mobios.mckoi.store
Interface FileBufferAccessor

public interface FileBufferAccessor

An abstraction for accessing an underlying file through a buffering strategy. Implementations of this could include a simple RandomAccessFile paging system that uses Java 1.4 memory mapping facilities, or not.

Author:

Tobias Downer

Method Summary

void	flush() Flushes any pending contents of the buffer from memory to the file.
int	readByte(long position) Reads a single byte from the given position in the given RandomAccessFile that has been assigned the given id value.
int	readByteArray(long position, byte[] buf, int off, int len) Reads a byte array from the given position in the file.
void	sizeChange(long old_file_length, long new_file_length) Notifies the buffering strategy that the size of the file has changed.
void	writeByte(long position, byte b) Writes a single byte to the given position in the file.
int	writeByteArray(long position, byte[] buf, int off, int len) Writes a byte array to the given position in the file.

Method Detail

readByte

int readByte(long position)
             throws IOException

Reads a single byte from the given position in the given RandomAccessFile that has been assigned the given id value.

Throws:

IOException

readByteArray

int readByteArray(long position,
                  byte[] buf,
                  int off,
                  int len)
                  throws IOException

Reads a byte array from the given position in the file. Returns the actual number of bytes read. The value returned should ALWAYS be the value given in 'len'.

Throws:

IOException

writeByte

void writeByte(long position,
               byte b)
               throws IOException

Writes a single byte to the given position in the file.

Throws:

IOException

writeByteArray

int writeByteArray(long position,
                   byte[] buf,
                   int off,
                   int len)
                   throws IOException

Writes a byte array to the given position in the file. Returns the actual number of bytes written. The value returned should ALWAYS be the value given in 'len'.

Throws:

IOException

flush

void flush()
           throws IOException

Flushes any pending contents of the buffer from memory to the file.

Throws:

IOException

sizeChange

void sizeChange(long old_file_length,
                long new_file_length)
                throws IOException

Notifies the buffering strategy that the size of the file has changed.

Throws:

IOException