byte[] data = xxxx;
MemoryModule memoryModule = MemoryModule.Create(data);

[UnmanagedFunctionPointer(CallingConvention.Cdecl)]
private delegate size_t FastLzma2CompressProc(byte[] dst, size_t dstCapacity, byte[] src, size_t srcSize, int compressionLevel, uint nbThreads);
[UnmanagedFunctionPointer(CallingConvention.Cdecl)]
private delegate size_t FastLzma2DecompressProc(byte[] dst, size_t dstCapacity, byte[] src, size_t compressedSize);
private static FastLzma2CompressProc FastLzma2Compress;
private static FastLzma2DecompressProc FastLzma2Decompress;

......

FastLzma2Compress = memoryModule.GetProcDelegate<FastLzma2CompressProc>("FL2_compressMt");
FastLzma2Decompress = memoryModule.GetProcDelegate<FastLzma2DecompressProc>("FL2_decompress");