lib/graph.h

   1 /*
   2  * Graph data structure.
   3  *
   4  * --
   5  * Copyright (C) 2016 Cumulus Networks, Inc.
   6  *
   7  * This file is part of GNU Zebra.
   8  *
   9  * GNU Zebra is free software; you can redistribute it and/or modify it
  10  * under the terms of the GNU General Public License as published by the
  11  * Free Software Foundation; either version 2, or (at your option) any
  12  * later version.
  13  *
  14  * GNU Zebra is distributed in the hope that it will be useful, but
  15  * WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  17  * General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License along
  20  * with this program; see the file COPYING; if not, write to the Free Software
  21  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
  22  */
  23
  24 #ifndef _ZEBRA_COMMAND_GRAPH_H
  25 #define _ZEBRA_COMMAND_GRAPH_H
  26
  27 #include "vector.h"
  28
  29 struct graph {
  30         vector nodes;
  31 };
  32
  33 struct graph_node {
  34         vector from; // nodes which have edges to this node
  35         vector to;   // nodes which this node has edges to
  36
  37         void *data;              // node data
  38         void (*del)(void *data); // deletion callback
  39 };
  40
  41 struct graph *graph_new(void);
  42
  43 /**
  44  * Creates a new node.
  45  *
  46  * @struct graph the graph this node exists in
  47  * @param[in] data this node's data
  48  * @param[in] del data deletion callback
  49  * @return the new node
  50  */
  51 struct graph_node *graph_new_node(struct graph *graph, void *data,
  52                                   void (*del)(void *));
  53
  54 /**
  55  * Deletes a node.
  56  *
  57  * Before deletion, this function removes all edges to and from this node from
  58  * any neighbor nodes.
  59  *
  60  * If *data and *del are non-null, the following call is made:
  61  *   (*node->del) (node->data);
  62  *
  63  * @param[in] graph the graph this node belongs to
  64  * @param[out] node pointer to node to delete
  65  */
  66 void graph_delete_node(struct graph *graph, struct graph_node *node);
  67
  68 /**
  69  * Makes a directed edge between two nodes.
  70  *
  71  * @param[in] from
  72  * @param[in] to
  73  * @return to
  74  */
  75 struct graph_node *graph_add_edge(struct graph_node *from,
  76                                   struct graph_node *to);
  77
  78 /**
  79  * Removes a directed edge between two nodes.
  80  *
  81  * @param[in] from
  82  * @param[in] to
  83  */
  84 void graph_remove_edge(struct graph_node *from, struct graph_node *to);
  85
  86 /**
  87  * Deletes a graph.
  88  * Calls graph_delete_node on each node before freeing the graph struct itself.
  89  *
  90  * @param graph the graph to delete
  91  */
  92 void graph_delete_graph(struct graph *graph);
  93
  94 #endif /* _ZEBRA_COMMAND_GRAPH_H */