123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217 |
- /*
- * $Id$
- * ============================================================================
- * The Apache Software License, Version 1.1
- * ============================================================================
- *
- * Copyright (C) 1999-2003 The Apache Software Foundation. All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without modifica-
- * tion, are permitted provided that the following conditions are met:
- *
- * 1. Redistributions of source code must retain the above copyright notice,
- * this list of conditions and the following disclaimer.
- *
- * 2. 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.
- *
- * 3. The end-user documentation included with the redistribution, if any, must
- * include the following acknowledgment: "This product includes software
- * developed by the Apache Software Foundation (http://www.apache.org/)."
- * Alternately, this acknowledgment may appear in the software itself, if
- * and wherever such third-party acknowledgments normally appear.
- *
- * 4. The names "FOP" and "Apache Software Foundation" must not be used to
- * endorse or promote products derived from this software without prior
- * written permission. For written permission, please contact
- * apache@apache.org.
- *
- * 5. Products derived from this software may not be called "Apache", nor may
- * "Apache" appear in their name, without prior written permission of the
- * Apache Software Foundation.
- *
- * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED 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
- * APACHE SOFTWARE FOUNDATION OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
- * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLU-
- * DING, 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.
- * ============================================================================
- *
- * This software consists of voluntary contributions made by many individuals
- * on behalf of the Apache Software Foundation and was originally created by
- * James Tauber <jtauber@jtauber.com>. For more information on the Apache
- * Software Foundation, please see <http://www.apache.org/>.
- */
- package org.apache.fop.render.ps;
-
- import java.io.FilterOutputStream;
- import java.io.OutputStream;
- import java.io.IOException;
-
- /**
- * This class applies a RunLengthEncode filter to the stream.
- *
- * @author <a href="mailto:smwolke@geistig.com">Stephen Wolke</a>
- * @version $Id$
- */
- public class RunLengthEncodeOutputStream extends FilterOutputStream
- implements Finalizable {
-
- private static final int MAX_SEQUENCE_COUNT = 127;
- private static final int END_OF_DATA = 128;
- private static final int BYTE_MAX = 256;
-
- private static final int NOT_IDENTIFY_SEQUENCE = 0;
- private static final int START_SEQUENCE = 1;
- private static final int IN_SEQUENCE = 2;
- private static final int NOT_IN_SEQUENCE = 3;
-
- private int runCount = 0;
- private int isSequence = NOT_IDENTIFY_SEQUENCE;
- private byte[] runBuffer = new byte[MAX_SEQUENCE_COUNT + 1];
-
-
- /** @see java.io.FilterOutputStream **/
- public RunLengthEncodeOutputStream(OutputStream out) {
- super(out);
- }
-
-
- /** @see java.io.FilterOutputStream **/
- public void write(byte b)
- throws java.io.IOException {
- runBuffer[runCount] = b;
-
- switch (runCount) {
- case 0:
- runCount = 0;
- isSequence = NOT_IDENTIFY_SEQUENCE;
- runCount++;
- break;
- case 1:
- if (runBuffer[runCount] != runBuffer[runCount - 1]) {
- isSequence = NOT_IN_SEQUENCE;
- }
- runCount++;
- break;
- case 2:
- if (runBuffer[runCount] != runBuffer[runCount - 1]) {
- isSequence = NOT_IN_SEQUENCE;
- } else {
- if (isSequence == NOT_IN_SEQUENCE) {
- isSequence = START_SEQUENCE;
- } else {
- isSequence = IN_SEQUENCE;
- }
- }
- runCount++;
- break;
- case MAX_SEQUENCE_COUNT:
- if (isSequence == IN_SEQUENCE) {
- out.write(BYTE_MAX - (MAX_SEQUENCE_COUNT - 1));
- out.write(runBuffer[runCount - 1]);
- runBuffer[0] = runBuffer[runCount];
- runCount = 1;
- } else {
- out.write(MAX_SEQUENCE_COUNT);
- out.write(runBuffer, 0, runCount + 1);
- runCount = 0;
- }
- isSequence = NOT_IDENTIFY_SEQUENCE;
- break;
- default:
- switch (isSequence) {
- case IN_SEQUENCE:
- if (runBuffer[runCount] != runBuffer[runCount - 1]) {
- out.write(BYTE_MAX - (runCount - 1));
- out.write(runBuffer[runCount - 1]);
- runBuffer[0] = runBuffer[runCount];
- runCount = 1;
- isSequence = NOT_IDENTIFY_SEQUENCE;
- break;
- }
- runCount++;
- break;
- case NOT_IN_SEQUENCE:
- if (runBuffer[runCount] == runBuffer[runCount - 1]) {
- isSequence = START_SEQUENCE;
- }
- runCount++;
- break;
- case START_SEQUENCE:
- if (runBuffer[runCount] == runBuffer[runCount - 1]) {
- out.write(runCount - 3);
- out.write(runBuffer, 0, runCount - 2);
- runBuffer[0] = runBuffer[runCount];
- runBuffer[1] = runBuffer[runCount];
- runBuffer[2] = runBuffer[runCount];
- runCount = 3;
- isSequence = IN_SEQUENCE;
- break;
- } else {
- isSequence = NOT_IN_SEQUENCE;
- runCount++;
- break;
- }
- }
- }
- }
-
-
- /** @see java.io.FilterOutputStream **/
- public void write(byte[] b)
- throws IOException {
-
- for (int i = 0; i < b.length; i++) {
- this.write(b[i]);
- }
- }
-
-
- /** @see java.io.FilterOutputStream **/
- public void write(byte[] b, int off, int len)
- throws IOException {
-
- for (int i = 0; i < len; i++) {
- this.write(b[off + i]);
- }
- }
-
-
- /** @see org.apache.fop.render.ps.Finalizable **/
- public void finalizeStream()
- throws IOException {
- switch (isSequence) {
- case IN_SEQUENCE:
- out.write(BYTE_MAX - (runCount - 1));
- out.write(runBuffer[runCount - 1]);
- break;
- default:
- out.write(runCount - 1);
- out.write(runBuffer, 0, runCount);
- }
-
- out.write(END_OF_DATA);
-
- flush();
- if (out instanceof Finalizable) {
- ((Finalizable) out).finalizeStream();
- }
- }
-
-
- /** @see java.io.FilterOutputStream **/
- public void close()
- throws IOException {
- finalizeStream();
- super.close();
- }
-
- }
|