Package org.apache.jackrabbit.oak.spi.state

Interface NodeStore

All Known Implementing Classes:

MemoryNodeStore, ProxyNodeStore

public interface NodeStore

Storage abstraction for trees. At any given point in time the stored tree is rooted at a single immutable node state.

This is a low-level interface that doesn't cover functionality like merging concurrent changes or rejecting new tree states based on some higher-level consistency constraints.

Method Summary

Modifier and Type	Method	Description
@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.
@NotNull org.apache.jackrabbit.oak.api.Blob	createBlob(InputStream inputStream)	Create a Blob from the given input stream.
@Nullable org.apache.jackrabbit.oak.api.Blob	getBlob(@NotNull String reference)	Get a blob by its reference.
@NotNull NodeState	getRoot()	Returns the latest state of the tree.
@NotNull NodeState	merge(@NotNull NodeBuilder builder, @NotNull CommitHook commitHook, @NotNull CommitInfo info)	Merges the changes between the base and head states of the given builder to this store.
@NotNull NodeState	rebase(@NotNull NodeBuilder builder)	Rebases the changes between the base and head states of the given builder on top of the current root state.
boolean	release(@NotNull String checkpoint)	Releases the provided checkpoint.
NodeState	reset(@NotNull NodeBuilder builder)	Reset the passed builder by throwing away all its changes and setting its base state to the current root state.
@Nullable NodeState	retrieve(@NotNull String checkpoint)	Retrieves the root node from a previously created repository checkpoint.

Method Detail

getRoot

@NotNull
@NotNull NodeState getRoot()

Returns the latest state of the tree.

Returns:

root node state

merge

@NotNull
@NotNull NodeState merge(@NotNull
                         @NotNull NodeBuilder builder,
                         @NotNull
                         @NotNull CommitHook commitHook,
                         @NotNull
                         @NotNull CommitInfo info)
                  throws org.apache.jackrabbit.oak.api.CommitFailedException

Merges the changes between the base and head states of the given builder to this store.

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:

org.apache.jackrabbit.oak.api.CommitFailedException - if the merge failed

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

rebase

@NotNull
@NotNull NodeState rebase(@NotNull
                          @NotNull NodeBuilder builder)

Rebases the changes between the base and head states of the given builder on top of the current root state. The base state of the given builder becomes the latest root state of the repository, and the head state will contain the rebased changes.

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

NodeState reset(@NotNull
                @NotNull NodeBuilder builder)

Reset the passed builder by throwing away all its changes and setting its base state to the current root state.

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

@NotNull
@NotNull org.apache.jackrabbit.oak.api.Blob createBlob(InputStream inputStream)
                                                throws IOException

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

Parameters:

inputStream - The input stream for the Blob

Returns:

The Blob representing inputStream

Throws:

IOException - If an error occurs while reading from the stream

getBlob

@Nullable
@Nullable org.apache.jackrabbit.oak.api.Blob getBlob(@NotNull
                                                     @NotNull String reference)

Get a blob by its reference.

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

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 checkpointInfo(String) method. Its semantics is entirely application specific.

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
@NotNull String checkpoint(long lifetime)

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 checkpoint(long, Map) passing an empty map for its 2nd argument.

Parameters:

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

Returns:

string reference of this checkpoint

checkpointInfo

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

Retrieve the properties associated with a checkpoint.

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
@NotNull Iterable<String> checkpoints()

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

Returns:

valid checkpoints.

retrieve

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

Retrieves the root node from a previously created repository checkpoint.

Parameters:

checkpoint - string reference of a checkpoint

Returns:

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

release

boolean release(@NotNull
                @NotNull String checkpoint)

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

Parameters:

checkpoint - string reference of a checkpoint

Returns:

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