xref: /netbsd-src/external/bsd/tmux/dist/hyperlinks.c (revision 890b6d91a44b7fcb2dfbcbc1e93463086e462d2d)
1 /* $OpenBSD$ */
2 
3 /*
4  * Copyright (c) 2021 Will <author@will.party>
5  * Copyright (c) 2022 Jeff Chiang <pobomp@gmail.com>
6  *
7  * Permission to use, copy, modify, and distribute this software for any
8  * purpose with or without fee is hereby granted, provided that the above
9  * copyright notice and this permission notice appear in all copies.
10  *
11  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
12  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
13  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
14  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
15  * WHATSOEVER RESULTING FROM LOSS OF MIND, USE, DATA OR PROFITS, WHETHER
16  * IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
17  * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
18  */
19 
20 #include <sys/types.h>
21 
22 #include <stdlib.h>
23 #include <string.h>
24 
25 #include "tmux.h"
26 
27 /*
28  * OSC 8 hyperlinks, described at:
29  *
30  *     https://gist.github.com/egmontkob/eb114294efbcd5adb1944c9f3cb5feda
31  *
32  * Each hyperlink and ID combination is assigned a number ("inner" in this
33  * file) which is stored in an extended grid cell and maps into a tree here.
34  *
35  * Each URI has one inner number and one external ID (which tmux uses to send
36  * the hyperlink to the terminal) and one internal ID (which is received from
37  * the sending application inside tmux).
38  *
39  * Anonymous hyperlinks are each unique and are not reused even if they have
40  * the same URI (terminals will not want to tie them together).
41  */
42 
43 #define MAX_HYPERLINKS 5000
44 
45 static long long hyperlinks_next_external_id = 1;
46 static u_int global_hyperlinks_count;
47 
48 struct hyperlinks_uri {
49 	struct hyperlinks	*tree;
50 
51 	u_int			 inner;
52 	const char		*internal_id;
53 	const char		*external_id;
54 	const char		*uri;
55 
56 	TAILQ_ENTRY(hyperlinks_uri) list_entry;
57 	RB_ENTRY(hyperlinks_uri)    by_inner_entry;
58 	RB_ENTRY(hyperlinks_uri)    by_uri_entry; /* by internal ID and URI */
59 };
60 RB_HEAD(hyperlinks_by_uri_tree, hyperlinks_uri);
61 RB_HEAD(hyperlinks_by_inner_tree, hyperlinks_uri);
62 
63 TAILQ_HEAD(hyperlinks_list, hyperlinks_uri);
64 static struct hyperlinks_list global_hyperlinks =
65     TAILQ_HEAD_INITIALIZER(global_hyperlinks);
66 
67 struct hyperlinks {
68 	u_int				next_inner;
69 	struct hyperlinks_by_inner_tree	by_inner;
70 	struct hyperlinks_by_uri_tree	by_uri;
71 	u_int				references;
72 };
73 
74 static int
75 hyperlinks_by_uri_cmp(struct hyperlinks_uri *left, struct hyperlinks_uri *right)
76 {
77 	int	r;
78 
79 	if (*left->internal_id == '\0' || *right->internal_id == '\0') {
80 		/*
81 		 * If both URIs are anonymous, use the inner for comparison so
82 		 * that they do not match even if the URI is the same - each
83 		 * anonymous URI should be unique.
84 		 */
85 		if (*left->internal_id != '\0')
86 			return (-1);
87 		if (*right->internal_id != '\0')
88 			return (1);
89 		return (left->inner - right->inner);
90 	}
91 
92 	r = strcmp(left->internal_id, right->internal_id);
93 	if (r != 0)
94 		return (r);
95 	return (strcmp(left->uri, right->uri));
96 }
97 RB_PROTOTYPE_STATIC(hyperlinks_by_uri_tree, hyperlinks_uri, by_uri_entry,
98     hyperlinks_by_uri_cmp);
99 RB_GENERATE_STATIC(hyperlinks_by_uri_tree, hyperlinks_uri, by_uri_entry,
100     hyperlinks_by_uri_cmp);
101 
102 static int
103 hyperlinks_by_inner_cmp(struct hyperlinks_uri *left,
104     struct hyperlinks_uri *right)
105 {
106 	return (left->inner - right->inner);
107 }
108 RB_PROTOTYPE_STATIC(hyperlinks_by_inner_tree, hyperlinks_uri, by_inner_entry,
109     hyperlinks_by_inner_cmp);
110 RB_GENERATE_STATIC(hyperlinks_by_inner_tree, hyperlinks_uri, by_inner_entry,
111     hyperlinks_by_inner_cmp);
112 
113 /* Remove a hyperlink. */
114 static void
115 hyperlinks_remove(struct hyperlinks_uri *hlu)
116 {
117 	struct hyperlinks	*hl = hlu->tree;
118 
119 	TAILQ_REMOVE(&global_hyperlinks, hlu, list_entry);
120 	global_hyperlinks_count--;
121 
122 	RB_REMOVE(hyperlinks_by_inner_tree, &hl->by_inner, hlu);
123 	RB_REMOVE(hyperlinks_by_uri_tree, &hl->by_uri, hlu);
124 
125 	free(__UNCONST(hlu->internal_id));
126 	free(__UNCONST(hlu->external_id));
127 	free(__UNCONST(hlu->uri));
128 	free(hlu);
129 }
130 
131 /* Store a new hyperlink or return if it already exists. */
132 u_int
133 hyperlinks_put(struct hyperlinks *hl, const char *uri_in,
134     const char *internal_id_in)
135 {
136 	struct hyperlinks_uri	 find, *hlu;
137 	char			*uri, *internal_id, *external_id;
138 
139 	/*
140 	 * Anonymous URI are stored with an empty internal ID and the tree
141 	 * comparator will make sure they never match each other (so each
142 	 * anonymous URI is unique).
143 	 */
144 	if (internal_id_in == NULL)
145 		internal_id_in = "";
146 
147 	utf8_stravis(&uri, uri_in, VIS_OCTAL|VIS_CSTYLE);
148 	utf8_stravis(&internal_id, internal_id_in, VIS_OCTAL|VIS_CSTYLE);
149 
150 	if (*internal_id_in != '\0') {
151 		find.uri = uri;
152 		find.internal_id = internal_id;
153 
154 		hlu = RB_FIND(hyperlinks_by_uri_tree, &hl->by_uri, &find);
155 		if (hlu != NULL) {
156 			free (uri);
157 			free (internal_id);
158 			return (hlu->inner);
159 		}
160 	}
161 	xasprintf(&external_id, "tmux%llX", hyperlinks_next_external_id++);
162 
163 	hlu = xcalloc(1, sizeof *hlu);
164 	hlu->inner = hl->next_inner++;
165 	hlu->internal_id = internal_id;
166 	hlu->external_id = external_id;
167 	hlu->uri = uri;
168 	hlu->tree = hl;
169 	RB_INSERT(hyperlinks_by_uri_tree, &hl->by_uri, hlu);
170 	RB_INSERT(hyperlinks_by_inner_tree, &hl->by_inner, hlu);
171 
172 	TAILQ_INSERT_TAIL(&global_hyperlinks, hlu, list_entry);
173 	if (++global_hyperlinks_count == MAX_HYPERLINKS)
174 		hyperlinks_remove(TAILQ_FIRST(&global_hyperlinks));
175 
176 	return (hlu->inner);
177 }
178 
179 /* Get hyperlink by inner number. */
180 int
181 hyperlinks_get(struct hyperlinks *hl, u_int inner, const char **uri_out,
182     const char **internal_id_out, const char **external_id_out)
183 {
184 	struct hyperlinks_uri	find, *hlu;
185 
186 	find.inner = inner;
187 
188 	hlu = RB_FIND(hyperlinks_by_inner_tree, &hl->by_inner, &find);
189 	if (hlu == NULL)
190 		return (0);
191 	if (internal_id_out != NULL)
192 		*internal_id_out = hlu->internal_id;
193 	if (external_id_out != NULL)
194 		*external_id_out = hlu->external_id;
195 	*uri_out = hlu->uri;
196 	return (1);
197 }
198 
199 /* Initialize hyperlink set. */
200 struct hyperlinks *
201 hyperlinks_init(void)
202 {
203 	struct hyperlinks	*hl;
204 
205 	hl = xcalloc(1, sizeof *hl);
206 	hl->next_inner = 1;
207 	RB_INIT(&hl->by_uri);
208 	RB_INIT(&hl->by_inner);
209 	hl->references = 1;
210 	return (hl);
211 }
212 
213 /* Copy hyperlink set. */
214 struct hyperlinks *
215 hyperlinks_copy(struct hyperlinks *hl)
216 {
217 	hl->references++;
218 	return (hl);
219 }
220 
221 /* Free all hyperlinks but not the set itself. */
222 void
223 hyperlinks_reset(struct hyperlinks *hl)
224 {
225 	struct hyperlinks_uri	*hlu, *hlu1;
226 
227 	RB_FOREACH_SAFE(hlu, hyperlinks_by_inner_tree, &hl->by_inner, hlu1)
228 		hyperlinks_remove(hlu);
229 }
230 
231 /* Free hyperlink set. */
232 void
233 hyperlinks_free(struct hyperlinks *hl)
234 {
235 	if (--hl->references == 0) {
236 		hyperlinks_reset(hl);
237 		free(hl);
238 	}
239 }
240