org.eclipse.rdf4j.sail.nativerdf.datastore

Class DataStore

java.lang.Object

org.eclipse.rdf4j.sail.nativerdf.datastore.DataStore

All Implemented Interfaces:

Closeable, AutoCloseable

public class DataStore
extends Object
implements Closeable

Class that provides indexed storage and retrieval of arbitrary length data.

Author:

Arjohn Kampman

Constructor Summary

Constructors

Constructor and Description
DataStore(File dataDir, String filePrefix)
DataStore(File dataDir, String filePrefix, boolean forceSync)

Method Summary

Modifier and Type	Method and Description
void	clear() Removes all values from the DataStore.
void	close() Closes the DataStore, releasing any file references, etc.
byte[]	getData(int id) Gets the value for the specified ID.
int	getID(byte[] queryData) Gets the ID for the specified value.
int	getMaxID() Returns the maximum value-ID that is in use.
static void	main(String[] args)
int	storeData(byte[] data) Stores the supplied value and returns the ID that has been assigned to it.
void	sync() Synchronizes any recent changes to the data to disk.

Methods inherited from class java.lang.Object

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

Constructor Detail

DataStore

public DataStore(File dataDir,
                 String filePrefix)
          throws IOException

Throws:

IOException

DataStore

public DataStore(File dataDir,
                 String filePrefix,
                 boolean forceSync)
          throws IOException

Throws:

IOException

Method Detail

getData

public byte[] getData(int id)
               throws IOException

Gets the value for the specified ID.

Parameters:

id - A value ID, should be larger than 0.

Returns:

The value for the ID, or null if no such value could be found.

Throws:

IOException - If an I/O error occurred.

getID

public int getID(byte[] queryData)
          throws IOException

Gets the ID for the specified value.

Parameters:

queryData - The value to get the ID for, must not be null.

Returns:

The ID for the specified value, or -1 if no such ID could be found.

Throws:

IOException - If an I/O error occurred.

getMaxID

public int getMaxID()
             throws IOException

Returns the maximum value-ID that is in use.

Returns:

The largest ID, or 0 if the store does not contain any values.

Throws:

IOException - If an I/O error occurs.

storeData

public int storeData(byte[] data)
              throws IOException

Stores the supplied value and returns the ID that has been assigned to it. In case the data to store is already present, the ID of this existing data is returned.

Parameters:

data - The data to store, must not be null.

Returns:

The ID that has been assigned to the value.

Throws:

IOException - If an I/O error occurred.

sync

public void sync()
          throws IOException

Synchronizes any recent changes to the data to disk.

Throws:

IOException - If an I/O error occurred.

clear

public void clear()
           throws IOException

Removes all values from the DataStore.

Throws:

IOException - If an I/O error occurred.

close

public void close()
           throws IOException

Closes the DataStore, releasing any file references, etc. In case a transaction is currently open, it will be rolled back. Once closed, the DataStore can no longer be used.

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

Throws:

IOException - If an I/O error occurred.

main

public static void main(String[] args)
                 throws Exception

Throws:

Exception