Package eu.svjatoslav.sixth.data.store.file

Class FileDataStore

java.lang.Object

eu.svjatoslav.sixth.data.store.file.FileDataStore

All Implemented Interfaces:

DataStore

public class FileDataStore
extends Object
implements DataStore

DataStore backed by single filesystem file.

Constructor Summary

Constructors

Constructor	Description
FileDataStore(File backingFile)

Method Summary

Modifier and Type	Method	Description
void	close()	Close datastore.
int	createRecord(byte[] value)	Create new record and set its initial contents.
void	deleteRecord(int id)	Delete record identified by given ID.
long	getDefragmentationStartAddress(int allowedFragmentationPercent, List<eu.svjatoslav.sixth.data.store.file.EntryRecord> allEntryRecords)
void	increaseEntriesTable()
void	initializeFromExistingFile(File backingFile)
void	initializeNewFile(File backingFile)
int	readInt(long position)
long	readLong(long position)
byte[]	readRecord(int id)	Read entire record into byte array.
long	relocateEntry(eu.svjatoslav.sixth.data.store.file.EntryRecord record, long newLocation)
void	updateRecord(int id, byte[] value)	Update record with new value.
void	vacuum(int allowedFragmentationPercent)	Defragment empty space.
void	writeInt(long position, int value)
void	writeLong(long position, long value)

Methods inherited from class java.lang.Object

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

Constructor Detail

FileDataStore

public FileDataStore(File backingFile)
              throws IOException

Throws:

IOException

Method Detail

close

public void close()
           throws IOException

Description copied from interface: DataStore

Close datastore.

Specified by:

close in interface DataStore

Throws:

IOException

createRecord

public int createRecord(byte[] value)
                 throws IOException

Description copied from interface: DataStore

Create new record and set its initial contents.

Specified by:

createRecord in interface DataStore

Throws:

IOException

deleteRecord

public void deleteRecord(int id)
                  throws IOException

Description copied from interface: DataStore

Delete record identified by given ID. DataStore will mark given ID as unused, and could reuse this ID later for another newly created record.

Specified by:

deleteRecord in interface DataStore

Throws:

IOException

getDefragmentationStartAddress

public long getDefragmentationStartAddress(int allowedFragmentationPercent,
                                           List<eu.svjatoslav.sixth.data.store.file.EntryRecord> allEntryRecords)

increaseEntriesTable

public void increaseEntriesTable()
                          throws IOException

Throws:

IOException

initializeFromExistingFile

public void initializeFromExistingFile(File backingFile)
                                throws IOException

Throws:

IOException

initializeNewFile

public void initializeNewFile(File backingFile)
                       throws IOException

Throws:

IOException

readInt

public int readInt(long position)
            throws IOException

Throws:

IOException

readLong

public long readLong(long position)
              throws IOException

Throws:

IOException

readRecord

public byte[] readRecord(int id)
                  throws IOException

Description copied from interface: DataStore

Read entire record into byte array.

Specified by:

readRecord in interface DataStore

Throws:

IOException

relocateEntry

public long relocateEntry(eu.svjatoslav.sixth.data.store.file.EntryRecord record,
                          long newLocation)
                   throws IOException

Throws:

IOException

updateRecord

public void updateRecord(int id,
                         byte[] value)
                  throws IOException

Description copied from interface: DataStore

Update record with new value.

Specified by:

updateRecord in interface DataStore

Throws:

IOException

vacuum

public void vacuum(int allowedFragmentationPercent)
            throws IOException

Defragment empty space.

Parameters:

allowedFragmentationPercent - allowed maximum percentage of free space, relative to total used space.

Throws:

IOException

writeInt

public void writeInt(long position,
                     int value)
              throws IOException

Throws:

IOException

writeLong

public void writeLong(long position,
                      long value)
               throws IOException

Throws:

IOException