Function luaH_resize

third-party/lua-5.5.0/src/ltable.c:716–748

** Resize table 't' for the new given sizes. Both allocations (for ** the hash part and for the array part) can fail, which creates some ** subtleties. If the first allocation, for the hash part, fails, an ** error is raised and that is it. Otherwise, it copies the elements from ** the shrinking part of the array (if it is shrinking) into the new ** hash. Then it reallocates the array part. If th

** part.
*/
void luaH_resize (lua_State *L, Table *t, unsigned newasize,
                                          unsigned nhsize) {
  Table newt;  /* to keep the new hash part */
  unsigned oldasize = t->asize;
  Value *newarray;
  if (newasize > MAXASIZE)
    luaG_runerror(L, "table overflow");
  /* create new hash part with appropriate size into 'newt' */
  newt.flags = 0;
  setnodevector(L, &newt, nhsize);
  if (newasize < oldasize) {  /* will array shrink? */
    /* re-insert into the new hash the elements from vanishing slice */
    exchangehashpart(t, &newt);  /* pretend table has new hash */
    reinsertOldSlice(t, oldasize, newasize);
    exchangehashpart(t, &newt);  /* restore old hash (in case of errors) */
  }
  /* allocate new array */
  newarray = resizearray(L, t, oldasize, newasize);
  if (l_unlikely(newarray == NULL && newasize > 0)) {  /* allocation failed? */
    freehash(L, &newt);  /* release new hash part */
    luaM_error(L);  /* raise error (with array unchanged) */
  }
  /* allocation ok; initialize new part of the array */
  exchangehashpart(t, &newt);  /* 't' has the new hash ('newt' has the old) */
  t->array = newarray;  /* set new array part */
  t->asize = newasize;
  if (newarray != NULL)
    *lenhint(t) = newasize / 2u;  /* set an initial hint */
  clearNewSlice(t, oldasize, newasize);
  /* re-insert elements from old hash part into new parts */
  reinserthash(L, &newt, t);  /* 'newt' now has the old hash */
  freehash(L, &newt);  /* free old hash part */
}


void luaH_resizearray (lua_State *L, Table *t, unsigned int nasize) {