-/* Read/write "x" from/to "file" as bigendian representation of "size" bits.
- * Only multiples of 8 allowed for "size". On failure, return 1, else 0.
+/* Read/write "x" from/to "file" as bigendian representation of "size" bits. On
+ * failure, return 1, else 0. (As of of now, all extern read/write functions
+ * build on top of these.)
*
- * As of of now, all other read/write functions build on top of these. TODO:
- * Consider externing these so-far internal functions and dropping the
- * interfaces to them, instead relying on their internal validity checks.
- * (Usage of padded memory copies instead of directly manipulating * x as is
- * done in read_uint* would need to be added, though.)
+ * Only use multiples of 8 greater or equal 32 for "size". Originally a bit
+ * number check prefaced the code of both functions. It was removed as redundant
+ * due to all possible "size" values being hardcoded into the library (i.e. in
+ * all extern functions calling / wrapping around either function). If this ever
+ * changes, (re-)insert:
+ *
+ * if (0 != size && size <= 32 && 0 != size % 8)
+ * {
+ * return 1;
+ * }
*/
static uint8_t read_uintX_bigendian(FILE * file, uint32_t * x, uint8_t size);
static uint8_t write_uintX_bigendian(FILE * file, uint32_t x, uint8_t size);
-
static uint8_t read_uintX_bigendian(FILE * file, uint32_t * x, uint8_t size)
{
- if (0 != size % 8) /* This bit number validity check is redundant */
- { /* as long as this function is only available */
- return 1; /* through extern interfaces pre-defining the */
- } /* bit number. TODO: Consider dropping it. */
- int16_t bitshift = size - 8;
-
* x = 0;
+ int16_t bitshift = size - 8;
int test;
for (; bitshift >= 0; bitshift = bitshift - 8)
{
static uint8_t write_uintX_bigendian(FILE * file, uint32_t x, uint8_t size)
{
- if (0 != size % 8) /* See comment */
- { /* on identical */
- return 1; /* code block in */
- } /* read_uintX_bigendian(). */
int16_t bitshift = size - 8;
-
for (; bitshift >= 0; bitshift = bitshift - 8)
{
if (EOF == fputc((x >> bitshift) & 0xFF, file))
extern uint8_t read_uint16_bigendian(FILE * file, uint16_t * x)
{
- /* See read_uint8() introductory comment for rationale. */
+ /* See read_uint8() introductory code comment for rationale. */
uint32_t y = * x;
uint8_t err = read_uintX_bigendian(file, &y, 16);
* x = (uint16_t) y;