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

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

public class DataFile

extends Object

Class supplying access to a data file. A data file stores data sequentially. Each entry starts with the entry's length (4 bytes), followed by the data itself. File offsets are used to identify entries.

Version:

$Revision: 1.11.4.4 $

Author:

Arjohn Kampman

Nested Class Summary

class

DataFile.DataIterator

Constructor Summary

DataFile(File file)

Method Summary

void	clear()
void	close()
void	commitTransaction()
byte[]	getData(long offset, boolean dirtyReads) Gets the data that is stored at the specified offset.
DataFile.DataIterator	iterator()
void	rollbackTransaction()
void	startTransaction(boolean isolateTransaction)
long	storeData(byte[] data) Stores the specified data and returns the byte-offset at which it has been stored.
void	updateData(long offset, byte[] data) Updates (replaces) the data at the specified offset with the supplied data.

Methods inherited from class java.lang.Object

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

Constructor Detail

DataFile

public DataFile(File file)
         throws IOException

Method Detail

startTransaction

public void startTransaction(boolean isolateTransaction)
                      throws IOException

Throws:

IOException

commitTransaction

public void commitTransaction()
                       throws IOException

Throws:

IOException

rollbackTransaction

public void rollbackTransaction()
                         throws IOException

Throws:

IOException

storeData

public long storeData(byte[] data)
               throws IOException

Stores the specified data and returns the byte-offset at which it has been stored.

Throws:

IOException

updateData

public void updateData(long offset,
                       byte[] data)
                throws IOException

Updates (replaces) the data at the specified offset with the supplied data.

Throws:

IOException

getData

public byte[] getData(long offset,
                      boolean dirtyReads)
               throws IOException

Gets the data that is stored at the specified offset.

Parameters:

offset - An offset in the data file.

dirtyReads - Flag indicating whether data that hasn't been committed yet should be searched too.

Returns:

The data that was found on the specified offset.

Throws:

IOException - If an I/O error occurred.

clear

public void clear()
           throws IOException

Throws:

IOException

close

public void close()
           throws IOException

Throws:

IOException

iterator

public DataFile.DataIterator iterator()