Package io.deephaven.util.datastructures

Class SubscriptionSet<LISTENER_TYPE>

java.lang.Object

io.deephaven.util.datastructures.SubscriptionSet<LISTENER_TYPE>

public class SubscriptionSet<LISTENER_TYPE>
extends Object

Array-backed set that stores generic listener objects, only enforcing hard reachability on listeners that are SubstitutionWeakReferences.

All public operations (except clear and isEmpty) are O(n). All comparisons are based on object reference equality.

Requires external synchronization for thread safe usage, except where otherwise noted.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
class	SubscriptionSet.Entry	Subscription entry, allowing state associated with a listener.

Constructor Summary

Constructors

Constructor	Description
SubscriptionSet()

Method Summary

Modifier and Type	Method	Description
final boolean	add(LISTENER_TYPE listener, SubscriptionSet<LISTENER_TYPE>.@NotNull Entry entry)	Add a listener to the set, if it's not already present.
final void	clear()	Remove all listeners.
final boolean	collect()	Clean up any GC'd subscriptions.
final <NOTIFICATION_TYPE> boolean	deliverNotification(@NotNull BiConsumer<LISTENER_TYPE,NOTIFICATION_TYPE> procedure, NOTIFICATION_TYPE notification, boolean activeOnly)	Dispatch a unary notification to all subscribers.
final boolean	deliverNotification(@NotNull Consumer<LISTENER_TYPE> procedure, boolean activeOnly)	Dispatch a nullary notification to all subscribers.
final boolean	isEmpty()	Check if this set is empty, without cleaning up existing subscriptions.
final SubscriptionSet<LISTENER_TYPE>.Entry	makeEntryFor(LISTENER_TYPE listener)	Make an entry for a listener, in order to pass it to add(Object, SubscriptionSet.Entry).
final boolean	remove(LISTENER_TYPE listener)	Remove a listener from the set, if it's present.

Methods inherited from class java.lang.Object

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

Constructor Details

SubscriptionSet

public SubscriptionSet()

Method Details

clear

public final void clear()

Remove all listeners.

isEmpty

public final boolean isEmpty()

Check if this set is empty, without cleaning up existing subscriptions.

Returns:

Whether this set is empty

collect

public final boolean collect()

Clean up any GC'd subscriptions.

Returns:

Whether this operation caused the set to become empty

makeEntryFor

public final SubscriptionSet<LISTENER_TYPE>.Entry makeEntryFor(LISTENER_TYPE listener)

Make an entry for a listener, in order to pass it to add(Object, SubscriptionSet.Entry). May be called without holding any locks.

Parameters:

listener - The listener

Returns:

A new entry for the listener

add

public final boolean add(@NotNull
 LISTENER_TYPE listener,
 @NotNull
 SubscriptionSet<LISTENER_TYPE>.@NotNull Entry entry)

Add a listener to the set, if it's not already present. Clean up any GC'd subscriptions. See makeEntryFor(Object).

Parameters:

listener - The listener to be added

entry - An entry for the listener to be added

Returns:

Whether this operation caused the set to become non-empty

remove

public final boolean remove(LISTENER_TYPE listener)

Remove a listener from the set, if it's present. Clean up any GC'd subscriptions.

Parameters:

listener - The listener to remove

Returns:

Whether this operation caused the set to become empty

deliverNotification

public final boolean deliverNotification(@NotNull
 @NotNull Consumer<LISTENER_TYPE> procedure,
 boolean activeOnly)

Dispatch a nullary notification to all subscribers. Clean up any GC'd subscriptions.

Parameters:

procedure - The notification procedure to invoke

activeOnly - Whether to restrict this notification to active subscriptions only

Returns:

Whether this operation caused the set to become empty

deliverNotification

public final <NOTIFICATION_TYPE> boolean deliverNotification(@NotNull
 @NotNull BiConsumer<LISTENER_TYPE,NOTIFICATION_TYPE> procedure,
 @Nullable
 NOTIFICATION_TYPE notification,
 boolean activeOnly)

Dispatch a unary notification to all subscribers. Clean up any GC'd subscriptions.

Parameters:

procedure - The notification procedure to invoke

notification - The notification to deliver

activeOnly - Whether to restrict this notification to active subscriptions only

Returns:

Whether this operation caused the set to become empty