/*
Return the element at index in the queue, and deletes it from inside
the queue.
*/
int q_delete_item(queue q, int index) {
assert(0 <= index && index < q_length(q));
int val;
if(index == 0) {
q_node_t *new_head = q->head->next;
val = q->head->val;
free(q->head);
q->head = new_head;
if (q->length == 0) {
q->tail = 0;
}
} else {
q_node_t *previousNode = q_get_node(q, index - 1);
q_node_t *newNext = previousNode->next->next;
val = previousNode->next->val;
free(previousNode->next);
previousNode->next = newNext;
if(previousNode->next == 0){
q->tail = previousNode;
}
}
q->length--;
return val;
}
void
q_add_to_rear(int fd)
{
q_nodeptr q_new = q_get_node();
assert(fd >= 0 && fd <= max_size);
assert(q_new);
DBG_Q("q_add_to_rear: adding fd %d\n", fd);
q_new->fd = fd;
q_new->prev = q_rear;
q_new->next = NULL;
assert(fd_array[fd] == NULL);
fd_array[fd] = q_new;
if (q_rear) {
DBG_Q("q_add_to_rear old q_rear %p = %d\n", q_rear, q_rear->fd);
q_rear->next = q_new;
}
if (q_front == NULL) {
q_front = q_new;
}
q_rear = q_new;
cur_size++;
DBG_Q("q_add_to_rear: new q_rear %p = %d cur_size = %d\n",
q_rear, q_rear->fd, cur_size);
}
/*
Get the element of the queue at position index,
where the head of the queue is position 0, and the
tail is at position length(q)-1
*/
int q_get_item(queue q, int index) {
assert(0 <= index && index < q_length(q));
return q_get_node(q, index)->val;
}
