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An Open Source JavaFX PDF Viewer
/*
* ===========================================
* Java Pdf Extraction Decoding Access Library
* ===========================================
*
* Project Info: http://www.idrsolutions.com
* Help section for developers at http://www.idrsolutions.com/support/
*
* (C) Copyright 1997-2015 IDRsolutions and Contributors.
*
* This file is part of JPedal/JPDF2HTML5
*
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* ---------------
* Flate.java
* ---------------
*/
package org.jpedal.io.filter;
import org.jpedal.objects.raw.PdfDictionary;
import org.jpedal.objects.raw.PdfObject;
import org.jpedal.utils.LogWriter;
import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import org.jpedal.utils.repositories.FastByteArrayOutputStream;
import java.io.InputStream;
import java.util.Map;
import java.util.zip.Inflater;
/**
* flate
*/
public class Flate extends BaseFilter implements PdfFilter{
//default values
private int predictor = 1,colors = 1,bitsPerComponent = 8,columns = 1;
private boolean hasError;
public Flate(final PdfObject decodeParms) {
super(decodeParms);
if(decodeParms!=null){
final int newBitsPerComponent = decodeParms.getInt(PdfDictionary.BitsPerComponent);
if(newBitsPerComponent!=-1) {
bitsPerComponent=newBitsPerComponent;
}
final int newColors = decodeParms.getInt(PdfDictionary.Colors);
if(newColors!=-1) {
colors=newColors;
}
final int columnsSet = decodeParms.getInt(PdfDictionary.Columns);
if(columnsSet!=-1) {
columns=columnsSet;
}
predictor = decodeParms.getInt(PdfDictionary.Predictor);
}
}
/**
* flate decode - use a byte array stream to decompress data in memory
*
*/
@Override
public byte[] decode(byte[] data) throws Exception {
int bufSize = 512000;
FastByteArrayOutputStream bos=null;
boolean failed=true;
final int orgSize=data.length;
/**
* decompress byte[]
*/
if (data != null) {
while(failed){ //sometimes partly valid so loop to try this
// create a inflater and initialize it Inflater inf=new Inflater();
final Inflater inf = new Inflater();
inf.setInput(data);
final int size = data.length;
bos = new FastByteArrayOutputStream(size);
if (size < bufSize) {
bufSize = size;
}
final byte[] buf = new byte[bufSize];
//int debug = 20;
int count;
try{
while (!inf.finished()) {
count = inf.inflate(buf);
bos.write(buf, 0, count);
if (inf.getRemaining() == 0) {
break;
}
}
failed=false;
}catch(final Exception ee){
if(LogWriter.isOutput()) {
LogWriter.writeLog("Exception in Flate "+ee);
}
failed=true;
hasError=true;
//retrun on small streams
if(data.length==orgSize && data.length>10000){
failed=false;
}else if(data.length>10){
final byte[] newData=new byte[data.length-1];
System.arraycopy(data,0,newData,0,data.length-1);
data=newData;
}else {
failed=false;
}
}
}
data = bos.toByteArray();
return applyPredictor(predictor, data, colors, bitsPerComponent, columns);
}
return data;
}
@Override
public void decode(final BufferedInputStream bis, final BufferedOutputStream streamCache, final String cacheName, final Map cachedObjects) throws Exception{
this.bis=bis;
this.streamCache=streamCache;
this.cachedObjects=cachedObjects;
/**
* decompress cached object
*/
if (bis != null) {
InputStream inf=null;
try {
// create a inflater and initialize it Inflater inf=new
// Inflater();
// if((predictor==1) || (predictor==10) )
inf = new java.util.zip.InflaterInputStream(bis);
// else
// inf=new DecodePredictor(null, predictor,params,new
// java.util.zip.InflaterInputStream(bis));
while (true) {
final int b = inf.read();
if ((inf.available() == 0) || (b == -1)) {
break;
}
streamCache.write(b);
}
if (predictor != 1 && predictor != 10) {
streamCache.flush();
streamCache.close();
if (cacheName != null) {
setupCachedObjectForDecoding(cacheName);
}
}
} catch (final Exception e) {
e.printStackTrace();
if(LogWriter.isOutput()) {
LogWriter.writeLog("Exception " + e + " accessing Flate filter ");
}
}finally {
if(inf!=null){
inf.close();
}
}
}
applyPredictor(predictor, null, colors, bitsPerComponent, columns);
}
@Override
public boolean hasError(){
return hasError;
}
}