains a single instance.</param>
/// <returns>The unique string key for this item</returns>
public static string GetKey(MetricDefinition metricDefinition, string instanceName)
{
//make sure the metric definition object isn't null
if (metricDefinition == null)
{
throw new ArgumentNullException(nameof(metricDefinition));
}
return(GetKey(metricDefinition.MetricTypeName, metricDefinition.CategoryName, metricDefinition.CounterName, instanceName));
}
/// <summary>
/// Takes an instance name or complete metric name and normalizes it to a metric name so it can be used to look up a metric
/// </summary>
/// <param name="metricDefinition">The metric definition to look for metrics within</param>
/// <param name="metricKey">The instance name or complete metric name</param>
/// <returns></returns>
internal static string NormalizeKey(MetricDefinition metricDefinition, string metricKey)
{
string returnVal;
string trueMetricKey;
bool prependDefinitionName = false;
//Did we get a null? If we got a null, we know we need to pre-pend the definition (and it isn't safe to do any more testing)
if (metricKey == null)
{
prependDefinitionName = true;
trueMetricKey = null;
}
else
{
//trim the input for subsequent testing to see what we get
trueMetricKey = metricKey.Trim();
if (string.IsNullOrEmpty(trueMetricKey))
{
//we know we need to pre-pend the definition name
prependDefinitionName = true;
}
else
{
//OK, a true key is a full name, so see if the key we got STARTS with our definition name
if (trueMetricKey.Length < metricDefinition.Name.Length)
{
//the key we got is shorter than the length of the metric definition name, so it can't include the metric definition name.
prependDefinitionName = true;
}
else
{
//now check the start of the string to see what we get
if (trueMetricKey.StartsWith(metricDefinition.Name, StringComparison.Ordinal) == false)
{
//they aren't the same at least as long as the metric definition name is, so we assume we need to pre-pend.
prependDefinitionName = true;
}
}
}
}
//If the value we got was just the instance name, we need to put the metric definition's key in front of it.
if (prependDefinitionName)
{
returnVal = GetKey(metricDefinition, trueMetricKey);
}
else
{
returnVal = trueMetricKey;
}
return(returnVal);
}
/// <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>
/// Determines whether the collection contains an element with the specified key.
/// </summary>
/// <param name="key">The metric name to locate in the collection</param>
/// <returns>true if the collection contains an element with the key; otherwise, false.</returns>
public bool ContainsKey(string key)
{
//we do a few cute tricks to normalize the key before checking it to be tolerant of what users do
string trueKey = MetricDefinition.NormalizeKey(m_MetricDefinition, key);
lock (m_Lock)
{
//gateway to our alternate inner dictionary
return(m_DictionaryByName.ContainsKey(trueKey));
}
}
/// <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 IMetric value)
{
//we do a few cute tricks to normalize the key before checking it to be tolerant of what users do
string trueKey = MetricDefinition.NormalizeKey(m_MetricDefinition, key);
lock (m_Lock)
{
//gateway to our inner dictionary try get value
return(m_DictionaryByName.TryGetValue(trueKey, out value));
}
}
/// <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>
/// 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>
/// Retrieve metric object by its name
/// </summary>
/// <param name="key"></param>
/// <returns></returns>
public IMetric this[string key]
{
get
{
//we do a few cute tricks to normalize the key before checking it to be tolerant of what users do
string trueKey = MetricDefinition.NormalizeKey(m_MetricDefinition, key);
lock (m_Lock)
{
return(m_DictionaryByName[trueKey]);
}
}
}
/// <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>
/// Add an existing metric packet object to our collection for the supplied packet.
/// </summary>
/// <param name="newDefinitionPacket">The new metric packet object to add.</param>
internal MetricDefinition Add(MetricDefinitionPacket newDefinitionPacket)
{
//just do the null check - the rest of the checks (like dupe checks) are done in the normal add routine
if (newDefinitionPacket == null)
{
throw new ArgumentNullException(nameof(newDefinitionPacket), "A metric packet object must be provided to add it to the collection.");
}
//create a new metric object to wrap the supplied metric packet
MetricDefinition newDefinition = new MetricDefinition(this, newDefinitionPacket);
//and call our mainstream add method which does the rest of our checks.
Add(newDefinition);
//return the newly added object so our caller doesn't have to go digging for it
return(newDefinition);
}
/// <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)
{
}
/// <summary>
/// Determines if the provided object is identical to this object.
/// </summary>
/// <param name="obj">The object to compare this object to</param>
/// <returns>True if the other object is also a MetricDefinition and represents the same data.</returns>
public override bool Equals(object obj)
{
MetricDefinition otherMetricDefinition = obj as MetricDefinition;
return(Equals(otherMetricDefinition)); // Just have type-specific Equals do the check (it even handles null)
}
