[PDFBOX-4508] Unexpected slowness filling forms with CJK

• Type: Improvement
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 2.0.14
• Fix Version/s: 2.0.15, 3.0.0 PDFBox
• Component/s: AcroForm, Documentation
• Labels: Optimization
• Assignee: Tilman Hausherr
• Reporter: Tilman Hausherr
• Created: 06/Apr/19 09:11
• Updated: 12/Apr/19 14:39
• Resolved: 07/Apr/19 08:28

Description

As reported by William Pietri in the users mailing list:

If I go through this and fill every field with roman text using the default font, it takes circa 2 seconds, which is fine. If I fill it with an added Arabic font, it takes circa 7 seconds. And if I use a CJK font, it takes circa 140 seconds, which seems like a lot. This is with PDFBox 2.0.14 and the Oracle 1.8.201 JDK on Linux.

And the message "OpenType Layout tables used in font NotoSansCJKsc-Medium are not implemented in PDFBox and will be ignored " comes up for every field, which suggests that the font is opened each time.

I can confirm this, also with a different font (ArialUni).

PDDocument doc = PDDocument.load(new File("i-130.pdf"));
PDResources res = doc.getDocumentCatalog().getAcroForm().getDefaultResources();
PDFont font = PDType0Font.load(doc, new FileInputStream(new File("NotoSansCJKsc-Medium.ttf")), false);
String fontName = res.add(font).getName();
long start = System.currentTimeMillis();
for (Iterator<PDField> it = doc.getDocumentCatalog().getAcroForm().getFieldIterator(); it.hasNext();)
{
    PDField field = it.next();
    if (field instanceof PDTextField)
    {
        PDTextField textField = (PDTextField) field;
        textField.setDefaultAppearance("/" + fontName + " 0 Tf 0 g");
        textField.setValue("中国");
        long end = System.currentTimeMillis();
        System.out.println("Filled " + textField.getFullyQualifiedName() + " in " + (end - start) + "ms");
        start = end;
    }
}
doc.save(new File("i-130-filled.pdf"));