All Downloads are FREE. Search and download functionalities are using the official Maven repository.
Many resources are needed to download a project. Please understand that we have to compensate our server costs. Thank you in advance.
Project price only 1 $
You can buy this project and download/modify it how often you want.
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 1997-2017 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
*
* ---------------
* LinearizedHintTable.java
* ---------------
*/
package org.jpedal.io;
import java.nio.ByteBuffer;
import java.nio.channels.FileChannel;
import java.util.HashMap;
import java.util.Map;
import org.jpedal.objects.raw.PdfDictionary;
import org.jpedal.objects.raw.PdfObject;
import org.jpedal.utils.LogWriter;
/**
* 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; pageReached < N; pageReached++) {
pageObjectCount[pageReached + 1] = leastNumberOfObjects + getBitsFromByteStream(bitReached, bitsNeededforObjectCount, hintTableData);
objectCount += pageObjectCount[pageReached + 1];
bitReached += bitsNeededforObjectCount;
}
//lookup table of object counts for Page number
obj[1] = O;
if (N > 1) //catch for single page
{
obj[2] = 1;
}
for (int pageReached = 3; pageReached < N; pageReached++) {
obj[pageReached] = obj[pageReached - 1] + pageObjectCount[pageReached - 1];
}
//align to start of byte
bitReached = ((bitReached + 7) >> 3) << 3;
if (showHeader) {
System.out.println("Object offsets");
}
//page offsets
for (int pageReached = 0; pageReached < N; pageReached++) {
pageLength[pageReached + 1] = smallestPageSize + getBitsFromByteStream(bitReached, bitsNeededforPageSize, hintTableData);
bitReached += bitsNeededforPageSize;
}
if (showHeader) {
System.out.println("Page start");
}
//and cumulative lookup table
for (int pageReached = 0; pageReached < N; pageReached++) {
if (pageReached == 0) {
pageStart[pageReached + 1] = Ooffset;
} else {
pageStart[pageReached + 1] = pageStart[pageReached] + pageLength[pageReached];
}
}
//align to start of byte
//bitReached=((bitReached+7)>>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 < bytesNeeded; ii++) {
int nextValue = (hintTableData[startByte + ii] & 255);
if (debug) {
System.out.println(ii + "=" + nextValue + ' ' + Integer.toBinaryString(nextValue));
}
//mask out any unneeded top bytes in first byte
if (ii == 0) {
nextValue &= mask[startOffset];
//System.out.println(ii+" (after mask)="+nextValue+" "+Integer.toBinaryString(nextValue));
}
value += (nextValue << shift[bytesNeeded - (ii + 1)]);
}
if (debug) {
System.out.println("total now =" + value + ' ' + Integer.toBinaryString(value));
}
//shift down to correct position
value >>= endShift;
if (debug) {
System.out.println(">>>>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 = startRefs.get(key);
final int end = 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;
}
if (size < end || (end - start < 1)) {
return null;
}
byte[] data;
try {
synchronized (fos) {
final ByteBuffer buf = ByteBuffer.allocateDirect(bufSize);
fos.read(buf, start);
buf.clear();
data = new byte[buf.capacity()];
buf.get(data, 0, data.length);
}
} catch (final Exception e) {
LogWriter.writeLog("Exception: " + e.getMessage());
data = null;
}
return data;
}
/**
* store offsets to all objects cached on disk
*
* @param ref
* @param startObjPtr
* @param endObjPtr
*/
public void storeOffset(final int ref, final int startObjPtr, final int endObjPtr) {
startRefs.put(ref, startObjPtr);
endRefs.put(ref, endObjPtr);
}
public void setFinishedReading() {
finishedReading = true;
}
}
