]>
Commit | Line | Data |
---|---|---|
1 | // SPDX-License-Identifier: GPL-2.0-or-later | |
2 | /* | |
3 | * Graph data structure. | |
4 | * | |
5 | * -- | |
6 | * Copyright (C) 2016 Cumulus Networks, Inc. | |
7 | */ | |
8 | ||
9 | #ifndef _ZEBRA_COMMAND_GRAPH_H | |
10 | #define _ZEBRA_COMMAND_GRAPH_H | |
11 | ||
12 | #include <stdbool.h> | |
13 | #include "vector.h" | |
14 | #include "buffer.h" | |
15 | ||
16 | #ifdef __cplusplus | |
17 | extern "C" { | |
18 | #endif | |
19 | ||
20 | struct graph { | |
21 | vector nodes; | |
22 | }; | |
23 | ||
24 | struct graph_node { | |
25 | vector from; // nodes which have edges to this node | |
26 | vector to; // nodes which this node has edges to | |
27 | ||
28 | void *data; // node data | |
29 | void (*del)(void *data); // deletion callback | |
30 | }; | |
31 | ||
32 | struct graph *graph_new(void); | |
33 | ||
34 | /** | |
35 | * Creates a new node. | |
36 | * | |
37 | * @struct graph the graph this node exists in | |
38 | * @param[in] data this node's data | |
39 | * @param[in] del data deletion callback | |
40 | * @return the new node | |
41 | */ | |
42 | struct graph_node *graph_new_node(struct graph *graph, void *data, | |
43 | void (*del)(void *)); | |
44 | ||
45 | /** | |
46 | * Deletes a node. | |
47 | * | |
48 | * Before deletion, this function removes all edges to and from this node from | |
49 | * any neighbor nodes. | |
50 | * | |
51 | * If *data and *del are non-null, the following call is made: | |
52 | * (*node->del) (node->data); | |
53 | * | |
54 | * @param[in] graph the graph this node belongs to | |
55 | * @param[out] node pointer to node to delete | |
56 | */ | |
57 | void graph_delete_node(struct graph *graph, struct graph_node *node); | |
58 | ||
59 | /** | |
60 | * Makes a directed edge between two nodes. | |
61 | * | |
62 | * @param[in] from | |
63 | * @param[in] to | |
64 | * @return to | |
65 | */ | |
66 | struct graph_node *graph_add_edge(struct graph_node *from, | |
67 | struct graph_node *to); | |
68 | ||
69 | /** | |
70 | * Removes a directed edge between two nodes. | |
71 | * | |
72 | * @param[in] from | |
73 | * @param[in] to | |
74 | */ | |
75 | void graph_remove_edge(struct graph_node *from, struct graph_node *to); | |
76 | ||
77 | /** | |
78 | * Deletes a graph. | |
79 | * Calls graph_delete_node on each node before freeing the graph struct itself. | |
80 | * | |
81 | * @param graph the graph to delete | |
82 | */ | |
83 | void graph_delete_graph(struct graph *graph); | |
84 | ||
85 | /* | |
86 | * Finds a node in the graph. | |
87 | * | |
88 | * @param[in] graph the graph to search in | |
89 | * @param[in] data the data to key off | |
90 | * @return the first graph node whose data pointer matches `data` | |
91 | */ | |
92 | struct graph_node *graph_find_node(struct graph *graph, void *data); | |
93 | ||
94 | ||
95 | /* | |
96 | * Determines whether two nodes have a directed edge between them. | |
97 | * | |
98 | * @param from | |
99 | * @param to | |
100 | * @return whether there is a directed edge from `from` to `to`. | |
101 | */ | |
102 | bool graph_has_edge(struct graph_node *from, struct graph_node *to); | |
103 | ||
104 | /* | |
105 | * Depth-first search. | |
106 | * | |
107 | * Performs a depth-first traversal of the given graph, visiting each node | |
108 | * exactly once and calling the user-provided callback for each visit. | |
109 | * | |
110 | * @param graph the graph to operate on | |
111 | * @param start the node to take as the root | |
112 | * @param dfs_cb callback called for each node visited in the traversal | |
113 | * @param arg argument to provide to dfs_cb | |
114 | */ | |
115 | void graph_dfs(struct graph *graph, struct graph_node *start, | |
116 | void (*dfs_cb)(struct graph_node *, void *), void *arg); | |
117 | ||
118 | #ifndef BUILDING_CLIPPY | |
119 | /* | |
120 | * Clippy relies on a small subset of sources in lib/, but it cannot link | |
121 | * libfrr since clippy itself is required to build libfrr. Instead it directly | |
122 | * includes the sources it needs. One of these is the command graph | |
123 | * implementation, which wraps this graph implementation. Since we need to use | |
124 | * the buffer.[ch] sources here, which indirectly rely on most of libfrr, we | |
125 | * have to ignore them when compiling clippy to avoid build dependency issues. | |
126 | * | |
127 | * TODO: Fix clippy build. | |
128 | */ | |
129 | ||
130 | /* | |
131 | * Default node printer for use with graph_dump_dot. | |
132 | * | |
133 | * @param gn the node to print | |
134 | * @param buf the buffer to print into | |
135 | */ | |
136 | void graph_dump_dot_default_print_cb(struct graph_node *gn, struct buffer *buf); | |
137 | ||
138 | /* | |
139 | * Prints a graph in the DOT language. | |
140 | * | |
141 | * The generated output is produced from a depth-first traversal of the graph. | |
142 | * | |
143 | * @param graph the graph to print | |
144 | * @param start the node to take as the root | |
145 | * @param pcb callback called for each node in the traversal that should | |
146 | * print the node in the DOT language. Passing NULL for this argument | |
147 | * will use the default printer. See graph_dump_dot_default_print_cb for | |
148 | * an example. | |
149 | * @return representation of graph in DOT language, allocated with MTYPE_TMP. | |
150 | * Caller is responsible for freeing this string. | |
151 | */ | |
152 | char *graph_dump_dot(struct graph *graph, struct graph_node *start, | |
153 | void (*pcb)(struct graph_node *, struct buffer *buf)); | |
154 | ||
155 | #endif /* BUILDING_CLIPPY */ | |
156 | ||
157 | #ifdef __cplusplus | |
158 | } | |
159 | #endif | |
160 | ||
161 | #endif /* _ZEBRA_COMMAND_GRAPH_H */ |