Some optimizsations in TUI (#3325)

* Do not allocate String for static status, use Cow instead, eg we allocate "Running" string at every refresh
* Use static dispatch for Views instead of Box<dyn View>
* Update only the current view
* Simplify Listener trait

src/bin/tui/logs.rs

@@ -28,9 +28,9 @@ use std::collections::VecDeque;
 pub struct TUILogsView;
 
 impl TUILogsView {
-	pub fn create() -> Box<dyn View> {
+	pub fn create() -> impl View {
 		let logs_view = ResizedView::with_full_screen(LogBufferView::new(200).with_name("logs"));
-		Box::new(logs_view.with_name(VIEW_LOGS))
+		logs_view.with_name(VIEW_LOGS)
 	}
 
 	pub fn update(c: &mut Cursive, entry: LogEntry) {

src/bin/tui/menu.rs

@@ -29,7 +29,7 @@ use crate::tui::constants::{
 	VIEW_PEER_SYNC, VIEW_VERSION,
 };
 
-pub fn create() -> Box<dyn View> {
+pub fn create() -> impl View {
 	let mut main_menu = SelectView::new().h_align(HAlign::Left).with_name(MAIN_MENU);
 	main_menu
 		.get_mut()
@@ -83,5 +83,5 @@ pub fn create() -> Box<dyn View> {
 		.child(TextView::new("Enter     : Select"))
 		.child(TextView::new("Esc       : Back  "))
 		.child(TextView::new("Q         : Quit  "));
-	Box::new(main_menu)
+	main_menu
 }

src/bin/tui/mining.rs

@@ -165,9 +165,9 @@ impl TableViewItem<DiffColumn> for DiffBlock {
 /// Mining status view
 pub struct TUIMiningView;
 
-impl TUIStatusListener for TUIMiningView {
+impl TUIMiningView {
 	/// Create the mining view
-	fn create() -> Box<dyn View> {
+	pub fn create() -> impl View {
 		let devices_button = Button::new_raw("Mining Server Status", |s| {
 			let _ = s.call_on_name("mining_stack_view", |sv: &mut StackView| {
 				let pos = sv.find_layer_from_name("mining_device_view").unwrap();
@@ -307,9 +307,11 @@ impl TUIStatusListener for TUIMiningView {
 			let _ = c.focus_name(MAIN_MENU);
 		});
 
-		Box::new(mining_view.with_name(VIEW_MINING))
+		mining_view.with_name(VIEW_MINING)
+	}
 }
 
+impl TUIStatusListener for TUIMiningView {
 	/// update
 	fn update(c: &mut Cursive, stats: &ServerStats) {
 		c.call_on_name("diff_cur_height", |t: &mut TextView| {

src/bin/tui/peers.rs

@@ -121,8 +121,8 @@ impl TableViewItem<PeerColumn> for PeerStats {
 
 pub struct TUIPeerView;
 
-impl TUIStatusListener for TUIPeerView {
-	fn create() -> Box<dyn View> {
+impl TUIPeerView {
+	pub fn create() -> impl View {
 		let table_view = TableView::<PeerStats, PeerColumn>::new()
 			.column(PeerColumn::Address, "Address", |c| c.width_percent(16))
 			.column(PeerColumn::State, "State", |c| c.width_percent(8))
@@ -159,9 +159,11 @@ impl TUIStatusListener for TUIPeerView {
 				let _ = c.focus_name(MAIN_MENU);
 			});
 
-		Box::new(peer_status_view)
+		peer_status_view
+	}
 }
 
+impl TUIStatusListener for TUIPeerView {
 	fn update(c: &mut Cursive, stats: &ServerStats) {
 		let lp = stats
 			.peer_stats

src/bin/tui/status.rs

@@ -20,6 +20,7 @@ use cursive::traits::Identifiable;
 use cursive::view::View;
 use cursive::views::{LinearLayout, ResizedView, TextView};
 use cursive::Cursive;
+use std::borrow::Cow;
 
 use crate::tui::constants::VIEW_BASIC_STATUS;
 use crate::tui::types::TUIStatusListener;
@@ -32,11 +33,11 @@ const NANO_TO_MILLIS: f64 = 1.0 / 1_000_000.0;
 pub struct TUIStatusView;
 
 impl TUIStatusView {
-	fn update_sync_status(sync_status: SyncStatus) -> String {
+	pub fn update_sync_status(sync_status: SyncStatus) -> Cow<'static, str> {
 		match sync_status {
-			SyncStatus::Initial => "Initializing".to_string(),
-			SyncStatus::NoSync => "Running".to_string(),
-			SyncStatus::AwaitingPeers(_) => "Waiting for peers".to_string(),
+			SyncStatus::Initial => Cow::Borrowed("Initializing"),
+			SyncStatus::NoSync => Cow::Borrowed("Running"),
+			SyncStatus::AwaitingPeers(_) => Cow::Borrowed("Waiting for peers"),
 			SyncStatus::HeaderSync {
 				current_height,
 				highest_height,
@@ -46,7 +47,7 @@ impl TUIStatusView {
 				} else {
 					current_height * 100 / highest_height
 				};
-				format!("Sync step 1/7: Downloading headers: {}%", percent)
+				Cow::Owned(format!("Sync step 1/7: Downloading headers: {}%", percent))
 			}
 			SyncStatus::TxHashsetDownload(stat) => {
 				if stat.total_size > 0 {
@@ -55,23 +56,23 @@ impl TUIStatusView {
 					let fin = Utc::now().timestamp_nanos();
 					let dur_ms = (fin - start) as f64 * NANO_TO_MILLIS;
 
-					format!("Sync step 2/7: Downloading {}(MB) chain state for state sync: {}% at {:.1?}(kB/s)",
+					Cow::Owned(format!("Sync step 2/7: Downloading {}(MB) chain state for state sync: {}% at {:.1?}(kB/s)",
 							stat.total_size / 1_000_000,
 							percent,
 							if dur_ms > 1.0f64 { stat.downloaded_size.saturating_sub(stat.prev_downloaded_size) as f64 / dur_ms as f64 } else { 0f64 },
-					)
+					))
 				} else {
 					let start = stat.start_time.timestamp_millis();
 					let fin = Utc::now().timestamp_millis();
 					let dur_secs = (fin - start) / 1000;
 
-					format!("Sync step 2/7: Downloading chain state for state sync. Waiting remote peer to start: {}s",
+					Cow::Owned(format!("Sync step 2/7: Downloading chain state for state sync. Waiting remote peer to start: {}s",
 							dur_secs,
-					)
+					))
 				}
 			}
 			SyncStatus::TxHashsetSetup => {
-				"Sync step 3/7: Preparing chain state for validation".to_string()
+				Cow::Borrowed("Sync step 3/7: Preparing chain state for validation")
 			}
 			SyncStatus::TxHashsetRangeProofsValidation {
 				rproofs,
@@ -82,10 +83,10 @@ impl TUIStatusView {
 				} else {
 					0
 				};
-				format!(
+				Cow::Owned(format!(
 					"Sync step 4/7: Validating chain state - range proofs: {}%",
 					r_percent
-				)
+				))
 			}
 			SyncStatus::TxHashsetKernelsValidation {
 				kernels,
@@ -96,16 +97,16 @@ impl TUIStatusView {
 				} else {
 					0
 				};
-				format!(
+				Cow::Owned(format!(
 					"Sync step 5/7: Validating chain state - kernels: {}%",
 					k_percent
-				)
+				))
 			}
 			SyncStatus::TxHashsetSave => {
-				"Sync step 6/7: Finalizing chain state for state sync".to_string()
+				Cow::Borrowed("Sync step 6/7: Finalizing chain state for state sync")
 			}
 			SyncStatus::TxHashsetDone => {
-				"Sync step 6/7: Finalized chain state for state sync".to_string()
+				Cow::Borrowed("Sync step 6/7: Finalized chain state for state sync")
 			}
 			SyncStatus::BodySync {
 				current_height,
@@ -116,16 +117,14 @@ impl TUIStatusView {
 				} else {
 					current_height * 100 / highest_height
 				};
-				format!("Sync step 7/7: Downloading blocks: {}%", percent)
-			}
-			SyncStatus::Shutdown => "Shutting down, closing connections".to_string(),
+				Cow::Owned(format!("Sync step 7/7: Downloading blocks: {}%", percent))
 			}
+			SyncStatus::Shutdown => Cow::Borrowed("Shutting down, closing connections"),
 		}
 	}
 
-impl TUIStatusListener for TUIStatusView {
 	/// Create basic status view
-	fn create() -> Box<dyn View> {
+	pub fn create() -> impl View {
 		let basic_status_view = ResizedView::with_full_screen(
 			LinearLayout::new(Orientation::Vertical)
 				.child(
@@ -232,9 +231,11 @@ impl TUIStatusListener for TUIStatusView {
 						.child(TextView::new("  ").with_name("basic_network_info")),
 				), //.child(logo_view)
 		);
-		Box::new(basic_status_view.with_name(VIEW_BASIC_STATUS))
+		basic_status_view.with_name(VIEW_BASIC_STATUS)
+	}
 }
 
+impl TUIStatusListener for TUIStatusView {
 	fn update(c: &mut Cursive, stats: &ServerStats) {
 		let basic_status = TUIStatusView::update_sync_status(stats.sync_status);
 

src/bin/tui/types.rs

@@ -15,7 +15,6 @@
 //! Types specific to the UI module
 
 use crate::servers::ServerStats;
-use cursive::view::View;
 use cursive::Cursive;
 
 /// Main message struct to communicate between the UI and
@@ -28,8 +27,6 @@ pub enum UIMessage {
 /// and updates itself
 
 pub trait TUIStatusListener {
-	/// create the view, to return to the main UI controller
-	fn create() -> Box<dyn View>;
 	/// Update according to status update contents
 	fn update(c: &mut Cursive, stats: &ServerStats);
 }

src/bin/tui/ui.rs

@@ -26,14 +26,17 @@ use cursive::theme::{BaseColor, BorderStyle, Color, Theme};
 use cursive::traits::Boxable;
 use cursive::traits::Identifiable;
 use cursive::utils::markup::StyledString;
-use cursive::views::{BoxedView, CircularFocus, Dialog, LinearLayout, Panel, StackView, TextView};
+use cursive::views::{
+	CircularFocus, Dialog, LinearLayout, Panel, SelectView, StackView, TextView, ViewRef,
+};
 use cursive::Cursive;
 use std::sync::mpsc;
 use std::{thread, time};
 
+use super::constants::MAIN_MENU;
 use crate::built_info;
 use crate::servers::Server;
-use crate::tui::constants::ROOT_STACK;
+use crate::tui::constants::{ROOT_STACK, VIEW_BASIC_STATUS, VIEW_MINING, VIEW_PEER_SYNC};
 use crate::tui::types::{TUIStatusListener, UIMessage};
 use crate::tui::{logs, menu, mining, peers, status, version};
 use grin_util::logger::LogEntry;
@@ -106,7 +109,7 @@ impl UI {
 			.child(Panel::new(TextView::new(title_string).full_width()))
 			.child(
 				LinearLayout::new(Orientation::Horizontal)
-					.child(Panel::new(BoxedView::new(main_menu)))
+					.child(Panel::new(main_menu))
 					.child(Panel::new(root_stack)),
 			);
 
@@ -144,12 +147,17 @@ impl UI {
 
 		// Process any pending UI messages
 		while let Some(message) = self.ui_rx.try_iter().next() {
+			let menu: ViewRef<SelectView<&str>> = self.cursive.find_name(MAIN_MENU).unwrap();
+			if let Some(selection) = menu.selection() {
 				match message {
-				UIMessage::UpdateStatus(update) => {
-					status::TUIStatusView::update(&mut self.cursive, &update);
-					mining::TUIMiningView::update(&mut self.cursive, &update);
-					peers::TUIPeerView::update(&mut self.cursive, &update);
-					version::TUIVersionView::update(&mut self.cursive, &update);
+					UIMessage::UpdateStatus(update) => match *selection {
+						VIEW_BASIC_STATUS => {
+							status::TUIStatusView::update(&mut self.cursive, &update)
+						}
+						VIEW_MINING => mining::TUIMiningView::update(&mut self.cursive, &update),
+						VIEW_PEER_SYNC => peers::TUIPeerView::update(&mut self.cursive, &update),
+						_ => {}
+					},
 				}
 			}
 		}

src/bin/tui/version.rs

@@ -18,19 +18,16 @@ use cursive::direction::Orientation;
 use cursive::traits::Identifiable;
 use cursive::view::View;
 use cursive::views::{LinearLayout, ResizedView, TextView};
-use cursive::Cursive;
 
 use crate::tui::constants::VIEW_VERSION;
-use crate::tui::types::TUIStatusListener;
 
 use crate::info_strings;
-use crate::servers::ServerStats;
 
 pub struct TUIVersionView;
 
-impl TUIStatusListener for TUIVersionView {
+impl TUIVersionView {
 	/// Create basic status view
-	fn create() -> Box<dyn View> {
+	pub fn create() -> Box<dyn View> {
 		let (basic_info, detailed_info) = info_strings();
 		let basic_status_view = ResizedView::with_full_screen(
 			LinearLayout::new(Orientation::Vertical)
@@ -40,7 +37,4 @@ impl TUIStatusListener for TUIVersionView {
 		);
 		Box::new(basic_status_view.with_name(VIEW_VERSION))
 	}
-
-	/// update
-	fn update(_c: &mut Cursive, _stats: &ServerStats) {}
 }