org.apache.jackrabbit.oak.api

Interface Root

public interface Root

A Root instance serves as a container for a Tree. It is obtained from a ContentSession, which governs accessibility and visibility of the Tree and its sub trees.

All root instances created by a content session become invalid after the content session is closed. Any method called on an invalid root instance will throw an InvalidStateException.

Tree instances may become non existing after a call to refresh(), rebase() or commit(). Any write access to non existing Tree instances will cause an InvalidStateException.

See Also:

Existence and iterability of trees

Field Summary

Fields

Modifier and Type	Field and Description
static java.lang.String	COMMIT_PATH Name of the entry of the commit path in the info map in commit(java.util.Map)

Method Summary

Modifier and Type	Method and Description
void	commit() Atomically persists all changes made to the tree attached to this root.
void	commit(@NotNull java.util.Map<java.lang.String,java.lang.Object> info) Atomically persists all changes made to the tree attached to this root.
@NotNull Blob	createBlob(@NotNull java.io.InputStream stream) Reads (and closes) the given stream and returns a Blob that contains that binary.
@Nullable Blob	getBlob(@NotNull java.lang.String reference) Get a blob by its reference.
@NotNull ContentSession	getContentSession() Get the ContentSession from which this root was acquired
@NotNull QueryEngine	getQueryEngine() Get the query engine.
@NotNull Tree	getTree(@NotNull java.lang.String path) Retrieve the possible non existing Tree at the given absolute path.
boolean	hasPendingChanges() Determine whether there are changes on this tree
boolean	move(java.lang.String sourcePath, java.lang.String destPath) Move the child located at sourcePath to a child at destPath.
void	rebase() Rebase this root instance to the latest revision.
void	refresh() Reverts all changes made to this root and refreshed to the latest trunk.

Field Detail

COMMIT_PATH

static final java.lang.String COMMIT_PATH

Name of the entry of the commit path in the info map in commit(java.util.Map)

See Also:

Constant Field Values

Method Detail

move

boolean move(java.lang.String sourcePath,
             java.lang.String destPath)

Move the child located at sourcePath to a child at destPath. Both paths must be absolute and resolve to a child located beneath this root.
This method does nothing and returns false if

• the tree at sourcePath does not exist or is not accessible,
• the parent of the tree at destinationPath does not exist or is not accessible,
• a tree already exists at destinationPath.

If a tree at destinationPath exists but is not accessible to the editing content session this method succeeds but a subsequent commit() will detect the violation and fail.

Parameters:

sourcePath - The source path

destPath - The destination path

Returns:

true on success, false otherwise.

getTree

@NotNull
@NotNull Tree getTree(@NotNull
                               @NotNull java.lang.String path)

Retrieve the possible non existing Tree at the given absolute path. The path must resolve to a tree in this root.

Parameters:

path - absolute path to the tree

Returns:

tree at the given path.

rebase

void rebase()

Rebase this root instance to the latest revision. After a call to this method, trees obtained through getTree(String) may become non existing.

refresh

void refresh()

Reverts all changes made to this root and refreshed to the latest trunk. After a call to this method, trees obtained through getTree(String) may become non existing.

commit

void commit(@NotNull
            @NotNull java.util.Map<java.lang.String,java.lang.Object> info)
     throws CommitFailedException

Atomically persists all changes made to the tree attached to this root.

If info contains a mapping for COMMIT_PATH and the associated value is a string, implementations may throw a CommitFailedException if there are changes outside of the subtree designated by that path and the implementation does not support such partial commits. However all implementation must handler the case where a path designates a subtree that contains all unpersisted changes.

The info map is passed to the underlying storage as a part of the internal commit information attached to this commit. The commit information will be made available to local observers but will not be visible to observers on other cluster nodes.

After a successful operation the root is automatically refreshed, such that trees previously obtained through getTree(String) may become non existing.

Parameters:

info - commit information

Throws:

CommitFailedException - if the commit failed

commit

void commit()
     throws CommitFailedException

Atomically persists all changes made to the tree attached to this root. Calling this method is equivalent to calling the commit(Map info) method with an empty info map.

Throws:

CommitFailedException - if the commit failed

hasPendingChanges

boolean hasPendingChanges()

Determine whether there are changes on this tree

Returns:

true iff this tree was modified

getQueryEngine

@NotNull
@NotNull QueryEngine getQueryEngine()

Get the query engine.

Returns:

the query engine

createBlob

@NotNull
@NotNull Blob createBlob(@NotNull
                                  @NotNull java.io.InputStream stream)
                           throws java.io.IOException

Reads (and closes) the given stream and returns a Blob that contains that binary. The returned blob will remain valid at least until the ContentSession of this root is closed, or longer if it has been committed as a part of a content update.

The implementation may decide to persist the blob at any point during or between this method method call and a commit() that includes the blob, but the blob will become visible to other sessions only after such a commit.

Parameters:

stream - the stream for reading the binary

Returns:

the blob that was created

Throws:

java.io.IOException - if the stream could not be read

getBlob

@Nullable
@Nullable Blob getBlob(@NotNull
                                 @NotNull java.lang.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()

getContentSession

@NotNull
@NotNull ContentSession getContentSession()

Get the ContentSession from which this root was acquired

Returns:

the associated ContentSession

Throws:

java.lang.UnsupportedOperationException