[svn] Don't reuse IP addresses proven to be faulty, unless only such ones remain.

[wget] / src / host.c

diff --git a/src/host.c b/src/host.c
index c31cc05fa0cdfba7d8c6f3d883b1f49428332d30..eede86fe51064c603ec2de0910ab93a459a6b3e0 100644 (file)
--- a/src/host.c
+++ b/src/host.c
@@ -72,18 +72,21 @@ struct address_list {
   int count;                   /* number of adrresses */
   unsigned char *buffer;       /* buffer which holds all of them. */
 
+  int faulty;                  /* number of addresses known not to
+                                  work. */
   int refcount;                        /* so we know whether to free it or
                                   not. */
 };
 
 #define ADDR_LOCATION(al, index) ((al)->buffer + index * IP4_ADDRESS_LENGTH)
 
-/* Return the number of addresses in the list. */
+/* Get the bounds of the address list.  */
 
-int
-address_list_count (struct address_list *al)
+void
+address_list_get_bounds (struct address_list *al, int *start, int *end)
 {
-  return al->count;
+  *start = al->faulty;
+  *end   = al->count;
 }
 
 /* Copy address number INDEX to IP_STORE.  */
@@ -92,6 +95,7 @@ void
 address_list_copy_one (struct address_list *al, int index,
                       unsigned char *ip_store)
 {
+  assert (index >= al->faulty && index < al->count);
   memcpy (ip_store, ADDR_LOCATION (al, index), IP4_ADDRESS_LENGTH);
 }
 
@@ -108,6 +112,21 @@ address_list_match_all (struct address_list *al1, struct address_list *al2)
                      al1->count * IP4_ADDRESS_LENGTH);
 }
 
+/* Mark the INDEXth element of AL as faulty, so that the next time
+   this address list is used, the faulty element will be skipped.  */
+
+void
+address_list_set_faulty (struct address_list *al, int index)
+{
+  ++al->faulty;
+  if (al->faulty >= al->count)
+    /* All addresses have been proven faulty.  Since there's not much
+       sense in returning the user an empty address list the next
+       time, we'll rather make them all clean, so that they can be
+       retried anew.  */
+    al->faulty = 0;
+}
+
 /* Create an address_list out of a NULL-terminated list of addresses,
    as returned by gethostbyname.  */