X-Git-Url: http://git.ozlabs.org/?a=blobdiff_plain;f=ccan%2Fagar%2Fagar.c;h=0baab325b58e678ba108e3fa2a09257ca92b6d86;hb=696c9b68f6334835f13037a83dd5a11c1c8129c7;hp=0ee34e9ab94c63cd7c765870c43dd85531a44115;hpb=fd96a212810bff1574b047c9079e3e050feb8a28;p=ccan

diff --git a/ccan/agar/agar.c b/ccan/agar/agar.c
index 0ee34e9a..0baab325 100644
--- 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);
+}