diff -r 3d93cd78aa20 -r 21082350a590 src/array_list.c --- a/src/array_list.c Sun Nov 20 16:28:03 2022 +0100 +++ b/src/array_list.c Sun Nov 20 16:58:51 2022 +0100 @@ -101,6 +101,45 @@ return CX_ARRAY_COPY_SUCCESS; } +#define CX_ARRAY_SWAP_SBO_SIZE 512 + +void cx_array_swap( + void *arr, + size_t elem_size, + size_t idx1, + size_t idx2 +) { + /* short circuit */ + if (idx1 == idx2) return; + + char sbo_mem[CX_ARRAY_SWAP_SBO_SIZE]; + void *tmp; + + /* decide if we can use the local buffer */ + if (elem_size > CX_ARRAY_SWAP_SBO_SIZE) { + tmp = malloc(elem_size); + /* we don't want to enforce error handling */ + if (tmp == NULL) abort(); + } else { + tmp = sbo_mem; + } + + /* calculate memory locations */ + char *left = arr, *right = arr; + left += idx1 * elem_size; + right += idx2 * elem_size; + + /* three-way swap */ + memcpy(tmp, left, elem_size); + memcpy(left, right, elem_size); + memcpy(right, tmp, elem_size); + + /* free dynamic memory, if it was needed */ + if (tmp != sbo_mem) { + free(tmp); + } +} + /* HIGH LEVEL ARRAY LIST FUNCTIONS */ typedef struct { @@ -290,7 +329,12 @@ } static void cx_arl_reverse(struct cx_list_s *list) { - + if (list->size < 2) return; + void *data = ((cx_array_list const *) list)->data; + size_t half = list->size / 2; + for (size_t i = 0; i < half; i++) { + cx_array_swap(data, list->itemsize, i, list->size - 1 - i); + } } static bool cx_arl_iter_valid(struct cx_iterator_s const *iter) {