org.infinispan.persistence.support

Class DelegatingNonBlockingStore<K,V>

java.lang.Object

org.infinispan.persistence.support.DelegatingNonBlockingStore<K,V>

All Implemented Interfaces:

NonBlockingStore<K,V>

Direct Known Subclasses:

AsyncNonBlockingStore

public abstract class DelegatingNonBlockingStore<K,V>
extends Object
implements NonBlockingStore<K,V>

Nested Class Summary

Nested classes/interfaces inherited from interface org.infinispan.persistence.spi.NonBlockingStore

NonBlockingStore.Characteristic, NonBlockingStore.SegmentedPublisher<Type>

Constructor Summary

Constructors

Constructor and Description
DelegatingNonBlockingStore()

Method Summary

Modifier and Type	Method and Description
CompletionStage<Void>	addSegments(IntSet segments) Invoked when a node becomes an owner of the given segments.
CompletionStage<Long>	approximateSize(IntSet segments) Returns an estimation of the amount of entries that map to the given segments in the store.
CompletionStage<Void>	batch(int publisherCount, org.reactivestreams.Publisher<NonBlockingStore.SegmentedPublisher<Object>> removePublisher, org.reactivestreams.Publisher<NonBlockingStore.SegmentedPublisher<MarshallableEntry<K,V>>> writePublisher) Writes and removes the entries provided by the Publishers into the store.
Set<NonBlockingStore.Characteristic>	characteristics() Returns a set of characteristics for this store and its elements.
CompletionStage<Void>	clear() Clears all entries from the store.
CompletionStage<Void>	commit(Transaction transaction) Commit changes in the provided transaction to the underlying store.
CompletionStage<Boolean>	containsKey(int segment, Object key) Returns a stage that will contain whether the value can be found in the store.
abstract NonBlockingStore<K,V>	delegate()
CompletionStage<Boolean>	delete(int segment, Object key) Removes the entry for given key and segment from the store returning a stage that when completes normally contains whether the entry was actually removed or not.
boolean	ignoreCommandWithFlags(long commandFlags) Some stores may not want to perform operations based on if a command has certain flags.
CompletionStage<Boolean>	isAvailable() Returns a stage that, when complete, returns a boolean indicating whether the current store can be accessed for requests.
CompletionStage<MarshallableEntry<K,V>>	load(int segment, Object key) Returns a stage that will contain the value loaded from the store.
CompletionStage<Void>	prepareWithModifications(Transaction transaction, int publisherCount, org.reactivestreams.Publisher<NonBlockingStore.SegmentedPublisher<Object>> removePublisher, org.reactivestreams.Publisher<NonBlockingStore.SegmentedPublisher<MarshallableEntry<K,V>>> writePublisher) Write remove and put modifications to the store in the prepare phase, which should not yet persisted until the same transaction is committed via NonBlockingStore.commit(Transaction) or they are discarded if the transaction is rolled back via NonBlockingStore.rollback(Transaction).
org.reactivestreams.Publisher<MarshallableEntry<K,V>>	publishEntries(IntSet segments, Predicate<? super K> filter, boolean includeValues) Publishes entries from this store that are in one of the provided segments and also pass the provided filter.
org.reactivestreams.Publisher<K>	publishKeys(IntSet segments, Predicate<? super K> filter) Publishes keys from this store that are in one of the provided segments and also pass the provided filter.
org.reactivestreams.Publisher<MarshallableEntry<K,V>>	purgeExpired() Returns a Publisher that, after it is subscribed to, removes any expired entries from the store and publishes them to the returned Publisher.
CompletionStage<Void>	removeSegments(IntSet segments) Invoked when a node loses ownership of the given segments.
CompletionStage<Void>	rollback(Transaction transaction) Roll back the changes from the provided transaction to the underlying store.
CompletionStage<Long>	size(IntSet segments) Returns the amount of entries that map to the given segments in the store.
CompletionStage<Void>	start(InitializationContext ctx) The first method to invoke so that the store can be configured and additional steps, such as connecting through a socket or opening file descriptors, are performed.
CompletionStage<Void>	stop() This method is invoked when the cache is being shutdown.
CompletionStage<Void>	write(int segment, MarshallableEntry<? extends K,? extends V> entry) Writes the entry to the store for the given segment returning a stage that completes normally when it is finished.

Methods inherited from class java.lang.Object

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

Constructor Detail

DelegatingNonBlockingStore

public DelegatingNonBlockingStore()

Method Detail

delegate

public abstract NonBlockingStore<K,V> delegate()

start

public CompletionStage<Void> start(InitializationContext ctx)

Description copied from interface: NonBlockingStore

The first method to invoke so that the store can be configured and additional steps, such as connecting through a socket or opening file descriptors, are performed.

The provided InitializationContext contains many helpful objects, including the configuration of the cache and store, concurrency utilities such as BlockingManager or an executor reserved for non-blocking operations only InitializationContext.getNonBlockingExecutor().

This method is guaranteed not to be invoked concurrently with other operations. This means other methods are not invoked on this store until after the returned Stage completes.

It is expected that an implementation should be able to "restart" by invoking start a second time if NonBlockingStore.stop() has been invoked and allowed for its stage to complete.

Specified by:

start in interface NonBlockingStore<K,V>

Parameters:

ctx - initialization context used to initialize this store.

Returns:

a stage that, when complete, indicates that this store has started successfully.

stop

public CompletionStage<Void> stop()

Description copied from interface: NonBlockingStore

This method is invoked when the cache is being shutdown. It is expected that all resources related to the store are freed when the returned stage is complete.

This method is guaranteed not to be invoked concurrently with other operations. This means other methods are not invoked on this store until after the returned Stage completes.

It is expected that an implementation should be able to "restart" by invoking NonBlockingStore.start(InitializationContext) a second time if stop has been invoked and allowed for its stage to complete.

Specified by:

stop in interface NonBlockingStore<K,V>

Returns:

a stage that, when complete, indicates that this store has stopped.

characteristics

public Set<NonBlockingStore.Characteristic> characteristics()

Description copied from interface: NonBlockingStore

Returns a set of characteristics for this store and its elements. This method may be invoked multiple times to determine which methods of the store can be used and how the data in the store can be handled.

Refer to NonBlockingStore.Characteristic and its values for descriptions of each characteristic for stores.

Specified by:

characteristics in interface NonBlockingStore<K,V>

Returns:

the set of characteristics that this store supports.

isAvailable

public CompletionStage<Boolean> isAvailable()

Description copied from interface: NonBlockingStore

Returns a stage that, when complete, returns a boolean indicating whether the current store can be accessed for requests. This can be useful for store implementations that rely on an external source, such as a remote database, that may become unreachable. This can reduce sending requests to a store that is not available, as subsequent cache requests will result in a StoreUnavailableException being thrown until the store becomes available again.

Store availability is is polled periodically to update the status of stores if their availability changes. This method is not invoked concurrently with itself. In other words, this method is not invoked until after the previous stage has completed. However this method is invoked concurrently with other operations, except for NonBlockingStore.start(InitializationContext) and NonBlockingStore.stop().

If a store is configured to be StoreConfiguration.async() and the store becomes unavailable, then it is possible for the cache operations to be accepted in the interim period between the loss of availability and the modification-queue becoming full. This allows for this store to be unavailable for short periods of time without a StoreUnavailableException being thrown; however if the store does not become available before the queue fills, then a StoreUnavailableException is thrown.

Specified by:

isAvailable in interface NonBlockingStore<K,V>

Returns:

stage that, when complete, indicates if the store is available.

load

public CompletionStage<MarshallableEntry<K,V>> load(int segment,
                                                    Object key)

Description copied from interface: NonBlockingStore

Returns a stage that will contain the value loaded from the store. If a MarshallableEntry needs to be created here, InitializationContext.getMarshallableEntryFactory() ()} and InitializationContext.getByteBufferFactory() should be used.

Summary of Characteristics Effects

Characteristic	Effect
NonBlockingStore.Characteristic.WRITE_ONLY	This method will never be invoked.
NonBlockingStore.Characteristic.EXPIRATION	When set this method must not return expired entries.
NonBlockingStore.Characteristic.SEGMENTABLE	When this is not set the provided segment parameter may be ignored.

If a problem is encountered, it is recommended to wrap any created/caught Throwable in a PersistenceException and the stage be completed exceptionally.

Specified by:

load in interface NonBlockingStore<K,V>

Parameters:

segment - the segment for the given key if segmentation is enabled, otherwise 0.

key - key of the entry to load.

Returns:

a stage that, when complete, contains the store value or null if not present.

containsKey

public CompletionStage<Boolean> containsKey(int segment,
                                            Object key)

Description copied from interface: NonBlockingStore

Returns a stage that will contain whether the value can be found in the store.

Summary of Characteristics Effects

Characteristic	Effect
NonBlockingStore.Characteristic.WRITE_ONLY	This method will never be invoked.
NonBlockingStore.Characteristic.EXPIRATION	When set this method must not return true if the entry was expired.
NonBlockingStore.Characteristic.SEGMENTABLE	When this is not set the provided segment parameter may be ignored.

If a problem is encountered, it is recommended to wrap any created/caught Throwable in a PersistenceException and the stage be completed exceptionally.

Specified by:

containsKey in interface NonBlockingStore<K,V>

Parameters:

segment - the segment for the given key if segmentation is enabled, otherwise 0.

key - key of the entry to check.

Returns:

a stage that, when complete, contains a boolean stating if the value is contained in the store.

write

public CompletionStage<Void> write(int segment,
                                   MarshallableEntry<? extends K,? extends V> entry)

Description copied from interface: NonBlockingStore

Writes the entry to the store for the given segment returning a stage that completes normally when it is finished.

Summary of Characteristics Effects

Characteristic	Effect
NonBlockingStore.Characteristic.READ_ONLY	This method will never be invoked.
NonBlockingStore.Characteristic.EXPIRATION	When set, this method must store the expiration metadata.
NonBlockingStore.Characteristic.SEGMENTABLE	When set, this method must ensure the segment is stored with the entry.

If a problem is encountered, it is recommended to wrap any created/caught Throwable in a PersistenceException and the stage be completed exceptionally.

Specified by:

write in interface NonBlockingStore<K,V>

Parameters:

segment - the segment for the given key if segmentation is enabled, otherwise 0.

entry - the entry to persist to the store.

Returns:

a stage that when complete indicates that the store has written the value.

delete

public CompletionStage<Boolean> delete(int segment,
                                       Object key)

Description copied from interface: NonBlockingStore

Removes the entry for given key and segment from the store returning a stage that when completes normally contains whether the entry was actually removed or not.

Summary of Characteristics Effects

Characteristic	Effect
NonBlockingStore.Characteristic.READ_ONLY	This method will never be invoked.
NonBlockingStore.Characteristic.SEGMENTABLE	When this is not set the provided segment parameter may be ignored.

If a problem is encountered, it is recommended to wrap any created/caught Throwable in a PersistenceException and the stage be completed exceptionally.

Specified by:

delete in interface NonBlockingStore<K,V>

Parameters:

segment - the segment for the given key if segmentation is enabled, otherwise 0.

key - key of the entry to delete from the store.

Returns:

a stage that when complete contains a boolean stating if the value was removed from the store.

addSegments

public CompletionStage<Void> addSegments(IntSet segments)

Description copied from interface: NonBlockingStore

Invoked when a node becomes an owner of the given segments. Some store implementations may require initializing additional resources when a new segment is required. For example a store could store entries in a different file per segment.

Summary of Characteristics Effects

Characteristic	Effect
NonBlockingStore.Characteristic.SHAREABLE	If the store has this characteristic and is configured to be StoreConfiguration.shared(), this method will never be invoked.
NonBlockingStore.Characteristic.SEGMENTABLE	This method is invoked only if the store has this characteristic and configured to be StoreConfiguration.segmented().

If a problem is encountered, it is recommended to wrap any created/caught Throwable in a PersistenceException and the stage be completed exceptionally.

Specified by:

addSegments in interface NonBlockingStore<K,V>

Parameters:

segments - the segments to add.

Returns:

a stage that, when complete, indicates that the segments have been added.

removeSegments

public CompletionStage<Void> removeSegments(IntSet segments)

Description copied from interface: NonBlockingStore

Invoked when a node loses ownership of the given segments. A store must then remove any entries that map to the given segments and can remove any resources related to the given segments. For example, a database store can delete rows of the given segment or a file-based store can delete files related to the given segments.

Summary of Characteristics Effects

Characteristic	Effect
NonBlockingStore.Characteristic.SHAREABLE	If the store has this characteristic and is configured to be StoreConfiguration.shared(), this method will never be invoked.
NonBlockingStore.Characteristic.SEGMENTABLE	This method is invoked only if the store has this characteristic and configured to be StoreConfiguration.segmented().

If a problem is encountered, it is recommended to wrap any created/caught Throwable in a PersistenceException and the stage be completed exceptionally.

Specified by:

removeSegments in interface NonBlockingStore<K,V>

Parameters:

segments - the segments to remove.

Returns:

a stage that, when complete, indicates that the segments have been removed.

clear

public CompletionStage<Void> clear()

Description copied from interface: NonBlockingStore

Clears all entries from the store.

Summary of Characteristics Effects

Characteristic	Effect
NonBlockingStore.Characteristic.READ_ONLY	This method will never be invoked.

If a problem is encountered, it is recommended to wrap any created/caught Throwable in a PersistenceException and the stage be completed exceptionally.

Specified by:

clear in interface NonBlockingStore<K,V>

Returns:

a stage that, when complete, indicates that the store has been cleared.

batch

public CompletionStage<Void> batch(int publisherCount,
                                   org.reactivestreams.Publisher<NonBlockingStore.SegmentedPublisher<Object>> removePublisher,
                                   org.reactivestreams.Publisher<NonBlockingStore.SegmentedPublisher<MarshallableEntry<K,V>>> writePublisher)

Description copied from interface: NonBlockingStore

Writes and removes the entries provided by the Publishers into the store. Both are provided in the same method so that a batch may be performed as a single atomic operation if desired, although it is up to the store to manage its batching. If needed a store may generate batches of a configured size by using the StoreConfiguration.maxBatchSize() setting.

Each of the Publishers may publish up to publisherCount publishers where each publisher is separated by the segment each entry maps to. Failure to request at least publisherCount publishers from the Publisher may cause a deadlock. Many reactive tools have methods such as flatMap that take an argument of how many concurrent subscriptions it manages, which is perfectly matched with this argument.

WARNING: For performance reasons neither Publisher will emit any NonBlockingStore.SegmentedPublishers until both the write and remove Publisher are subscribed to. These Publishers should also be only subscribed to once.

Summary of Characteristics Effects

Characteristic	Effect
NonBlockingStore.Characteristic.READ_ONLY	This method will never be invoked.
NonBlockingStore.Characteristic.SEGMENTABLE	If not set, the provided publisherCount parameter has a value of 1, which means there is only be one SegmentedPublisher to subscribe to.

If a problem is encountered, it is recommended to wrap any created/caught Throwable in a PersistenceException and the stage be completed exceptionally.

Specified by:

batch in interface NonBlockingStore<K,V>

Parameters:

publisherCount - the maximum number of SegmentPublishers either publisher will publish

removePublisher - publishes what keys should be removed from the store

writePublisher - publishes the entries to write to the store

Returns:

a stage that when complete signals that the store has written the values

size

public CompletionStage<Long> size(IntSet segments)

Description copied from interface: NonBlockingStore

Returns the amount of entries that map to the given segments in the store.

Summary of Characteristics Effects

Characteristic	Effect
NonBlockingStore.Characteristic.BULK_READ	This method is only invoked if the store has this characteristic.
NonBlockingStore.Characteristic.SEGMENTABLE	When this is not set the provided segments parameter may be ignored.

If a problem is encountered, it is recommended to wrap any created/caught Throwable in a PersistenceException and the stage be completed exceptionally.

Specified by:

size in interface NonBlockingStore<K,V>

Parameters:

segments - the segments for which the entries are counted.

Returns:

a stage that, when complete, contains the count of how many entries are present for the given segments.

approximateSize

public CompletionStage<Long> approximateSize(IntSet segments)

Description copied from interface: NonBlockingStore

Returns an estimation of the amount of entries that map to the given segments in the store. This is similar to NonBlockingStore.size(IntSet) except that it is not strict about the returned size. For instance, this method might ignore if an entry is expired or if the store has some underlying optimizations to eventually have a consistent size.

Summary of Characteristics Effects

Characteristic	Effect
NonBlockingStore.Characteristic.BULK_READ	This method is only invoked if the store has this characteristic.
NonBlockingStore.Characteristic.SEGMENTABLE	When this is not set the provided segments parameter may be ignored.

If a problem is encountered, it is recommended to wrap any created/caught Throwable in a PersistenceException and the stage be completed exceptionally.

Specified by:

approximateSize in interface NonBlockingStore<K,V>

Parameters:

segments - the segments for which the entries are counted.

Returns:

a stage that, when complete, contains the count of how many entries are present for the given segments.

publishEntries

public org.reactivestreams.Publisher<MarshallableEntry<K,V>> publishEntries(IntSet segments,
                                                                            Predicate<? super K> filter,
                                                                            boolean includeValues)

Description copied from interface: NonBlockingStore

Publishes entries from this store that are in one of the provided segments and also pass the provided filter. The returned publisher must support being subscribed to any number of times. That is subsequent invocations of Publisher.subscribe(Subscriber) should provide independent views of the underlying entries to the Subscribers. Entries should not retrieved until a given Subscriber requests them via the Subscription.request(long) method.

Subscribing to the returned Publisher should not block the invoking thread. It is the responsibility of the store implementation to ensure this occurs. If however the store must block to perform an operation it is recommended to wrap your Publisher before returning with the BlockingManager.blockingPublisher(Publisher) method and it will handle subscription and observation on the blocking and non-blocking executors respectively.

Summary of Characteristics Effects

Characteristic	Effect
NonBlockingStore.Characteristic.BULK_READ	This method is only invoked if the store has this characteristic.
NonBlockingStore.Characteristic.EXPIRATION	When set the returned publisher must not return expired entries.
NonBlockingStore.Characteristic.SEGMENTABLE	When this is not set the provided segments parameter may be ignored.

Specified by:

publishEntries in interface NonBlockingStore<K,V>

Parameters:

segments - a set of segments to filter entries by. This will always be non null.

filter - a filter to filter they keys by. If this is null then no additional filtering should be done after segments.

Returns:

a publisher that provides the keys from the store.

publishKeys

public org.reactivestreams.Publisher<K> publishKeys(IntSet segments,
                                                    Predicate<? super K> filter)

Description copied from interface: NonBlockingStore

Publishes keys from this store that are in one of the provided segments and also pass the provided filter. The returned publisher must support being subscribed to any number of times. That is subsequent invocations of Publisher.subscribe(Subscriber) should provide independent views of the underlying keys to the Subscribers. Keys should not retrieved until a given Subscriber requests them via the Subscription.request(long) method.

Subscribing to the returned Publisher should not block the invoking thread. It is the responsibility of the store implementation to ensure this occurs. If however the store must block to perform an operation it is recommended to wrap your Publisher before returning with the BlockingManager.blockingPublisher(Publisher) method and it will handle subscription and observation on the blocking and non blocking executors respectively.

Summary of Characteristics Effects

Characteristic	Effect
NonBlockingStore.Characteristic.BULK_READ	This method is only invoked if the store has this characteristic.
NonBlockingStore.Characteristic.EXPIRATION	When set the returned publisher must not return expired keys.
NonBlockingStore.Characteristic.SEGMENTABLE	When this is not set the provided segments parameter may be ignored.

Specified by:

publishKeys in interface NonBlockingStore<K,V>

Parameters:

segments - a set of segments to filter keys by. This will always be non null.

filter - a filter to filter they keys by. If this is null then no additional filtering should be done after segments.

Returns:

a publisher that provides the keys from the store.

purgeExpired

public org.reactivestreams.Publisher<MarshallableEntry<K,V>> purgeExpired()

Description copied from interface: NonBlockingStore

Returns a Publisher that, after it is subscribed to, removes any expired entries from the store and publishes them to the returned Publisher.

When the Publisher is subscribed to, it is expected to do point-in-time expiration and should not return a Publisher that has infinite entries or never completes.

Subscribing to the returned Publisher should not block the invoking thread. It is the responsibility of the store implementation to ensure this occurs. If however the store must block to perform an operation it is recommended to wrap your Publisher before returning with the BlockingManager.blockingPublisher(Publisher) method and it will handle subscription and observation on the blocking and non blocking executors respectively.

Summary of Characteristics Effects

Characteristic	Effect
NonBlockingStore.Characteristic.EXPIRATION	This method is only invoked if the store has this characteristic.

If a problem is encountered, it is recommended to wrap any created/caught Throwable in a PersistenceException and the stage be completed exceptionally.

Specified by:

purgeExpired in interface NonBlockingStore<K,V>

Returns:

a Publisher that publishes the entries that are expired at the time of subscription.

prepareWithModifications

public CompletionStage<Void> prepareWithModifications(Transaction transaction,
                                                      int publisherCount,
                                                      org.reactivestreams.Publisher<NonBlockingStore.SegmentedPublisher<Object>> removePublisher,
                                                      org.reactivestreams.Publisher<NonBlockingStore.SegmentedPublisher<MarshallableEntry<K,V>>> writePublisher)

Description copied from interface: NonBlockingStore

Write remove and put modifications to the store in the prepare phase, which should not yet persisted until the same transaction is committed via NonBlockingStore.commit(Transaction) or they are discarded if the transaction is rolled back via NonBlockingStore.rollback(Transaction).

Each of the Publishers may publish up to publisherCount publishers where each publisher is separated by the segment each entry maps to. Failure to request at least publisherCount publishers from the Publisher may cause a deadlock. Many reactive tools have methods such as flatMap that take an argument of how many concurrent subscriptions it manages, which is perfectly matched with this argument.

WARNING: For performance reasons neither Publisher will emit any NonBlockingStore.SegmentedPublishers until both the write and remove Publisher are subscribed to. These Publishers should also be only subscribed to once.

Summary of Characteristics Effects

Characteristic	Effect
NonBlockingStore.Characteristic.TRANSACTIONAL	This method is invoked only if the store has this characteristic.

If a problem is encountered, it is recommended to wrap any created/caught Throwable in a PersistenceException and the stage be completed exceptionally.

Specified by:

prepareWithModifications in interface NonBlockingStore<K,V>

Parameters:

transaction - the current transactional context.

publisherCount - the maximum number of SegmentPublishers either publisher will publish

removePublisher - publishes what keys should be removed from the store

writePublisher - publishes the entries to write to the store

Returns:

a stage that when complete signals that the store has written the values

commit

public CompletionStage<Void> commit(Transaction transaction)

Description copied from interface: NonBlockingStore

Commit changes in the provided transaction to the underlying store.

Summary of Characteristics Effects

Characteristic	Effect
NonBlockingStore.Characteristic.TRANSACTIONAL	This method is invoked only if the store has this characteristic.

If a problem is encountered, it is recommended to wrap any created/caught Throwable in a PersistenceException and the stage be completed exceptionally.

Specified by:

commit in interface NonBlockingStore<K,V>

Parameters:

transaction - the current transactional context.

Returns:

a stage that, when completed, indicates that the transaction was committed.

rollback

public CompletionStage<Void> rollback(Transaction transaction)

Description copied from interface: NonBlockingStore

Roll back the changes from the provided transaction to the underlying store.

Summary of Characteristics Effects

Characteristic	Effect
NonBlockingStore.Characteristic.TRANSACTIONAL	This method is invoked only if the store has this characteristic.

If a problem is encountered, it is recommended to wrap any created/caught Throwable in a PersistenceException and the stage be completed exceptionally.

Specified by:

rollback in interface NonBlockingStore<K,V>

Parameters:

transaction - the current transactional context.

Returns:

a stage that, when completed, indicates that the transaction was rolled back.

ignoreCommandWithFlags

public boolean ignoreCommandWithFlags(long commandFlags)

Description copied from interface: NonBlockingStore

Some stores may not want to perform operations based on if a command has certain flags. This method is currently only used for testing single write operations. This method may be removed at any time as it is experimental, it is not recommended for end users to implement it.

Specified by:

ignoreCommandWithFlags in interface NonBlockingStore<K,V>

Parameters:

commandFlags - the flags attributed to the command when performing the operation.

Returns:

whether the operation should occur.