agar: Remove unnecessary NULL check

[ccan] / ccan / agar / agar.c

diff --git a/ccan/agar/agar.c b/ccan/agar/agar.c
index 0ee34e9ab94c63cd7c765870c43dd85531a44115..0baab325b58e678ba108e3fa2a09257ca92b6d86 100644 (file)
--- a/ccan/agar/agar.c
+++ b/ccan/agar/agar.c
@@ -59,7 +59,7 @@ static struct aga_node *nr_to_n(struct agar_state *sr, const void *nr)
                assert(rc);
        }
 
-       return nn ? &nn->n : NULL;
+       return &nn->n;
 }
 
 static const void *n_to_nr(struct agar_state *sr, const struct aga_node *n)
@@ -291,3 +291,48 @@ void agar_dijkstra_complete(struct agar_state *sr)
        aga_dijkstra_complete(&sr->g);
 }
 
+
+/*
+ * Bellman-Ford algorithm
+ */
+
+struct agar_state *agar_bellman_ford_new(void *ctx, struct agar_graph *gr,
+                                        const void *nr)
+{
+       struct agar_state *sr = agar_new(ctx, gr);
+
+       if (aga_bellman_ford_start(&sr->g, nr_to_n(sr, nr)) < 0) {
+               tal_free(sr);
+               return NULL;
+       }
+
+       return sr;
+}
+
+bool agar_bellman_ford_path(struct agar_state *sr, const void *destr,
+                           aga_icost_t *total_cost,
+                           const void **prevr, const void **prevedge)
+{
+       struct aga_node *dest = nr_to_n(sr, destr);
+       struct aga_node *prev;
+
+       if (!aga_bellman_ford_path(&sr->g, dest, total_cost, &prev, prevedge))
+               return false;
+
+       /*
+        * When destr is the same as the source node, there obviously
+        * isn't a previous node or edge.  In that case aga sets them
+        * to NULL.  But for agar, NULL could be a valid node
+        * references (particularly if using ptrint).  So we don't
+        * have much choice here but to leave *prevr as undefined when
+        * destr is the source node. */
+       if (prevr && prev)
+               *prevr = n_to_nr(sr, prev);
+
+       return true;
+}
+
+void agar_bellman_ford_complete(struct agar_state *sr)
+{
+       aga_bellman_ford_complete(&sr->g);
+}