perf(screen): Store line count as an attr in Screen

src/core/ev_handler.rs

@@ -33,7 +33,11 @@ pub fn handle_event(
     match ev {
         Command::SetData(text) => {
             p.screen.orig_text = text;
-            command_queue.push_back(Command::FormatRedrawDisplay);
+            p.format_lines();
+            p.screen.line_count = p.screen.orig_text.lines().count();
+            if !p.running.lock().is_uninitialized() {
+                display::draw_full(&mut out, p)?;
+            }
         }
         Command::UserInput(InputEvent::Exit) => {
             p.exit();
@@ -253,7 +257,10 @@ pub fn handle_event(
             } else {
                 p.message = Some(text.to_string());
             }
-            command_queue.push_back(Command::FormatRedrawPrompt);
+            p.format_prompt();
+            if !p.running.lock().is_uninitialized() {
+                display::write_prompt(out, &p.displayed_prompt, p.rows.try_into().unwrap())?;
+            }
         }
         Command::SetLineNumbers(ln) => {
             p.line_numbers = ln;

src/screen.rs

@@ -4,6 +4,7 @@
 pub struct Screen {
     pub(crate) orig_text: String,
     pub(crate) formatted_lines: Vec<String>,
+    pub(crate) line_count: usize,
 }
 
 impl Screen {
@@ -16,8 +17,8 @@ impl Screen {
     ///
     /// NOTE: This operation might be expensive if the text data is too large.
     #[must_use]
-    pub fn line_count(&self) -> usize {
-        self.orig_text.lines().count()
+    pub fn get_line_count(&self) -> usize {
+        self.line_count
     }
     /// Returns all the text within the bounds
     pub(crate) fn get_formatted_lines_with_bounds(&self, start: usize, end: usize) -> &[String] {
@@ -36,6 +37,7 @@ impl Default for Screen {
         Self {
             orig_text: String::with_capacity(100 * 1024),
             formatted_lines: Vec::with_capacity(500 * 1024),
+            line_count: 0,
         }
     }
 }

src/state.rs

@@ -259,6 +259,7 @@ impl PagerState {
             #[cfg(feature = "search")]
             &self.search_state.search_term,
         );
+
         #[cfg(feature = "search")]
         {
             self.search_state.search_idx = format_result.append_search_idx;
@@ -384,12 +385,19 @@ impl PagerState {
         // * Push text
         // * Add number of lines we added to the original line count
         // * Count the digits again
-        let old_lc = self.screen.orig_text.lines().count();
+        let old_lc = self.screen.get_line_count();
         let old_lc_dgts = minus_core::digits(old_lc);
 
         self.screen.orig_text.push_str(text);
 
-        let new_lc = old_lc + text.lines().count();
+        let new_lc = old_lc
+            + text
+                .lines()
+                .count()
+                // NOTE: Reduce one if we are attaching to the last line, otherwise the attaching
+                // line will be counted twice.
+                .saturating_sub(if append { 0 } else { 1 });
+        self.screen.line_count = new_lc;
         let new_lc_dgts = minus_core::digits(new_lc);
 
         let append_opts = text::FormatOpts {