Package org.apache.jackrabbit.oak.segment.file

Class TarRevisions

java.lang.Object

org.apache.jackrabbit.oak.segment.file.TarRevisions

All Implemented Interfaces:

Closeable, AutoCloseable, Revisions

public class TarRevisions
extends Object
implements Revisions, Closeable

This implementation of Revisions is backed by a journal file where the current head is persisted by calling tryFlush(Flusher).

The setHead(Function, Option...) method supports a timeout Revisions.Option, which can be retrieved through factory methods of this class.

Instance of this class must be bind(SegmentStore, SegmentIdProvider, Supplier) bound} to a SegmentStore otherwise its method throw IllegalStateExceptions.

Nested Class Summary

Nested classes/interfaces inherited from interface org.apache.jackrabbit.oak.segment.Revisions

Revisions.Option

Field Summary

Fields

Modifier and Type	Field	Description
static Revisions.Option	EXPEDITE_OPTION	Option to cause set head calls to be expedited.
static Revisions.Option	INFINITY	Timeout option approximating no time out (Long.MAX_VALUE days).

Constructor Summary

Constructors

Constructor	Description
TarRevisions(SegmentNodeStorePersistence persistence)	Create a new instance placing the journal log file into the passed directory.

Method Summary

Modifier and Type	Method	Description
void	close()	Close the underlying journal file.
@NotNull RecordId	getHead()	Returns the record id of the head state.
@NotNull RecordId	getPersistedHead()	Returns the persisted to disk record id of the head state.
RecordId	setHead(@NotNull Function<RecordId,RecordId> newHead, @NotNull Revisions.Option... options)	This implementation blocks if a concurrent call is already in progress.
boolean	setHead(@NotNull RecordId expected, @NotNull RecordId head, @NotNull Revisions.Option... options)	This implementation blocks if a concurrent call to setHead(Function, Option...) is already in progress.
static Revisions.Option	timeout(long time, TimeUnit unit)	Factory method for creating a timeout option.

Methods inherited from class java.lang.Object

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

Field Detail

EXPEDITE_OPTION

public static final Revisions.Option EXPEDITE_OPTION

Option to cause set head calls to be expedited. That is, cause them to skip the queue of any other callers waiting to complete that don't have this option specified.

INFINITY

public static final Revisions.Option INFINITY

Timeout option approximating no time out (Long.MAX_VALUE days).

Constructor Detail

TarRevisions

public TarRevisions(SegmentNodeStorePersistence persistence)
             throws IOException

Create a new instance placing the journal log file into the passed directory.

Parameters:

persistence - object representing the segment persistence

Throws:

IOException

Method Detail

timeout

public static Revisions.Option timeout(long time,
                                       TimeUnit unit)

Factory method for creating a timeout option.

getHead

@NotNull
public @NotNull RecordId getHead()

Description copied from interface: Revisions

Returns the record id of the head state. The returned id is a valid id for a SegmentNodeState.

Specified by:

getHead in interface Revisions

Returns:

id of the head state

getPersistedHead

@NotNull
public @NotNull RecordId getPersistedHead()

Description copied from interface: Revisions

Returns the persisted to disk record id of the head state. The returned id is a valid id for a SegmentNodeState.

Specified by:

getPersistedHead in interface Revisions

Returns:

id of the head state

setHead

public boolean setHead(@NotNull
                       @NotNull RecordId expected,
                       @NotNull
                       @NotNull RecordId head,
                       @NotNull
                       @NotNull Revisions.Option... options)

This implementation blocks if a concurrent call to setHead(Function, Option...) is already in progress.

Specified by:

setHead in interface Revisions

Parameters:

options - zero or one expedite option for expediting this call

expected - the expected head for the update to take place

head - the new head to update to

Returns:

true if the current head was successfully updated, false otherwise.

Throws:

IllegalArgumentException - on any non recognised option.

See Also:

EXPEDITE_OPTION

setHead

public RecordId setHead(@NotNull
                        @NotNull Function<RecordId,RecordId> newHead,
                        @NotNull
                        @NotNull Revisions.Option... options)
                 throws InterruptedException

This implementation blocks if a concurrent call is already in progress.

Specified by:

setHead in interface Revisions

Parameters:

newHead - function mapping an record id to the record id to which the current head id should be set. If it returns null the head remains unchanged and setHead returns false.

options - zero or one timeout options specifying how long to block

Returns:

the record id of the root node if the current head was successfully updated, null otherwise.

Throws:

InterruptedException

IllegalArgumentException - on any non recognised option.

See Also:

timeout(long, TimeUnit), INFINITY

close

public void close()
           throws IOException

Close the underlying journal file.

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable

Throws:

IOException