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 flush(Callable).

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

Instance of this class must be 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 and 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).
static String	JOURNAL_FILE_NAME

Constructor Summary

Constructors

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

Method Summary

Modifier and Type	Method and Description
void	close() Close the underlying journal file.
void	flush(Callable<Void> persisted) Flush the id of the current head to the journal after a call to persisted.
RecordId	getHead() Returns the record id of the head state.
boolean	setHead(com.google.common.base.Function<RecordId,RecordId> newHead, Revisions.Option... options) This implementation blocks if a concurrent call is already in progress.
boolean	setHead(RecordId expected, RecordId head, Revisions.Option... options) This implementation blocks if a concurrent call to Revisions.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

JOURNAL_FILE_NAME

public static final String JOURNAL_FILE_NAME

See Also:

Constant Field Values

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(@Nonnull
                    File directory)
             throws IOException

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

Parameters:

directory - directory of the journal file

Throws:

IOException

Method Detail

timeout

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

Factory method for creating a timeout option.

flush

public void flush(@Nonnull
                  Callable<Void> persisted)
           throws IOException

Flush the id of the current head to the journal after a call to persisted. This method does nothing and returns immediately if called concurrently and a call is already in progress.

Parameters:

persisted - call back for upstream dependencies to ensure the current head state is actually persisted before its id is written to the head state.

Throws:

IOException

getHead

@Nonnull
public 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

setHead

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

This implementation blocks if a concurrent call to Revisions.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 boolean setHead(@Nonnull
                       com.google.common.base.Function<RecordId,RecordId> newHead,
                       @Nonnull
                       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:

true if the current head was successfully updated, false 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 Closeable

Specified by:

close in interface AutoCloseable

Throws:

IOException