Function listRotateHeadToTail

app/redis-6.2.6/src/adlist.c:346–358

Rotate the list removing the head node and inserting it to the tail. */

/* Rotate the list removing the head node and inserting it to the tail. */
void listRotateHeadToTail(list *list) {
    if (listLength(list) <= 1) return;

    listNode *head = list->head;
    /* Detach current head */
    list->head = head->next;
    list->head->prev = NULL;
    /* Move it as tail */
    list->tail->next = head;
    head->next = NULL;
    head->prev = list->tail;
    list->tail = head;
}

/* Add all the elements of the list 'o' at the end of the
 * list 'l'. The list 'other' remains empty but otherwise valid. */