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-rw-r--r--src/vppinfra/graph.c182
1 files changed, 182 insertions, 0 deletions
diff --git a/src/vppinfra/graph.c b/src/vppinfra/graph.c
new file mode 100644
index 00000000..98a29046
--- /dev/null
+++ b/src/vppinfra/graph.c
@@ -0,0 +1,182 @@
+/*
+ * Copyright (c) 2015 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+#include <vppinfra/graph.h>
+
+/* Set link distance, creating link if not found. */
+u32
+graph_set_link (graph_t * g, u32 src, u32 dst, u32 distance)
+{
+ graph_node_t *src_node, *dst_node;
+ graph_link_t *l;
+ u32 old_distance;
+
+ /* The following validate will not work if src or dst are on the
+ pool free list. */
+ if (src < vec_len (g->nodes))
+ ASSERT (!pool_is_free_index (g->nodes, src));
+ if (dst < vec_len (g->nodes))
+ ASSERT (!pool_is_free_index (g->nodes, dst));
+
+ /* Make new (empty) nodes to make src and dst valid. */
+ pool_validate_index (g->nodes, clib_max (src, dst));
+
+ src_node = pool_elt_at_index (g->nodes, src);
+ dst_node = pool_elt_at_index (g->nodes, dst);
+
+ l = graph_dir_get_link_to_node (&src_node->next, dst);
+ if (l)
+ {
+ old_distance = l->distance;
+ l->distance = distance;
+
+ l = graph_dir_get_link_to_node (&dst_node->prev, src);
+ l->distance = distance;
+ }
+ else
+ {
+ uword li_next, li_prev;
+
+ old_distance = ~0;
+
+ li_next = graph_dir_add_link (&src_node->next, dst, distance);
+ li_prev = graph_dir_add_link (&dst_node->prev, src, distance);
+
+ l = vec_elt_at_index (src_node->next.links, li_next);
+ l->link_to_self_index = li_prev;
+
+ l = vec_elt_at_index (dst_node->prev.links, li_prev);
+ l->link_to_self_index = li_next;
+ }
+
+ return old_distance;
+}
+
+void
+graph_del_link (graph_t * g, u32 src, u32 dst)
+{
+ graph_node_t *src_node, *dst_node;
+
+ src_node = pool_elt_at_index (g->nodes, src);
+ dst_node = pool_elt_at_index (g->nodes, dst);
+
+ graph_dir_del_link (&src_node->next, dst);
+ graph_dir_del_link (&dst_node->next, src);
+}
+
+/* Delete source node and all links from other nodes from/to source. */
+uword
+graph_del_node (graph_t * g, u32 src)
+{
+ graph_node_t *src_node, *n;
+ uword index;
+ graph_link_t *l;
+
+ src_node = pool_elt_at_index (g->nodes, src);
+
+ vec_foreach (l, src_node->next.links)
+ {
+ n = pool_elt_at_index (g->nodes, l->node_index);
+ graph_dir_del_link (&n->prev, src);
+ }
+
+ vec_foreach (l, src_node->prev.links)
+ {
+ n = pool_elt_at_index (g->nodes, l->node_index);
+ graph_dir_del_link (&n->next, src);
+ }
+
+ graph_dir_free (&src_node->next);
+ graph_dir_free (&src_node->prev);
+
+ index = src_node - g->nodes;
+ pool_put (g->nodes, src_node);
+ memset (src_node, ~0, sizeof (src_node[0]));
+
+ return index;
+}
+
+uword
+unformat_graph (unformat_input_t * input, va_list * args)
+{
+ graph_t *g = va_arg (*args, graph_t *);
+ typedef struct
+ {
+ u32 src, dst, distance;
+ } T;
+ T *links = 0, *l;
+ uword result;
+
+ while (1)
+ {
+ vec_add2 (links, l, 1);
+ if (!unformat (input, "%d%d%d", &l->src, &l->dst, &l->distance))
+ break;
+ }
+ _vec_len (links) -= 1;
+ result = vec_len (links) > 0;
+ vec_foreach (l, links)
+ {
+ graph_set_link (g, l->src, l->dst, l->distance);
+ graph_set_link (g, l->dst, l->src, l->distance);
+ }
+
+ vec_free (links);
+ return result;
+}
+
+u8 *
+format_graph_node (u8 * s, va_list * args)
+{
+ graph_t *g = va_arg (*args, graph_t *);
+ u32 node_index = va_arg (*args, u32);
+
+ if (g->format_node)
+ s = format (s, "%U", g->format_node, g, node_index);
+ else
+ s = format (s, "%d", node_index);
+
+ return s;
+}
+
+u8 *
+format_graph (u8 * s, va_list * args)
+{
+ graph_t *g = va_arg (*args, graph_t *);
+ graph_node_t *n;
+ graph_link_t *l;
+ uword indent = format_get_indent (s);
+
+ s = format (s, "graph %d nodes", pool_elts (g->nodes));
+ /* *INDENT-OFF* */
+ pool_foreach (n, g->nodes, ({
+ s = format (s, "\n%U", format_white_space, indent + 2);
+ s = format (s, "%U -> ", format_graph_node, g, n - g->nodes);
+ vec_foreach (l, n->next.links)
+ s = format (s, "%U (%d), ",
+ format_graph_node, g, l->node_index,
+ l->distance);
+ }));
+ /* *INDENT-ON* */
+
+ return s;
+}
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */