com.twelvemonkeys.io

Class FileCacheSeekableStream

java.lang.Object

java.io.InputStream

com.twelvemonkeys.io.SeekableInputStream

com.twelvemonkeys.io.FileCacheSeekableStream

All Implemented Interfaces:

Seekable, Closeable, AutoCloseable

public final class FileCacheSeekableStream
extends SeekableInputStream

A SeekableInputStream implementation that caches data in a temporary File.

Temporary files are created as specified in File.createTempFile(String, String, java.io.File).

Version:

$Id: //depot/branches/personal/haraldk/twelvemonkeys/release-2/twelvemonkeys-core/src/main/java/com/twelvemonkeys/io/FileCacheSeekableStream.java#5 $

Author:

Harald Kuhr

See Also:

MemoryCacheSeekableStream, FileSeekableStream, File.createTempFile(String, String), RandomAccessFile

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	AbstractCachedSeekableStream.StreamCache An abstract stream cache.

Field Summary

Fields

Modifier and Type	Field and Description
protected InputStream	stream The backing stream
protected long	streamPosition The stream positon in the backing stream (stream)

Fields inherited from class com.twelvemonkeys.io.SeekableInputStream

markedPositions

Constructor Summary

Constructors

Constructor and Description
FileCacheSeekableStream(InputStream pStream) Creates a FileCacheSeekableStream reading from the given InputStream.
FileCacheSeekableStream(InputStream pStream, String pTempBaseName) Creates a FileCacheSeekableStream reading from the given InputStream.
FileCacheSeekableStream(InputStream pStream, String pTempBaseName, File pTempDir) Creates a FileCacheSeekableStream reading from the given InputStream.

Method Summary

Methods

Modifier and Type	Method and Description
int	available()
protected void	closeImpl()
protected void	flushBeforeImpl(long pPosition) Discards the initial portion of the stream prior to the indicated postion.
protected AbstractCachedSeekableStream.StreamCache	getCache()
boolean	isCached() Returns true if this Seekable stream caches data itself in order to allow seeking backwards.
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.
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 void	syncPosition()

Methods inherited from class com.twelvemonkeys.io.SeekableInputStream

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

Methods inherited from class java.lang.Object

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

Field Detail

stream

protected final InputStream stream

The backing stream

streamPosition

protected long streamPosition

The stream positon in the backing stream (stream)

Constructor Detail

FileCacheSeekableStream

public FileCacheSeekableStream(InputStream pStream)
                        throws IOException

Creates a FileCacheSeekableStream reading from the given InputStream. Data will be cached in a temporary file.

Parameters:

pStream - the InputStream to read from

Throws:

IOException - if the temporary file cannot be created, or cannot be opened for random access.

FileCacheSeekableStream

public FileCacheSeekableStream(InputStream pStream,
                       String pTempBaseName)
                        throws IOException

Creates a FileCacheSeekableStream reading from the given InputStream. Data will be cached in a temporary file, with the given base name.

Parameters:

pStream - the InputStream to read from

pTempBaseName - optional base name for the temporary file

Throws:

IOException - if the temporary file cannot be created, or cannot be opened for random access.

FileCacheSeekableStream

public FileCacheSeekableStream(InputStream pStream,
                       String pTempBaseName,
                       File pTempDir)
                        throws IOException

Creates a FileCacheSeekableStream reading from the given InputStream. Data will be cached in a temporary file, with the given base name, in the given directory

Parameters:

pStream - the InputStream to read from

pTempBaseName - optional base name for the temporary file

pTempDir - optional temp directory

Throws:

IOException - if the temporary file cannot be created, or cannot be opened for random access.

Method Detail

isCachedMemory

public final 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.

Specified by:

isCachedMemory in interface Seekable

Returns:

true if this Seekable caches data in main memory.

See Also:

Seekable.isCached(), Seekable.isCachedFile()

isCachedFile

public final 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.

Specified by:

isCachedFile in interface Seekable

Returns:

true if this Seekable caches data in a temporary file.

See Also:

Seekable.isCached(), Seekable.isCachedMemory()

closeImpl

protected void closeImpl()
                  throws IOException

Throws:

IOException

read

public int read()
         throws IOException

Throws:

IOException

read

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

Throws:

IOException

getCache

protected final AbstractCachedSeekableStream.StreamCache getCache()

available

public int available()
              throws IOException

Overrides:

available 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()

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)