/*
* Copyright (c) 2008, Harald Kuhr
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* * Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* * Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* * Neither the name of the copyright holder nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
package com.twelvemonkeys.io;
import java.io.
IOException;
import java.io.
OutputStream;
import java.util.
Stack;
/**
* Abstract base class for {@code OutputStream}s implementing the
* {@code Seekable} interface.
* <p/>
* @see SeekableInputStream
*
* @author <a href="mailto:harald.kuhr@gmail.com">Harald Kuhr</a>
* @version $Id: //depot/branches/personal/haraldk/twelvemonkeys/release-2/twelvemonkeys-core/src/main/java/com/twelvemonkeys/io/SeekableOutputStream.java#2 $
*/
public abstract class
SeekableOutputStream extends
OutputStream implements
Seekable {
// TODO: Implement
long
position;
long
flushedPosition;
boolean
closed;
protected
Stack<
Long>
markedPositions = new
Stack<
Long>();
/// Outputstream overrides
@
Override
public final void
write(byte
pBytes[]) throws
IOException {
write(
pBytes, 0,
pBytes != null ?
pBytes.length : 1);
}
/// Seekable implementation
// TODO: This is common behaviour/implementation with SeekableInputStream,
// probably a good idea to extract a delegate..?
public final void
seek(long
pPosition) throws
IOException {
checkOpen();
// TODO: This is correct according to javax.imageio (IndexOutOfBoundsException),
// but it's inconsistent with reset that throws IOException...
if (
pPosition <
flushedPosition) {
throw new
IndexOutOfBoundsException("position < flushedPosition!");
}
seekImpl(
pPosition);
position =
pPosition;
}
protected abstract void
seekImpl(long
pPosition) throws
IOException;
public final void
mark() {
markedPositions.
push(
position);
}
public final void
reset() throws
IOException {
checkOpen();
if (!
markedPositions.
isEmpty()) {
long
newPos =
markedPositions.
pop();
// TODO: This is correct according to javax.imageio (IOException),
// but it's inconsistent with seek that throws IndexOutOfBoundsException...
if (
newPos <
flushedPosition) {
throw new
IOException("Previous marked position has been discarded!");
}
seek(
newPos);
}
}
public final void
flushBefore(long
pPosition) throws
IOException {
if (
pPosition <
flushedPosition) {
throw new
IndexOutOfBoundsException("position < flushedPosition!");
}
if (
pPosition >
getStreamPosition()) {
throw new
IndexOutOfBoundsException("position > getStreamPosition()!");
}
checkOpen();
flushBeforeImpl(
pPosition);
flushedPosition =
pPosition;
}
protected abstract void
flushBeforeImpl(long
pPosition) throws
IOException;
@
Override
public final void
flush() throws
IOException {
flushBefore(
flushedPosition);
}
public final long
getFlushedPosition() throws
IOException {
checkOpen();
return
flushedPosition;
}
public final long
getStreamPosition() throws
IOException {
checkOpen();
return
position;
}
protected final void
checkOpen() throws
IOException {
if (
closed) {
throw new
IOException("closed");
}
}
@
Override
public final void
close() throws
IOException {
checkOpen();
closed = true;
closeImpl();
}
protected abstract void
closeImpl() throws
IOException;
}