/*
* Copyright (c) 2007, intarsys consulting GmbH
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* - Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* - Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* - Neither the name of intarsys nor the names of its contributors may be used
* to endorse or promote products derived from this software without specific
* prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
package de.intarsys.pdf.st;
import java.io.IOException;
import java.util.Iterator;
import java.util.NoSuchElementException;
import de.intarsys.pdf.cos.COSArray;
import de.intarsys.pdf.cos.COSDictionary;
import de.intarsys.pdf.cos.COSDocument;
import de.intarsys.pdf.cos.COSInteger;
import de.intarsys.pdf.cos.COSName;
import de.intarsys.pdf.cos.COSObject;
import de.intarsys.pdf.cos.COSObjectKey;
import de.intarsys.pdf.cos.COSTrailer;
import de.intarsys.pdf.crypt.ISystemSecurityHandler;
import de.intarsys.pdf.parser.COSLoadException;
import de.intarsys.pdf.writer.COSWriter;
/**
* A section in a XRef.
* <p>
* The XRef allows random access to the objects in the PDF file.
* <p>
* A XRef section is the part of a pdf document starting with a "xref" token. It
* consists of several, non contiguous subsections, one additional for each
* incremental update.
*/
public abstract class STXRefSection {
public static final COSName DK_XRefStm = COSName.constant("XRefStm"); //$NON-NLS-1$
private STXRefSubsection xRefSubsection;
private long offset = -1;
private STDocument doc;
private STXRefSection previous;
protected STXRefSection(STDocument doc) {
this(doc, -1);
}
protected STXRefSection(STDocument doc, long offset) {
this.doc = doc;
this.offset = offset;
xRefSubsection = new STXRefSubsection(this, 0);
xRefSubsection.addEntry(new STXRefEntryFree(new COSObjectKey(0, 65535),
0));
}
public void addEntry(STXRefEntry entry) {
STXRefSubsection prev = null;
STXRefSubsection current = getXRefSubsection();
int number = entry.getObjectNumber();
while (current != null) {
if (number < current.getStart()) {
STXRefSubsection newSection = new STXRefSubsection(this, number);
newSection.setNext(current);
if (prev != null) {
prev.setNext(newSection);
} else {
setXRefSubsection(newSection);
}
newSection.addEntry(entry);
return;
}
if (current.getStart() <= number && number <= current.getStop()) {
current.addEntry(entry);
return;
}
prev = current;
current = current.getNext();
}
STXRefSubsection newSection = new STXRefSubsection(this, number);
newSection.setNext(null);
if (prev != null) {
prev.setNext(newSection);
} else {
setXRefSubsection(newSection);
}
newSection.addEntry(entry);
}
public boolean contains(int number) {
STXRefSubsection current = getXRefSubsection();
while (current != null) {
if (number < current.getStart()) {
return false;
}
if (current.getStart() <= number && number < current.getStop()) {
return true;
}
current = current.getNext();
}
return false;
}
/**
* The "trailer" dictionary associated with the XRef section.
*
* @return The "trailer" dictionary associated with the XRef section.
*/
public abstract COSDictionary cosGetDict();
public COSObject cosGetEncryption() {
return cosGetDict().get(COSTrailer.DK_Encrypt);
}
abstract public COSObject cosGetObject();
public void cosSetEncryption(COSObject encryption) {
cosGetDict().put(COSTrailer.DK_Encrypt, encryption);
}
protected void createNewSubsection(int pStart) {
}
public abstract STXRefSection createSuccessor();
public Iterator entryIterator() {
return new Iterator() {
private Iterator currentIterator;
private STXRefSubsection myNext = getXRefSubsection();
public boolean hasNext() {
if (currentIterator != null && currentIterator.hasNext()) {
return true;
}
if (myNext != null) {
currentIterator = myNext.getEntries().iterator();
myNext = myNext.getNext();
// must enter recursive!
return hasNext();
}
return false;
}
public Object next() {
if (hasNext()) {
return currentIterator.next();
}
throw new NoSuchElementException();
}
public void remove() {
throw new UnsupportedOperationException();
}
};
}
public STDocument getDoc() {
return doc;
}
public STXRefEntry getEntry(int number) {
STXRefSubsection current = getXRefSubsection();
while (current != null) {
if (number < current.getStart()) {
return null;
}
if (current.getStart() <= number && number < current.getStop()) {
return current.getEntry(number);
}
current = current.getNext();
}
return null;
}
public COSArray getID() {
return cosGetDict().get(COSTrailer.DK_ID).asArray();
}
public int getIncrementalCount() {
if (getPrevious() == null) {
return 1;
} else {
// todo maybe we should check linearization in another way
if (cosGetDict().get(COSTrailer.DK_Root).isNull()) {
// part of linearized structure
return getPrevious().getIncrementalCount();
} else {
return getPrevious().getIncrementalCount() + 1;
}
}
}
public int getMaxObjectNumber() {
STXRefSubsection current = getXRefSubsection();
while (current != null) {
if (current.getNext() != null) {
current = current.getNext();
} else {
return current.getStop();
}
}
return 0;
}
public long getOffset() {
return offset;
}
public STXRefSection getPrevious() {
return previous;
}
/**
* @return offset of previous trailer dict or -1 if none exists
*/
public int getPreviousOffset() {
COSInteger value = cosGetDict().get(COSTrailer.DK_Prev).asInteger();
if (value == null) {
return -1;
}
return value.intValue();
}
protected int getPreviousXRefStmOffset() {
COSInteger value = cosGetDict().get(DK_XRefStm).asInteger();
if (value == null) {
return -1;
}
return value.intValue();
}
/**
* The total number of indirect objects in the document.
*
* @return The total number of indirect objects in the document.
*/
public int getSize() {
COSInteger value = cosGetDict().get(COSTrailer.DK_Size).asInteger();
if (value == null) {
return -1;
}
return value.intValue();
}
/**
* The object number of the first object in this section.
*
* @return The object number of the first object in this section.
*/
public int getStart() {
return getXRefSubsection().getStart();
}
public abstract AbstractXRefWriter getWriter(COSWriter cosWriter);
protected int getXRefStmOffset() {
COSInteger value = cosGetDict().get(DK_XRefStm).asInteger();
if (value == null) {
return -1;
}
return value.intValue();
}
/**
* The first subsection in this section. All other subsections are
* implemented as a linked list.
*
* @return The first subsection in this section.
*/
public STXRefSubsection getXRefSubsection() {
return xRefSubsection;
}
protected abstract boolean isStreamed();
public COSObject load(int objectNumber,
ISystemSecurityHandler securityHandler) throws IOException,
COSLoadException {
if (contains(objectNumber)) {
return getEntry(objectNumber).load(getDoc(), securityHandler);
}
if (getPrevious() != null) {
return getPrevious().load(objectNumber, securityHandler);
}
return null;
}
protected void setCOSDoc(COSDocument doc) {
doc.add(cosGetObject());
}
protected void setID(COSArray id) {
cosGetDict().put(COSTrailer.DK_ID, id);
}
protected void setOffset(long offset) {
this.offset = offset;
}
protected void setPrevious(STXRefSection xRefSection) {
this.previous = xRefSection;
if (getPreviousOffset() != xRefSection.getOffset()) {
setPreviousOffset(xRefSection.getOffset());
}
}
protected void setPreviousOffset(long offset) {
cosGetDict().put(COSTrailer.DK_Prev, COSInteger.create((int) offset));
}
protected void setSize(int size) {
cosGetDict().put(COSTrailer.DK_Size, COSInteger.create(size));
}
protected void setXRefStmOffset(long xrefStmOffset) {
cosGetDict().put(DK_XRefStm, COSInteger.create((int) xrefStmOffset));
}
protected void setXRefSubsection(STXRefSubsection newXRef) {
this.xRefSubsection = newXRef;
STXRefSubsection current = getXRefSubsection();
while (current != null) {
current.setXRefSection(this);
current = current.getNext();
}
}
public Iterator subsectionIterator() {
return new Iterator() {
private STXRefSubsection current = getXRefSubsection();
public boolean hasNext() {
return current != null;
}
public Object next() {
if (current == null) {
throw new NoSuchElementException();
}
STXRefSubsection result = current;
current = current.getNext();
return result;
}
public void remove() {
throw new UnsupportedOperationException();
}
};
}
}
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