Interface QueueStore<T>

Type Parameters:

T - queue item type

public interface QueueStore<T>

Service Provider Interface (SPI) for backing a DistributedQueue with an external persistent store.

Queue entries are identified by monotonically increasing Long item IDs. Implementations are expected to be thread-safe.

Method Summary

Modifier and Type	Method	Description
void	delete(Long key)	Delete one persisted queue item.
default void	deleteAll(Collection<Long> keys)	Delete multiple persisted queue items.
@Nullable T	load(Long key)	Load one persisted queue item.
default @Nullable Map<Long,T>	loadAll(Collection<Long> keys)	Load multiple queue items.
default @Nullable Set<Long>	loadAllKeys()	Load all persisted queue item IDs.
void	store(Long key, T value)	Persist one queue item.
default void	storeAll(Map<Long, ? extends T> map)	Persist multiple queue items.

Method Details

store

void store(Long key,
 T value)

Persist one queue item.

Parameters:

key - queue item ID

value - item value

storeAll

default void storeAll(Map<Long, ? extends T> map)

Persist multiple queue items. Override when the backing store can batch writes more efficiently.

Parameters:

map - entries to persist

delete

void delete(Long key)

Delete one persisted queue item.

Parameters:

key - queue item ID

deleteAll

default void deleteAll(Collection<Long> keys)

Delete multiple persisted queue items.

Parameters:

keys - queue item IDs

load

@Nullable T load(Long key)

Load one persisted queue item.

Parameters:

key - queue item ID

Returns:

stored item, or null when absent

loadAll

default @Nullable Map<Long,T> loadAll(Collection<Long> keys)

Load multiple queue items.

Parameters:

keys - queue item IDs

Returns:

loaded entries, or null when none were loaded

loadAllKeys

default @Nullable Set<Long> loadAllKeys()

Load all persisted queue item IDs. The queue sorts IDs ascending during recovery, so implementations do not need to return them in FIFO order.

Returns:

item IDs, or null when no keys are available