Class AbstractCachedSeekableStream

java.lang.Object

java.io.InputStream

com.twelvemonkeys.io.SeekableInputStream

com.twelvemonkeys.io.AbstractCachedSeekableStream

All Implemented Interfaces:

Seekable, Closeable, AutoCloseable

Direct Known Subclasses:

FileCacheSeekableStream, MemoryCacheSeekableStream

abstract class AbstractCachedSeekableStream
extends SeekableInputStream

Represents a cached seekable stream, that reads through a cache.

Version:

$Id: //depot/branches/personal/haraldk/twelvemonkeys/release-2/twelvemonkeys-core/src/main/java/com/twelvemonkeys/io/AbstractCachedSeekableStream.java#2 $

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
(package private) static class	AbstractCachedSeekableStream.StreamCache	An abstract stream cache.

Field Summary

Fields

Modifier and Type	Field	Description
private AbstractCachedSeekableStream.StreamCache	cache
protected final InputStream	stream	The backing stream
protected long	streamPosition	The stream positon in the backing stream (stream)

Fields inherited from class SeekableInputStream

closed, flushedPosition, markedPositions, position

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	AbstractCachedSeekableStream(InputStream pStream, AbstractCachedSeekableStream.StreamCache pCache)

Method Summary

Modifier and Type	Method	Description
int	available()
protected void	closeImpl()
protected void	flushBeforeImpl(long pPosition)	Discards the initial portion of the stream prior to the indicated postion.
protected final AbstractCachedSeekableStream.StreamCache	getCache()
final boolean	isCached()	Returns true if this Seekable stream caches data itself in order to allow seeking backwards.
abstract boolean	isCachedFile()	Returns true if this Seekable stream caches data itself in order to allow seeking backwards, and the cache is kept in a temporary file.
abstract boolean	isCachedMemory()	Returns true if this Seekable stream caches data itself in order to allow seeking backwards, and the cache is kept in main memory.
int	read()
int	read(byte[] pBytes, int pOffset, int pLength)
protected void	seekImpl(long pPosition)
protected final void	syncPosition()

Methods inherited from class SeekableInputStream

checkOpen, close, finalize, flush, flushBefore, getFlushedPosition, getStreamPosition, mark, mark, markSupported, read, reset, seek, skip

Methods inherited from class InputStream

nullInputStream, readAllBytes, readNBytes, readNBytes, skipNBytes, transferTo

Methods inherited from class Object

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

Field Details

stream

protected final InputStream stream

The backing stream

streamPosition

protected long streamPosition

The stream positon in the backing stream (stream)

cache

private AbstractCachedSeekableStream.StreamCache cache

Constructor Details

AbstractCachedSeekableStream

protected AbstractCachedSeekableStream(InputStream pStream,
 AbstractCachedSeekableStream.StreamCache pCache)

Method Details

getCache

protected final AbstractCachedSeekableStream.StreamCache getCache()

available

public int available()
              throws IOException

Overrides:

available in class InputStream

Throws:

IOException

read

public int read()
         throws IOException

Specified by:

read in class InputStream

Throws:

IOException

read

public int read(byte[] pBytes,
 int pOffset,
 int pLength)
         throws IOException

Overrides:

read in class InputStream

Throws:

IOException

syncPosition

protected final void syncPosition()
                           throws IOException

Throws:

IOException

isCached

public final boolean isCached()

Description copied from interface: Seekable

Returns true if this Seekable stream caches data itself in order to allow seeking backwards. Applications may consult this in order to decide how frequently, or whether, to flush in order to conserve cache resources.

Returns:

true if this Seekable caches data.

See Also:

• Seekable.isCachedMemory()
• Seekable.isCachedFile()

isCachedMemory

public abstract boolean isCachedMemory()

Description copied from interface: Seekable

Returns true if this Seekable stream caches data itself in order to allow seeking backwards, and the cache is kept in main memory. Applications may consult this in order to decide how frequently, or whether, to flush in order to conserve cache resources.

Returns:

true if this Seekable caches data in main memory.

See Also:

• Seekable.isCached()
• Seekable.isCachedFile()

isCachedFile

public abstract boolean isCachedFile()

Description copied from interface: Seekable

Returns true if this Seekable stream caches data itself in order to allow seeking backwards, and the cache is kept in a temporary file. Applications may consult this in order to decide how frequently, or whether, to flush in order to conserve cache resources.

Returns:

true if this Seekable caches data in a temporary file.

See Also:

• Seekable.isCached()
• Seekable.isCachedMemory()

seekImpl

protected void seekImpl(long pPosition)
                 throws IOException

Specified by:

seekImpl in class SeekableInputStream

Throws:

IOException

flushBeforeImpl

protected void flushBeforeImpl(long pPosition)

Description copied from class: SeekableInputStream

Discards the initial portion of the stream prior to the indicated postion.

Specified by:

flushBeforeImpl in class SeekableInputStream

Parameters:

pPosition - the position to flush to

See Also:

• SeekableInputStream.flushBefore(long)

closeImpl

protected void closeImpl()
                  throws IOException

Specified by:

closeImpl in class SeekableInputStream

Throws:

IOException