Array of items to write. The data is read directly.
That is, in 1 or 2-byte mode, the lower byte(s) in
each cell are used directly, rather than performing
any casts from a 4-byte number to a smaller number.
int num_items
Number of items in the array.
int size
Size of each item in the array in bytes.
Valid sizes are 1, 2, or 4.