问弗洛里安的Grisu2算法是如何工作的？

EN

    //    cached_power function:

static const uint64_t powers_ten[] = {0xbf29dcaba82fdeae , 0xeef453d6923bd65a,...};  
//how do these numbers precomputed 
static const int powers_ten_e[] = {-1203 , -1200 , -1196 , -1193 , -1190 , ...};//and what do they mean?

static diy_fp_t cached_power(int k) 
{//does this function mean give k and return the normalized 10^k diy_fp_t?
      diy_fp_t res;
      int index = 343 + k;//why add 343?
      res.f = powers_ten[index];
      res.e = powers_ten_e[index];
      return res;
}

void digit_gen(diy_fp_t Mp, diy_fp_t delta,//Is Mp normalized?
char* buffer, int* len, int* K) 
{
     uint32_t div; int d, kappa; diy_fp_t one;
     one.f = ((uint64_t)1) << -Mp.e; one.e = Mp.e;//what if Mp.e is positive? what's the purpose of one?
     uint32_t p1 = Mp.f >> -one.e; /// Mp_cut// what does p1 mean?
     uint64_t p2 = Mp.f & (one.f - 1);//what does p2 mean?
     *len = 0; kappa = 3; div = TEN2;//why kappa=3 and div=100? is kappa related to div?
    while (kappa > 0) 
    {    /// Mp_inv1  //what does this loop mean?
         d = p1 / div;
         if (d || *len) buffer[(*len)++] = '0' + d;
         p1 %= div; kappa--; div /= 10;
         if ((((uint64_t)p1) << -one.e) + p2 <= delta.f) 
         { /// Mp_delta
             *K += kappa; return;
         }
    }
    do 
    {  //what does this loop mean?
         p2 *= 10;
         d = p2 >> -one.e;
         if (d || *len) buffer[(*len)++] = '0' + d; /// Mp_inv2
         p2 &= one.f - 1; kappa--; delta.f *= 10;// p2&=one.f-1 means what?
    } while (p2 > delta.f);
    *K += kappa;
}