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/*
* ===========================================
* 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
*
* ---------------
* CompressedObjects.java
* ---------------
*/
package org.jpedal.io.types;
import java.util.Map;
import org.jpedal.exception.PdfException;
import org.jpedal.io.RandomAccessBuffer;
import org.jpedal.utils.LogWriter;
import org.jpedal.utils.NumberUtils;
/**
*
*/
public class CompressedObjects {
/**
* @param First
* @param compressedStream
*/
public static void extractCompressedObjectOffset(final Map offsetStart, final Map offsetEnd, final int First, final byte[] compressedStream,
final int compressedID, final Offsets offset) {
String lastKey = null, key, offsetRef;
int startKey, endKey, startOff, endOff, id;
//read the offsets table
for (int ii = 0; ii < First; ii++) {
if (compressedStream.length == 0) {
continue;
}
//ignore any gaps between entries
ii = StreamReaderUtils.skipSpaces(compressedStream, ii);
/*work out key size*/
startKey = ii;
if (startKey == First) {
continue;
}
while (compressedStream[ii] != 32 && compressedStream[ii] != 13 && compressedStream[ii] != 10) {
ii++;
}
endKey = ii - 1;
/*extract key as String and Number*/
int length = endKey - startKey + 1;
key = getString(compressedStream, startKey, length);
id = NumberUtils.parseInt(startKey, startKey + length, compressedStream);
/*move to offset*/
ii = StreamReaderUtils.skipSpaces(compressedStream, ii);
/*get size*/
startOff = ii;
while ((compressedStream[ii] != 32 && compressedStream[ii] != 13 && compressedStream[ii] != 10) && (ii < First)) {
ii++;
}
endOff = ii - 1;
/*extract offset*/
length = endOff - startOff + 1;
offsetRef = getString(compressedStream, startOff, length);
/*
* save values if in correct block (can list items over-written in another compressed obj)
*/
if (compressedID == offset.elementAt(id)) {
offsetStart.put(key, offsetRef);
//save end as well
if (lastKey != null) {
offsetEnd.put(lastKey, offsetRef);
}
lastKey = key;
}
}
}
static String getString(final byte[] compressedStream, final int startOff, final int length) {
final char[] newCommand = new char[length];
for (int i = 0; i < length; i++) {
newCommand[i] = (char) compressedStream[startOff + i];
}
return new String(newCommand);
}
public static int readCompressedOffsets(int pntr, int current, final int numbEntries, final int[] fieldSizes, final byte[] xrefs, final Offsets offset, final RandomAccessBuffer pdf_datafile) throws PdfException {
//now parse the stream and extract values
final boolean debug = false;
if (debug) {
System.out.println("===============read offsets============= current=" + current + " numbEntries=" + numbEntries);
}
final int[] defaultValue = {1, 0, 0};
boolean hasCase0 = false;
for (int i = 0; i < numbEntries; i++) {
//read the next 3 values
final int[] nextValue = new int[3];
for (int ii = 0; ii < 3; ii++) {
if (fieldSizes[ii] == 0) {
nextValue[ii] = defaultValue[ii];
} else {
nextValue[ii] = getWord(xrefs, pntr, fieldSizes[ii]);
pntr += fieldSizes[ii];
}
}
//handle values appropriately
final int id;
int gen;
switch (nextValue[0]) {
case 0: //linked list of free objects
current++;
hasCase0 = nextValue[1] == 0 && nextValue[2] == 0;
if (debug) {
System.out.println("case 0 nextFree=" + nextValue[1] + " gen=" + nextValue[2]);
}
break;
case 1: //non-compressed
id = nextValue[1];
gen = nextValue[2];
if (debug) {
System.out.println("case 1 current=" + current + " id=" + id + " byteOffset=" + nextValue[1] + " gen=" + nextValue[2]);
}
//if number equals offsetRef , test if valid
boolean refIsvalid = true;
if (current == id) {
refIsvalid = false;
//allow for idiot setting in some files
//(ie LT2 Protokoll GV Aug 2012_oD_Teil4.pdf)
try {
//get the data and see if genuine match
final int size = 20;
final byte[] data = new byte[size];
pdf_datafile.seek(current);
pdf_datafile.read(data); //get next chars
//find space
int ptr = 0;
for (int ii = 0; ii < size; ii++) {
if (data[ii] == 32 || data[ii] == 10 || data[ii] == 13) {
ptr = ii;
ii = size;
}
}
if (ptr > 0) {
final int ref = NumberUtils.parseInt(0, ptr, data);
if (ref == current) {
refIsvalid = true;
}
}
} catch (final Exception ee) {
refIsvalid = false;
LogWriter.writeLog("Ref is invalid " + ee);
}
}
if (refIsvalid || !hasCase0) {
offset.storeObjectOffset(current, id, gen, false, false);
}
current++;
break;
case 2: //compressed
id = nextValue[1];
//gen=nextValue[2];
if (debug) {
System.out.println("case 2 current=" + current + " object number=" + id + " index=" + gen);
}
offset.storeObjectOffset(current, id, 0, true, false);
current++;
break;
default:
throw new PdfException("Exception Unsupported Compression mode with value " + nextValue[0]);
}
}
return pntr;
}
/**
* Utility method used during processing of type1C files
*/
static int getWord(final byte[] content, final int index, final int size) {
int result = 0;
for (int i = 0; i < size; i++) {
result = (result << 8) + (content[index + i] & 0xff);
}
return result;
}
}
