Use a binary search to locate msgnum in cached_msglist

diff --git a/citadel/msgbase.c b/citadel/msgbase.c
index 2f62309d931073a8d374baf37287fe58a11445f0..eb1c53ce51a4e6bc9a25819bc13f1ccb223fca5a 100644 (file)
--- a/citadel/msgbase.c
+++ b/citadel/msgbase.c
@@ -1528,10 +1528,22 @@ int check_cached_msglist(long msgnum) {
        if (CC->cached_num_msgs == 0) return om_access_denied;          /* nothing to check */
 
 
-       /* FIXME FIXME SLOW SEARCH DO NOT LET THIS GO INTO PRODUCTION */
-       int i;
-       for (i=0; i < CC->cached_num_msgs ; ++i) {
-               if (CC->cached_msglist[i] == msgnum) return om_ok;
+       /* Do a binary search within the cached_msglist for the requested msgnum */
+       int min = 0;
+       int max = (CC->cached_num_msgs - 1);
+
+       while (max >= min) {
+               syslog(LOG_DEBUG, "\033[35m Checking from %d to %d \033[0m\n", min, max);
+               int middle = min + (max-min) / 2 ;
+               if (msgnum == CC->cached_msglist[middle]) {
+                       return om_ok;
+               }
+               if (msgnum > CC->cached_msglist[middle]) {
+                       min = middle + 1;
+               }
+               else {
+                       max = middle - 1;
+               }
        }
 
        return om_access_denied;