What is the mechanism of saccharification by H2SO4?

We have been estimating total carbohydrate by Umbreit method/ Anthrone method in college. The website I have been reading says that $\ce{H\_2SO\_4}$ and heat is used to treat a polysaccharide solution yield hexoses and pentoses which further undergo dehydration to form hydroxymethylfurfural and furfural respectively. These compounds when react with Anthrone form coloured compounds. 


I have been wondering what the mechanism of hydrolysis of polysaccharide is?


