Review

5

com/itextpdf/text/pdf/PdfReader.java

eliminateSharedStreams()

class PdfReader {
    /** Eliminates shared streams if they exist. */
    public void eliminateSharedStreams() {
        if (!sharedStreams)
            return;
        sharedStreams = false;
        if (pageRefs.size() == 1)
            return;
        ArrayList<PRIndirectReference> newRefs = new ArrayList<PRIndirectReference>();
        ArrayList<PRStream> newStreams = new ArrayList<PRStream>();
        IntHashtable visited = new IntHashtable();
        for (int k = 1; k <= pageRefs.size(); ++k) {
            PdfDictionary page = pageRefs.getPageN(k);
            if (page == null)
                continue;
            PdfObject contents = getPdfObject(page.get(PdfName.CONTENTS));
            if (contents == null)
                continue;
            if (contents.isStream()) {
                PRIndirectReference ref = (PRIndirectReference)page.get(PdfName.CONTENTS);
                if (visited.containsKey(ref.getNumber())) {
                    // need to duplicate
                    newRefs.add(ref);
                    newStreams.add(new PRStream((PRStream)contents, null));
                }
                else
                    visited.put(ref.getNumber(), 1);
            }
            else if (contents.isArray()) {
                PdfArray array = (PdfArray)contents;
                for (int j = 0; j < array.size(); ++j) {
                    PRIndirectReference ref = (PRIndirectReference)array.getPdfObject(j);
                    if (visited.containsKey(ref.getNumber())) {
                        // need to duplicate
                        newRefs.add(ref);
                        newStreams.add(new PRStream((PRStream)getPdfObject(ref), null));
                    }
                    else
                        visited.put(ref.getNumber(), 1);
                }
            }
        }
        if (newStreams.isEmpty())
            return;
        for (int k = 0; k < newStreams.size(); ++k) {
            xrefObj.add(newStreams.get(k));
            PRIndirectReference ref = newRefs.get(k);
            ref.setNumber(xrefObj.size() - 1, 0);
        }
    }

}

class PdfReader.PageRefs {
        protected PRIndirectReference getSinglePage(final int n) {
            PdfDictionary acc = new PdfDictionary();
            PdfDictionary top = reader.rootPages;
            int base = 0;
            while (true) {
                for (int k = 0; k < pageInhCandidates.length; ++k) {
                    PdfObject obj = top.get(pageInhCandidates[k]);
                    if (obj != null)
                        acc.put(pageInhCandidates[k], obj);
                }
                PdfArray kids = (PdfArray)PdfReader.getPdfObjectRelease(top.get(PdfName.KIDS));
                for (Iterator<PdfObject> it = kids.listIterator(); it.hasNext();) {
                    PRIndirectReference ref = (PRIndirectReference)it.next();
                    PdfDictionary dic = (PdfDictionary)getPdfObject(ref);
                    int last = reader.lastXrefPartial;
                    PdfObject count = getPdfObjectRelease(dic.get(PdfName.COUNT));
                    reader.lastXrefPartial = last;
                    int acn = 1;
                    if (count != null && count.type() == PdfObject.NUMBER)
                        acn = ((PdfNumber)count).intValue();
                    if (n < base + acn) {
                        if (count == null) {
                            dic.mergeDifferent(acc);
                            return ref;
                        }
                        reader.releaseLastXrefPartial();
                        top = dic;
                        break;
                    }
                    reader.releaseLastXrefPartial();
                    base += acn;
                }
            }
        }

}