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Freeze::Evictor

Overview

local interface Evictor extends ::Ice::ServantLocator

An automatic Ice object persistence manager, based on the evictor pattern. The evictor is a servant locator implementation that stores the persistent state of its objects in a database. Any number of objects can be registered with an evictor, but only a configurable number of servants are active at a time. These active servants reside in a queue; the least recently used servant in the queue is the first to be evicted when a new servant is activated.

Derived Classes and Interfaces

BackgroundSaveEvictor
TransactionalEvictor

See Also

ServantInitializer

Operation Index

setSize
Set the size of the evictor's servant queue.
getSize
Get the size of the evictor's servant queue.
add
Add a servant to this evictor.
addFacet
Like add, but with a facet.
remove
Permanently destroy an Ice object.
removeFacet
Like remove, but with a facet.
hasObject
Returns true if the given identity is managed by the evictor with the default facet.
hasFacet
Like hasObject, but with a facet.
getIterator
Get an iterator for the identities managed by the evictor.

Operations

void setSize(int sz)

Set the size of the evictor's servant queue. This is the maximum number of servants the evictor keeps active. Requests to set the queue size to a value smaller than zero are ignored.

Parameters

sz
The size of the servant queue. If the evictor currently holds more than sz servants in its queue, it evicts enough servants to match the new size. Note that this operation can block if the new queue size is smaller than the current number of servants that are servicing requests. In this case, the operation waits until a sufficient number of servants complete their requests.

Exceptions

EvictorDeactivatedException
Raised if a the evictor has been deactivated.

See Also

getSize

int getSize()

Get the size of the evictor's servant queue.

Return Value

The size of the servant queue.

Exceptions

EvictorDeactivatedException
Raised if a the evictor has been deactivated.

See Also

setSize

Object* add(Object servant, ::Ice::Identity id)

Add a servant to this evictor. The state of the servant passed to this operation will be saved in the evictor's persistent store.

Parameters

servant
The servant to add.
id
The identity of the Ice object that is implemented by the servant.

Return Value

A proxy that matches the given identity and this evictor's object adapter.

Exceptions

::Ice::AlreadyRegisteredException
Raised if the evictor already has an object with this identity.
DatabaseException
Raised if a database failure occurred.
EvictorDeactivatedException
Raised if the evictor has been deactivated.

See Also

addFacet
remove
removeFacet

Object* addFacet(Object servant, ::Ice::Identity id, string facet)

Like add, but with a facet. Calling add(servant, id) is equivalent to calling addFacet with an empty facet.

Parameters

servant
The servant to add.
id
The identity of the Ice object that is implemented by the servant.
facet
The facet. An empty facet means the default facet.

Return Value

A proxy that matches the given identity and this evictor's object adapter.

Exceptions

::Ice::AlreadyRegisteredException
Raised if the evictor already has an object with this identity.
DatabaseException
Raised if a database failure occurred.
EvictorDeactivatedException
Raised if the evictor has been deactivated.

See Also

add
remove
removeFacet

Object remove(::Ice::Identity id)

Permanently destroy an Ice object.

Parameters

id
The identity of the Ice object.

Return Value

The removed servant.

Exceptions

::Ice::NotRegisteredException
Raised if this identity was not registered with the evictor.
DatabaseException
Raised if a database failure occurred.
EvictorDeactivatedException
Raised if the evictor has been deactivated.

See Also

add
removeFacet

Object removeFacet(::Ice::Identity id, string facet)

Like remove, but with a facet. Calling remove(id) is equivalent to calling removeFacet with an empty facet.

Parameters

id
The identity of the Ice object.
facet
The facet. An empty facet means the default facet.

Return Value

The removed servant.

Exceptions

::Ice::NotRegisteredException
Raised if this identity was not registered with the evictor.
DatabaseException
Raised if a database failure occurred.
EvictorDeactivatedException
Raised if the evictor has been deactivated.

See Also

remove
addFacet

bool hasObject(::Ice::Identity id)

Returns true if the given identity is managed by the evictor with the default facet.

Return Value

true if the identity is managed by the evictor, false otherwise.

Exceptions

DatabaseException
Raised if a database failure occurred.
EvictorDeactivatedException
Raised if a the evictor has been deactivated.

bool hasFacet(::Ice::Identity id, string facet)

Like hasObject, but with a facet. Calling hasObject(id) is equivalent to calling @link #hasFacet] with an empty facet.

Return Value

true if the identity is managed by the evictor for the given facet, false otherwise.

Exceptions

DatabaseException
Raised if a database failure occurred.
EvictorDeactivatedException
Raised if a the evictor has been deactivated.

EvictorIterator getIterator(string facet, int batchSize)

Get an iterator for the identities managed by the evictor.

Parameters

facet
The facet. An empty facet means the default facet.
batchSize
Internally, the Iterator retrieves the identities in batches of size batchSize. Selecting a small batchSize can have an adverse effect on performance.

Return Value

A new iterator.

Exceptions

EvictorDeactivatedException
Raised if a the evictor has been deactivated.

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