Hi,
These functions are internal to the shipping plugin allowing us to store the shipping data and not performing webservice calls for each pages.
These functions are just for the shipping plugins and just cache that data ; nothing else, nothing more.
And all is automatic and for sure, if the cart changed, the shipping cache is invalidated so the shipping plugins will re-call the webservices with the new cart.
Regards,
Jerome - Obsidev.com
HikaMarket & HikaSerial developer / HikaShop core dev team.
Also helping the HikaShop support team when having some time or couldn't sleep.
By the way, do not send me private message, use the "contact us" form instead.