tui: add live-adjustable refresh interval (#20)

Signed-off-by: chang-ning <spiderpower02@gmail.com>

Author: crazyguitar

src/main.rs

@@ -5,7 +5,7 @@ mod stat;
 mod tui;
 
 use std::io;
-use std::time::{Duration, Instant};
+use std::time::Instant;
 
 fn run_tui() -> io::Result<()> {
     crossterm::terminal::enable_raw_mode()?;
@@ -16,11 +16,10 @@ fn run_tui() -> io::Result<()> {
     let mut terminal = ratatui::Terminal::new(backend)?;
     let mut app = tui::app::App::new();
 
-    let interval = Duration::from_secs(1);
-    let mut last_refresh = Instant::now() - interval;
+    let mut last_refresh = Instant::now() - app.refresh_interval;
 
     loop {
-        if last_refresh.elapsed() >= interval {
+        if last_refresh.elapsed() >= app.refresh_interval {
             app.refresh_stats();
             last_refresh = Instant::now();
         }

src/tui/app.rs

@@ -2,7 +2,7 @@ use super::theme::Theme;
 use crate::net::{self, IfStats, NetRate};
 use crate::stat::{self, PortStat};
 use std::collections::VecDeque;
-use std::time::Instant;
+use std::time::{Duration, Instant};
 
 use std::collections::HashMap;
 
@@ -77,6 +77,13 @@ impl TableColumn {
 
 pub const BAR_WIDTH: usize = 12;
 
+/// Stats refresh interval bounds (seconds). Floor matches the 200ms event-poll
+/// so input stays responsive even at the fastest setting.
+pub const REFRESH_DEFAULT_SECS: f64 = 1.0;
+const REFRESH_MIN_SECS: f64 = 0.2;
+const REFRESH_MAX_SECS: f64 = 10.0;
+const REFRESH_STEP_SECS: f64 = 0.5;
+
 /// All counter names that can be added as extra columns.
 pub const EXTRA_COUNTERS: &[&str] = &[
     "send_bytes",
@@ -274,7 +281,6 @@ pub struct App {
     prev_stats: Vec<PortStat>,
     prev_ifstats: Vec<IfStats>,
     prev_time: Instant,
-    pub elapsed: f64,
     pub rolling_avg: RollingAvgState,
     pub show_rolling_avg: bool,
     pub show_window_input: bool,
@@ -285,6 +291,7 @@ pub struct App {
     pub h_scroll: usize,
     pub h_scroll_max: usize,
     pub table_offset: usize,
+    pub refresh_interval: Duration,
     cached_display: Vec<PortThroughput>,
 }
 
@@ -346,7 +353,6 @@ impl App {
             prev_stats: stats,
             prev_ifstats: ifstats,
             prev_time: Instant::now(),
-            elapsed: 1.0,
             rolling_avg: RollingAvgState::new(ROLLING_AVG_DEFAULT_WINDOW),
             show_rolling_avg: false,
             show_window_input: false,
@@ -357,6 +363,7 @@ impl App {
             h_scroll: 0,
             h_scroll_max: 0,
             table_offset: 0,
+            refresh_interval: Duration::from_secs_f64(REFRESH_DEFAULT_SECS),
             cached_display: Vec::new(),
         }
     }
@@ -370,7 +377,6 @@ impl App {
         if elapsed < 0.1 {
             return;
         }
-        self.elapsed = elapsed;
         self.throughputs = compute_throughputs(&self.prev_stats, &curr, elapsed);
         self.prev_stats = curr;
 
@@ -474,6 +480,18 @@ impl App {
         }
     }
 
+    /// Slow the refresh by one step (longer interval), clamped to the max.
+    pub fn increase_refresh_interval(&mut self) {
+        let secs = (self.refresh_interval.as_secs_f64() + REFRESH_STEP_SECS).min(REFRESH_MAX_SECS);
+        self.refresh_interval = Duration::from_secs_f64(secs);
+    }
+
+    /// Speed the refresh up by one step (shorter interval), clamped to the min.
+    pub fn decrease_refresh_interval(&mut self) {
+        let secs = (self.refresh_interval.as_secs_f64() - REFRESH_STEP_SECS).max(REFRESH_MIN_SECS);
+        self.refresh_interval = Duration::from_secs_f64(secs);
+    }
+
     pub fn open_window_input(&mut self) {
         self.window_input_buf = self.rolling_avg.window_secs.to_string();
         self.show_window_input = true;

src/tui/events.rs

@@ -55,6 +55,8 @@ fn handle_normal_mode(app: &mut App, key: KeyCode) {
         KeyCode::Char('a') => app.toggle_rolling_avg(),
         KeyCode::Char('+') | KeyCode::Char('=') => app.increase_avg_window(),
         KeyCode::Char('-') => app.decrease_avg_window(),
+        KeyCode::Char('>') => app.increase_refresh_interval(),
+        KeyCode::Char('<') => app.decrease_refresh_interval(),
         KeyCode::Char('w') => app.open_window_input(),
         KeyCode::Char('c') => app.open_column_picker(),
         _ => {}
@@ -71,6 +73,8 @@ fn handle_detail_mode(app: &mut App, key: KeyCode) {
         KeyCode::Char('a') => app.toggle_rolling_avg(),
         KeyCode::Char('+') | KeyCode::Char('=') => app.increase_avg_window(),
         KeyCode::Char('-') => app.decrease_avg_window(),
+        KeyCode::Char('>') => app.increase_refresh_interval(),
+        KeyCode::Char('<') => app.decrease_refresh_interval(),
         KeyCode::Char('w') => app.open_window_input(),
         KeyCode::Char('c') => app.open_column_picker(),
         _ => {}

src/tui/ui.rs

@@ -25,6 +25,7 @@ const HELP_KEYS: &[(&str, &str)] = &[
     ("+ / =", "Increase avg window (+1s)"),
     ("-", "Decrease avg window (-1s)"),
     ("w", "Set avg window (custom)"),
+    ("< / >", "Refresh faster / slower (±0.5s)"),
     ("c", "Configure columns"),
     ("h", "Toggle this help"),
     ("q", "Quit"),
@@ -122,6 +123,12 @@ fn header_line2(app: &App, tc: &ThemeColors) -> Line<'static> {
         String::new()
     };
 
+    let status = format!(
+        " │ refresh: {:.1}s │ theme: {}",
+        app.refresh_interval.as_secs_f64(),
+        app.theme.label()
+    );
+
     Line::from(vec![
         styled(
             &format!(" RDMA: {} device{}", n, if n == 1 { "" } else { "s" }),
@@ -134,11 +141,7 @@ fn header_line2(app: &App, tc: &ThemeColors) -> Line<'static> {
         styled(&format!("{:.2} Gbps", total_rx), tc.good, false),
         styled(" │ Drops: ", tc.muted, false),
         styled(&format!("{:.0}/s", total_drops), drop_color, false),
-        styled(
-            &format!(" │ {:.1}s │ theme: {}", app.elapsed, app.theme.label()),
-            tc.muted,
-            false,
-        ),
+        styled(&status, tc.muted, false),
         styled(&avg_label, tc.accent, false),
     ])
 }
@@ -655,19 +658,17 @@ fn draw_status_bar(frame: &mut Frame, app: &App, area: Rect, tc: &ThemeColors) {
     } else {
         "  a:avg  w:set".to_string()
     };
-    let line = Line::from(vec![
-        Span::styled(
-            " NORMAL ",
-            Style::default()
-                .fg(tc.status_fg)
-                .bg(tc.status_bg)
-                .add_modifier(Modifier::BOLD),
-        ),
-        Span::styled(
-            format!(" ↑↓/jk:nav  {}  t:theme  h:help  q:quit{}", hint, avg_hint),
-            Style::default().fg(tc.muted),
-        ),
-    ]);
+    let keys = format!(
+        " ↑↓/jk:nav  {}  t:theme  <>:refresh  h:help  q:quit{}",
+        hint, avg_hint
+    );
+    let mode_style = Style::default()
+        .fg(tc.status_fg)
+        .bg(tc.status_bg)
+        .add_modifier(Modifier::BOLD);
+    let mode = Span::styled(" NORMAL ", mode_style);
+    let keys = Span::styled(keys, Style::default().fg(tc.muted));
+    let line = Line::from(vec![mode, keys]);
     frame.render_widget(Paragraph::new(line), area);
 }