PDF file size

Version 6.1.0

In this article

• Maximum PDF file size
• Defining maximum file size

Maximum PDF file size

Starting with PDFsharp 6.1, PDF files now can be larger than 2 gibibytes (2^31 = 2,147,483,648 bytes or 2.1 GB) by default.

The new theoretical maximum size is now only limited by the largest entry in the XRef table. Offsets in a PDF file are stored in this table and have exactly 10 decimal figures. So the file can now have a maximum size of about 10 gigabyte (9,999,999,999 byte).

Such large PDF files may be useful in prepress where PDF files can contain hundreds of high-resolution images.

Defining maximum file size

To allow files larger than 2 gibibytes, all file size and offset variables in the source code are switched form Int32 to Int64. The constant USE_LONG_SIZE defines a global using SizeType of either 32 or 64 bit.

#if USE_LONG_SIZE
    global using SizeType = System.Int64;
#else
    global using SizeType = System.Int32;
#endif

You can change the constant USE_LONG_SIZE in the Directory.Build.targets file.

<Project>
  <PropertyGroup>
    …
    <DefineConstants>$(DefineConstants);USE_LONG_SIZE;…</DefineConstants>
  </PropertyGroup>
</Project>

If you use PDFsharp on a 32 bit operating system like a Raspberry Pi running a 32 bit Linux, it may be useful to recompile PDFsharp with a 32 bit SizeType. Just rename USE_LONG_SIZE to e.g. USE_LONG_SIZE_XXX. Maybe this brings minimal performance or memory usage benefits.