Module org.sejda.io

Package org.sejda.io

Class MemoryMappedSeekableSource

java.lang.Object

org.sejda.io.BaseSeekableSource

org.sejda.io.MemoryMappedSeekableSource

All Implemented Interfaces:

Closeable, AutoCloseable, Channel, ReadableByteChannel, SeekableSource

public class MemoryMappedSeekableSource
extends BaseSeekableSource

A SeekableSource implementation based on MappedByteBuffer. To overcome the int limit of the MappedByteBuffer, this source implement a pagination algorithm allowing to open files of any size. The size of the pages can be configured using the SeekableSources.MEMORY_MAPPED_PAGE_SIZE_PROPERTY system property.

Field Summary

Fields

Modifier and Type	Field	Description
private final ThreadBoundCopiesSupplier<MemoryMappedSeekableSource>	localCopiesSupplier
private static final org.slf4j.Logger	LOG
private static final long	MB_256
private final List<ByteBuffer>	pages
private final long	pageSize
private long	position
private final long	size
private Consumer<? super ByteBuffer>	unmapper

Constructor Summary

Constructors

Modifier	Constructor	Description
	MemoryMappedSeekableSource(File file)
	MemoryMappedSeekableSource(Path path)
private	MemoryMappedSeekableSource(MemoryMappedSeekableSource parent)

Method Summary

Modifier and Type	Method	Description
void	close()
long	position()
SeekableSource	position(long position)	Sets the source position.
int	read()	Reads a byte of data from this source.
int	read(ByteBuffer dst)
private int	readPage(ByteBuffer dst, int pageNumber, int bufferPosition)
long	size()
SeekableSource	view(long startingPosition, long length)

Methods inherited from class org.sejda.io.BaseSeekableSource

id, isOpen, requireOpen

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.sejda.io.SeekableSource

asInputStream, asNewInputStream, back, back, forward, peek, peekBack, reset

Field Details

LOG

private static final org.slf4j.Logger LOG

MB_256

private static final long MB_256

See Also:

• Constant Field Values

pageSize

private final long pageSize

pages

private final List<ByteBuffer> pages

position

private long position

size

private final long size

localCopiesSupplier

private final ThreadBoundCopiesSupplier<MemoryMappedSeekableSource> localCopiesSupplier

unmapper

private Consumer<? super ByteBuffer> unmapper

Constructor Details

MemoryMappedSeekableSource

public MemoryMappedSeekableSource(Path path)
                           throws IOException

Throws:

IOException

MemoryMappedSeekableSource

public MemoryMappedSeekableSource(File file)
                           throws IOException

Throws:

IOException

MemoryMappedSeekableSource

private MemoryMappedSeekableSource(MemoryMappedSeekableSource parent)

Method Details

position

public long position()

Returns:

the current source position as a positive long

size

public long size()

Returns:

The source size, measured in bytes

position

public SeekableSource position(long position)

Description copied from interface: SeekableSource

Sets the source position. Setting the position to a value that is greater than the source's size is legal but does not change the size of the source. A later attempt to read bytes at such a position will immediately return an end-of-file indication.

Parameters:

position - a non-negative long for the new position

Returns:

this source

read

public int read(ByteBuffer dst)
         throws IOException

Throws:

IOException

readPage

private int readPage(ByteBuffer dst,
 int pageNumber,
 int bufferPosition)

read

public int read()
         throws IOException

Description copied from interface: SeekableSource

Reads a byte of data from this source. The byte is returned as an integer in the range 0 to 255 ( 0x00-0xff ).

Returns:

the next byte of data, or -1 if there is no more data.

Throws:

IOException

close

public void close()
           throws IOException

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Channel

Specified by:

close in interface Closeable

Overrides:

close in class BaseSeekableSource

Throws:

IOException

view

public SeekableSource view(long startingPosition,
 long length)
                    throws IOException

Returns:

a readable view of a portion of this SeekableSource. Reading from the view doesn't affect the SeekableSource position. Closing the SeekableSource makes all the views unreadable but closing the view has no effect on the SeekableSource. A view may or may not work on a thread bound copy of the SeekableSource so as a general rule it should not be created and handed to other threads.

Throws:

IOException - if something goes wrong while creating the view