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16d7c050 QY |
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 | * | |
896014f4 DL |
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 | |
16d7c050 QY |
22 | */ |
23 | ||
24 | #ifndef _ZEBRA_COMMAND_GRAPH_H | |
25 | #define _ZEBRA_COMMAND_GRAPH_H | |
26 | ||
9428e089 | 27 | #include <stdbool.h> |
16d7c050 | 28 | #include "vector.h" |
58f8a9ec | 29 | #include "buffer.h" |
16d7c050 | 30 | |
5e244469 RW |
31 | #ifdef __cplusplus |
32 | extern "C" { | |
33 | #endif | |
34 | ||
d62a17ae | 35 | struct graph { |
36 | vector nodes; | |
1eb5e8dc | 37 | }; |
16d7c050 | 38 | |
d62a17ae | 39 | struct graph_node { |
40 | vector from; // nodes which have edges to this node | |
41 | vector to; // nodes which this node has edges to | |
16d7c050 | 42 | |
d62a17ae | 43 | void *data; // node data |
44 | void (*del)(void *data); // deletion callback | |
16d7c050 QY |
45 | }; |
46 | ||
d62a17ae | 47 | struct graph *graph_new(void); |
1eb5e8dc | 48 | |
16d7c050 QY |
49 | /** |
50 | * Creates a new node. | |
51 | * | |
52 | * @struct graph the graph this node exists in | |
53 | * @param[in] data this node's data | |
54 | * @param[in] del data deletion callback | |
55 | * @return the new node | |
56 | */ | |
d62a17ae | 57 | struct graph_node *graph_new_node(struct graph *graph, void *data, |
58 | void (*del)(void *)); | |
16d7c050 QY |
59 | |
60 | /** | |
61 | * Deletes a node. | |
62 | * | |
63 | * Before deletion, this function removes all edges to and from this node from | |
64 | * any neighbor nodes. | |
65 | * | |
16d7c050 QY |
66 | * If *data and *del are non-null, the following call is made: |
67 | * (*node->del) (node->data); | |
68 | * | |
ba06a3a0 | 69 | * @param[in] graph the graph this node belongs to |
16d7c050 QY |
70 | * @param[out] node pointer to node to delete |
71 | */ | |
d62a17ae | 72 | void graph_delete_node(struct graph *graph, struct graph_node *node); |
16d7c050 QY |
73 | |
74 | /** | |
75 | * Makes a directed edge between two nodes. | |
76 | * | |
77 | * @param[in] from | |
78 | * @param[in] to | |
79 | * @return to | |
80 | */ | |
d62a17ae | 81 | struct graph_node *graph_add_edge(struct graph_node *from, |
82 | struct graph_node *to); | |
16d7c050 QY |
83 | |
84 | /** | |
ba06a3a0 | 85 | * Removes a directed edge between two nodes. |
16d7c050 | 86 | * |
ba06a3a0 QY |
87 | * @param[in] from |
88 | * @param[in] to | |
89 | */ | |
d62a17ae | 90 | void graph_remove_edge(struct graph_node *from, struct graph_node *to); |
ba06a3a0 QY |
91 | |
92 | /** | |
93 | * Deletes a graph. | |
16d7c050 QY |
94 | * Calls graph_delete_node on each node before freeing the graph struct itself. |
95 | * | |
96 | * @param graph the graph to delete | |
97 | */ | |
d62a17ae | 98 | void graph_delete_graph(struct graph *graph); |
16d7c050 | 99 | |
9428e089 QY |
100 | /* |
101 | * Finds a node in the graph. | |
102 | * | |
103 | * @param[in] graph the graph to search in | |
104 | * @param[in] data the data to key off | |
105 | * @return the first graph node whose data pointer matches `data` | |
106 | */ | |
107 | struct graph_node *graph_find_node(struct graph *graph, void *data); | |
108 | ||
109 | ||
110 | /* | |
111 | * Determines whether two nodes have a directed edge between them. | |
112 | * | |
113 | * @param from | |
114 | * @param to | |
115 | * @return whether there is a directed edge from `from` to `to`. | |
116 | */ | |
117 | bool graph_has_edge(struct graph_node *from, struct graph_node *to); | |
118 | ||
58f8a9ec QY |
119 | /* |
120 | * Depth-first search. | |
121 | * | |
122 | * Performs a depth-first traversal of the given graph, visiting each node | |
123 | * exactly once and calling the user-provided callback for each visit. | |
124 | * | |
125 | * @param graph the graph to operate on | |
126 | * @param start the node to take as the root | |
127 | * @param dfs_cb callback called for each node visited in the traversal | |
128 | * @param arg argument to provide to dfs_cb | |
129 | */ | |
130 | void graph_dfs(struct graph *graph, struct graph_node *start, | |
131 | void (*dfs_cb)(struct graph_node *, void *), void *arg); | |
132 | ||
133 | #ifndef BUILDING_CLIPPY | |
134 | /* | |
135 | * Clippy relies on a small subset of sources in lib/, but it cannot link | |
136 | * libfrr since clippy itself is required to build libfrr. Instead it directly | |
137 | * includes the sources it needs. One of these is the command graph | |
138 | * implementation, which wraps this graph implementation. Since we need to use | |
139 | * the buffer.[ch] sources here, which indirectly rely on most of libfrr, we | |
140 | * have to ignore them when compiling clippy to avoid build dependency issues. | |
141 | * | |
142 | * TODO: Fix clippy build. | |
143 | */ | |
144 | ||
145 | /* | |
146 | * Default node printer for use with graph_dump_dot. | |
147 | * | |
148 | * @param gn the node to print | |
149 | * @param buf the buffer to print into | |
150 | */ | |
151 | void graph_dump_dot_default_print_cb(struct graph_node *gn, struct buffer *buf); | |
152 | ||
153 | /* | |
154 | * Prints a graph in the DOT language. | |
155 | * | |
156 | * The generated output is produced from a depth-first traversal of the graph. | |
157 | * | |
158 | * @param graph the graph to print | |
159 | * @param start the node to take as the root | |
160 | * @param pcb callback called for each node in the traversal that should | |
161 | * print the node in the DOT language. Passing NULL for this argument | |
162 | * will use the default printer. See graph_dump_dot_default_print_cb for | |
163 | * an example. | |
164 | * @return representation of graph in DOT language, allocated with MTYPE_TMP. | |
165 | * Caller is responsible for freeing this string. | |
166 | */ | |
167 | char *graph_dump_dot(struct graph *graph, struct graph_node *start, | |
168 | void (*pcb)(struct graph_node *, struct buffer *buf)); | |
169 | ||
170 | #endif /* BUILDING_CLIPPY */ | |
5e244469 RW |
171 | |
172 | #ifdef __cplusplus | |
173 | } | |
174 | #endif | |
175 | ||
16d7c050 | 176 | #endif /* _ZEBRA_COMMAND_GRAPH_H */ |