Class RefCountedConcurrentDictionary<TKey, TValue>

Represents a thread-safe collection of reference-counted key/value pairs that can be accessed by multiple threads concurrently. Values that don't yet exist are automatically created using a caller supplied value factory method, and when their final refcount is released they are removed from the dictionary.

Inheritance

object

RefCountedConcurrentDictionary<TKey, TValue>

Inherited Members

object.Equals(object)

object.Equals(object, object)

object.GetHashCode()

object.GetType()

object.MemberwiseClone()

object.ReferenceEquals(object, object)

object.ToString()

Namespace: SixLabors.ImageSharp.Web.Synchronization

Assembly: SixLabors.ImageSharp.Web.dll

Syntax

public class RefCountedConcurrentDictionary<TKey, TValue> where TKey : notnull where TValue : class

Type Parameters

Name	Description
TKey	The type of the key.
TValue	The value for the dictionary.

Constructors

RefCountedConcurrentDictionary(IEqualityComparer<TKey>, Func<TKey, TValue>, Action<TValue>?)

Initializes a new instance of the RefCountedConcurrentDictionary<TKey, TValue> class that is empty, has the default concurrency level and capacity,, and uses the specified IEqualityComparer<T>.

Declaration

public RefCountedConcurrentDictionary(IEqualityComparer<TKey> comparer, Func<TKey, TValue> valueFactory, Action<TValue>? valueReleaser)

Parameters

Type	Name	Description
IEqualityComparer<TKey>	comparer	The IEqualityComparer<T> implementation to use when comparing keys.
Func<TKey, TValue>	valueFactory	Factory method that generates a new TValue for a given TKey.
Action<TValue>	valueReleaser	Optional callback that is used to cleanup TValues after their final ref count is released.

RefCountedConcurrentDictionary(Func<TKey, TValue>, Action<TValue>?)

Initializes a new instance of the RefCountedConcurrentDictionary<TKey, TValue> class that is empty, has the default concurrency level, has the default initial capacity, and uses the default comparer for the key type.

Declaration

public RefCountedConcurrentDictionary(Func<TKey, TValue> valueFactory, Action<TValue>? valueReleaser = null)

Parameters

Type	Name	Description
Func<TKey, TValue>	valueFactory	Factory method that generates a new TValue for a given TKey.
Action<TValue>	valueReleaser	Optional callback that is used to cleanup TValues after their final ref count is released.

RefCountedConcurrentDictionary(int, int, IEqualityComparer<TKey>, Func<TKey, TValue>, Action<TValue>?)

Initializes a new instance of the RefCountedConcurrentDictionary<TKey, TValue> class that is empty, has the specified concurrency level, has the specified initial capacity, and uses the specified IEqualityComparer<T>.

Declaration

public RefCountedConcurrentDictionary(int concurrencyLevel, int capacity, IEqualityComparer<TKey> comparer, Func<TKey, TValue> valueFactory, Action<TValue>? valueReleaser)

Parameters

Type	Name	Description
int	concurrencyLevel	The estimated number of threads that will access the RefCountedConcurrentDictionary<TKey, TValue> concurrently
int	capacity	The initial number of elements that the RefCountedConcurrentDictionary<TKey, TValue> can contain.
IEqualityComparer<TKey>	comparer	The IEqualityComparer<T> implementation to use when comparing keys.
Func<TKey, TValue>	valueFactory	Factory method that generates a new TValue for a given TKey.
Action<TValue>	valueReleaser	Optional callback that is used to cleanup TValues after their final ref count is released.

RefCountedConcurrentDictionary(int, int, Func<TKey, TValue>, Action<TValue>?)

Initializes a new instance of the RefCountedConcurrentDictionary<TKey, TValue> class that is empty, has the specified concurrency level and capacity, and uses the default comparer for the key type.

Declaration

public RefCountedConcurrentDictionary(int concurrencyLevel, int capacity, Func<TKey, TValue> valueFactory, Action<TValue>? valueReleaser = null)

Parameters

Type	Name	Description
int	concurrencyLevel	The estimated number of threads that will access the RefCountedConcurrentDictionary<TKey, TValue> concurrently
int	capacity	The initial number of elements that the RefCountedConcurrentDictionary<TKey, TValue> can contain.
Func<TKey, TValue>	valueFactory	Factory method that generates a new TValue for a given TKey.
Action<TValue>	valueReleaser	Optional callback that is used to cleanup TValues after their final ref count is released.

Methods

Get(TKey)

Obtains a reference to the value corresponding to the specified key. If no such value exists in the dictionary, then a new value is generated using the value factory method supplied in the constructor. To prevent leaks, this reference MUST be released via Release(TKey).

Declaration

public TValue Get(TKey key)

Parameters

Type	Name	Description
TKey	key	The key of the element to add ref.

Returns

Type	Description
TValue	The referenced object.

Release(TKey)

Releases a reference to the value corresponding to the specified key. If this reference was the last remaining reference to the value, then the value is removed from the dictionary, and the optional value releaser callback is invoked.

Declaration

public void Release(TKey key)

Parameters

Type	Name	Description
TKey	key	THe key of the element to release.