org.neo4j.kernel.api.scan

Interface LabelScanStore

All Superinterfaces:

Lifecycle

public interface LabelScanStore
extends Lifecycle

Stores label-->nodes mappings. It receives updates in the form of condensed label->node transaction data and can iterate through all nodes for any given label.

Method Summary

Methods

Modifier and Type	Method and Description
void	force() Forces all changes to disk.
void	init() Initializes the store.
LabelScanReader	newReader() From the point a LabelScanReader is created till it's closed the contents it returns cannot change, i.e.
void	recover(Iterable<NodeLabelUpdate> updates) Recover updates the store with a stream of updates of label->node mappings.
void	shutdown() Shuts down the store and all resources acquired by it.
ResourceIterator<File>	snapshotStoreFiles()
void	start() Starts the store.
void	stop()
void	updateAndCommit(Iterable<NodeLabelUpdate> updates) Update the store with a stream of updates of label->node mappings.

Method Detail

updateAndCommit

void updateAndCommit(Iterable<NodeLabelUpdate> updates)
                     throws IOException

Update the store with a stream of updates of label->node mappings.

Parameters:

updates - the updates to store.

Throws:

IOException - if there was a problem updating the store.

recover

void recover(Iterable<NodeLabelUpdate> updates)
             throws IOException

Recover updates the store with a stream of updates of label->node mappings. Done during the recovery phase of the database startup. Updates here may contain duplicates with what's already in the store so extra care needs to be taken to ensure correctness after these updates.

Parameters:

updates - the updates to store.

Throws:

IOException - if there was a problem updating the store.

force

void force()
           throws org.neo4j.kernel.impl.nioneo.store.UnderlyingStorageException

Forces all changes to disk. Called at certain points from within Neo4j for example when rotating the logical log. After completion of this call there cannot be any essential state that hasn't been forced to disk.

Throws:

org.neo4j.kernel.impl.nioneo.store.UnderlyingStorageException - if there was a problem forcing the state to persistent storage.

newReader

LabelScanReader newReader()

From the point a LabelScanReader is created till it's closed the contents it returns cannot change, i.e. it honors repeatable reads.

Returns:

a LabelScanReader capable of retrieving nodes for labels.

snapshotStoreFiles

ResourceIterator<File> snapshotStoreFiles()
                                          throws IOException

Throws:

IOException

init

void init()
          throws IOException

Initializes the store. After this has been called recovery updates can be processed.

Specified by:

init in interface Lifecycle

Throws:

IOException

start

void start()
           throws IOException

Starts the store. After this has been called updates can be processed.

Specified by:

start in interface Lifecycle

Throws:

IOException

stop

void stop()
          throws IOException

Specified by:

stop in interface Lifecycle

Throws:

IOException

shutdown

void shutdown()
              throws IOException

Shuts down the store and all resources acquired by it.

Specified by:

shutdown in interface Lifecycle

Throws:

IOException