Class NullImplementation.NullCache

A ICache that contains nothing and does nothing.

Inheritance

object

NullImplementation.NullCollection

NullImplementation.NullCache

NullImplementation.NullObservableCache

Implements

Inherited Members

NullImplementation.NullCollection.CopyTo(Array, int)

NullImplementation.NullCollection.Count

NullImplementation.NullCollection.SyncRoot

NullImplementation.NullCollection.IsSynchronized

NullImplementation.NullCollection.GetEnumerator()

NullImplementation.NullCollection.Equals(object)

NullImplementation.NullCollection.GetHashCode()

NullImplementation.NullCollection.ReadExternal(IPofReader)

NullImplementation.NullCollection.WriteExternal(IPofWriter)

NullImplementation.NullCollection.EMPTY_ENUMERATOR

object.Equals(object, object)

object.GetType()

object.MemberwiseClone()

object.ReferenceEquals(object, object)

object.ToString()

Namespace: Tangosol.Util

Assembly: Coherence.dll

Syntax

public class NullImplementation.NullCache : NullImplementation.NullCollection, IPortableObject, ICache, IDictionary, ICollection, IEnumerable

Fields

Instance

Since the cache contains no information, only one ever has to exist.

Declaration

public static readonly ICache Instance

Field Value

Type	Description
ICache

Properties

Entries

Gets a collection of ICacheEntry instances within the cache.

Declaration

public ICollection Entries { get; }

Property Value

Type	Description
ICollection

IsFixedSize

Gets a value indicating whether the dictionary object has a fixed size.

Declaration

public bool IsFixedSize { get; }

Property Value

Type	Description
bool	true if the dictionary object has a fixed size; otherwise, false.

IsReadOnly

Gets a value indicating whether the dictionary object is read-only.

Declaration

public bool IsReadOnly { get; }

Property Value

Type	Description
bool	true if the dictionary object is read-only; otherwise, false.

this[object]

Gets or sets the element with the specified key.

Declaration

public object this[object key] { get; set; }

Parameters

Type	Name	Description
object	key	The key of the element to get or set.

Property Value

Type	Description
object	The element with the specified key.

Keys

Gets an ICollection object containing the keys of the dictionary.

Declaration

public ICollection Keys { get; }

Property Value

Type	Description
ICollection	An ICollection object containing the keys of the dictionary.

Values

Gets an ICollection object containing the values in the dictionary.

Declaration

public ICollection Values { get; }

Property Value

Type	Description
ICollection	An ICollection object containing the values in the dictionary.

Methods

Add(object, object)

Adds an element with the provided key and value to the dictionary.

Declaration

public void Add(object key, object value)

Parameters

Type	Name	Description
object	key	The object to use as the key of the element to add.
object	value	The object to use as the value of the element to add.

Clear()

Removes all elements from the dictionary.

Declaration

public void Clear()

Contains(object)

Determines whether the dictionary object contains an element with the specified key.

Declaration

public bool Contains(object key)

Parameters

Type	Name	Description
object	key	The key to locate in the dictionary.

Returns

Type	Description
bool	true if the dictionary contains an element with the key; otherwise, false.

GetAll(ICollection)

Get the values for all the specified keys, if they are in the cache.

Declaration

public IDictionary GetAll(ICollection keys)

Parameters

Type	Name	Description
ICollection	keys	A collection of keys that may be in the named cache.

Returns

Type	Description
IDictionary	A dictionary of keys to values for the specified keys passed in `keys`.

Remarks

For each key that is in the cache, that key and its corresponding value will be placed in the dictionary that is returned by this method. The absence of a key in the returned dictionary indicates that it was not in the cache, which may imply (for caches that can load behind the scenes) that the requested data could not be loaded.

The result of this method is defined to be semantically the same as the following implementation, without regards to threading issues:

IDictionary dict = new AnyDictionary();
// could be a Hashtable (but does not have to)
foreach (object key in colKeys)
{
    object value = this[key];
    if (value != null || Contains(key))
    {
        dict[key] = value;
    }
}
return dict;

Insert(object, object)

Associates the specified value with the specified key in this cache.

Declaration

public object Insert(object key, object value)

Parameters

Type	Name	Description
object	key	Key with which the specified value is to be associated.
object	value	Value to be associated with the specified key.

Returns

Type	Description
object	Previous value associated with specified key, or `null` if there was no mapping for key. A `null` return can also indicate that the dictionary previously associated `null` with the specified key, if the implementation supports `null` values.

Remarks

If the cache previously contained a mapping for this key, the old value is replaced.

Invoking this method is equivalent to the following call:

Insert(key, value, CacheExpiration.Default);

Insert(object, object, long)

Associates the specified value with the specified key in this cache.

Declaration

public object Insert(object key, object value, long millis)

Parameters

Type	Name	Description
object	key	Key with which the specified value is to be associated.
object	value	Value to be associated with the specified key.
long	millis	The number of milliseconds until the cache entry will expire, also referred to as the entry's "time to live"; pass DEFAULT to use the cache's default time-to-live setting; pass NEVER to indicate that the cache entry should never expire; this milliseconds value is not a date/time value, but the amount of time object will be kept in the cache.

Returns

Type	Description
object	Previous value associated with specified key, or `null` if there was no mapping for key. A `null` return can also indicate that the cache previously associated `null` with the specified key, if the implementation supports `null` values.

Remarks

If the cache previously contained a mapping for this key, the old value is replaced.

This variation of the Insert(object, object) method allows the caller to specify an expiry (or "time to live") for the cache entry.

Exceptions

Type	Condition
NotSupportedException	If the requested expiry is a positive value and the implementation does not support expiry of cache entries.

InsertAll(IDictionary)

Copies all of the mappings from the specified dictionary to this cache (optional operation).

Declaration

public void InsertAll(IDictionary dictionary)

Parameters

Type	Name	Description
IDictionary	dictionary	Mappings to be stored in this cache.

Remarks

These mappings will replace any mappings that this cache had for any of the keys currently in the specified dictionary.

Exceptions

Type	Condition
InvalidCastException	If the class of a key or value in the specified dictionary prevents it from being stored in this cache.
InvalidOperationException	If the lock could not be succesfully obtained for some key.
NullReferenceException	This cache does not permit `null` keys or values, and the specified key or value is `null`.

Remove(object)

Removes the element with the specified key from the dictionary.

Declaration

public void Remove(object key)

Parameters

Type	Name	Description
object	key	The key of the element to remove.

Implements

IPortableObject

ICache

IDictionary

ICollection

IEnumerable