Class BufferedChannelImageInputStream

java.lang.Object

javax.imageio.stream.ImageInputStreamImpl

com.twelvemonkeys.imageio.stream.BufferedChannelImageInputStream

All Implemented Interfaces:

Closeable, DataInput, AutoCloseable, ImageInputStream

final class BufferedChannelImageInputStream
extends ImageInputStreamImpl

A buffered ImageInputStream that is backed by a SeekableByteChannel and provides greatly improved performance compared to FileCacheImageInputStream or MemoryCacheImageInputStream for shorter reads, like single byte or bit reads.

Field Summary

Fields

Modifier and Type	Field	Description
private byte[]	buffer
private int	bufferLimit
private int	bufferPos
private ByteBuffer	byteBuffer
private SeekableByteChannel	channel
private Closeable	closeable
private static final Closeable	CLOSEABLE_STUB
(package private) static final int	DEFAULT_BUFFER_SIZE
private final ByteBuffer	integralCache
private final byte[]	integralCacheArray

Fields inherited from class ImageInputStreamImpl

bitOffset, byteOrder, flushedPos, streamPos

Constructor Summary

Constructors

Modifier	Constructor	Description
(package private)	BufferedChannelImageInputStream(Cache cache)	Constructs a BufferedChannelImageInputStream that will read from a given Cache.
	BufferedChannelImageInputStream(File file)	Constructs a BufferedChannelImageInputStream that will read from a given File.
	BufferedChannelImageInputStream(FileInputStream inputStream)	Constructs a BufferedChannelImageInputStream that will read from a given FileInputStream.
	BufferedChannelImageInputStream(RandomAccessFile file)	Constructs a BufferedChannelImageInputStream that will read from a given RandomAccessFile.
	BufferedChannelImageInputStream(SeekableByteChannel channel)	Constructs a BufferedChannelImageInputStream that will read from a given SeekableByteChannel.
private	BufferedChannelImageInputStream(SeekableByteChannel channel, boolean closeChannelOnClose)
	BufferedChannelImageInputStream(Path file)	Constructs a BufferedChannelImageInputStream that will read from a given Path.

Method Summary

Modifier and Type	Method	Description
private boolean	bufferEmpty()
void	close()
private boolean	fillBuffer()
void	flushBefore(long pos)
long	length()
int	read()
int	read(byte[] bytes, int offset, int length)
private int	readBuffered(byte[] bytes, int offset, int length)
private int	readDirect(byte[] bytes, int offset, int length)
int	readInt()
long	readLong()
short	readShort()
void	seek(long position)
void	setByteOrder(ByteOrder byteOrder)

Methods inherited from class ImageInputStreamImpl

checkClosed, finalize, flush, getBitOffset, getByteOrder, getFlushedPosition, getStreamPosition, isCached, isCachedFile, isCachedMemory, mark, read, readBit, readBits, readBoolean, readByte, readBytes, readChar, readDouble, readFloat, readFully, readFully, readFully, readFully, readFully, readFully, readFully, readFully, readLine, readUnsignedByte, readUnsignedInt, readUnsignedShort, readUTF, reset, setBitOffset, skipBytes, skipBytes

Methods inherited from class Object

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

Field Details

CLOSEABLE_STUB

private static final Closeable CLOSEABLE_STUB

DEFAULT_BUFFER_SIZE

static final int DEFAULT_BUFFER_SIZE

See Also:

• Constant Field Values

byteBuffer

private ByteBuffer byteBuffer

buffer

private byte[] buffer

bufferPos

private int bufferPos

bufferLimit

private int bufferLimit

integralCache

private final ByteBuffer integralCache

integralCacheArray

private final byte[] integralCacheArray

channel

private SeekableByteChannel channel

closeable

private Closeable closeable

Constructor Details

BufferedChannelImageInputStream

public BufferedChannelImageInputStream(File file)
                                throws IOException

Constructs a BufferedChannelImageInputStream that will read from a given File.

Parameters:

file - a File to read from.

Throws:

IllegalArgumentException - if file is null.

SecurityException - if a security manager is installed, and it denies read access to the file.

IOException - if an I/O error occurs while opening the file.

BufferedChannelImageInputStream

public BufferedChannelImageInputStream(Path file)
                                throws IOException

Constructs a BufferedChannelImageInputStream that will read from a given Path.

Parameters:

file - a Path to read from.

Throws:

IllegalArgumentException - if file is null.

UnsupportedOperationException - if the file is associated with a provider that does not support creating file channels.

IOException - if an I/O error occurs while opening the file.

SecurityException - if a security manager is installed, and it denies read access to the file.

BufferedChannelImageInputStream

public BufferedChannelImageInputStream(RandomAccessFile file)

Constructs a BufferedChannelImageInputStream that will read from a given RandomAccessFile.

Parameters:

file - a RandomAccessFile to read from.

Throws:

IllegalArgumentException - if file is null.

BufferedChannelImageInputStream

public BufferedChannelImageInputStream(FileInputStream inputStream)

Constructs a BufferedChannelImageInputStream that will read from a given FileInputStream.

Closing this stream will not close the FileInputStream.

Parameters:

inputStream - a FileInputStream to read from.

Throws:

IllegalArgumentException - if inputStream is null.

BufferedChannelImageInputStream

public BufferedChannelImageInputStream(SeekableByteChannel channel)

Constructs a BufferedChannelImageInputStream that will read from a given SeekableByteChannel.

Closing this stream will not close the SeekableByteChannel.

Parameters:

channel - a SeekableByteChannel to read from.

Throws:

IllegalArgumentException - if channel is null.

BufferedChannelImageInputStream

BufferedChannelImageInputStream(Cache cache)

Constructs a BufferedChannelImageInputStream that will read from a given Cache.

Closing this stream will close the Cache.

Parameters:

cache - a SeekableByteChannel to read from.

Throws:

IllegalArgumentException - if channel is null.

BufferedChannelImageInputStream

private BufferedChannelImageInputStream(SeekableByteChannel channel,
 boolean closeChannelOnClose)

Method Details

fillBuffer

private boolean fillBuffer()
                    throws IOException

Throws:

IOException

bufferEmpty

private boolean bufferEmpty()

setByteOrder

public void setByteOrder(ByteOrder byteOrder)

Specified by:

setByteOrder in interface ImageInputStream

Overrides:

setByteOrder in class ImageInputStreamImpl

read

public int read()
         throws IOException

Specified by:

read in interface ImageInputStream

Specified by:

read in class ImageInputStreamImpl

Throws:

IOException

read

public int read(byte[] bytes,
 int offset,
 int length)
         throws IOException

Specified by:

read in interface ImageInputStream

Specified by:

read in class ImageInputStreamImpl

Throws:

IOException

readDirect

private int readDirect(byte[] bytes,
 int offset,
 int length)
                throws IOException

Throws:

IOException

readBuffered

private int readBuffered(byte[] bytes,
 int offset,
 int length)

length

public long length()

Specified by:

length in interface ImageInputStream

Overrides:

length in class ImageInputStreamImpl

close

public void close()
           throws IOException

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable

Specified by:

close in interface ImageInputStream

Overrides:

close in class ImageInputStreamImpl

Throws:

IOException

readShort

public short readShort()
                throws IOException

Specified by:

readShort in interface DataInput

Specified by:

readShort in interface ImageInputStream

Overrides:

readShort in class ImageInputStreamImpl

Throws:

IOException

readInt

public int readInt()
            throws IOException

Specified by:

readInt in interface DataInput

Specified by:

readInt in interface ImageInputStream

Overrides:

readInt in class ImageInputStreamImpl

Throws:

IOException

readLong

public long readLong()
              throws IOException

Specified by:

readLong in interface DataInput

Specified by:

readLong in interface ImageInputStream

Overrides:

readLong in class ImageInputStreamImpl

Throws:

IOException

seek

public void seek(long position)
          throws IOException

Specified by:

seek in interface ImageInputStream

Overrides:

seek in class ImageInputStreamImpl

Throws:

IOException

flushBefore

public void flushBefore(long pos)
                 throws IOException

Specified by:

flushBefore in interface ImageInputStream

Overrides:

flushBefore in class ImageInputStreamImpl

Throws:

IOException