Package org.apache.jackrabbit.oak.segment.memory

Class MemoryStoreRevisions

java.lang.Object

org.apache.jackrabbit.oak.segment.memory.MemoryStoreRevisions

All Implemented Interfaces:

Revisions

public class MemoryStoreRevisions
extends Object
implements Revisions

This is a simple in memory Revisions implementation. It is non blocking and does not support any Revisions.Options.

Nested Class Summary

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

Revisions.Option

Constructor Summary

Constructors

Constructor	Description
MemoryStoreRevisions()

Method Summary

Modifier and Type	Method	Description
void	bind(MemoryStore store)	Bind this instance to a store.
@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)	Not supported: throws UnsupportedOperationException
boolean	setHead(@NotNull RecordId expected, @NotNull RecordId head, @NotNull Revisions.Option... options)	Atomically set the record id of the current head state to the given head state if the current head state matches the expected value.

Methods inherited from class java.lang.Object

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

Constructor Details

MemoryStoreRevisions

public MemoryStoreRevisions()

Method Details

bind

public void bind(MemoryStore store)
          throws IOException

Bind this instance to a store.

Throws:

IOException

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)

Description copied from interface: Revisions

Atomically set the record id of the current head state to the given head state if the current head state matches the expected value.

All record ids must be valid ids for SegmentNodeStates.

The locking behaviour of this method regarding implementation specific.

Specified by:

setHead in interface Revisions

Parameters:

expected - the expected head for the update to take place

head - the new head to update to

options - implementation specific options

Returns:

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

setHead

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

Not supported: throws UnsupportedOperationException

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.

options - implementation specific options

Returns:

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

Throws:

UnsupportedOperationException - always

InterruptedException - Blocking implementations may throw this exception whe interrupted.