agi.foundation.tracking

(agi.foundation.tracking-2024r2.jar)

Class EntitySet<TEntity extends IEntityIdentifier>

java.lang.Object

agi.foundation.tracking.EntitySet<TEntity>

Type Parameters:

TEntity - The type of entity in the set.

public class EntitySet<TEntity extends IEntityIdentifier>
extends Object

This class holds and manages a collection of tracked entities. All interactions with instances of this class must happen inside a Transaction, guaranteeing snapshot isolation.

See Also:

Transactions topic

Constructor Summary

Constructors

Constructor and Description
EntitySet(TransactionContext context) Initializes a new instance.
EntitySet(TransactionContext context, Object owner) Initializes a new instance.

Method Summary

Modifier and Type	Method and Description
void	add(Transaction transaction, TEntity entity) Adds an entity.
void	addChanged(EventHandler<EntitySetChangedEventArgs<TEntity>> value) Adds a handler for an event that is raised when entities are added to or removed from this entity set.
void	clear(Transaction transaction) Removes all entities from this entity set.
void	ensure(Transaction transaction, Object id) Ensures that the entity with a specified EntityIdentifier (get) is not removed or replaced with a different entity with the same identifier before a transaction is committed.
void	ensureAll(Transaction transaction) Ensures that the entity set does not change at all before the transaction is committed.
TransactionContext	getContext() Gets the context used for transactions on this entity set.
int	getCount(Transaction transaction) Gets the number of entities in this entity set.
Collection<TEntity>	getEntities(Transaction transaction) Gets a read-only collection of all the entities in the entity set.
TEntity	getEntityById(Transaction transaction, Object id) Gets the entity with the given EntityIdentifier (get).
Object	getOwner() Gets the owner of this entity set.
void	remove(Transaction transaction, Object id) Removes an entity.
void	remove(Transaction transaction, TEntity entity) Removes an entity.
void	removeChanged(EventHandler<EntitySetChangedEventArgs<TEntity>> value) Removes a handler for an event that is raised when entities are added to or removed from this entity set.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

EntitySet

public EntitySet(@Nonnull
                 TransactionContext context)

Initializes a new instance.

Parameters:

context - The transaction context that is shared by all entities in this entity set.

EntitySet

public EntitySet(@Nonnull
                 TransactionContext context,
                 Object owner)

Initializes a new instance.

Parameters:

context - The transaction context that is shared by all entities in this entity set.

owner - The owner of this entity set.

Method Detail

addChanged

public final void addChanged(EventHandler<EntitySetChangedEventArgs<TEntity>> value)

Adds a handler for an event that is raised when entities are added to or removed from this entity set.

Parameters:

value - The handler.

removeChanged

public final void removeChanged(EventHandler<EntitySetChangedEventArgs<TEntity>> value)

Removes a handler for an event that is raised when entities are added to or removed from this entity set.

Parameters:

value - The handler.

getEntityById

public final TEntity getEntityById(@Nonnull
                                   Transaction transaction,
                                   Object id)

Gets the entity with the given EntityIdentifier (get).

Parameters:

transaction - The transaction in which to get the entity.

id - The ID of the entity to retrieve.

Returns:

The entity with the specified ID, or null if no entity with the given ID exists.

getCount

public final int getCount(@Nonnull
                          Transaction transaction)

Gets the number of entities in this entity set.

Parameters:

transaction - The transaction in which to retrieve the number of entities.

Returns:

The number of entities in this entity set.

getEntities

@Nonnull
public final Collection<TEntity> getEntities(@Nonnull
                                                       Transaction transaction)

Gets a read-only collection of all the entities in the entity set.

Parameters:

transaction - The transaction in which to enumerate the entities.

Returns:

A read-only collection of entities.

add

public final void add(@Nonnull
                      Transaction transaction,
                      @Nonnull
                      TEntity entity)

Adds an entity.

Parameters:

transaction - The transaction in which to add the entity.

entity - The entity to add.

remove

public final void remove(@Nonnull
                         Transaction transaction,
                         Object id)

Removes an entity.

Parameters:

transaction - The transaction in which to remove the entity.

id - The ID of the entity to remove.

remove

public final void remove(@Nonnull
                         Transaction transaction,
                         @Nonnull
                         TEntity entity)

Removes an entity.

Parameters:

transaction - The transaction in which to remove the entity.

entity - The entity to remove.

clear

public final void clear(@Nonnull
                        Transaction transaction)

Removes all entities from this entity set.

Parameters:

transaction - The transaction in which to remove all entities.

ensure

public final void ensure(@Nonnull
                         Transaction transaction,
                         Object id)

Ensures that the entity with a specified EntityIdentifier (get) is not removed or replaced with a different entity with the same identifier before a transaction is committed. If another transaction commits first and removes or replaces the entity, the transaction will raise a TransactionConflictException when it is committed. It is valid to call this method with an id that is not present in the entity set. In that case, a TransactionConflictException will be thrown if an entity with id is added to the entity set in another transaction.

Parameters:

transaction - The transaction for which to ensure an entity identifier.

id - The entity identifier to ensure.

ensureAll

public final void ensureAll(@Nonnull
                            Transaction transaction)

Ensures that the entity set does not change at all before the transaction is committed. If another transaction commits first and makes any changes to the entity set at all, this transaction will raise a TransactionConflictException when it is committed.

Parameters:

transaction - The transaction for which the entity set should not change.

getContext

public final TransactionContext getContext()

Gets the context used for transactions on this entity set.

getOwner

public final Object getOwner()

Gets the owner of this entity set.