ExpiringCollection(TItem) Class

ExpiringCollectionTItem Class

Manages a self-expiring collection of items.

Inheritance Hierarchy

SystemObject
  VirtualRadar.InterfaceExpiringCollectionTItem
    VirtualRadar.InterfaceExpiringDictionaryTKey, TValue
    VirtualRadar.InterfaceExpiringListT

Namespace: VirtualRadar.Interface
Assembly: VirtualRadar.Interface (in VirtualRadar.Interface.dll) Version: 1.0.0.0 (1.0.0.0)

Syntax

C++

Copy

public abstract class ExpiringCollection<TItem> : IDisposable
where TItem : class

Public MustInherit Class ExpiringCollection(Of TItem As Class)
	Implements IDisposable

generic<typename TItem>
where TItem : ref class
public ref class ExpiringCollection abstract : IDisposable

[<AbstractClassAttribute>]
type ExpiringCollection<'TItem when 'TItem : not struct> =  
    class
        interface IDisposable
    end

Type Parameters

TItem: The type of item being held by the collection.

The ExpiringCollectionTItem type exposes the following members.

Constructors

	Name	Description
	ExpiringCollectionTItem	Creates a new object.

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Properties

	Name	Description
	AfterCheckForExpiredItemsDelegate	Gets or sets an optional delegate that is called after the check for expired items is made.
	BeforeCheckForExpiredItemsDelegate	Gets or sets an optional delegate that is called before the check is made for expired items.
	Count	When overridden by the derivee this returns the current count of items in the collection.
	CountChangedDelegate	Gets or sets an optional delegate that is called when the count changes. The new count is passed to the delegate. The list is locked to the calling thread while the delegate is running. The delegate will occasionally be called on a background thread.
	ExpireMilliseconds	Gets or sets the minimum number of milliseconds that an item can remain within the list.
	MillisecondsBetweenChecks	Gets or sets the minimum number of milliseconds to wait between checks for expiring items.

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Methods

	Name	Description
	ChangeIntervals	Changes the intervals for the expiration of items and the interval between checks.
	Clear	When overridden by a derivee this clears the collection and unhooks all events.
	Dispose	See interface docs.
	Dispose(Boolean)	Disposes of or finalises the object.
	DoRemoveExpiredItems	When overridden by the derivee this should remove all items that have a timestamp that is less than or equal to the threshold passed across.
	Equals	Determines whether the specified Object is equal to the current Object. (Inherited from Object.)
	Finalize	Finalises the object. (Overrides ObjectFinalize.)
	GetHashCode	Serves as a hash function for a particular type. (Inherited from Object.)
	GetType	Gets the Type of the current instance. (Inherited from Object.)
	HookHeartbeat	Hooks the heartbeat event. Must be called from within a lock.
	Lock	Calls the action passed across with the list locked. Do not perform an action that will attempt to lock the list from another thread, it will block.
	MemberwiseClone	Creates a shallow copy of the current Object. (Inherited from Object.)
	OnCountChanged	Called by the derivee to inform the owner of the collection that the count has changed. Always call this from within a lock.
	RemoveExpiredItems	Removes expired items.
	ToString	Returns a string that represents the current object. (Inherited from Object.)
	UnhookHeartbeat	Unhooks the heartbeat service if hooked. Must be called from within a lock.

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Fields

	Name	Description
	_Clock	The clock that provides timestamps.
	_SyncLock	The lock object that controls access to the other fields.

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Remarks

When an item is added to this collection it is given a timestamp. The items in the collection are periodically checked, if they have been in the collection for longer than ExpireMilliseconds then they are removed.

This class is disposable. However, Dispose() just clears the collection. Clearing the collection releases all hooks, so it is kind-of permissible to not dispose of these objects - once the last item in the collection expires the class will automatically unhook itself and become eligible for finalising (if there are no strong references to it). However it is better if you can dispose of it when you are finished with it.

Reference

VirtualRadar.Interface Namespace