Add support for OSC 8 hyperlinks (a VTE extension now supported by other

terminals such as iTerm2). Originally written by me then extended and
completed by first Will Noble and later Jeff Chiang. GitHub issues 911,
2621, 2890, 3240.

1 files changed, 225 insertions, 0 deletions

diff --git a/usr.bin/tmux/hyperlinks.c b/usr.bin/tmux/hyperlinks.c
new file mode 100644
index 00000000000..6e336ecf70b
--- /dev/null
+++ b/usr.bin/tmux/hyperlinks.c
@@ -0,0 +1,225 @@
+/* $OpenBSD: hyperlinks.c,v 1.1 2022/06/30 09:55:53 nicm Exp $ */
+
+/*
+ * Copyright (c) 2021 Will <author@will.party>
+ * Copyright (c) 2022 Jeff Chiang <pobomp@gmail.com>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF MIND, USE, DATA OR PROFITS, WHETHER
+ * IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
+ * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <sys/types.h>
+
+#include <stdlib.h>
+#include <string.h>
+#include <vis.h>
+
+#include "tmux.h"
+
+/*
+ * OSC 8 hyperlinks, described at:
+ *
+ *     https://gist.github.com/egmontkob/eb114294efbcd5adb1944c9f3cb5feda
+ *
+ * Each hyperlink and ID combination is assigned a number ("inner" in this
+ * file) which is stored in an extended grid cell and maps into a tree here.
+ *
+ * Each URI has one inner number and one external ID (which tmux uses to send
+ * the hyperlink to the terminal) and one internal ID (which is received from
+ * the sending application inside tmux).
+ *
+ * Anonymous hyperlinks are each unique and are not reused even if they have
+ * the same URI (terminals will not want to tie them together).
+ */
+
+#define MAX_HYPERLINKS 5000
+
+static uint64_t hyperlinks_next_external_id = 1;
+static u_int global_hyperlinks_count;
+
+struct hyperlinks_uri {
+	struct hyperlinks	*tree;
+
+	u_int			 inner;
+	const char		*internal_id;
+	const char		*external_id;
+	const char		*uri;
+
+	TAILQ_ENTRY(hyperlinks_uri) list_entry;
+	RB_ENTRY(hyperlinks_uri)    by_inner_entry;
+	RB_ENTRY(hyperlinks_uri)    by_uri_entry; /* by internal ID and URI */
+};
+RB_HEAD(hyperlinks_by_uri_tree, hyperlinks_uri);
+RB_HEAD(hyperlinks_by_inner_tree, hyperlinks_uri);
+
+TAILQ_HEAD(hyperlinks_list, hyperlinks_uri);
+static struct hyperlinks_list global_hyperlinks =
+    TAILQ_HEAD_INITIALIZER(global_hyperlinks);
+
+struct hyperlinks {
+	u_int				next_inner;
+	struct hyperlinks_by_inner_tree	by_inner;
+	struct hyperlinks_by_uri_tree	by_uri;
+};
+
+static int
+hyperlinks_by_uri_cmp(struct hyperlinks_uri *left, struct hyperlinks_uri *right)
+{
+	int	r;
+
+	if (*left->internal_id == '\0' || *right->internal_id == '\0') {
+		/*
+		 * If both URIs are anonymous, use the inner for comparison so
+		 * that they do not match even if the URI is the same - each
+		 * anonymous URI should be unique.
+		 */
+		if (*left->internal_id != '\0')
+			return (-1);
+		if (*right->internal_id != '\0')
+			return (1);
+		return (left->inner - right->inner);
+	}
+
+	r = strcmp(left->internal_id, right->internal_id);
+	if (r != 0)
+		return (r);
+	return (strcmp(left->uri, right->uri));
+}
+RB_PROTOTYPE_STATIC(hyperlinks_by_uri_tree, hyperlinks_uri, by_uri_entry,
+    hyperlinks_by_uri_cmp);
+RB_GENERATE_STATIC(hyperlinks_by_uri_tree, hyperlinks_uri, by_uri_entry,
+    hyperlinks_by_uri_cmp);
+
+static int
+hyperlinks_by_inner_cmp(struct hyperlinks_uri *left,
+    struct hyperlinks_uri *right)
+{
+	return (left->inner - right->inner);
+}
+RB_PROTOTYPE_STATIC(hyperlinks_by_inner_tree, hyperlinks_uri, by_inner_entry,
+    hyperlinks_by_inner_cmp);
+RB_GENERATE_STATIC(hyperlinks_by_inner_tree, hyperlinks_uri, by_inner_entry,
+    hyperlinks_by_inner_cmp);
+
+/* Remove a hyperlink. */
+static void
+hyperlinks_remove(struct hyperlinks_uri *hlu)
+{
+	struct hyperlinks	*hl = hlu->tree;
+
+	TAILQ_REMOVE(&global_hyperlinks, hlu, list_entry);
+	global_hyperlinks_count--;
+
+	RB_REMOVE(hyperlinks_by_inner_tree, &hl->by_inner, hlu);
+	RB_REMOVE(hyperlinks_by_uri_tree, &hl->by_uri, hlu);
+
+	free((void *)hlu->internal_id);
+	free((void *)hlu->external_id);
+	free((void *)hlu->uri);
+	free(hlu);
+}
+
+/* Store a new hyperlink or return if it already exists. */
+u_int
+hyperlinks_put(struct hyperlinks *hl, const char *uri_in,
+    const char *internal_id_in)
+{
+	struct hyperlinks_uri	 find, *hlu;
+	char			*uri, *internal_id, *external_id;
+
+	/*
+	 * Anonymous URI are stored with an empty internal ID and the tree
+	 * comparator will make sure they never match each other (so each
+	 * anonymous URI is unique).
+	 */
+	if (internal_id_in == NULL)
+		internal_id_in = "";
+
+	utf8_stravis(&uri, uri_in, VIS_OCTAL|VIS_CSTYLE);
+	utf8_stravis(&internal_id, internal_id_in, VIS_OCTAL|VIS_CSTYLE);
+
+	if (*internal_id_in != '\0') {
+		find.uri = uri;
+		find.internal_id = internal_id;
+
+		hlu = RB_FIND(hyperlinks_by_uri_tree, &hl->by_uri, &find);
+		if (hlu != NULL) {
+			free (uri);
+			free (internal_id);
+			return (hlu->inner);
+		}
+	}
+	xasprintf(&external_id, "tmux%llX", hyperlinks_next_external_id++);
+
+	hlu = xcalloc(1, sizeof *hlu);
+	hlu->inner = hl->next_inner++;
+	hlu->internal_id = internal_id;
+	hlu->external_id = external_id;
+	hlu->uri = uri;
+	hlu->tree = hl;
+	RB_INSERT(hyperlinks_by_uri_tree, &hl->by_uri, hlu);
+	RB_INSERT(hyperlinks_by_inner_tree, &hl->by_inner, hlu);
+
+	TAILQ_INSERT_TAIL(&global_hyperlinks, hlu, list_entry);
+	if (++global_hyperlinks_count == MAX_HYPERLINKS)
+		hyperlinks_remove(TAILQ_FIRST(&global_hyperlinks));
+
+	return (hlu->inner);
+}
+
+/* Get hyperlink by inner number. */
+int
+hyperlinks_get(struct hyperlinks *hl, u_int inner, const char **uri_out,
+    const char **external_id_out)
+{
+	struct hyperlinks_uri	find, *hlu;
+
+	find.inner = inner;
+
+	hlu = RB_FIND(hyperlinks_by_inner_tree, &hl->by_inner, &find);
+	if (hlu == NULL)
+		return (0);
+	*external_id_out = hlu->external_id;
+	*uri_out = hlu->uri;
+	return (1);
+}
+
+/* Initialize hyperlink set. */
+struct hyperlinks *
+hyperlinks_init(void)
+{
+	struct hyperlinks	*hl;
+
+	hl = xcalloc(1, sizeof *hl);
+	hl->next_inner = 1;
+	RB_INIT(&hl->by_uri);
+	RB_INIT(&hl->by_inner);
+	return (hl);
+}
+
+/* Free all hyperlinks but not the set itself. */
+void
+hyperlinks_reset(struct hyperlinks *hl)
+{
+	struct hyperlinks_uri	*hlu, *hlu1;
+
+	RB_FOREACH_SAFE(hlu, hyperlinks_by_inner_tree, &hl->by_inner, hlu1)
+		hyperlinks_remove(hlu);
+}
+
+/* Free hyperlink set. */
+void
+hyperlinks_free(struct hyperlinks *hl)
+{
+	hyperlinks_reset(hl);
+	free(hl);
+}