org.garret.perst
Class MappedFile

java.lang.Object
  org.garret.perst.MappedFile

All Implemented Interfaces:

IFile

public class MappedFile

extends java.lang.Object

implements IFile

Class using NIO mapping file on virtual mapping. Useing this class instead standard OSFile can significantly increase speed of application in some cases.

Constructor Summary

MappedFile(java.lang.String filePath, long initialSize, boolean readOnly)

Method Summary

void	close() Close file
long	length() Length of the file
boolean	lock() Lock file
int	read(long pos, byte[] buf) Reade data from the file
void	sync() Flush all fiels changes to the disk
void	write(long pos, byte[] buf) Write data to the file

Methods inherited from class java.lang.Object

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

Constructor Detail

MappedFile

public MappedFile(java.lang.String filePath,
                  long initialSize,
                  boolean readOnly)

Method Detail

close

public void close()

Description copied from interface: IFile

Close file

Specified by:

close in interface IFile

length

public long length()

Description copied from interface: IFile

Length of the file

Specified by:

length in interface IFile

Returns:

length of file in bytes

lock

public boolean lock()

Description copied from interface: IFile

Lock file

Specified by:

lock in interface IFile

Returns:

true if file was successfully locked or locking in not implemented, false if file is locked by some other applciation

read

public int read(long pos,
                byte[] buf)

Description copied from interface: IFile

Reade data from the file

Specified by:

read in interface IFile

Parameters:

pos - offset in the file

buf - array to receive readen data (size is always equal to database page size)

Returns:

number of bytes actually readen

sync

public void sync()

Description copied from interface: IFile

Flush all fiels changes to the disk

Specified by:

sync in interface IFile

write

public void write(long pos,
                  byte[] buf)

Description copied from interface: IFile

Write data to the file

Specified by:

write in interface IFile

Parameters:

pos - offset in the file

buf - array with data to be writter (size is always equal to database page size)