Add a new function which returns the next element after the one provided, if it exists in the list.
Signed-off-by: Simon Glass sjg@chromium.org ---
(no changes since v1)
include/alist.h | 34 +++++++++++++++++++++++++++++++ lib/alist.c | 21 +++++++++++++++++++ test/lib/alist.c | 52 ++++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 107 insertions(+)
diff --git a/include/alist.h b/include/alist.h index 2c78ede201e..97523af37a6 100644 --- a/include/alist.h +++ b/include/alist.h @@ -71,6 +71,21 @@ static inline bool alist_has(struct alist *lst, uint index) return index < lst->count; }
+/** + * alist_calc_index() - Calculate the index of an item in the list + * + * The returned element number will be -1 if the list is empty or the pointer + * pointers to before the list starts. + * + * If the pointer points to after the last item, the calculated element-number + * will be returned, even though it is greater than lst->count + * + * @lst: alist to check + * @ptr: pointer to check + * Return: element number of the pointer + */ +int alist_calc_index(const struct alist *lst, const void *ptr); + /** * alist_err() - Check if the alist is still valid * @@ -190,6 +205,25 @@ bool alist_expand_by(struct alist *lst, uint inc_by); #define alist_add(_lst, _obj) \ ((typeof(_obj) *)alist_add_ptr(_lst, &(_obj)))
+/** get next entry as a constant */ +#define alist_next(_lst, _objp) \ + ((const typeof(_objp))alist_next_ptrd(_lst, _objp)) + +/** get next entry, which can be written to */ +#define alist_nextw(_lst, _objp) \ + ((typeof(_objp))alist_next_ptrd(_lst, _objp)) + +/** + * alist_next_ptrd() - Get a pointer to the next list element + * + * This returns NULL if the requested element is beyond lst->count + * + * @lst: List to check + * @ptr: Pointer to current element (must be valid) + * Return: Pointer to next element, or NULL if @ptr is the last + */ +const void *alist_next_ptrd(const struct alist *lst, const void *ptr); + /** * alist_init() - Set up a new object list * diff --git a/lib/alist.c b/lib/alist.c index b7928cad520..7730fe0d473 100644 --- a/lib/alist.c +++ b/lib/alist.c @@ -106,6 +106,27 @@ const void *alist_get_ptr(const struct alist *lst, uint index) return lst->data + index * lst->obj_size; }
+int alist_calc_index(const struct alist *lst, const void *ptr) +{ + uint index; + + if (!lst->count || ptr < lst->data) + return -1; + + index = (ptr - lst->data) / lst->obj_size; + + return index; +} + +const void *alist_next_ptrd(const struct alist *lst, const void *ptr) +{ + int index = alist_calc_index(lst, ptr); + + assert(index != -1); + + return alist_get_ptr(lst, index + 1); +} + void *alist_ensure_ptr(struct alist *lst, uint index) { uint minsize = index + 1; diff --git a/test/lib/alist.c b/test/lib/alist.c index d41845c7e6c..96092affec9 100644 --- a/test/lib/alist.c +++ b/test/lib/alist.c @@ -240,3 +240,55 @@ static int lib_test_alist_add(struct unit_test_state *uts) return 0; } LIB_TEST(lib_test_alist_add, 0); + +/* Test alist_next() */ +static int lib_test_alist_next(struct unit_test_state *uts) +{ + const struct my_struct *ptr; + struct my_struct data, *ptr2; + struct alist lst; + ulong start; + + start = ut_check_free(); + + ut_assert(alist_init_struct(&lst, struct my_struct)); + data.val = 123; + data.other_val = 0; + alist_add(&lst, data); + + data.val = 321; + alist_add(&lst, data); + + data.val = 789; + alist_add(&lst, data); + + ptr = alist_get(&lst, 0, struct my_struct); + ut_assertnonnull(ptr); + ut_asserteq(123, ptr->val); + + ptr = alist_next(&lst, ptr); + ut_assertnonnull(ptr); + ut_asserteq(321, ptr->val); + + ptr2 = (struct my_struct *)ptr; + ptr2 = alist_nextw(&lst, ptr2); + ut_assertnonnull(ptr2); + + ptr = alist_next(&lst, ptr); + ut_assertnonnull(ptr); + ut_asserteq(789, ptr->val); + ut_asserteq_ptr(ptr, ptr2); + ptr2->val = 89; + ut_asserteq(89, ptr->val); + + ptr = alist_next(&lst, ptr); + ut_assertnull(ptr); + + alist_uninit(&lst); + + /* Check for memory leaks */ + ut_assertok(ut_check_delta(start)); + + return 0; +} +LIB_TEST(lib_test_alist_next, 0);