vis-marks: greatly simplify jumplist management

As far as I could tell from the code this was supposed to be a
fixed size LRU cache of sets of selection regions. The structure
had a maximum size member but it was never set or used.
Furthermore there was some very complicated management of 2
parallel sets of regions. Instead of that mess just treat the
cache as a circular buffer.

Note that this is really not that useful at the moment. While the
selection regions are saved and restored the editor mode is not.
Therefore the selection is visible but not in any way usable. That
will be fixed in the next commit.

1 files changed, 27 insertions, 81 deletions

diff --git a/vis-marks.c b/vis-marks.c
index 6d63877..a44e727 100644
--- a/vis-marks.c
+++ b/vis-marks.c
@@ -104,115 +104,61 @@ void vis_mark_set(Win *win, enum VisMark id, Array *sel) {
 	mark_set(win, mark_from(win->vis, id), sel);
 }
 
-void marklist_init(MarkList *list, size_t max) {
-	Array mark;
-	mark_init(&mark);
-	array_init_sized(&list->prev, sizeof(Array));
-	array_reserve(&list->prev, max);
-	array_add(&list->prev, &mark);
-	array_init_sized(&list->next, sizeof(Array));
-	array_reserve(&list->next, max);
-}
-
-void marklist_release(MarkList *list) {
-	for (size_t i = 0, len = list->prev.len; i < len; i++)
-		array_release(array_get(&list->prev, i));
-	array_release(&list->prev);
-	for (size_t i = 0, len = list->next.len; i < len; i++)
-		array_release(array_get(&list->next, i));
-	array_release(&list->next);
-}
-
-static bool marklist_push(Win *win, MarkList *list, Array *sel) {
-	Array *top = array_peek(&list->prev);
-	if (top) {
+void vis_jumplist_save(Vis *vis)
+{
+	Win   *win = vis->win;
+	Array  sel = view_selections_get_all(&win->view);
+	Array *top = win->mark_set_lru + (win->mark_set_lru_cursor % LENGTH(win->mark_set_lru));
+	bool done = false;
+	if (top->len) {
 		Array top_sel = mark_get(win, top);
-		bool eq = vis_mark_equal(&top_sel, sel);
+		/* NOTE: avoid pushing duplicate sets into cache */
+		done = vis_mark_equal(&top_sel, &sel);
 		array_release(&top_sel);
-		if (eq)
-			return true;
 	}
 
-	for (size_t i = 0, len = list->next.len; i < len; i++)
-		array_release(array_get(&list->next, i));
-	array_clear(&list->next);
-	Array arr;
-	mark_init(&arr);
-	if (list->prev.len >= list->prev.count) {
-		Array *tmp = array_get(&list->prev, 0);
-		arr = *tmp;
-		array_remove(&list->prev, 0);
+	if (!done) {
+		Array *arr = win->mark_set_lru + (win->mark_set_lru_cursor++ % LENGTH(win->mark_set_lru));
+		mark_set(win, arr, &sel);
 	}
-	mark_set(win, &arr, sel);
-	return array_push(&list->prev, &arr);
-}
 
-bool vis_jumplist_save(Vis *vis) {
-	Array sel = view_selections_get_all(&vis->win->view);
-	bool ret = marklist_push(vis->win, &vis->win->jumplist, &sel);
 	array_release(&sel);
-	return ret;
 }
 
-static bool marklist_prev(Win *win, MarkList *list) {
+void vis_jumplist_prev(Vis *vis)
+{
+	Win  *win  = vis->win;
 	View *view = &win->view;
-	bool restore = false;
 	Array cur = view_selections_get_all(view);
 	bool anchored = view_selections_primary_get(view)->anchored;
-	Array *top = array_peek(&list->prev);
-	if (!top)
-		goto out;
-	Array top_sel = mark_get(win, top);
-	restore = !vis_mark_equal(&top_sel, &cur);
-	if (restore)
-		view_selections_set_all(view, &top_sel, anchored);
-	array_release(&top_sel);
-	if (restore)
-		goto out;
-
-	while (list->prev.len > 1) {
-		Array *prev = array_pop(&list->prev);
-		array_push(&list->next, prev);
-		prev = array_peek(&list->prev);
-		Array sel = mark_get(win, prev);
-		restore = sel.len > 0;
-		if (restore)
+
+	Array *top = win->mark_set_lru + (--win->mark_set_lru_cursor % LENGTH(win->mark_set_lru));
+	if (top->len) {
+		Array sel = mark_get(win, top);
+		if (!vis_mark_equal(top, &cur)) {
 			view_selections_set_all(view, &sel, anchored);
+		}
 		array_release(&sel);
-		if (restore)
-			goto out;
 	}
-out:
 	array_release(&cur);
-	return restore;
 }
 
-static bool marklist_next(Win *win, MarkList *list) {
+void vis_jumplist_next(Vis *vis)
+{
+	Win  *win  = vis->win;
 	View *view = &win->view;
 	bool anchored = view_selections_primary_get(view)->anchored;
-	for (;;) {
-		Array *next = array_pop(&list->next);
-		if (!next)
-			return false;
+	Array *next = win->mark_set_lru + (win->mark_set_lru_cursor++ % LENGTH(win->mark_set_lru));
+
+	if (next->len) {
 		Array sel = mark_get(win, next);
 		if (sel.len > 0) {
 			view_selections_set_all(view, &sel, anchored);
 			array_release(&sel);
-			array_push(&list->prev, next);
-			return true;
 		}
-		array_release(next);
 	}
 }
 
-bool vis_jumplist_prev(Vis *vis) {
-	return marklist_prev(vis->win, &vis->win->jumplist);
-}
-
-bool vis_jumplist_next(Vis *vis) {
-	return marklist_next(vis->win, &vis->win->jumplist);
-}
-
 enum VisMark vis_mark_from(Vis *vis, char mark) {
 	if (mark >= 'a' && mark <= 'z')
 		return VIS_MARK_a + mark - 'a';