com.github.mjdev.libaums.driver

Interface BlockDeviceDriver

All Known Implementing Classes:

Partition, ScsiBlockDevice

public interface BlockDeviceDriver

This interface describes a simple block device with a certain block size and the ability to read and write at a certain device offset.

Method Summary

Modifier and Type	Method and Description
int	getBlockSize() Returns the block size of the block device.
void	init() Initializes the block device for further use.
void	read(long deviceOffset, java.nio.ByteBuffer buffer) Reads from the block device at a certain offset into the given buffer.
void	write(long deviceOffset, java.nio.ByteBuffer buffer) Writes to the block device at a certain offset from the given buffer.

Method Detail

init

void init()
   throws java.io.IOException

Initializes the block device for further use. This method should be called before doing anything else on the block device.

Throws:

java.io.IOException - If initializing fails

read

void read(long deviceOffset,
          java.nio.ByteBuffer buffer)
   throws java.io.IOException

Reads from the block device at a certain offset into the given buffer. The amount of bytes to be read are determined by Buffer.remaining().

The deviceOffset can either be the amount of bytes or a logical block addressing using the block size. To get the bytes in the last case you have to multiply the lba with the block size (offset * getBlockSize()).

Parameters:

deviceOffset - The offset where the reading should begin.

buffer - The buffer where the data should be read into.

Throws:

java.io.IOException - If reading fails.

write

void write(long deviceOffset,
           java.nio.ByteBuffer buffer)
    throws java.io.IOException

Writes to the block device at a certain offset from the given buffer. The amount of bytes to be written are determined by Buffer.remaining().

The deviceOffset can either be the amount of bytes or a logical block addressing using the block size. To get the bytes in the last case you have to multiply the lba with the block size (offset * getBlockSize()).

Parameters:

deviceOffset - The offset where the writing should begin.

buffer - The buffer with the data to be transferred.

Throws:

java.io.IOException - If writing fails.

getBlockSize

int getBlockSize()

Returns the block size of the block device. Every block device can only read and store bytes in a specific block with a certain size.

That means that it is only possible to read or write hole blocks!

Returns:

The block size in bytes, mostly 512 bytes.