OPTIM: cfgparse: speed up duplicate server detection

Surprisingly, the duplicate server name detection has never made use
of the names tree, so lookups were still in O(N^2). It took 1 second
to validate 50k servers spread into 25 backends at 2k per backend.

By simply using the tree (and since the current server already is in
the tree), we just have to walk using ebpt_prev_dup to visit previous
servers with the same name. We can then detect which ones conflict
without having an ID set and error. The config check time is now 1/4
of the previous one for 2k servers per backend, and more importantly
it will make it simpler to check for any duplicates later.

diff --git a/src/cfgparse.c b/src/cfgparse.c
index 27c1119c0ccb4aac082b79d7cdef99fa0b3a4bc0..83592556f79d79286185a0634113ba38393fc1e1 100644 (file)
--- a/src/cfgparse.c
+++ b/src/cfgparse.c
@@ -3748,16 +3748,23 @@ out_uri_auth_compat:
                 * in order to avoid combinatory explosion if all servers have the same
                 * name. We do that only for servers which do not have an explicit ID,
                 * because these IDs were made also for distinguishing them and we don't
-                * want to annoy people who correctly manage them.
+                * want to annoy people who correctly manage them. Since servers names
+                * are stored in a tree before landing here, we simply have to check for
+                * the current server's duplicates to spot conflicts.
                 */
                for (newsrv = curproxy->srv; newsrv; newsrv = newsrv->next) {
                        struct server *other_srv;
 
-                       if (newsrv->puid)
+                       /* Note: internal servers are not always registered and
+                        * they do not conflict.
+                        */
+                       if (!newsrv->conf.name.node.leaf_p)
                                continue;
 
-                       for (other_srv = curproxy->srv; other_srv && other_srv != newsrv; other_srv = other_srv->next) {
-                               if (!other_srv->puid && strcmp(other_srv->id, newsrv->id) == 0) {
+                       for (other_srv = newsrv;
+                            (other_srv = container_of_safe(ebpt_prev_dup(&other_srv->conf.name),
+                                                           struct server, conf.name)); ) {
+                               if (!newsrv->puid && !other_srv->puid) {
                                        ha_alert("parsing [%s:%d] : %s '%s', another server named '%s' was already defined at line %d, please use distinct names.\n",
                                                   newsrv->conf.file, newsrv->conf.line,
                                                   proxy_type_str(curproxy), curproxy->id,