/*
*
* This file is part of the iText (R) project.
Copyright (c) 1998-2017 iText Group NV
* Authors: Bruno Lowagie, Paulo Soares, et al.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License version 3
* as published by the Free Software Foundation with the addition of the
* following permission added to Section 15 as permitted in Section 7(a):
* FOR ANY PART OF THE COVERED WORK IN WHICH THE COPYRIGHT IS OWNED BY
* ITEXT GROUP. ITEXT GROUP DISCLAIMS THE WARRANTY OF NON INFRINGEMENT
* OF THIRD PARTY RIGHTS
*
* This program 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 Affero General Public License for more details.
* You should have received a copy of the GNU Affero General Public License
* along with this program; if not, see http://www.gnu.org/licenses or write to
* the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
* Boston, MA, 02110-1301 USA, or download the license from the following URL:
* http://itextpdf.com/terms-of-use/
*
* The interactive user interfaces in modified source and object code versions
* of this program must display Appropriate Legal Notices, as required under
* Section 5 of the GNU Affero General Public License.
*
* In accordance with Section 7(b) of the GNU Affero General Public License,
* a covered work must retain the producer line in every PDF that is created
* or manipulated using iText.
*
* You can be released from the requirements of the license by purchasing
* a commercial license. Buying such a license is mandatory as soon as you
* develop commercial activities involving the iText software without
* disclosing the source code of your own applications.
* These activities include: offering paid services to customers as an ASP,
* serving PDFs on the fly in a web application, shipping iText with a closed
* source product.
*
* For more information, please contact iText Software Corp. at this
* address: sales@itextpdf.com
*/
package com.itextpdf.text.pdf;
import java.io.IOException;
import java.util.Arrays;
import java.util.HashMap;
/**
* Creates a number tree.
* @author Paulo Soares
*/
public class PdfNumberTree {
private static final int leafSize = 64;
/**
* Creates a number tree.
* @param items the item of the number tree. The key is an <CODE>Integer</CODE>
* and the value is a <CODE>PdfObject</CODE>.
* @param writer the writer
* @throws IOException on error
* @return the dictionary with the number tree.
*/
public static <O extends PdfObject> PdfDictionary writeTree(HashMap<Integer, O> items, PdfWriter writer) throws IOException {
if (items.isEmpty())
return null;
Integer numbers[] = new Integer[items.size()];
numbers = items.keySet().toArray(numbers);
Arrays.sort(numbers);
if (numbers.length <= leafSize) {
PdfDictionary dic = new PdfDictionary();
PdfArray ar = new PdfArray();
for (int k = 0; k < numbers.length; ++k) {
ar.add(new PdfNumber(numbers[k].intValue()));
ar.add(items.get(numbers[k]));
}
dic.put(PdfName.NUMS, ar);
return dic;
}
int skip = leafSize;
PdfIndirectReference kids[] = new PdfIndirectReference[(numbers.length + leafSize - 1) / leafSize];
for (int k = 0; k < kids.length; ++k) {
int offset = k * leafSize;
int end = Math.min(offset + leafSize, numbers.length);
PdfDictionary dic = new PdfDictionary();
PdfArray arr = new PdfArray();
arr.add(new PdfNumber(numbers[offset].intValue()));
arr.add(new PdfNumber(numbers[end - 1].intValue()));
dic.put(PdfName.LIMITS, arr);
arr = new PdfArray();
for (; offset < end; ++offset) {
arr.add(new PdfNumber(numbers[offset].intValue()));
arr.add(items.get(numbers[offset]));
}
dic.put(PdfName.NUMS, arr);
kids[k] = writer.addToBody(dic).getIndirectReference();
}
int top = kids.length;
while (true) {
if (top <= leafSize) {
PdfArray arr = new PdfArray();
for (int k = 0; k < top; ++k)
arr.add(kids[k]);
PdfDictionary dic = new PdfDictionary();
dic.put(PdfName.KIDS, arr);
return dic;
}
skip *= leafSize;
int tt = (numbers.length + skip - 1 )/ skip;
for (int k = 0; k < tt; ++k) {
int offset = k * leafSize;
int end = Math.min(offset + leafSize, top);
PdfDictionary dic = new PdfDictionary();
PdfArray arr = new PdfArray();
arr.add(new PdfNumber(numbers[k * skip].intValue()));
arr.add(new PdfNumber(numbers[Math.min((k + 1) * skip, numbers.length) - 1].intValue()));
dic.put(PdfName.LIMITS, arr);
arr = new PdfArray();
for (; offset < end; ++offset) {
arr.add(kids[offset]);
}
dic.put(PdfName.KIDS, arr);
kids[k] = writer.addToBody(dic).getIndirectReference();
}
top = tt;
}
}
private static void iterateItems(PdfDictionary dic, HashMap<Integer, PdfObject> items) {
PdfArray nn = (PdfArray)PdfReader.getPdfObjectRelease(dic.get(PdfName.NUMS));
if (nn != null) {
for (int k = 0; k < nn.size(); ++k) {
PdfNumber s = (PdfNumber)PdfReader.getPdfObjectRelease(nn.getPdfObject(k++));
items.put(Integer.valueOf(s.intValue()), nn.getPdfObject(k));
}
}
else if ((nn = (PdfArray)PdfReader.getPdfObjectRelease(dic.get(PdfName.KIDS))) != null) {
for (int k = 0; k < nn.size(); ++k) {
PdfDictionary kid = (PdfDictionary)PdfReader.getPdfObjectRelease(nn.getPdfObject(k));
iterateItems(kid, items);
}
}
}
public static HashMap<Integer, PdfObject> readTree(PdfDictionary dic) {
HashMap<Integer, PdfObject> items = new HashMap<Integer, PdfObject>();
if (dic != null)
iterateItems(dic, items);
return items;
}
}