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org.jpedal.io.types.Stream Maven / Gradle / Ivy
/*
* ===========================================
* Java Pdf Extraction Decoding Access Library
* ===========================================
*
* Project Info: http://www.idrsolutions.com
* Help section for developers at http://www.idrsolutions.com/support/
*
* (C) Copyright 1997-2017 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
*
* ---------------
* Stream.java
* ---------------
*/
package org.jpedal.io.types;
import org.jpedal.constants.PDFflags;
import static org.jpedal.io.ObjectDecoder.debugFastCode;
import static org.jpedal.io.ObjectDecoder.padding;
import org.jpedal.io.PdfFileReader;
import org.jpedal.io.security.DecryptionFactory;
import org.jpedal.objects.raw.PdfDictionary;
import org.jpedal.objects.raw.PdfObject;
/**
*
*/
public class Stream {
public static void readStreamData(final PdfObject pdfObject, final int i, final byte[] raw, final int length, final PdfFileReader objectReader) {
for (int xx = i; xx < length - 5; xx++) {
//avoid reading on subobject ie << /DecodeParams << >> >>
if (raw[xx] == '>' && raw[xx + 1] == '>') {
break;
}
if (raw[xx] == 's' && raw[xx + 1] == 't' && raw[xx + 2] == 'r'
&& raw[xx + 3] == 'e' && raw[xx + 4] == 'a'
&& raw[xx + 5] == 'm') {
if (debugFastCode) {
System.out.println(padding + "1. Stream found afterwards");
}
if (!pdfObject.isCached()) {
Stream.readStreamIntoObject(pdfObject, xx, raw, objectReader);
}
xx = length;
}
}
}
public static void readStreamIntoObject(final PdfObject pdfObject, final int j, final byte[] data, final PdfFileReader objectReader) {
final DecryptionFactory decryption = objectReader.getDecryptionObject();
final int count = data.length;
if (debugFastCode) {
System.out.println(padding + "Looking for stream");
}
byte[] stream = null;
for (int a = j; a < count; a++) {
if ((data[a] == 115) && (data[a + 1] == 116) && (data[a + 2] == 114)
&& (data[a + 3] == 101) && (data[a + 4] == 97) && (data[a + 5] == 109)) {
//ignore these characters and first return
a += 6;
while (data[a] == 32) {
a++;
}
if (data[a] == 13 && data[a + 1] == 10) //allow for double linefeed
{
a += 2;
} //see /PDFdata/baseline_screens/11jun/Agency discl. Wabash.pdf
else if (data[a] == 10 && data[a + 1] == 10 && data[a + 2] == 10 && data[a + 3] == -1) { //allow for double linefeed on jpeg
a += 3;
} else if (data[a] == 10 && data[a + 1] == 10 && data[a + 2] == -1) { //allow for double linefeed on jpeg
a += 2;
} else if (data[a] == 10 || data[a] == 13) {
a++;
}
final int start = a;
a--; //move pointer back 1 to allow for zero length stream
/*
* if Length set and valid use it
*/
int streamLength = 0;
final int setStreamLength = pdfObject.getInt(PdfDictionary.Length);
if (debugFastCode) {
System.out.println(padding + "setStreamLength=" + setStreamLength);
}
boolean isValid = false;
if (setStreamLength > 0) { //we also manually check if set to zero in PDF (case 27390)
streamLength = setStreamLength;
//System.out.println("1.streamLength="+streamLength);
a = start + streamLength;
if (a < count && data[a] == 13 && (a + 1 < count) && data[a + 1] == 10) {
a += 2;
}
//check validity
if (count > (a + 9) && data[a] == 101 && data[a + 1] == 110 && data[a + 2] == 100
&& data[a + 3] == 115 && data[a + 4] == 116
&& data[a + 5] == 114 && data[a + 6] == 101 && data[a + 7] == 97 && data[a + 8] == 109) {
} else {
final int current = a;
//check forwards
if (a < count) {
while (true) {
a++;
if (isValid || a == count) {
break;
}
if (count - a > 9 && data[a] == 101 && data[a + 1] == 110 && data[a + 2] == 100 && data[a + 3] == 115 && data[a + 4] == 116
&& data[a + 5] == 114 && data[a + 6] == 101 && data[a + 7] == 97 && data[a + 8] == 109) {
streamLength = a - start;
isValid = true;
}
}
}
if (!isValid) {
a = current;
if (a > count) {
a = count;
}
//check backwords
while (true) {
a--;
if (isValid || a < 0) {
break;
}
if (data[a] == 101 && data[a + 1] == 110 && data[a + 2] == 100 && data[a + 3] == 115 && data[a + 4] == 116
&& data[a + 5] == 114 && data[a + 6] == 101 && data[a + 7] == 97 && data[a + 8] == 109) {
streamLength = a - start;
isValid = true;
}
}
}
}
//use correct figure if encrypted
if (decryption != null && decryption.getBooleanValue(PDFflags.IS_FILE_ENCRYPTED)) {
streamLength = setStreamLength;
}
} else {
/*workout length and check if length set*/
final int end;
while (true) { //find end
a++;
if (a == count) {
break;
}
if (data[a] == 101 && data[a + 1] == 110 && data[a + 2] == 100 && data[a + 3] == 115 && data[a + 4] == 116
&& data[a + 5] == 114 && data[a + 6] == 101 && data[a + 7] == 97 && data[a + 8] == 109) {
break;
}
}
end = a - 1;
if ((end > start)) {
streamLength = end - start + 1;
}
}
//lose trailing 10s or 13s
if (streamLength > 1 && !(decryption != null && decryption.getBooleanValue(PDFflags.IS_FILE_ENCRYPTED))) { // && !isValid){
final int ptr = start + streamLength - 1;
// SUP-3495 with 10,13,10,e where 10 is genuine data
final boolean ignoreOddCase = (count - ptr > 4 && data[ptr] == 10 && data[ptr + 1] == 13 && data[ptr + 2] == 10 && data[ptr + 3] == 'e');
if (ptr < count && ((data[ptr] == 10 && !ignoreOddCase)
|| (data[ptr] == 13 && (ptr > 0 && data[ptr - 1] == 10)))) {
streamLength--;
}
}
/*
* read stream into object from memory
*/
if (start + streamLength > count) {
streamLength = count - start;
}
//@speed - switch off and investigate
if (streamLength < 0) {
return;
}
if (streamLength < 0) {
throw new RuntimeException("Negative stream length " + streamLength + " start=" + start + " count=" + count);
}
stream = new byte[streamLength];
System.arraycopy(data, start, stream, 0, streamLength);
a = count;
}
}
if (debugFastCode && stream != null) {
System.out.println(padding + "stream read saved into " + pdfObject);
}
if (pdfObject != null) {
pdfObject.setStream(stream);
//and decompress now forsome objects
if (pdfObject.decompressStreamWhenRead()) {
objectReader.readStream(pdfObject, true, true, false, pdfObject.getObjectType() == PdfDictionary.Metadata, pdfObject.isCompressedStream(), null);
}
}
}
}
