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 {
  31   vector nodes;
  32 };
  33
  34 struct graph_node
  35 {
  36   vector from;                  // nodes which have edges to this node
  37   vector to;                    // nodes which this node has edges to
  38
  39   void *data;                   // node data
  40   void (*del) (void *data);     // deletion callback
  41 };
  42
  43 struct graph *
  44 graph_new (void);
  45
  46 /**
  47  * Creates a new node.
  48  *
  49  * @struct graph the graph this node exists in
  50  * @param[in] data this node's data
  51  * @param[in] del data deletion callback
  52  * @return the new node
  53  */
  54 struct graph_node *
  55 graph_new_node (struct graph *graph, void *data, void (*del) (void*));
  56
  57 /**
  58  * Deletes a node.
  59  *
  60  * Before deletion, this function removes all edges to and from this node from
  61  * any neighbor nodes.
  62  *
  63  * If *data and *del are non-null, the following call is made:
  64  *   (*node->del) (node->data);
  65  *
  66  * @param[in] graph the graph this node belongs to
  67  * @param[out] node pointer to node to delete
  68  */
  69 void
  70 graph_delete_node (struct graph *graph, struct graph_node *node);
  71
  72 /**
  73  * Makes a directed edge between two nodes.
  74  *
  75  * @param[in] from
  76  * @param[in] to
  77  * @return to
  78  */
  79 struct graph_node *
  80 graph_add_edge (struct graph_node *from, struct graph_node *to);
  81
  82 /**
  83  * Removes a directed edge between two nodes.
  84  *
  85  * @param[in] from
  86  * @param[in] to
  87  */
  88 void
  89 graph_remove_edge (struct graph_node *from, struct graph_node *to);
  90
  91 /**
  92  * Deletes a graph.
  93  * Calls graph_delete_node on each node before freeing the graph struct itself.
  94  *
  95  * @param graph the graph to delete
  96  */
  97 void
  98 graph_delete_graph (struct graph *graph);
  99
 100 #endif /* _ZEBRA_COMMAND_GRAPH_H */