cz.o2.proxima.direct.commitlog

Class CommitLogReaders.ForwardingCommitLogReader

java.lang.Object

cz.o2.proxima.direct.commitlog.CommitLogReaders.ForwardingCommitLogReader

All Implemented Interfaces:

CommitLogReader

Direct Known Subclasses:

CommitLogReaders.LimitedCommitLogReader

Enclosing class:

CommitLogReaders

private static class CommitLogReaders.ForwardingCommitLogReader
extends java.lang.Object
implements CommitLogReader

Nested Class Summary

Nested classes/interfaces inherited from interface cz.o2.proxima.direct.commitlog.CommitLogReader

CommitLogReader.Factory<T extends CommitLogReader>

Field Summary

Fields

Modifier and Type	Field and Description
private CommitLogReader	delegate

Constructor Summary

Constructors

Modifier	Constructor and Description
private	ForwardingCommitLogReader(CommitLogReader delegate)

Method Summary

Modifier and Type	Method and Description
CommitLogReader.Factory<?>	asFactory() Convert instance of this reader to CommitLogReader.Factory suitable for serialization.
java.util.List<Partition>	getPartitions() Retrieve list of partitions of this commit log.
java.net.URI	getUri() Retrieve URI representing this resource.
boolean	hasExternalizableOffsets() Signals the user that offsets used by this reader can be externalized and reused later.
ObserveHandle	observe(java.lang.String name, Position position, LogObserver observer) Subscribe observer by name to the commit log.
ObserveHandle	observeBulk(java.lang.String name, Position position, boolean stopAtCurrent, LogObserver observer) Subscribe to the commit log in a bulk fashion.
ObserveHandle	observeBulkOffsets(java.util.Collection<Offset> offsets, boolean stopAtCurrent, LogObserver observer) Consume from given offsets in a bulk fashion.
ObserveHandle	observeBulkPartitions(java.lang.String name, java.util.Collection<Partition> partitions, Position position, boolean stopAtCurrent, LogObserver observer) Subscribe to given partitions in a bulk fashion.
ObserveHandle	observePartitions(java.lang.String name, java.util.Collection<Partition> partitions, Position position, boolean stopAtCurrent, LogObserver observer) Subscribe to given set of partitions.
java.lang.String	toString()

Methods inherited from class java.lang.Object

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

Methods inherited from interface cz.o2.proxima.direct.commitlog.CommitLogReader

observe, observeBulk, observeBulk, observeBulkOffsets, observeBulkPartitions, observeBulkPartitions, observeBulkPartitions, observePartitions, observePartitions, observePartitions

Field Detail

delegate

private final CommitLogReader delegate

Constructor Detail

ForwardingCommitLogReader

private ForwardingCommitLogReader(CommitLogReader delegate)

Method Detail

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

getUri

public java.net.URI getUri()

Description copied from interface: CommitLogReader

Retrieve URI representing this resource.

Specified by:

getUri in interface CommitLogReader

Returns:

URI representing this resource

getPartitions

public java.util.List<Partition> getPartitions()

Description copied from interface: CommitLogReader

Retrieve list of partitions of this commit log.

Specified by:

getPartitions in interface CommitLogReader

Returns:

list of partitions of this reader

observe

public ObserveHandle observe(java.lang.String name,
                             Position position,
                             LogObserver observer)

Description copied from interface: CommitLogReader

Subscribe observer by name to the commit log. Each observer maintains its own position in the commit log, so that the observers with different names do not interfere If multiple observers share the same name, then the ingests are load-balanced between them (in an undefined manner). This is a non blocking call.

Specified by:

observe in interface CommitLogReader

Parameters:

name - identifier of the consumer

position - the position to seek for in the commit log

observer - the observer to subscribe to the commit log

Returns:

ObserveHandle to asynchronously cancel the observation

observePartitions

public ObserveHandle observePartitions(java.lang.String name,
                                       java.util.Collection<Partition> partitions,
                                       Position position,
                                       boolean stopAtCurrent,
                                       LogObserver observer)

Description copied from interface: CommitLogReader

Subscribe to given set of partitions. If you use this call then the reader stops being automatically load balanced and the set of partitions can only be changed by call to this method again.

Specified by:

observePartitions in interface CommitLogReader

Parameters:

name - name of the observer

partitions - the list of partitions to subscribe to

position - the position to seek to in the partitions

stopAtCurrent - when true then stop the observer as soon as it reaches most recent record

observer - the observer to subscribe to the partitions

Returns:

ObserveHandle to asynchronously cancel the observation

observeBulk

public ObserveHandle observeBulk(java.lang.String name,
                                 Position position,
                                 boolean stopAtCurrent,
                                 LogObserver observer)

Description copied from interface: CommitLogReader

Subscribe to the commit log in a bulk fashion. That implies that elements are not committed one-by-one, but in a bulks, where all elements in a bulk are committed at once. This is useful for micro-batching approach of data processing.

Specified by:

observeBulk in interface CommitLogReader

Parameters:

name - name of the observer

position - the position to seek to in the partitions

stopAtCurrent - when true then stop the observer as soon as it reaches most recent record

observer - the observer to subscribe

Returns:

ObserveHandle to asynchronously cancel the observation

observeBulkPartitions

public ObserveHandle observeBulkPartitions(java.lang.String name,
                                           java.util.Collection<Partition> partitions,
                                           Position position,
                                           boolean stopAtCurrent,
                                           LogObserver observer)

Description copied from interface: CommitLogReader

Subscribe to given partitions in a bulk fashion.

Specified by:

observeBulkPartitions in interface CommitLogReader

Parameters:

name - name of the observer

partitions - the partitions to subscribe to

position - the position to seek to in the partitions

stopAtCurrent - when true then stop the observer as soon as it reaches most recent record

observer - the observer to subscribe to the partitions

Returns:

ObserveHandle to asynchronously cancel the observation

observeBulkOffsets

public ObserveHandle observeBulkOffsets(java.util.Collection<Offset> offsets,
                                        boolean stopAtCurrent,
                                        LogObserver observer)

Description copied from interface: CommitLogReader

Consume from given offsets in a bulk fashion. A typical use-case for this type of consumption is to first use CommitLogReader.observeBulkPartitions(java.lang.String, java.util.Collection<cz.o2.proxima.storage.Partition>, cz.o2.proxima.storage.commitlog.Position, cz.o2.proxima.direct.commitlog.LogObserver), observe for some time, than interrupt the consumption, store associated offsets and resume the consumption from these offsets later

Specified by:

observeBulkOffsets in interface CommitLogReader

Parameters:

offsets - the @{link Offset}s to subscribe to

stopAtCurrent - true if the processing should stop at current offsets

observer - the observer to subscribe to the offsets

Returns:

ObserveHandle to asynchronously cancel the observation

asFactory

public CommitLogReader.Factory<?> asFactory()

Description copied from interface: CommitLogReader

Convert instance of this reader to CommitLogReader.Factory suitable for serialization.

Specified by:

asFactory in interface CommitLogReader

Returns:

the CommitLogReader.Factory representing this reader

hasExternalizableOffsets

public boolean hasExternalizableOffsets()

Description copied from interface: CommitLogReader

Signals the user that offsets used by this reader can be externalized and reused later.

Specified by:

hasExternalizableOffsets in interface CommitLogReader

Returns:

true if Offsets of this reader are externalizable