org.openrdf.sesame.sailimpl.nativerdf.datastore
Class DataStore

java.lang.Object
  org.openrdf.sesame.sailimpl.nativerdf.datastore.DataStore

public class DataStore

extends Object

Class that provides indexed storage and retrieval of RDF values.

Constructor Summary

DataStore(File dataDir, String filePrefix)

Method Summary

void	clear() Removes all values from the DataStore.
void	close() Closes the DataStore, releasing any file references, etc.
void	commitTransaction() Commits a transaction, applying all updates that have been performed during the transaction.
byte[]	getData(int id) Gets the value for the specified ID.
byte[]	getData(int id, boolean dirtyReads) Gets the value for the specified ID, optionally searching the non-commited data.
int	getID(byte[] queryData) Gets the ID for the specified value.
int	getID(byte[] queryData, boolean dirtyReads) Gets the ID for the specified value, optionally search the non-committed data.
int	getMaxID() Returns the maximum ID value.
static void	main(String[] args)
void	rollbackTransaction() Rolls back all updates that have been performed in the current transaction and closes it.
void	startTransaction() Starts a transaction.
int	storeData(byte[] data) Stores the supplied value and returns the ID that has been assigned to it.

Methods inherited from class java.lang.Object

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

Constructor Detail

DataStore

public DataStore(File dataDir,
                 String filePrefix)
          throws IOException

Method Detail

getData

public byte[] getData(int id)
               throws IOException

Gets the value for the specified ID.

Parameters:

id - A value ID.

Returns:

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

Throws:

IOException - If an I/O error occurred.

getData

public byte[] getData(int id,
                      boolean dirtyReads)
               throws IOException

Gets the value for the specified ID, optionally searching the non-commited data.

Parameters:

id - A value ID.

dirtyReads - Flag indicating whether the non-commited data should be searched.

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 - A value.

Returns:

The ID for the specified value, or 0 if no such ID could be found.

Throws:

IOException - If an I/O error occurred.

getID

public int getID(byte[] queryData,
                 boolean dirtyReads)
          throws IOException

Gets the ID for the specified value, optionally search the non-committed data.

Parameters:

queryData - A value.

dirtyReads - Flag indicating whether the non-commited data should be searched.

Returns:

The ID for the specified value, or 0 if no such ID could be found.

Throws:

IOException - If an I/O error occurred.

getMaxID

public int getMaxID()
             throws IOException

Returns the maximum ID value.

Throws:

IOException

startTransaction

public void startTransaction()
                      throws IOException

Starts a transaction. This prepares the DataStore for upcoming updates to the stored data.

Throws:

IOException - If an I/O error occurred.

commitTransaction

public void commitTransaction()
                       throws IOException

Commits a transaction, applying all updates that have been performed during the transaction.

Throws:

IOException - If an I/O error occurred.

rollbackTransaction

public void rollbackTransaction()
                         throws IOException

Rolls back all updates that have been performed in the current transaction and closes it.

Throws:

IOException - If an I/O error occurred.

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. This method can only be called as part of a transaction.

Parameters:

data - The data to store.

Returns:

The ID that has been assigned to the value.

Throws:

IOException - If an I/O error occurred.

See Also:

startTransaction(), commitTransaction()

clear

public void clear()
           throws IOException

Removes all values from the DataStore. This method can only be called as part of a transaction. The DataStore will not be cleared until the transaction is committed.

Throws:

IOException - If an I/O error occurred.

See Also:

startTransaction(), commitTransaction()

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.

Throws:

IOException - If an I/O error occurred.

main

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

Throws:

Exception