move cirular queue removal into its own function

svn:r957

diff --git a/evdns.c b/evdns.c
index 8ce311e004de09741da601e4e60d0421da123fb0..2c99baa12ea7a5931a8896a5c4ea974a305d8a75 100644 (file)
--- a/evdns.c
+++ b/evdns.c
@@ -341,6 +341,7 @@ static const int global_nameserver_timeouts_length = sizeof(global_nameserver_ti
 
 static struct nameserver *nameserver_pick(struct evdns_base *base);
 static void evdns_request_insert(struct evdns_request *req, struct evdns_request **head);
+static void evdns_request_remove(struct evdns_request *req, struct evdns_request **head);
 static void nameserver_ready_callback(evutil_socket_t fd, short events, void *arg);
 static int evdns_transmit(struct evdns_base *base);
 static int evdns_request_transmit(struct evdns_request *req);
@@ -566,16 +567,8 @@ request_trans_id_set(struct evdns_request *const req, const u16 trans_id) {
 static void
 request_finished(struct evdns_request *const req, struct evdns_request **head) {
        struct evdns_base *base = req->base;
-       if (head) {
-               if (req->next == req) {
-                       /* only item in the list */
-                       *head = NULL;
-               } else {
-                       req->next->prev = req->prev;
-                       req->prev->next = req->next;
-                       if (*head == req) *head = req->next;
-               }
-       }
+       if (head)
+               evdns_request_remove(req, head);
 
        log(EVDNS_LOG_DEBUG, "Removing timeout for request %lx",
            (unsigned long) req);
@@ -633,16 +626,8 @@ evdns_requests_pump_waiting_queue(struct evdns_base *base) {
                struct evdns_request *req;
                /* move a request from the waiting queue to the inflight queue */
                assert(base->req_waiting_head);
-               if (base->req_waiting_head->next == base->req_waiting_head) {
-                       /* only one item in the queue */
-                       req = base->req_waiting_head;
-                       base->req_waiting_head = NULL;
-               } else {
-                       req = base->req_waiting_head;
-                       req->next->prev = req->prev;
-                       req->prev->next = req->next;
-                       base->req_waiting_head = req->next;
-               }
+               req = base->req_waiting_head;
+               evdns_request_remove(req, &base->req_waiting_head);
 
                base->global_requests_waiting--;
                base->global_requests_inflight++;
@@ -2252,6 +2237,20 @@ evdns_nameserver_ip_add(const char *ip_as_string) {
        return evdns_base_nameserver_ip_add(current_base, ip_as_string);
 }
 
+/* remove from the queue */
+static void
+evdns_request_remove(struct evdns_request *req, struct evdns_request **head)
+{
+       if (req->next == req) {
+               /* only item in the list */
+               *head = NULL;
+       } else {
+               req->next->prev = req->prev;
+               req->prev->next = req->next;
+               if (*head == req) *head = req->next;
+       }
+}
+
 /* insert into the tail of the queue */
 static void
 evdns_request_insert(struct evdns_request *req, struct evdns_request **head) {
@@ -2770,13 +2769,7 @@ evdns_base_set_max_requests_inflight(struct evdns_base *base, int maxinflight)
                for (i = 0; i < old_n_heads; ++i) {
                        while (old_heads[i]) {
                                req = old_heads[i];
-                               if (req->next == req) {
-                                       old_heads[i] = NULL;
-                               } else {
-                                       old_heads[i] = req->next;
-                                       req->next->prev = req->prev;
-                                       req->prev->next = req->next;
-                               }
+                               evdns_request_remove(req, &old_heads[i]);
                                evdns_request_insert(req, &new_heads[req->trans_id % n_heads]);
                        }
                }