hyperlinks.c

   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((void *)hlu->internal_id);
 126         free((void *)hlu->external_id);
 127         free((void *)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 }