org.jpedal.io.LinearizedHintTable 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 1997-2015 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
*
* ---------------
* LinearizedHintTable.java
* ---------------
*/
package org.jpedal.io;
import org.jpedal.objects.raw.PdfDictionary;
import org.jpedal.objects.raw.PdfObject;
import org.jpedal.utils.LogWriter;
import java.nio.ByteBuffer;
import java.nio.channels.FileChannel;
import java.util.HashMap;
import java.util.Map;
/**
* Java representation of Linear hint tabke defined in F3/F4 of PDF spec
*/
public class LinearizedHintTable {
//private PdfObject linearObj;
//private PdfObject hintObj;
private final Map startRefs=new HashMap();
private final Map endRefs=new HashMap();
private static final int[] mask={255,127,63,31,15,7,3,1};
private static final int[] shift={0,8,16,24};
private int[] pageObjectCount;
private int[] obj;
private int[] pageLength;
private long[] pageStart;
private final FileChannel fos;
private boolean finishedReading;
public LinearizedHintTable(final FileChannel fos){
this.fos=fos;
}
public void readTable(final PdfObject hintObj, final PdfObject linearObj, final int O, final long Ooffset) {
//this.hintObj=hintObj;
//this.linearObj=linearObj;
final byte[] hintTableData=hintObj.getDecodedStream();
//int S=hintObj.getInt(PdfDictionary.S);
final int N=linearObj.getInt(PdfDictionary.N);
//int L=linearObj.getInt(PdfDictionary.L);
if(hintTableData!=null && hintTableData.length>0) {
parseHintTable(N, O, Ooffset, hintTableData);
}
//parseSharedObjectHintTable(N, S, hintTableData);
}
private void parseHintTable(final int N, final int O, final long Ooffset, final byte[] hintTableData){
int startByte=0;
//arrays to populate
//treat zero as empty and 1 is first page
pageObjectCount=new int[N+1];
obj=new int[N+1];
pageStart=new long[N+1];
pageLength=new int[N+1];
//final int[] sharedObjects=new int[N+1];
//int[] sharedObjectsIdentifier=new int[N+1];
//int[] objectNumerator=new int[N+1];
/**
* read page offset hint table header (Appendix F F3 in PDF Ref)
*/
final boolean showHeader=false;
if(showHeader) {
System.out.println("-----header----");
}
//item 1
final int leastNumberOfObjects=((hintTableData[startByte]& 255)<<24)+((hintTableData[startByte+1]& 255)<<16)+((hintTableData[startByte+2]& 255)<<8)+(hintTableData[startByte+3]& 255);
if(showHeader) {
System.out.println("1=" + leastNumberOfObjects + " ( " + hintTableData[startByte] + ' ' + hintTableData[startByte + 1] + ' ' + hintTableData[startByte + 2] + ' ' + hintTableData[startByte + 3] + " )");
}
startByte += 4;
//item 2
// word=((hintTableData[startByte]& 255)<<24)+((hintTableData[startByte+1]& 255)<<16)+((hintTableData[startByte+2]& 255)<<8)+(hintTableData[startByte+3]& 255);
// if(showHeader)
// System.out.println("2="+word+" ( "+hintTableData[startByte]+ ' ' +hintTableData[startByte+1]+ ' ' +hintTableData[startByte+2]+ ' ' +hintTableData[startByte+3]+" )");
startByte += 4;
//item 3
final int bitsNeededforObjectCount=(((hintTableData[startByte]& 255)<<8)+(hintTableData[startByte+1]& 255));
if(showHeader) {
System.out.println("3=" + bitsNeededforObjectCount + " ( " + hintTableData[startByte] + ' ' + hintTableData[startByte + 1] + " )");
}
startByte += 2;
//item 4
final int smallestPageSize=((hintTableData[startByte]& 255)<<24)+((hintTableData[startByte+1]& 255)<<16)+((hintTableData[startByte+2]& 255)<<8)+(hintTableData[startByte+3]& 255);
if(showHeader) {
System.out.println("4=" + smallestPageSize + " ( " + hintTableData[startByte] + ' ' + hintTableData[startByte + 1] + ' ' + hintTableData[startByte + 2] + ' ' + hintTableData[startByte + 3] + " )");
}
startByte += 4;
//item 5
final int bitsNeededforPageSize=(((hintTableData[startByte]& 255)<<8)+(hintTableData[startByte+1]& 255));
if(showHeader) {
System.out.println("5=" + bitsNeededforPageSize + " ( " + hintTableData[startByte] + ' ' + hintTableData[startByte + 1] + " )");
}
startByte += 2;
//item 6
// word=((hintTableData[startByte]& 255)<<24)+((hintTableData[startByte+1]& 255)<<16)+((hintTableData[startByte+2]& 255)<<8)+(hintTableData[startByte+3]& 255);
// if(showHeader)
// System.out.println("6="+word+" ( "+hintTableData[startByte]+ ' ' +hintTableData[startByte+1]+ ' ' +hintTableData[startByte+2]+ ' ' +hintTableData[startByte+3]+" )");
startByte += 4;
//item 7
// word=(((hintTableData[startByte]& 255)<<8)+(hintTableData[startByte+1]& 255));
// if(showHeader)
// System.out.println("7="+word+" ( "+hintTableData[startByte]+ ' ' +hintTableData[startByte+1]+" )");
startByte += 2;
//item 8
// word=((hintTableData[startByte]& 255)<<24)+((hintTableData[startByte+1]& 255)<<16)+((hintTableData[startByte+2]& 255)<<8)+(hintTableData[startByte+3]& 255);
// if(showHeader)
// System.out.println("8="+word+" ( "+hintTableData[startByte]+ ' ' +hintTableData[startByte+1]+ ' ' +hintTableData[startByte+2]+ ' ' +hintTableData[startByte+3]+" )");
startByte += 4;
//item 9
// word=(((hintTableData[startByte]& 255)<<8)+(hintTableData[startByte+1]& 255));
// if(showHeader)
// System.out.println("9="+word+" ( "+hintTableData[startByte]+ ' ' +hintTableData[startByte+1]+" )");
startByte += 2;
//item 10
//final int bitsNeededforSharedObject=(((hintTableData[startByte]& 255)<<8)+(hintTableData[startByte+1]& 255));
//if(showHeader)
// System.out.println("10="+bitsNeededforSharedObject+" ( "+hintTableData[startByte]+ ' ' +hintTableData[startByte+1]+" )");
startByte += 2;
//item 11
//int bitsNeededforSharedObjectIdentifier=(((hintTableData[startByte]& 255)<<8)+(hintTableData[startByte+1]& 255));
//if(showHeader)
// System.out.println("11="+bitsNeededforSharedObjectIdentifier+" ( "+hintTableData[startByte]+ ' ' +hintTableData[startByte+1]+" )");
startByte += 2;
//item 12
// int bitsNeededforObjectNumerator=(((hintTableData[startByte]& 255)<<8)+(hintTableData[startByte+1]& 255));
// if(showHeader)
// System.out.println("12="+bitsNeededforObjectNumerator+" ( "+hintTableData[startByte]+ ' ' +hintTableData[startByte+1]+" )");
startByte += 2;
//item 13
// int demominator=(((hintTableData[startByte]& 255)<<8)+(hintTableData[startByte+1]& 255));
// if(showHeader)
// System.out.println("13="+demominator+" ( "+hintTableData[startByte]+ ' ' +hintTableData[startByte+1]+" )");
startByte += 2;
/**
* read page offset hint table (Appendix F F4 in PDF Ref)
*/
int bitReached=startByte<<3; //start of F4 table
if(showHeader) {
System.out.println("Object count");
}
//object count
int objectCount=0;
for(int pageReached=0;pageReached1) //catch for single page
{
obj[2] = 1;
}
for(int pageReached=3;pageReached>3)<<3;
if(showHeader) {
System.out.println("Object offsets");
}
//page offsets
for(int pageReached=0;pageReached>3)<<3;
//shared object count
// for(int pageReached=0;pageReached>3)<<3;
//shared object identifier (note starts on PAGE 2)
// for(int pageReached=1;pageReached>3)<<3;
//object numerators
// for(int pageReached=0;pageReached<35;pageReached++){
// objectNumerator[pageReached+1]=getBitsFromByteStream(bitReached,bitsNeededforObjectNumerator,hintTableData );
// //System.out.println(objectNumerator[pageReached+1]+" / "+demominator);
// bitReached=bitReached+bitsNeededforPageSize;
// }
// int obj=O;
//show results at end
/**
for(int pageReached=1;pageReached<5;pageReached++){
System.out.println("-------------------------------------------------------------------------------");
if(pageReached==2)
obj=1;
System.out.println("Page "+pageReached+" pageObjectCount="+pageObjectCount[pageReached]+"page="+obj+" 0 R pageLength="+pageLength[pageReached]+" pageStart="+pageStart[pageReached]+" sharedObjects="+sharedObjects[pageReached]+" sharedObjectsIdentifier="+sharedObjectsIdentifier[pageReached]+" objectCount="+objectCount+" start="+pageStart[pageReached]+" length="+pageLength[pageReached]);
obj=obj+pageObjectCount[pageReached];
} /**/
}
//return an arbitary bit value from the stream
private static int getBitsFromByteStream(final int bitReached, final int bitsNeededforObjectCount, final byte[] hintTableData) {
final boolean debug=false;//bitsNeededforObjectCount==7;
int value=0;
//workout the number of bytes need
final int startByte=bitReached >>3;
final int startOffset=bitReached & 7;
final int bytesNeeded=((bitsNeededforObjectCount+startOffset) >>3)+1;
int endShift=(bytesNeeded<<3)-startOffset-bitsNeededforObjectCount;
if(startOffset==0) {
endShift = ((bytesNeeded << 3) - (bitsNeededforObjectCount)) & 7;
}
if(debug) {
System.out.println("------------------bitReached=" + bitReached + " bitsNeeded=" + (bytesNeeded * 8) + " startOffset=" + startOffset + " endShift=" + endShift);
}
//assume less than 32 as we will need to recode otherwise
if(bytesNeeded>4){
if(LogWriter.isRunningFromIDE){
throw new RuntimeException("Example of bits over 32 in Linearized table");
}
return 0;
}else{
//System.out.println("bytesNeeded="+bytesNeeded+" startByte="+startByte+" "+" startOffset="+startOffset);
//get the raw bytes
for(int ii=0;ii>>>returns " + value + ' ' + Integer.toBinaryString(value) + " endShift=" + endShift);
}
return value;
}
}
// private static void parseSharedObjectHintTable(int N,int S,byte[] hintTableData){
//
// int startByte=S;
// long word;
//
// //arrays to populate
// //treat zero as empty and 1 is first page
// int[] sharedObjectsLength=new int[N+1];
//
// /**
// * read page offset hint table header (Appendix F F5 in PDF Ref)
// */
//
// final boolean showHeader=true;
// if(showHeader)
// System.out.println("-----header----");
//
// //item 1
// int firstSharedObject=((hintTableData[startByte]& 255)<<24)+((hintTableData[startByte+1]& 255)<<16)+((hintTableData[startByte+2]& 255)<<8)+(hintTableData[startByte+3]& 255);
// if(showHeader)
// System.out.println("firstSharedObject="+firstSharedObject+" ( "+hintTableData[startByte]+ ' ' +hintTableData[startByte+1]+ ' ' +hintTableData[startByte+2]+ ' ' +hintTableData[startByte+3]+" )");
// startByte=startByte+4;
//
// //item 2
// int firstSharedObjectOffset=((hintTableData[startByte]& 255)<<24)+((hintTableData[startByte+1]& 255)<<16)+((hintTableData[startByte+2]& 255)<<8)+(hintTableData[startByte+3]& 255);
// if(showHeader)
// System.out.println("firstSharedObjectOffset="+firstSharedObjectOffset+" ( "+hintTableData[startByte]+ ' ' +hintTableData[startByte+1]+ ' ' +hintTableData[startByte+2]+ ' ' +hintTableData[startByte+3]+" )");
// startByte=startByte+4;
//
// //item 3
// int numberOfSharedObjectsOnFirstPage=((hintTableData[startByte]& 255)<<24)+((hintTableData[startByte+1]& 255)<<16)+((hintTableData[startByte+2]& 255)<<8)+(hintTableData[startByte+3]& 255);
// if(showHeader)
// System.out.println("numberOfSharedObjectsOnFirstPage="+numberOfSharedObjectsOnFirstPage+" ( "+hintTableData[startByte]+ ' ' +hintTableData[startByte+1]+ ' ' +hintTableData[startByte+2]+ ' ' +hintTableData[startByte+3]+" )");
// startByte=startByte+4;
//
// //item 4
// int numberOfSharedEntries=((hintTableData[startByte]& 255)<<24)+((hintTableData[startByte+1]& 255)<<16)+((hintTableData[startByte+2]& 255)<<8)+(hintTableData[startByte+3]& 255);
// if(showHeader)
// System.out.println("numberOfSharedEntries="+numberOfSharedEntries+" ( "+hintTableData[startByte]+ ' ' +hintTableData[startByte+1]+ ' ' +hintTableData[startByte+2]+ ' ' +hintTableData[startByte+3]+" )");
// startByte=startByte+4;
//
// //item 5
// int bitsNeededForSharedObjectGroup=(((hintTableData[startByte]& 255)<<8)+(hintTableData[startByte+1]& 255));
// if(showHeader)
// System.out.println("bitsNeededForSharedObjectGroup="+bitsNeededForSharedObjectGroup+" ( "+hintTableData[startByte]+ ' ' +hintTableData[startByte+1]+" )");
// startByte=startByte+2;
//
// //item 6
// int smallestSharedGroupObjectSize=((hintTableData[startByte]& 255)<<24)+((hintTableData[startByte+1]& 255)<<16)+((hintTableData[startByte+2]& 255)<<8)+(hintTableData[startByte+3]& 255);
// if(showHeader)
// System.out.println("smallestSharedGroupObjectSize="+smallestSharedGroupObjectSize+" ( "+hintTableData[startByte]+ ' ' +hintTableData[startByte+1]+ ' ' +hintTableData[startByte+2]+ ' ' +hintTableData[startByte+3]+" )");
// startByte=startByte+4;
//
// //item 7
// int smallestSharedGroupObjectLength=(((hintTableData[startByte]& 255)<<8)+(hintTableData[startByte+1]& 255));
// if(showHeader)
// System.out.println("smallestSharedGroupObjectLength="+smallestSharedGroupObjectLength+" ( "+hintTableData[startByte]+ ' ' +hintTableData[startByte+1]+" )");
// startByte=startByte+2;
//
// /**
// * now read table values
// */
//
// //align to start of byte
// //int bitReached=startByte<<3;
//
// //need to read page 1 then later pages
//
// //shared object lengths
//// for(int pageReached=0;pageReached>\n"+new String(buffer));
//
// }
/**
* return ref number for page of -1 if not yet set or page out of range
* @param rawPage
* @return
*/
public int getPageObjectRef(final int rawPage) {
//allow for data not read yet.
if(obj==null || obj.length<=rawPage) {
return -1;
}
return obj[rawPage];
}
/**
* return raw data for obj or null
* @param objID
* @return
*/
public synchronized byte[] getObjData(final int objID) {
if(finishedReading) {
return null;
}
final Integer key= objID;
//allow for data not read yet.
if(!startRefs.containsKey(key) || !endRefs.containsKey(key)) {
return null;
}
final int start= (Integer) startRefs.get(key);
final int end= (Integer) endRefs.get(key);
final int bufSize= end-start+1;
long size= 0;
try {
if(fos.isOpen()) {
size = fos.size() - 200;
}
} catch (final Exception e) {
LogWriter.writeLog("Exception: " + e.getMessage());
size=0;
}
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