net.openhft.chronicle.queue.impl.single

Class SingleChronicleQueueExcerpts.StoreTailer

java.lang.Object

net.openhft.chronicle.queue.impl.single.SingleChronicleQueueExcerpts.StoreTailer

All Implemented Interfaces:

ExcerptCommon<ExcerptTailer>, ExcerptTailer, ExcerptContext, net.openhft.chronicle.wire.MarshallableIn, net.openhft.chronicle.wire.SourceContext

Enclosing class:

SingleChronicleQueueExcerpts

public static class SingleChronicleQueueExcerpts.StoreTailer
extends Object
implements ExcerptTailer, net.openhft.chronicle.wire.SourceContext, ExcerptContext

Tailer

Field Summary

Fields inherited from interface net.openhft.chronicle.wire.MarshallableIn

MARSHALLABLE_IN_INTERN_SIZE

Constructor Summary

Constructors

Constructor and Description
StoreTailer(SingleChronicleQueue queue)
StoreTailer(SingleChronicleQueue queue, net.openhft.chronicle.core.values.LongValue indexValue)

Method Summary

Modifier and Type	Method and Description
ExcerptTailer	afterLastWritten(ChronicleQueue queue) Winds this Tailer to after the last entry which wrote an entry to the queue.
int	cycle() Returns the current cycle for this Trailer.
TailerDirection	direction() Returns the direction of this Tailer.
ExcerptTailer	direction(TailerDirection direction) Returns the direction of this Tailer.
Runnable	getCloserJob() Returns the task that will be run if a WeakReference referring this appender is registered with a clean-up task.
long	index() Returns the current index of this Trailer.
boolean	moveToIndex(long index) Moves the index for this Trailer to the provided index.
ExcerptTailer	originalToEnd()
boolean	peekDocument() Returns if it is likely that ExcerptTailer.readingDocument() would return a DocumentContext that provides excerpts to read.
ChronicleQueue	queue() Returns the backing ChronicleQueue to which this ExcerptCommon is attached to.
boolean	readAfterReplicaAcknowledged() Returns the Read After Replica Acknowledged property of this Trailer.
void	readAfterReplicaAcknowledged(boolean readAfterReplicaAcknowledged) Sets the Read After Replica Acknowledged property of this Trailer to the provided readAfterReplicaAcknowledged.
boolean	readDocument(net.openhft.chronicle.wire.ReadMarshallable reader)
static net.openhft.chronicle.wire.MessageHistory	readHistory(net.openhft.chronicle.wire.DocumentContext dc, net.openhft.chronicle.wire.MessageHistory history)
net.openhft.chronicle.wire.DocumentContext	readingDocument() Returns the DocumentContext for this ExcerptTailer.
net.openhft.chronicle.wire.DocumentContext	readingDocument(boolean includeMetaData) Returns the DocumentContext for this ExcerptTailer.
void	releaseResources() Can be used to manually release resources when this StoreTailer is no longer used.
void	setCycle(int cycle)
int	sourceId() Returns the source id of the backing ChronicleQueue to which this ExcerptCommon is attached to.
TailerState	state() Returns the TailerState of this Trailer.
boolean	striding() Returns the striding property of this Trailer.
ExcerptTailer	striding(boolean striding) Sets the striding property of this Trailer.
long	timeoutMS()
ExcerptTailer	toEnd() Moves the index for this Trailer to the end of the queue.
ExcerptTailer	toStart() Moves the index for this Trailer to the first existing excerpt in the queue.
String	toString()
net.openhft.chronicle.wire.Wire	wire()
net.openhft.chronicle.wire.Wire	wireForIndex()

Methods inherited from class java.lang.Object

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

Methods inherited from interface net.openhft.chronicle.wire.MarshallableIn

methodReader, methodReaderBuilder, readBytes, readBytes, readMap, readText, readText

Constructor Detail

StoreTailer

public StoreTailer(@NotNull
                   SingleChronicleQueue queue)

StoreTailer

public StoreTailer(@NotNull
                   SingleChronicleQueue queue,
                   net.openhft.chronicle.core.values.LongValue indexValue)

Method Detail

readHistory

@Nullable
public static net.openhft.chronicle.wire.MessageHistory readHistory(net.openhft.chronicle.wire.DocumentContext dc,
                                                                              net.openhft.chronicle.wire.MessageHistory history)

readDocument

public boolean readDocument(@NotNull
                            net.openhft.chronicle.wire.ReadMarshallable reader)

Specified by:

readDocument in interface net.openhft.chronicle.wire.MarshallableIn

readingDocument

@NotNull
public net.openhft.chronicle.wire.DocumentContext readingDocument()

Description copied from interface: ExcerptTailer

Returns the DocumentContext for this ExcerptTailer.

This is equivalent to MarshallableIn.readDocument(ReadMarshallable) but without the use of a lambda expression.

This method is the ExcerptTailer equivalent of WireIn.readingDocument()

Specified by:

readingDocument in interface ExcerptTailer

Specified by:

readingDocument in interface net.openhft.chronicle.wire.MarshallableIn

Returns:

the document context

wire

public net.openhft.chronicle.wire.Wire wire()

Specified by:

wire in interface ExcerptContext

wireForIndex

public net.openhft.chronicle.wire.Wire wireForIndex()

Specified by:

wireForIndex in interface ExcerptContext

timeoutMS

public long timeoutMS()

Specified by:

timeoutMS in interface ExcerptContext

sourceId

public int sourceId()

Description copied from interface: ExcerptCommon

Returns the source id of the backing ChronicleQueue to which this ExcerptCommon is attached to.

Specified by:

sourceId in interface ExcerptCommon<ExcerptTailer>

Specified by:

sourceId in interface net.openhft.chronicle.wire.SourceContext

Returns:

the source id of the backing ChronicleQueue

See Also:

ChronicleQueue.sourceId()

toString

@NotNull
public String toString()

Overrides:

toString in class Object

readingDocument

@NotNull
public net.openhft.chronicle.wire.DocumentContext readingDocument(boolean includeMetaData)

Description copied from interface: ExcerptTailer

Returns the DocumentContext for this ExcerptTailer.

This is equivalent to MarshallableIn.readDocument(ReadMarshallable) but without the use of a lambda expression.

This method is the ExcerptTailer equivalent of WireIn.readingDocument()

Specified by:

readingDocument in interface ExcerptTailer

Parameters:

includeMetaData - if the DocumentContext shall be meta data aware.

Returns:

the document context

peekDocument

public boolean peekDocument()

Description copied from interface: ExcerptTailer

Returns if it is likely that ExcerptTailer.readingDocument() would return a DocumentContext that provides excerpts to read. peekDocument() can be used after a message has been found by toStart() or readingDocument(). Until then only readingDocument() will find the first cycle.

Specified by:

peekDocument in interface ExcerptTailer

Specified by:

peekDocument in interface net.openhft.chronicle.wire.MarshallableIn

Returns:

if it is likely that ExcerptTailer.readingDocument() would return a DocumentContext that provides excerpts to read.

index

public long index()

Description copied from interface: ExcerptTailer

Returns the current index of this Trailer.

If this method is invoked within a try (tailer.readingDocument){ } block, returns the index of the current reading document. Otherwise, returns the next index to read.

The index includes the cycle and the sequence number within that cycle.

Specified by:

index in interface ExcerptTailer

Specified by:

index in interface net.openhft.chronicle.wire.SourceContext

Returns:

provides an index that includes the cycle number

cycle

public int cycle()

Description copied from interface: ExcerptTailer

Returns the current cycle for this Trailer.

Usually, each cycle will have its own unique data file to store excerpts.

Specified by:

cycle in interface ExcerptTailer

Returns:

Returns the current cycle for this Trailer

moveToIndex

public boolean moveToIndex(long index)

Description copied from interface: ExcerptTailer

Moves the index for this Trailer to the provided index.

The index contains both the cycle number and sequence number within the cycle.

If the index is not a valid index, the operation is undefined.

Specified by:

moveToIndex in interface ExcerptTailer

Parameters:

index - index to move to.

Returns:

if this is a valid index.

toStart

@NotNull
public final ExcerptTailer toStart()

Description copied from interface: ExcerptTailer

Moves the index for this Trailer to the first existing excerpt in the queue.

Specified by:

toStart in interface ExcerptTailer

Returns:

this ExcerptTrailer

toEnd

@NotNull
public ExcerptTailer toEnd()

Description copied from interface: ExcerptTailer

Moves the index for this Trailer to the end of the queue.

If the direction() == FORWARD, this will be the index position corresponding to one more than the last entry. Otherwise, the index will be the last excerpt.

This is not atomic with the appenders, in other words if a cycle has been added in the current millisecond, toEnd() may not see it, This is because for performance reasons, the queue.lastCycle() is cached, as finding the last cycle is expensive, it requires asking the directory for the Files.list() so, this cache is only refreshed if the call toEnd() is in a new millisecond. Hence a whole milliseconds with of data could be added to the chronicle-queue that toEnd() won’t see. For appenders that that are using the same queue instance ( and with then same JVM ), they can be informed that the last cycle has changed, this will yield better results, but atomicity can still not be guaranteed.

Specified by:

toEnd in interface ExcerptTailer

Returns:

this ExcerptTailer

striding

public ExcerptTailer striding(boolean striding)

Description copied from interface: ExcerptTailer

Sets the striding property of this Trailer.

When striding is enabled AND direction is BACKWARD, skip to the entries easiest to find, doesn't need to be every entry.

Specified by:

striding in interface ExcerptTailer

Parameters:

striding - skip to the indexStride if that is easy, doesn't always happen.

Returns:

this ExcerptTailer

striding

public boolean striding()

Description copied from interface: ExcerptTailer

Returns the striding property of this Trailer.

Specified by:

striding in interface ExcerptTailer

Returns:

the striding property of this Trailer

See Also:

ExcerptTailer.striding(boolean)

originalToEnd

@NotNull
public ExcerptTailer originalToEnd()

direction

public TailerDirection direction()

Description copied from interface: ExcerptTailer

Returns the direction of this Tailer.

The direction determines the direction of movement upon reading an excerpt.

Specified by:

direction in interface ExcerptTailer

Returns:

the direction of this Tailer

direction

@NotNull
public ExcerptTailer direction(TailerDirection direction)

Description copied from interface: ExcerptTailer

Returns the direction of this Tailer.

The direction determines the direction of movement upon reading an excerpt.

Specified by:

direction in interface ExcerptTailer

Parameters:

direction - which is either of NONE, FORWARD, BACKWARD

Returns:

this ExcerptTrailer

queue

@NotNull
public ChronicleQueue queue()

Description copied from interface: ExcerptCommon

Returns the backing ChronicleQueue to which this ExcerptCommon is attached to.

Specified by:

queue in interface ExcerptCommon<ExcerptTailer>

Returns:

the backing ChronicleQueue to which this ExcerptCommon is attached to

getCloserJob

public Runnable getCloserJob()

Description copied from interface: ExcerptTailer

Returns the task that will be run if a WeakReference referring this appender is registered with a clean-up task.

The task shall de-allocate any internal resources held.

Specified by:

getCloserJob in interface ExcerptTailer

Returns:

the task that will be run if a WeakReference referring this appender is registered with a clean-up task

releaseResources

public void releaseResources()

Can be used to manually release resources when this StoreTailer is no longer used.

readAfterReplicaAcknowledged

public void readAfterReplicaAcknowledged(boolean readAfterReplicaAcknowledged)

Description copied from interface: ExcerptTailer

Sets the Read After Replica Acknowledged property of this Trailer to the provided readAfterReplicaAcknowledged.

Enterprise Queue only: if replication enabled, setting this to true on a source queue ensures that this tailer will not read until at least one of the sinks has acknowledged receipt of the excerpt. This will block forever if no sinks acknowledge receipt.

Specified by:

readAfterReplicaAcknowledged in interface ExcerptTailer

Parameters:

readAfterReplicaAcknowledged - enable

readAfterReplicaAcknowledged

public boolean readAfterReplicaAcknowledged()

Description copied from interface: ExcerptTailer

Returns the Read After Replica Acknowledged property of this Trailer.

Enterprise Queue only: if replication enabled, setting this to true on a source queue ensures that this tailer will not read until at least one of the sinks has acknowledged receipt of the excerpt. This will block forever if no sinks acknowledge receipt.

Specified by:

readAfterReplicaAcknowledged in interface ExcerptTailer

Returns:

state

@NotNull
public TailerState state()

Description copied from interface: ExcerptTailer

Returns the TailerState of this Trailer.

Specified by:

state in interface ExcerptTailer

Returns:

the TailerState of this Trailer

See Also:

TailerState

afterLastWritten

@NotNull
public ExcerptTailer afterLastWritten(@NotNull
                                               ChronicleQueue queue)

Description copied from interface: ExcerptTailer

Winds this Tailer to after the last entry which wrote an entry to the queue.

Specified by:

afterLastWritten in interface ExcerptTailer

Parameters:

queue - which was written to.

Returns:

this ExcerptTailer

setCycle

public void setCycle(int cycle)