PdfReader unable to read PDF files larger than 2GB

[mvgian]

Describe the bug

When attempting to read PDF file larger than 2GB, the below exception is thrown. Would it be possible for OpenPDF to load large PDF files?

com.lowagie.text.pdf.PdfException: The PDF file is too large. Max 2GB. Size: 2264230616 at com.lowagie.text.pdf.MappedRandomAccessFile.init(MappedRandomAccessFile.java:137) at com.lowagie.text.pdf.MappedRandomAccessFile.<init>(MappedRandomAccessFile.java:88) at com.lowagie.text.pdf.RandomAccessFileOrArray.<init>(RandomAccessFileOrArray.java:139) at com.lowagie.text.pdf.RandomAccessFileOrArray.<init>(RandomAccessFileOrArray.java:90) at com.lowagie.text.pdf.PRTokeniser.<init>(PRTokeniser.java:111) at com.lowagie.text.pdf.PdfReader.<init>(PdfReader.java:179) at com.lowagie.text.pdf.PdfReader.<init>(PdfReader.java:167)

To Reproduce

Invoke new PDFReader() to a pdf with file size larger than 2GB

System

• OS: MacOS 15.4
• OpenPDF version: 2.0.3

[StevenStreasick]

Looking at the source code, it appears that the 2GB limit is selected, no matter the device, as the max PDF size when loading large PDF files. It appears that this was selected because of how the MappedRandomAccessFile class works, storing the FileChannel containing the PDF as a MappedByteBuffer, which both have a 2GB limit (size of an int) imposed by the Java library.

One potential solution would be to chunk the PDF into several MappedByteBuffers, each with a size less than 2GB, within the MappedRandomAccessFile. This is probably the 'simplest' fix.

Another potential solution could be to 'Stream' the PDF, but this would lose the ability to random read the file. However, I am not familiar enough with this code base to determine the effects that this option would have.