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Diffstat (limited to 'src/libnetdata/linked-lists.h')
| -rw-r--r-- | src/libnetdata/linked-lists.h | 133 |
1 files changed, 133 insertions, 0 deletions
diff --git a/src/libnetdata/linked-lists.h b/src/libnetdata/linked-lists.h new file mode 100644 index 000000000..033d11226 --- /dev/null +++ b/src/libnetdata/linked-lists.h @@ -0,0 +1,133 @@ +// SPDX-License-Identifier: GPL-3.0-or-later + +#ifndef NETDATA_LINKED_LISTS_H +#define NETDATA_LINKED_LISTS_H + +// --------------------------------------------------------------------------------------------- +// double linked list management +// inspired by https://github.com/troydhanson/uthash/blob/master/src/utlist.h + +#define DOUBLE_LINKED_LIST_PREPEND_ITEM_UNSAFE(head, item, prev, next) \ + do { \ + (item)->next = (head); \ + \ + if(likely(head)) { \ + (item)->prev = (head)->prev; \ + (head)->prev = (item); \ + } \ + else \ + (item)->prev = (item); \ + \ + (head) = (item); \ + } while (0) + +#define DOUBLE_LINKED_LIST_APPEND_ITEM_UNSAFE(head, item, prev, next) \ + do { \ + \ + (item)->next = NULL; \ + \ + if(likely(head)) { \ + (item)->prev = (head)->prev; \ + (head)->prev->next = (item); \ + (head)->prev = (item); \ + } \ + else { \ + (item)->prev = (item); \ + (head) = (item); \ + } \ + \ + } while (0) + +#define DOUBLE_LINKED_LIST_REMOVE_ITEM_UNSAFE(head, item, prev, next) \ + do { \ + fatal_assert((head) != NULL); \ + fatal_assert((item)->prev != NULL); \ + \ + if((item)->prev == (item)) \ + /* it is the only item in the list */ \ + (head) = NULL; \ + \ + else if((item) == (head)) { \ + /* it is the first item */ \ + fatal_assert((item)->next != NULL); \ + (item)->next->prev = (item)->prev; \ + (head) = (item)->next; \ + } \ + else { \ + /* it is any other item */ \ + (item)->prev->next = (item)->next; \ + \ + if ((item)->next) \ + (item)->next->prev = (item)->prev; \ + else \ + (head)->prev = (item)->prev; \ + } \ + \ + (item)->next = NULL; \ + (item)->prev = NULL; \ + } while (0) + +#define DOUBLE_LINKED_LIST_INSERT_ITEM_BEFORE_UNSAFE(head, existing, item, prev, next) \ + do { \ + if (existing) { \ + fatal_assert((head) != NULL); \ + fatal_assert((item) != NULL); \ + \ + (item)->next = (existing); \ + (item)->prev = (existing)->prev; \ + (existing)->prev = (item); \ + \ + if ((head) == (existing)) \ + (head) = (item); \ + else \ + (item)->prev->next = (item); \ + \ + } \ + else \ + DOUBLE_LINKED_LIST_APPEND_ITEM_UNSAFE(head, item, prev, next); \ + \ + } while (0) + +#define DOUBLE_LINKED_LIST_INSERT_ITEM_AFTER_UNSAFE(head, existing, item, prev, next) \ + do { \ + if (existing) { \ + fatal_assert((head) != NULL); \ + fatal_assert((item) != NULL); \ + \ + (item)->next = (existing)->next; \ + (item)->prev = (existing); \ + (existing)->next = (item); \ + \ + if ((item)->next) \ + (item)->next->prev = (item); \ + else \ + (head)->prev = (item); \ + } \ + else \ + DOUBLE_LINKED_LIST_PREPEND_ITEM_UNSAFE(head, item, prev, next); \ + \ + } while (0) + +#define DOUBLE_LINKED_LIST_APPEND_LIST_UNSAFE(head, head2, prev, next) \ + do { \ + if (head2) { \ + if (head) { \ + __typeof(head2) _head2_last_item = (head2)->prev; \ + \ + (head2)->prev = (head)->prev; \ + (head)->prev->next = (head2); \ + \ + (head)->prev = _head2_last_item; \ + } \ + else \ + (head) = (head2); \ + } \ + } while (0) + +#define DOUBLE_LINKED_LIST_FOREACH_FORWARD(head, var, prev, next) \ + for ((var) = (head); (var) ; (var) = (var)->next) + +#define DOUBLE_LINKED_LIST_FOREACH_BACKWARD(head, var, prev, next) \ + for ((var) = (head) ? (head)->prev : NULL ; (var) ; (var) = ((var) == (head)) ? NULL : (var)->prev) + +#endif //NETDATA_LINKED_LISTS_H |