uk.ac.starlink.fits

Class MultiByteBufferInput

java.lang.Object

uk.ac.starlink.fits.BlockInput

uk.ac.starlink.fits.MultiByteBufferInput

All Implemented Interfaces:

BasicInput

public class MultiByteBufferInput
extends BlockInput

Random-access BasicInput implementation based on a supplied array of byte buffers.

Since:

19 Mar 2021

Author:

Mark Taylor

Constructor Summary

Constructors

Constructor and Description
MultiByteBufferInput(ByteBuffer[] bufs) Constructor.

Method Summary

Modifier and Type	Method and Description
protected ByteBuffer	acquireBlock(int iblock) Obtains a buffer corresponding to a named block of the stream.
void	close() Releases resources belonging to this object.
long	getBlockOffset(int iblock, int offsetInBlock) Returns the offset into this stream corresponding to a given block index and offset into that block.
int[]	getBlockPos(long offset) Returns the block location of a given byte offset.

Methods inherited from class uk.ac.starlink.fits.BlockInput

getBlockCount, getOffset, isRandom, readByte, readBytes, readDouble, readFloat, readInt, readLong, readShort, seek, skip

Methods inherited from class java.lang.Object

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

Constructor Detail

MultiByteBufferInput

public MultiByteBufferInput(ByteBuffer[] bufs)

Constructor.

Parameters:

bufs - byte buffers holding data

Method Detail

getBlockPos

public int[] getBlockPos(long offset)

Description copied from class: BlockInput

Returns the block location of a given byte offset.

This does the opposite of getBlockOffset.

Specified by:

getBlockPos in class BlockInput

Parameters:

offset - offset into this input stream

Returns:

2-element array giving [blockIndex, offsetInBlock]

getBlockOffset

public long getBlockOffset(int iblock,
                           int offsetInBlock)

Description copied from class: BlockInput

Returns the offset into this stream corresponding to a given block index and offset into that block.

This does the opposite of getBlockPos.

Specified by:

getBlockOffset in class BlockInput

Parameters:

iblock - block index

offsetInBlock - offset into that block

Returns:

offset into stream

acquireBlock

protected ByteBuffer acquireBlock(int iblock)

Description copied from class: BlockInput

Obtains a buffer corresponding to a named block of the stream. The buffer's position must be zero. This method is called whenever a buffer is required which is not the same as the most recently used one.

Specified by:

acquireBlock in class BlockInput

Parameters:

iblock - block index

Returns:

byte buffer for given block, positioned at start

close

public void close()

Description copied from interface: BasicInput

Releases resources belonging to this object. Attempts to use it after a call to this method result in undefined behaviour.

Specified by:

close in interface BasicInput

Overrides:

close in class BlockInput