From: David Given <dg@cowlark.com>
Date: Fri, 16 Dec 2016 23:21:27 +0000 (+0100)
Subject: Massive graph performance boost by checking to see whether an edge already
X-Git-Url: https://git.ndcode.org/public/gitweb.cgi?a=commitdiff_plain;h=02678ba9d38deb77d1c8fdea7414b3294b42d02c;p=ack.git

Massive graph performance boost by checking to see whether an edge already
exists in the hash table before trying to add it.
---

diff --git a/modules/src/data/bigraph.c b/modules/src/data/bigraph.c
index 1e6a84151..4499563d6 100644
--- a/modules/src/data/bigraph.c
+++ b/modules/src/data/bigraph.c
@@ -130,10 +130,16 @@ void graph_add_edge(struct graph* g, void* data1, void* data2)
     struct vertex* v1 = find_or_add_vertex(g, data1);
     struct vertex* v2 = find_or_add_vertex(g, data2);
     struct edgenode* e;
+	struct edgenode template;
 
 	if (v1 == v2)
 		return;
 
+	template.this = v1;
+	template.other = v2;
+	if (hashtable_contains(&g->edges, &template))
+		return;
+
     add_edge(v1, v2);
     e = add_edge(v2, v1);