intel galileo mraa spi library

I have an Intel galileo board, that communicates with a shield over SPI. I'm porting an Arduino library for the shield to use the MRAA SPI library instead of the arduino SPI library. I've a question.

MRAA SPI library

According to the above link (MRAA SPI library)

1. Instead of SPI.begin() in the shield library I'm guessing that I replace this directly with spi = mraa_spi_init(0);Question where do I put mraa_spi_context spi; In the library's .cpp file or .h file? Or do I put it in main()?

Thank you