SafeDictionary<TKey, TValue> Class

Represents a thread-safe collection of key/value pairs that can be modified by multiple threads concurrently.

Inheritance Hierarchy

System.Object
  System.Collections.Hashtable
    CMS.Base.SafeDictionary<TKey, TValue>
      CMS.Base.StringSafeDictionary<TValue>

Namespace: CMS.Base
Assembly: CMS.Base (in CMS.Base.dll) Version: 10.0.0

Syntax

[SerializableAttribute]
public class SafeDictionary<TKey, TValue> : Hashtable, 
	ICloneThreadItem, IXmlSerializable, IGeneralIndexable<TKey, TValue>, IGeneralIndexable

Type Parameters

TKey

Key type

TValue

Value type

The SafeDictionary<TKey, TValue> type exposes the following members.

Constructors

	Name	Description
Public method	SafeDictionary<TKey, TValue>()	SafeDictionary constructor.
Public method	SafeDictionary<TKey, TValue>(IEqualityComparer)	SafeDictionary constructor.
Public method	SafeDictionary<TKey, TValue>(IDictionary, IEqualityComparer)	Constructor.
Public method	SafeDictionary<TKey, TValue>(SerializationInfo, StreamingContext)	De-serialization constructor.

Fields

	Name	Description
Protected field	mDefaultValue	Default value.
Protected field	mNullValue	Null value.
Protected field	mUseWeakReferences	If true, the weak references are used for the items so the memory can be cleared upon request

Properties

	Name	Description
Public property	AllowNulls	If true, the dictionary allows null values as valid.
Public property	CopyToNewThread	If true, the dictionary is copied (not cloned) to a new thread
Public property	DefaultValue	Default value.
Public property	IsEmpty	Returns true if the dictionary is empty
Public property	IsSynchronized	Returns true if dictionary is synchronized. (Overrides Hashtable.IsSynchronized.)
Public property	Item	Items indexer. Gets or sets the value in the dictionary.
Public property	Keys	Gets an Collection containing the keys in the System.Collections.Hashtable. (Overrides Hashtable.Keys.)
Public property	NullValue	Null value.
Public property Code example	SyncRoot	Gets an object that can be used to synchronize access to the SafeDictionary<TKey, TValue>. (Overrides Hashtable.SyncRoot.)
Public property	TypedKeys	Gets a typed collection of keys in this dictionary
Public property	TypedValues	Gets a typed collection of values in this dictionary
Public property Code example	UseWeakReferences	If true, the weak references are used for the items so the memory can be cleared upon request. The property can be set only when the dictionary is empty. To ensure thread-safety, you have to perform the check for emptiness and property assignment in a critical section (use SyncRoot for that purpose).
Public property	Values	Gets a Collection containing the values in the System.Collections.Hashtable. (Overrides Hashtable.Values.)

Methods

	Name	Description
Public method Code example	Add	Adds the value to the dictionary if it does not exist. Updates existing, if it does exist. (Overrides Hashtable.Add(Object, Object).)
Public method Code example	AddMultiple	Adds multiple items with same value to the dictionary
Public method	Clear	Removes all elements from the System.Collections.Hashtable. (Overrides Hashtable.Clear().)
Public method	Clone	Clones the dictionary (Overrides Hashtable.Clone().)
Public method	CloneForNewThread	Clones the object for new thread
Public method	Contains	Returns true if the dictionary contains the given key (Overrides Hashtable.Contains(Object).)
Public method	ContainsKey	Returns true if the dictionary contains the given key (Overrides Hashtable.ContainsKey(Object).)
Public method	ContainsValue	Returns true if the dictionary contains the given value (Overrides Hashtable.ContainsValue(Object).)
Protected method	CopyPropertiesTo	Copies the dictionary properties to the target dictionary
Public method Code example	CopyTo	Copies the System.Collections.Hashtable elements to a one-dimensional System.Array instance at the specified index. (Overrides Hashtable.CopyTo(Array, Int32).)
Protected method	GetInternalValue	Gets the value from the internal dictionary
Public method	GetObjectData	Object serialization. (Overrides Hashtable.GetObjectData(SerializationInfo, StreamingContext).)
Public method Code example	GetRealCount	Gets the real count of the objects in the dictionary.
Public method	Remove	Removes the element with the specified key from the System.Collections.Hashtable. (Overrides Hashtable.Remove(Object).)
Protected method	SetInternalValue	Sets the value in the internal dictionary
Public method	TryGetValue	Tries to get the value, returns true if the retrieval was successful.

Extension Methods

	Name	Description
Public Extension Method	AsIndexable<TKey, TValue>	Implicit conversion to indexable type with a specific values (Defined by DataExtensions.)

Remarks

Keep in mind that the operations of this class are thread-safe. However, a sequence of operations inherently cannot be thread-safe. If you want to perform multiple operations as one atomic operation, use the SyncRoot object.

In current implementation some read operations do not require locking (i.e. multiple threads can read even though some other thread has the lock). If your situation requires all the readers to wait when the dictionary is locked by some other thread, consider some other collection suitable for readers-writers synchronization problem.