Package org.apache.sis.internal.storage.io

Class MemoryDataTransfer

java.lang.Object

org.apache.sis.internal.storage.io.MemoryDataTransfer

All Implemented Interfaces:

Closeable, AutoCloseable, Channel, ReadableByteChannel, DataTransfer

final class MemoryDataTransfer
extends Object
implements DataTransfer, ReadableByteChannel

A DataTransfer with all data in the given buffer, without channel.

Implementation note: This class implements also an empty ReadableByteChannel as safety. When using ChannelDataInput without channel, only an existing Buffer pre-filled with the data should be used. If we have a bug in our reading process, the empty channel will cause an EOFException to be thrown instead of a NullPointerException.

Since:

0.7

Version:

1.1

Field Summary

Fields

Modifier and Type	Field	Description
private final ChannelDataInput.ArrayReader	reader	The actual DataTransfer implementation.

Constructor Summary

Constructors

Constructor	Description
MemoryDataTransfer(String filename, Buffer data)	Creates a in-memory data input for the given buffer.

Method Summary

Modifier and Type	Method	Description
void	close()	Does nothing - keep the channel open.
void	createDataArray(int length)	Creates a destination array of the given length.
Buffer	createView()	Creates a new buffer of the type required by the array to fill.
Object	dataArray()	Returns the data as a char[], short[], int[], long[], float[] or double[] array.
Buffer	dataArrayAsBuffer()	Returns DataTransfer.dataArray() wrapped in a buffer.
int	dataSizeShift()	Returns the size of the Java primitive type which is the element of the array.
String	filename()	Delegates to the actual implementation.
boolean	isOpen()	The channel is always open.
int	read(ByteBuffer dst)	Returns -1 since an empty channel has reached the end-of-stream.
(package private) DataTransfer	reader()	Returns the most efficient DataTransfer instance to use.
void	readFully(Buffer view, int offset, int length)	Reads length values from the buffer and stores them into the array known to subclass, starting at index offset.
void	seek(long position)	Moves to the given byte position in the buffer.
void	setDest(Object array)	Sets the destination to the given data array, which may be null.
Buffer	view()	Returns the view created by the last call to DataTransfer.createView(), or null if none.

Methods inherited from class java.lang.Object

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

Field Details

reader

private final ChannelDataInput.ArrayReader reader

The actual DataTransfer implementation.

Constructor Details

MemoryDataTransfer

MemoryDataTransfer(String filename,
 Buffer data)
            throws IOException

Creates a in-memory data input for the given buffer.

Throws:

IOException

Method Details

reader

DataTransfer reader()

Returns the most efficient DataTransfer instance to use.

seek

public void seek(long position)
          throws IOException

Moves to the given byte position in the buffer.

Specified by:

seek in interface DataTransfer

Parameters:

position - the position where to move.

Throws:

IOException - if the stream cannot be moved to the given position.

filename

public String filename()

Delegates to the actual implementation.

Specified by:

filename in interface DataTransfer

dataSizeShift

public int dataSizeShift()

Description copied from interface: DataTransfer

Returns the size of the Java primitive type which is the element of the array. The size is expressed as the number of bits to shift: java dataSize = 1 << dataSizeShift;

Specified by:

dataSizeShift in interface DataTransfer

dataArray

public Object dataArray()

Description copied from interface: DataTransfer

Returns the data as a char[], short[], int[], long[], float[] or double[] array. This is either the array given in argument to the subclass constructor, or the array created by DataTransfer.createDataArray(int).

Specified by:

dataArray in interface DataTransfer

dataArrayAsBuffer

public Buffer dataArrayAsBuffer()

Description copied from interface: DataTransfer

Returns DataTransfer.dataArray() wrapped in a buffer.

Specified by:

dataArrayAsBuffer in interface DataTransfer

view

public Buffer view()

Description copied from interface: DataTransfer

Returns the view created by the last call to DataTransfer.createView(), or null if none.

Specified by:

view in interface DataTransfer

createView

public Buffer createView()

Description copied from interface: DataTransfer

Creates a new buffer of the type required by the array to fill. This method is guaranteed to be invoked exactly once, after the ChannelData.buffer contains enough data.

Specified by:

createView in interface DataTransfer

createDataArray

public void createDataArray(int length)

Description copied from interface: DataTransfer

Creates a destination array of the given length.

Specified by:

createDataArray in interface DataTransfer

setDest

public void setDest(Object array)

Description copied from interface: DataTransfer

Sets the destination to the given data array, which may be null.

Specified by:

setDest in interface DataTransfer

readFully

public void readFully(Buffer view,
 int offset,
 int length)

Reads length values from the buffer and stores them into the array known to subclass, starting at index offset.

Specified by:

readFully in interface DataTransfer

Parameters:

view - ignored.

offset - the starting position within dest to write.

length - the number of values to read.

read

public int read(ByteBuffer dst)

Returns -1 since an empty channel has reached the end-of-stream.

Specified by:

read in interface ReadableByteChannel

isOpen

public boolean isOpen()

The channel is always open.

Specified by:

isOpen in interface Channel

close

public void close()
           throws IOException

Does nothing - keep the channel open.

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Channel

Specified by:

close in interface Closeable

Throws:

IOException