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
  20  * along with GNU Zebra; see the file COPYING.  If not, write to the Free
  21  * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
  22  * 02111-1307, USA.
  23  */
  24
  25 #ifndef _ZEBRA_COMMAND_GRAPH_H
  26 #define _ZEBRA_COMMAND_GRAPH_H
  27
  28 #include "vector.h"
  29
  30 struct graph
  31 {
  32   vector nodes;
  33 };
  34
  35 struct graph_node
  36 {
  37   vector from;                  // nodes which have edges to this node
  38   vector to;                    // nodes which this node has edges to
  39
  40   void *data;                   // node data
  41   void (*del) (void *data);     // deletion callback
  42 };
  43
  44 struct graph *
  45 graph_new (void);
  46
  47 /**
  48  * Creates a new node.
  49  *
  50  * @struct graph the graph this node exists in
  51  * @param[in] data this node's data
  52  * @param[in] del data deletion callback
  53  * @return the new node
  54  */
  55 struct graph_node *
  56 graph_new_node (struct graph *graph, void *data, void (*del) (void*));
  57
  58 /**
  59  * Deletes a node.
  60  *
  61  * Before deletion, this function removes all edges to and from this node from
  62  * any neighbor nodes.
  63  *
  64  * If *data and *del are non-null, the following call is made:
  65  *   (*node->del) (node->data);
  66  *
  67  * @param[in] graph the graph this node belongs to
  68  * @param[out] node pointer to node to delete
  69  */
  70 void
  71 graph_delete_node (struct graph *graph, struct graph_node *node);
  72
  73 /**
  74  * Makes a directed edge between two nodes.
  75  *
  76  * @param[in] from
  77  * @param[in] to
  78  * @return to
  79  */
  80 struct graph_node *
  81 graph_add_edge (struct graph_node *from, struct graph_node *to);
  82
  83 /**
  84  * Removes a directed edge between two nodes.
  85  *
  86  * @param[in] from
  87  * @param[in] to
  88  */
  89 void
  90 graph_remove_edge (struct graph_node *from, struct graph_node *to);
  91
  92 /**
  93  * Deletes a graph.
  94  * Calls graph_delete_node on each node before freeing the graph struct itself.
  95  *
  96  * @param graph the graph to delete
  97  */
  98 void
  99 graph_delete_graph (struct graph *graph);
 100
 101 #endif /* _ZEBRA_COMMAND_GRAPH_H */