Package org.apache.jackrabbit.oak.plugins.memory

Class MemoryNodeStore

java.lang.Object

org.apache.jackrabbit.oak.plugins.memory.MemoryNodeStore

All Implemented Interfaces:

Observable, NodeStore

public class MemoryNodeStore
extends Object
implements NodeStore, Observable

Basic in-memory node store implementation. Useful as a base class for more complex functionality.

Constructor Summary

Constructors

Constructor	Description
MemoryNodeStore()
MemoryNodeStore(NodeState state)

Method Summary

Modifier and Type	Method	Description
Closeable	addObserver(Observer observer)	Register a new Observer.
@NotNull String	checkpoint(long lifetime)	Creates a new checkpoint of the latest root of the tree.
@NotNull String	checkpoint(long lifetime, @NotNull Map<String,String> properties)	Creates a new checkpoint of the latest root of the tree.
@NotNull Map<String,String>	checkpointInfo(@NotNull String checkpoint)	Retrieve the properties associated with a checkpoint.
@NotNull Iterable<String>	checkpoints()	Returns all valid checkpoints.
ArrayBasedBlob	createBlob(InputStream inputStream)	Create a Blob from the given input stream.
Blob	getBlob(@NotNull String reference)	Get a blob by its reference.
NodeState	getRoot()	Returns the latest state of the tree.
Set<String>	listCheckpoints()	test purpose only!
NodeState	merge(@NotNull NodeBuilder builder, @NotNull CommitHook commitHook, @NotNull CommitInfo info)	This implementation is equal to first rebasing the builder and then applying it to a new branch and immediately merging it back.
NodeState	rebase(@NotNull NodeBuilder builder)	This implementation is equal to applying the differences between the builders base state and its head state to a fresh builder on the stores root state using ConflictAnnotatingRebaseDiff for resolving conflicts.
boolean	release(String checkpoint)	Releases the provided checkpoint.
NodeState	reset(@NotNull NodeBuilder builder)	This implementation is equal resetting the builder to the root of the store and returning the resulting node state from the builder.
@Nullable NodeState	retrieve(@NotNull String checkpoint)	Retrieves the root node from a previously created repository checkpoint.
String	toString()	Returns a string representation the head state of this node store.

Methods inherited from class java.lang.Object

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

Constructor Detail

MemoryNodeStore

public MemoryNodeStore(NodeState state)

MemoryNodeStore

public MemoryNodeStore()

Method Detail

toString

public String toString()

Returns a string representation the head state of this node store.

Overrides:

toString in class Object

addObserver

public Closeable addObserver(Observer observer)

Description copied from interface: Observable

Register a new Observer. Clients need to call Closeable.close() to stop getting notifications on the registered observer and to free up any resources associated with the registration.

Specified by:

addObserver in interface Observable

Returns:

a Closeable instance.

getRoot

public NodeState getRoot()

Description copied from interface: NodeStore

Returns the latest state of the tree.

Specified by:

getRoot in interface NodeStore

Returns:

root node state

merge

public NodeState merge(@NotNull
                       @NotNull NodeBuilder builder,
                       @NotNull
                       @NotNull CommitHook commitHook,
                       @NotNull
                       @NotNull CommitInfo info)
                throws CommitFailedException

This implementation is equal to first rebasing the builder and then applying it to a new branch and immediately merging it back.

Specified by:

merge in interface NodeStore

Parameters:

builder - the builder whose changes to apply

commitHook - the commit hook to apply while merging changes

info - commit info associated with this merge operation

Returns:

the node state resulting from the merge.

Throws:

CommitFailedException

IllegalArgumentException - if the builder is not acquired from a root state of this store

rebase

public NodeState rebase(@NotNull
                        @NotNull NodeBuilder builder)

This implementation is equal to applying the differences between the builders base state and its head state to a fresh builder on the stores root state using ConflictAnnotatingRebaseDiff for resolving conflicts.

Specified by:

rebase in interface NodeStore

Parameters:

builder - the builder to rebase

Returns:

the node state resulting from the rebase.

Throws:

IllegalArgumentException - if the builder is not acquired from a root state of this store

reset

public NodeState reset(@NotNull
                       @NotNull NodeBuilder builder)

This implementation is equal resetting the builder to the root of the store and returning the resulting node state from the builder.

Specified by:

reset in interface NodeStore

Parameters:

builder - the builder to reset

Returns:

the node state resulting from the reset.

Throws:

IllegalArgumentException - if the builder is not acquired from a root state of this store

createBlob

public ArrayBasedBlob createBlob(InputStream inputStream)
                          throws IOException

Description copied from interface: NodeStore

Create a Blob from the given input stream. The input stream is closed after this method returns.

Specified by:

createBlob in interface NodeStore

Parameters:

inputStream - The input stream for the Blob

Returns:

An instance of ArrayBasedBlob.

Throws:

IOException - If an error occurs while reading from the stream

getBlob

public Blob getBlob(@NotNull
                    @NotNull String reference)

Description copied from interface: NodeStore

Get a blob by its reference.

Specified by:

getBlob in interface NodeStore

Parameters:

reference - reference to the blob

Returns:

blob or null if the reference does not resolve to a blob.

See Also:

Blob.getReference()

checkpoint

@NotNull
public @NotNull String checkpoint(long lifetime,
                                  @NotNull
                                  @NotNull Map<String,String> properties)

Description copied from interface: NodeStore

Creates a new checkpoint of the latest root of the tree. The checkpoint remains valid for at least as long as requested and allows that state of the repository to be retrieved using the returned opaque string reference.

The properties passed to this methods are associated with the checkpoint and can be retrieved through the NodeStore.checkpointInfo(String) method. Its semantics is entirely application specific.

Specified by:

checkpoint in interface NodeStore

Parameters:

lifetime - time (in milliseconds, > 0) that the checkpoint should remain available

properties - properties to associate with the checkpoint

Returns:

string reference of this checkpoint

checkpoint

@NotNull
public @NotNull String checkpoint(long lifetime)

Description copied from interface: NodeStore

Creates a new checkpoint of the latest root of the tree. The checkpoint remains valid for at least as long as requested and allows that state of the repository to be retrieved using the returned opaque string reference.

This method is a shortcut for NodeStore.checkpoint(long, Map) passing an empty map for its 2nd argument.

Specified by:

checkpoint in interface NodeStore

Parameters:

lifetime - time (in milliseconds, > 0) that the checkpoint should remain available

Returns:

string reference of this checkpoint

checkpointInfo

@NotNull
public @NotNull Map<String,String> checkpointInfo(@NotNull
                                                        @NotNull String checkpoint)

Description copied from interface: NodeStore

Retrieve the properties associated with a checkpoint.

Specified by:

checkpointInfo in interface NodeStore

Parameters:

checkpoint - string reference of a checkpoint

Returns:

the properties associated with the checkpoint referenced by checkpoint or an empty map when there is no such checkpoint.

checkpoints

@NotNull
public @NotNull Iterable<String> checkpoints()

Description copied from interface: NodeStore

Returns all valid checkpoints. The returned Iterable provides a snapshot of valid checkpoints at the time this method is called. That is, the Iterable will not reflect checkpoints created after this method was called.

See NodeStore.checkpoint(long, Map) for a definition of a valid checkpoint.

Specified by:

checkpoints in interface NodeStore

Returns:

valid checkpoints.

retrieve

@Nullable
public @Nullable NodeState retrieve(@NotNull
                                    @NotNull String checkpoint)

Description copied from interface: NodeStore

Retrieves the root node from a previously created repository checkpoint.

Specified by:

retrieve in interface NodeStore

Parameters:

checkpoint - string reference of a checkpoint

Returns:

the root node of the checkpoint, or null if the checkpoint is no longer available

release

public boolean release(String checkpoint)

Description copied from interface: NodeStore

Releases the provided checkpoint. If the provided checkpoint doesn't exist this method should return true.

Specified by:

release in interface NodeStore

Parameters:

checkpoint - string reference of a checkpoint

Returns:

true if the checkpoint was successfully removed, or if it doesn't exist

listCheckpoints

public Set<String> listCheckpoints()

test purpose only!