fix(core): compact parser raw outputs over certain size

Author: AgentEnder

packages/nx/src/native/pseudo_terminal/pseudo_terminal.rs

@@ -91,7 +91,17 @@ impl PseudoTerminal {
         let quiet_clone = quiet.clone();
         let running_clone = running.clone();
 
-        let parser = Arc::new(RwLock::new(Parser::new(h, w, 10000)));
+        // Scrollback size matches PtyInstance::SCROLLBACK_SIZE (1000 rows).
+        // Larger values make resize reparse and all_contents_formatted() more
+        // expensive, which blocks the parser write lock and starves rendering.
+        const SCROLLBACK_SIZE: usize = 1000;
+        // When raw output exceeds this threshold, compact the parser to prevent
+        // unbounded Vec growth. Without this, extend_from_slice() eventually
+        // triggers multi-hundred-millisecond reallocs under the write lock,
+        // causing the TUI to hang progressively worse as output accumulates.
+        const MAX_RAW_OUTPUT_BYTES: usize = 5 * 1024 * 1024; // 5 MB
+
+        let parser = Arc::new(RwLock::new(Parser::new(h, w, SCROLLBACK_SIZE)));
         let parser_clone = parser.clone();
         let stdout_tx_clone = stdout_tx.clone();
         std::thread::spawn(move || {
@@ -111,7 +121,21 @@ impl PseudoTerminal {
                     debug!("Read {} bytes", len);
                     if is_within_nx_tui {
                         trace!("Processing data via vt100 for use in tui");
-                        parser_clone.write().process(&buf[..len]);
+                        let mut parser = parser_clone.write();
+                        parser.process(&buf[..len]);
+                        // Compact when raw output grows too large. Replays
+                        // the formatted screen state (bounded by SCROLLBACK_SIZE)
+                        // through a fresh parser, keeping raw_output small.
+                        if parser.get_raw_output().len() > MAX_RAW_OUTPUT_BYTES {
+                            let screen = parser.screen();
+                            let (rows, cols) = screen.size();
+                            let formatted = screen.all_contents_formatted();
+                            let scrollback = screen.scrollback();
+                            let mut compacted = Parser::new(rows, cols, SCROLLBACK_SIZE);
+                            compacted.process(&formatted);
+                            compacted.screen_mut().set_scrollback(scrollback);
+                            *parser = compacted;
+                        }
                     }
 
                     if !quiet {