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 };
  72
  73 static int
  74 hyperlinks_by_uri_cmp(struct hyperlinks_uri *left, struct hyperlinks_uri *right)
  75 {
  76         int     r;
  77
  78         if (*left->internal_id == '\0' || *right->internal_id == '\0') {
  79                 /*
  80                  * If both URIs are anonymous, use the inner for comparison so
  81                  * that they do not match even if the URI is the same - each
  82                  * anonymous URI should be unique.
  83                  */
  84                 if (*left->internal_id != '\0')
  85                         return (-1);
  86                 if (*right->internal_id != '\0')
  87                         return (1);
  88                 return (left->inner - right->inner);
  89         }
  90
  91         r = strcmp(left->internal_id, right->internal_id);
  92         if (r != 0)
  93                 return (r);
  94         return (strcmp(left->uri, right->uri));
  95 }
  96 RB_PROTOTYPE_STATIC(hyperlinks_by_uri_tree, hyperlinks_uri, by_uri_entry,
  97     hyperlinks_by_uri_cmp);
  98 RB_GENERATE_STATIC(hyperlinks_by_uri_tree, hyperlinks_uri, by_uri_entry,
  99     hyperlinks_by_uri_cmp);
 100
 101 static int
 102 hyperlinks_by_inner_cmp(struct hyperlinks_uri *left,
 103     struct hyperlinks_uri *right)
 104 {
 105         return (left->inner - right->inner);
 106 }
 107 RB_PROTOTYPE_STATIC(hyperlinks_by_inner_tree, hyperlinks_uri, by_inner_entry,
 108     hyperlinks_by_inner_cmp);
 109 RB_GENERATE_STATIC(hyperlinks_by_inner_tree, hyperlinks_uri, by_inner_entry,
 110     hyperlinks_by_inner_cmp);
 111
 112 /* Remove a hyperlink. */
 113 static void
 114 hyperlinks_remove(struct hyperlinks_uri *hlu)
 115 {
 116         struct hyperlinks       *hl = hlu->tree;
 117
 118         TAILQ_REMOVE(&global_hyperlinks, hlu, list_entry);
 119         global_hyperlinks_count--;
 120
 121         RB_REMOVE(hyperlinks_by_inner_tree, &hl->by_inner, hlu);
 122         RB_REMOVE(hyperlinks_by_uri_tree, &hl->by_uri, hlu);
 123
 124         free((void *)hlu->internal_id);
 125         free((void *)hlu->external_id);
 126         free((void *)hlu->uri);
 127         free(hlu);
 128 }
 129
 130 /* Store a new hyperlink or return if it already exists. */
 131 u_int
 132 hyperlinks_put(struct hyperlinks *hl, const char *uri_in,
 133     const char *internal_id_in)
 134 {
 135         struct hyperlinks_uri    find, *hlu;
 136         char                    *uri, *internal_id, *external_id;
 137
 138         /*
 139          * Anonymous URI are stored with an empty internal ID and the tree
 140          * comparator will make sure they never match each other (so each
 141          * anonymous URI is unique).
 142          */
 143         if (internal_id_in == NULL)
 144                 internal_id_in = "";
 145
 146         utf8_stravis(&uri, uri_in, VIS_OCTAL|VIS_CSTYLE);
 147         utf8_stravis(&internal_id, internal_id_in, VIS_OCTAL|VIS_CSTYLE);
 148
 149         if (*internal_id_in != '\0') {
 150                 find.uri = uri;
 151                 find.internal_id = internal_id;
 152
 153                 hlu = RB_FIND(hyperlinks_by_uri_tree, &hl->by_uri, &find);
 154                 if (hlu != NULL) {
 155                         free (uri);
 156                         free (internal_id);
 157                         return (hlu->inner);
 158                 }
 159         }
 160         xasprintf(&external_id, "tmux%llX", hyperlinks_next_external_id++);
 161
 162         hlu = xcalloc(1, sizeof *hlu);
 163         hlu->inner = hl->next_inner++;
 164         hlu->internal_id = internal_id;
 165         hlu->external_id = external_id;
 166         hlu->uri = uri;
 167         hlu->tree = hl;
 168         RB_INSERT(hyperlinks_by_uri_tree, &hl->by_uri, hlu);
 169         RB_INSERT(hyperlinks_by_inner_tree, &hl->by_inner, hlu);
 170
 171         TAILQ_INSERT_TAIL(&global_hyperlinks, hlu, list_entry);
 172         if (++global_hyperlinks_count == MAX_HYPERLINKS)
 173                 hyperlinks_remove(TAILQ_FIRST(&global_hyperlinks));
 174
 175         return (hlu->inner);
 176 }
 177
 178 /* Get hyperlink by inner number. */
 179 int
 180 hyperlinks_get(struct hyperlinks *hl, u_int inner, const char **uri_out,
 181     const char **internal_id_out, const char **external_id_out)
 182 {
 183         struct hyperlinks_uri   find, *hlu;
 184
 185         find.inner = inner;
 186
 187         hlu = RB_FIND(hyperlinks_by_inner_tree, &hl->by_inner, &find);
 188         if (hlu == NULL)
 189                 return (0);
 190         if (internal_id_out != NULL)
 191                 *internal_id_out = hlu->internal_id;
 192         if (external_id_out != NULL)
 193                 *external_id_out = hlu->external_id;
 194         *uri_out = hlu->uri;
 195         return (1);
 196 }
 197
 198 /* Initialize hyperlink set. */
 199 struct hyperlinks *
 200 hyperlinks_init(void)
 201 {
 202         struct hyperlinks       *hl;
 203
 204         hl = xcalloc(1, sizeof *hl);
 205         hl->next_inner = 1;
 206         RB_INIT(&hl->by_uri);
 207         RB_INIT(&hl->by_inner);
 208         return (hl);
 209 }
 210
 211 /* Free all hyperlinks but not the set itself. */
 212 void
 213 hyperlinks_reset(struct hyperlinks *hl)
 214 {
 215         struct hyperlinks_uri   *hlu, *hlu1;
 216
 217         RB_FOREACH_SAFE(hlu, hyperlinks_by_inner_tree, &hl->by_inner, hlu1)
 218                 hyperlinks_remove(hlu);
 219 }
 220
 221 /* Free hyperlink set. */
 222 void
 223 hyperlinks_free(struct hyperlinks *hl)
 224 {
 225         hyperlinks_reset(hl);
 226         free(hl);
 227 }