From 326a86ef927e1f161a6742edfca041a945c7a547 Mon Sep 17 00:00:00 2001
From: Aaron Krebs <aaron.krebs@everbase.net>
Date: Sat, 9 Aug 2014 22:05:34 +0200
Subject: [PATCH] Implemented API function to capture mesh edges.

---
 src/meshlink.c | 50 ++++++++++++++++++++++++++++++++++++++++++++++++++
 src/meshlink.h | 31 +++++++++++++++++++++++++++++++
 2 files changed, 81 insertions(+)

diff --git a/src/meshlink.c b/src/meshlink.c
index b8f3c969..6396163d 100644
--- a/src/meshlink.c
+++ b/src/meshlink.c
@@ -1836,6 +1836,56 @@ void meshlink_hint_address(meshlink_handle_t *mesh, meshlink_node_t *node, const
 	// @TODO do we want to fire off a connection attempt right away?
 }
 
+/* Return an array of edges in the current network graph.
+ * Data captures the current state and will not be updated.
+ * Caller must deallocate data when done.
+ */
+meshlink_edge_t **meshlink_get_all_edges_state(meshlink_handle_t *mesh, size_t *nmemb) {
+	if(!mesh || !nmemb) {
+		meshlink_errno = MESHLINK_EINVAL;
+		return NULL;
+	}
+
+	pthread_mutex_lock(&(mesh->mesh_mutex));
+	
+	meshlink_edge_t **result = NULL;
+	meshlink_edge_t *copy = NULL;
+
+	// mesh->edges->count is the max size
+	*nmemb = mesh->edges->count;
+
+	result = xzalloc(*nmemb * sizeof (meshlink_edge_t*));
+
+	if(result) {
+		meshlink_edge_t **p = result;
+		for splay_each(edge_t, e, mesh->edges) {
+			// skip edges that do not represent a two-directional connection
+			if((!e->reverse) || (e->reverse->to != e->from)) {
+				*nmemb--;
+				continue;
+			}
+			// copy the edge so it can't be mutated
+			copy = xzalloc(sizeof *copy);
+			copy->from = (meshlink_node_t*)e->from;
+			copy->to = (meshlink_node_t*)e->to;
+			//TODO fix conversion from sockaddr_t to sockaddr_storage
+			//copy->address = e->address.ss;
+			copy->options = e->options;
+			copy->weight = e->weight;
+			*p++ = copy;
+		}
+		// shrink result to the actual amount of memory used
+		result = realloc(result, *nmemb * sizeof (meshlink_edge_t*));
+	} else {
+		*nmemb = 0;
+		meshlink_errno = MESHLINK_ENOMEM;
+	}
+
+	pthread_mutex_unlock(&(mesh->mesh_mutex));
+
+	return result;
+}
+
 static void __attribute__((constructor)) meshlink_init(void) {
 	crypto_init();
 }
diff --git a/src/meshlink.h b/src/meshlink.h
index 6858b5bc..8bc8c706 100644
--- a/src/meshlink.h
+++ b/src/meshlink.h
@@ -48,6 +48,9 @@ typedef struct meshlink_handle meshlink_handle_t;
 /// A handle for a MeshLink node.
 typedef struct meshlink_node meshlink_node_t;
 
+/// A handle for a MeshLink edge.
+typedef struct meshlink_edge meshlink_edge_t;
+
 /// A handle for a MeshLink channel.
 typedef struct meshlink_channel meshlink_channel_t;
 
@@ -97,6 +100,15 @@ struct meshlink_channel {
 
 #endif // MESHLINK_INTERNAL_H
 
+// TODO documentation
+struct meshlink_edge {
+	struct meshlink_node *from;
+	struct meshlink_node *to;
+	struct sockaddr_storage address;
+	uint32_t options;
+	int weight;
+};
+
 /// Get the text for the given MeshLink error code.
 /** This function returns a pointer to the string containing the description of the given error code.
  *
@@ -608,6 +620,25 @@ extern ssize_t meshlink_channel_send(meshlink_handle_t *mesh, meshlink_channel_t
  */
 extern void meshlink_hint_address(meshlink_handle_t *mesh, meshlink_node_t *node, const struct sockaddr *addr);
 
+/// Get a list of edges.
+/** This function returns an array with copies of all known bidirectional edges.
+ *  The edges are copied to capture the mesh state at call time, since edges
+ *  mutate frequently. The nodes pointed to within the meshlink_edge_t type
+ *  are not copies; these are the same pointers that one would get from a call
+ *  to meshlink_get_all_nodes().
+ *
+ *  @param mesh         A handle which represents an instance of MeshLink.
+ *  @param nmemb        A pointer to a variable that will be filled with the number
+ *  			of edges in the returned array.
+ *
+ *  @return             A pointer to an array containing pointers to all known 
+ *  			edges, or NULL in case of an error.
+ *  			The caller must call free() on each element of this
+ *  			array (but not the contents of said elements),
+ *  			as well as the array itself when it is finished.
+ */
+extern meshlink_edge_t **meshlink_get_all_edges_state(meshlink_handle_t *mesh, size_t *nmemb);
+
 #ifdef __cplusplus
 }
 #endif
-- 
2.39.2