com.twelvemonkeys.io
Class SeekableOutputStream

java.lang.Object
  java.io.OutputStream
      com.twelvemonkeys.io.SeekableOutputStream

All Implemented Interfaces:

Seekable, Closeable, Flushable

public abstract class SeekableOutputStream
extends OutputStream
implements Seekable

Abstract base class for OutputStreams implementing the Seekable interface.

Version:

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

Author:

Harald Kuhr

See Also:

SeekableInputStream

Field Summary

protected Stack<Long>

markedPositions

Constructor Summary

SeekableOutputStream()

Method Summary

protected void	checkOpen()
void	close() Closes the stream.
protected abstract void	closeImpl()
void	flush() Discards the initial position of the stream prior to the current stream position.
void	flushBefore(long pPosition) Discards the initial portion of the stream prior to the indicated postion.
protected abstract void	flushBeforeImpl(long pPosition)
long	getFlushedPosition() Returns the earliest position in the stream to which seeking may be performed.
long	getStreamPosition() Returns the current byte position of the stream.
void	mark() Marks a position in the stream to be returned to by a subsequent call to reset.
void	reset() Returns the file pointer to its previous position, at the time of the most recent unmatched call to mark.
void	seek(long pPosition) Sets the current stream position to the desired location.
protected abstract void	seekImpl(long pPosition)
void	write(byte[] pBytes)

Methods inherited from class java.io.OutputStream

write, write

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.twelvemonkeys.io.Seekable

isCached, isCachedFile, isCachedMemory

Field Detail

markedPositions

protected Stack<Long> markedPositions

Constructor Detail

SeekableOutputStream

public SeekableOutputStream()

Method Detail

write

public final void write(byte[] pBytes)
                 throws IOException

Overrides:

write in class OutputStream

Throws:

IOException

seek

public final void seek(long pPosition)
                throws IOException

Description copied from interface: Seekable

Sets the current stream position to the desired location. The next read will occur at this location.

An IndexOutOfBoundsException will be thrown if pPosition is smaller than the flushed position (as returned by Seekable.getFlushedPosition()).

It is legal to seek past the end of the file; an EOFException will be thrown only if a read is performed.

Specified by:

seek in interface Seekable

Parameters:

pPosition - a long containing the desired file pointer position.

Throws:

IOException - if any other I/O error occurs.

seekImpl

protected abstract void seekImpl(long pPosition)
                          throws IOException

Throws:

IOException

mark

public final void mark()

Description copied from interface: Seekable

Marks a position in the stream to be returned to by a subsequent call to reset. Unlike a standard InputStream, all Seekable streams upport marking. Additionally, calls to mark and reset may be nested arbitrarily.

Unlike the mark methods declared by the Reader or InputStream interfaces, no readLimit parameter is used. An arbitrary amount of data may be read following the call to mark.

Specified by:

mark in interface Seekable

reset

public final void reset()
                 throws IOException

Description copied from interface: Seekable

Returns the file pointer to its previous position, at the time of the most recent unmatched call to mark.

Calls to reset without a corresponding call to mark will either:

• throw an IOException
• or, reset to the beginning of the stream.

An IOException will be thrown if the previous marked position lies in the discarded portion of the stream.

Specified by:

reset in interface Seekable

Throws:

IOException - if an I/O error occurs.

See Also:

InputStream.reset()

flushBefore

public final void flushBefore(long pPosition)
                       throws IOException

Description copied from interface: Seekable

Discards the initial portion of the stream prior to the indicated postion. Attempting to seek to an offset within the flushed portion of the stream will result in an IndexOutOfBoundsException.

Calling flushBefore may allow classes implementing this interface to free up resources such as memory or disk space that are being used to store data from the stream.

Specified by:

flushBefore in interface Seekable

Parameters:

pPosition - a long containing the length of the file prefix that may be flushed.

Throws:

IOException - if an I/O error occurs.

flushBeforeImpl

protected abstract void flushBeforeImpl(long pPosition)
                                 throws IOException

Throws:

IOException

flush

public final void flush()
                 throws IOException

Description copied from interface: Seekable

Discards the initial position of the stream prior to the current stream position. Equivalent to flushBefore(getStreamPosition()).

Specified by:

flush in interface Seekable

Specified by:

flush in interface Flushable

Overrides:

flush in class OutputStream

Throws:

IOException - if an I/O error occurs.

getFlushedPosition

public final long getFlushedPosition()
                              throws IOException

Description copied from interface: Seekable

Returns the earliest position in the stream to which seeking may be performed. The returned value will be the maximum of all values passed into previous calls to flushBefore.

Specified by:

getFlushedPosition in interface Seekable

Returns:

the earliest legal position for seeking, as a long.

Throws:

IOException - if an I/O error occurs.

getStreamPosition

public final long getStreamPosition()
                             throws IOException

Description copied from interface: Seekable

Returns the current byte position of the stream. The next read will take place starting at this offset.

Specified by:

getStreamPosition in interface Seekable

Returns:

a long containing the position of the stream.

Throws:

IOException - if an I/O error occurs.

checkOpen

protected final void checkOpen()
                        throws IOException

Throws:

IOException

close

public final void close()
                 throws IOException

Description copied from interface: Seekable

Closes the stream.

Specified by:

close in interface Seekable

Specified by:

close in interface Closeable

Overrides:

close in class OutputStream

Throws:

IOException - if the stream can't be closed.

closeImpl

protected abstract void closeImpl()
                           throws IOException

Throws:

IOException