Package cz.o2.proxima.direct.core.view

Interface CachedView

All Superinterfaces:

AttributeWriterBase, java.lang.AutoCloseable, java.io.Closeable, OnlineAttributeWriter, RandomAccessReader

All Known Implementing Classes:

LocalCachedPartitionedView, TransactionalCachedView

@Stable
public interface CachedView
extends RandomAccessReader, OnlineAttributeWriter

A view of commit-log that caches (and potentially checkpoints) data from partitions and makes in random accessible.

Client can provide callbacks to be called on data updates. Client might also update the view, all updates must be persisted in a way that will guarantee that subsequent reloads will contain the new data and that read-write operations have happens-before relation semantics.

Nested Class Summary

Nested Classes

Modifier and Type	Interface	Description
static interface	CachedView.Factory	Serializable factory for CachedView.

Nested classes/interfaces inherited from interface cz.o2.proxima.direct.core.AttributeWriterBase

AttributeWriterBase.Type

Nested classes/interfaces inherited from interface cz.o2.proxima.direct.core.randomaccess.RandomAccessReader

RandomAccessReader.GetRequest<T>, RandomAccessReader.Listing, RandomAccessReader.MultiFetch

Method Summary

Modifier and Type	Method	Description
CachedView.Factory	asFactory()	Convert instance of this view to CachedView.Factory suitable for serialization.
default void	assign(java.util.Collection<Partition> partitions)	Assign and make given partitions accessible by random reads.
default void	assign(java.util.Collection<Partition> partitions, BiConsumer<StreamElement,Pair<java.lang.Long,java.lang.Object>> updateCallback)	Assign and make given partitions accessible by random reads.
void	assign(java.util.Collection<Partition> partitions, BiConsumer<StreamElement,Pair<java.lang.Long,java.lang.Object>> updateCallback, java.time.Duration ttl)	Assign and make given partitions accessible by random reads.
default void	assign(java.util.Collection<Partition> partitions, java.time.Duration ttl)	Assign and make given partitions accessible by random reads.
void	cache(StreamElement element)	Cache given StreamElement into local cache without writing it to the underlying writer.
void	close()	Close allocated resources of this writer.
java.util.Collection<Partition>	getAssigned()	Retrieve currently assigned partitions.
default java.util.Collection<Partition>	getPartitions()	Retrieve all partitions of the underlying commit log.
java.util.Optional<ObserveHandle>	getRunningHandle()	Retrieve a running handle (if present).
CommitLogReader	getUnderlyingReader()	Retrieve underlying CommitLogReader.
OnlineAttributeWriter	getUnderlyingWriter()	Retrieve underlying OnlineAttributeWriter.

Methods inherited from interface cz.o2.proxima.direct.core.AttributeWriterBase

bulk, getUri, online

Methods inherited from interface cz.o2.proxima.direct.core.OnlineAttributeWriter

getType, isTransactional, rollback, transactional, write

Methods inherited from interface cz.o2.proxima.direct.core.randomaccess.RandomAccessReader

fetchOffset, get, get, get, get, get, getEntityDescriptor, listEntities, listEntities, multiFetch, scanWildcard, scanWildcard, scanWildcard, scanWildcard, scanWildcardAll, scanWildcardAll, scanWildcardAll, scanWildcardAll

Method Detail

assign

default void assign(java.util.Collection<Partition> partitions)

Assign and make given partitions accessible by random reads. If the view contains any partitions not listed in the collection, these partitions are dropped.

Parameters:

partitions - the partitions to cache locally

assign

default void assign(java.util.Collection<Partition> partitions,
                    java.time.Duration ttl)

Assign and make given partitions accessible by random reads. If the view contains any partitions not listed in the collection, these partitions are dropped.

Parameters:

partitions - the partitions to cache locally

ttl - maximaul Duration that an update should be kept in the cache NOTE: this is not a hard limit, it is only a signal, that after this time the element can be removed to free up memory

assign

default void assign(java.util.Collection<Partition> partitions,
                    BiConsumer<StreamElement,Pair<java.lang.Long,java.lang.Object>> updateCallback)

Assign and make given partitions accessible by random reads. If the view contains any partitions not listed in the collection, these partitions are dropped.

Parameters:

partitions - the partitions to cache locally

updateCallback - function that is called when cache gets updated the function takes the new ingest element and pair of the most recent object that was associated with the key and it's currently associated stamp

assign

void assign(java.util.Collection<Partition> partitions,
            BiConsumer<StreamElement,Pair<java.lang.Long,java.lang.Object>> updateCallback,
            @Nullable
            java.time.Duration ttl)

Assign and make given partitions accessible by random reads. If the view contains any partitions not listed in the collection, these partitions are dropped.

Parameters:

partitions - the partitions to cache locally

updateCallback - function that is called when cache gets updated the function takes the new ingest element and pair of the most recent object that was associated with the key and it's currently associated stamp

ttl - maximaul Duration that an update should be kept in the cache NOTE: this is not a hard limit, it is only a signal, that after this time the element can be removed to free up memory

getAssigned

java.util.Collection<Partition> getAssigned()

Retrieve currently assigned partitions.

Returns:

currently assigned partitions

cache

void cache(StreamElement element)

Cache given StreamElement into local cache without writing it to the underlying writer. This is used in conjunction with attribute family proxy.

Parameters:

element - the data to cache

getPartitions

default java.util.Collection<Partition> getPartitions()

Retrieve all partitions of the underlying commit log.

Returns:

all partitions of underlying commit log

getUnderlyingReader

CommitLogReader getUnderlyingReader()

Retrieve underlying CommitLogReader.

getUnderlyingWriter

OnlineAttributeWriter getUnderlyingWriter()

Retrieve underlying OnlineAttributeWriter. Note that using this write might not update the cache. In most cases, use OnlineAttributeWriter.write(StreamElement, CommitCallback) directly.

getRunningHandle

java.util.Optional<ObserveHandle> getRunningHandle()

Retrieve a running handle (if present).

asFactory

CachedView.Factory asFactory()

Convert instance of this view to CachedView.Factory suitable for serialization.

Specified by:

asFactory in interface AttributeWriterBase

Specified by:

asFactory in interface OnlineAttributeWriter

Specified by:

asFactory in interface RandomAccessReader

Returns:

the CachedView.Factory representing this view

close

void close()

Description copied from interface: AttributeWriterBase

Close allocated resources of this writer. This is supposed to be idempotent.

Specified by:

close in interface AttributeWriterBase

Specified by:

close in interface java.lang.AutoCloseable

Specified by:

close in interface java.io.Closeable