Question

What comparison mechanism does Nuget use during update operation to check if package content files were modified in the host project?

Answer 1

Nuget uses CRC (cyclic redundancy check) to compare original package files with versions already extracted in the host project.

It calculates 32-bit CRC for package file and extracted file and compare those values. Following Stream extension method is used for comparison:

    public static bool ContentEquals(this Stream stream, Stream otherStream)
    {
        return Crc32.Calculate(stream) == Crc32.Calculate(otherStream);
    }