Cache layout and performance fixes

examples/prototype.rs

@@ -82,7 +82,7 @@ struct App {
     progress: u16,
     data: Vec<u64>,
     data2: Vec<(f64, f64)>,
-    window: [f64; 2],
+    data3: Vec<(f64, f64)>,
     colors: [Color; 2],
     color_index: usize,
 }
@@ -109,6 +109,7 @@ fn main() {
 
     let mut rand_signal = RandomSignal::new(Range::new(0, 100));
     let mut sin_signal = SinSignal::new(4.0, 20.0);
+    let mut sin_signal2 = SinSignal::new(2.0, 10.0);
 
     let mut app = App {
         name: String::from("Test app"),
@@ -119,7 +120,7 @@ fn main() {
         progress: 0,
         data: rand_signal.clone().take(100).collect(),
         data2: sin_signal.clone().take(100).collect(),
-        window: [0.0, 100.0],
+        data3: sin_signal2.clone().take(100).collect(),
         colors: [Color::Magenta, Color::Red],
         color_index: 0,
     };
@@ -141,7 +142,7 @@ fn main() {
         let tx = tx.clone();
         loop {
             tx.send(Event::Tick).unwrap();
-            thread::sleep(time::Duration::from_millis(500));
+            thread::sleep(time::Duration::from_millis(1000));
         }
     });
 
@@ -184,8 +185,8 @@ fn main() {
                 app.data.pop();
                 app.data2.remove(0);
                 app.data2.push(sin_signal.next().unwrap());
-                app.window[0] += 1.0;
-                app.window[1] += 1.0;
+                app.data3.remove(0);
+                app.data3.push(sin_signal2.next().unwrap());
                 app.selected += 1;
                 if app.selected >= app.items.len() {
                     app.selected = 0;
@@ -206,14 +207,14 @@ fn draw(t: &mut Terminal, app: &App) {
         .direction(Direction::Vertical)
         .alignment(Alignment::Left)
         .chunks(&[Size::Fixed(7), Size::Min(5), Size::Fixed(3)])
-        .render(&Terminal::size().unwrap(), |chunks| {
+        .render(t, &Terminal::size().unwrap(), |t, chunks| {
             Block::default().borders(border::ALL).title("Graphs").render(&chunks[0], t);
             Group::default()
                 .direction(Direction::Vertical)
                 .alignment(Alignment::Left)
                 .margin(1)
                 .chunks(&[Size::Fixed(2), Size::Fixed(3)])
-                .render(&chunks[0], |chunks| {
+                .render(t, &chunks[0], |t, chunks| {
                     Gauge::default()
                         .block(Block::default().title("Gauge:"))
                         .bg(Color::Yellow)
@@ -234,7 +235,7 @@ fn draw(t: &mut Terminal, app: &App) {
                 .direction(Direction::Horizontal)
                 .alignment(Alignment::Left)
                 .chunks(&sizes)
-                .render(&chunks[1], |chunks| {
+                .render(t, &chunks[1], |t, chunks| {
                     List::default()
                         .block(Block::default().borders(border::ALL).title("List"))
                         .render(&chunks[0], t);
@@ -243,9 +244,10 @@ fn draw(t: &mut Terminal, app: &App) {
                             .block(Block::default()
                                 .borders(border::ALL)
                                 .title("Chart"))
-                            .x_axis(Axis::default().title("X").bounds(app.window))
+                            .x_axis(Axis::default().title("X").bounds([0.0, 100.0]))
                             .y_axis(Axis::default().title("Y").bounds([0.0, 40.0]))
-                            .datasets(&[Dataset::default().color(Color::Cyan).data(&app.data2)])
+                            .datasets(&[Dataset::default().color(Color::Cyan).data(&app.data2),
+                                        Dataset::default().color(Color::Yellow).data(&app.data3)])
                             .render(&chunks[1], t);
                     }
                 });

src/layout.rs

@@ -6,7 +6,10 @@ use cassowary::WeightedRelation::*;
 use cassowary::strength::{WEAK, REQUIRED};
 
 use buffer::Buffer;
+use terminal::Terminal;
+use util::hash;
 
+#[derive(Hash)]
 pub enum Alignment {
     Top,
     Left,
@@ -15,12 +18,13 @@ pub enum Alignment {
     Right,
 }
 
+#[derive(Hash)]
 pub enum Direction {
     Horizontal,
     Vertical,
 }
 
-#[derive(Debug, Clone, Copy)]
+#[derive(Debug, Clone, Copy, Hash, PartialEq, Eq)]
 pub struct Rect {
     pub x: u16,
     pub y: u16,
@@ -235,6 +239,7 @@ impl Element {
     }
 }
 
+#[derive(Hash)]
 pub struct Group {
     direction: Direction,
     alignment: Alignment,
@@ -273,14 +278,26 @@ impl Group {
         self.chunks = Vec::from(chunks);
         self
     }
-    pub fn render<F>(&self, area: &Rect, mut f: F)
-        where F: FnMut(&[Rect])
+    pub fn render<F>(&self, t: &mut Terminal, area: &Rect, mut f: F)
+        where F: FnMut(&mut Terminal, &[Rect])
     {
-        let chunks = split(area,
-                           &self.direction,
-                           &self.alignment,
-                           self.margin,
-                           &self.chunks);
-        f(&chunks);
+        let hash = hash(self, area);
+        let (cache_update, chunks) = match t.get_layout(hash) {
+            Some(chs) => (false, chs.to_vec()),
+            None => {
+                (true,
+                 split(area,
+                       &self.direction,
+                       &self.alignment,
+                       self.margin,
+                       &self.chunks))
+            }
+        };
+
+        f(t, &chunks);
+
+        if cache_update {
+            t.set_layout(hash, chunks);
+        }
     }
 }

src/terminal.rs

@@ -8,16 +8,19 @@ use termion::raw::{IntoRawMode, RawTerminal};
 use buffer::Buffer;
 use widgets::Widget;
 use layout::Rect;
-use util::hash;
 
 pub struct Terminal {
     stdout: RawTerminal<io::Stdout>,
+    layout_cache: HashMap<u64, Vec<Rect>>,
 }
 
 impl Terminal {
     pub fn new() -> Result<Terminal, io::Error> {
         let stdout = try!(io::stdout().into_raw_mode());
-        Ok(Terminal { stdout: stdout })
+        Ok(Terminal {
+            stdout: stdout,
+            layout_cache: HashMap::new(),
+        })
     }
 
     pub fn size() -> Result<Rect, io::Error> {
@@ -30,20 +33,29 @@ impl Terminal {
         })
     }
 
+    // FIXME: Clean cache to prevent memory leak
+    pub fn get_layout(&self, hash: u64) -> Option<&Vec<Rect>> {
+        self.layout_cache.get(&hash)
+    }
+
+    pub fn set_layout(&mut self, hash: u64, chunks: Vec<Rect>) {
+        self.layout_cache.insert(hash, chunks);
+    }
+
     pub fn render_buffer(&mut self, buffer: Buffer) {
+        let mut string = String::with_capacity(buffer.area().area() as usize);
         for (i, cell) in buffer.content().iter().enumerate() {
             let (lx, ly) = buffer.pos_of(i).unwrap();
             let (x, y) = (lx + buffer.area().x, ly + buffer.area().y);
             if cell.symbol != "" {
-                write!(self.stdout,
-                       "{}{}{}{}",
-                       termion::cursor::Goto(x + 1, y + 1),
-                       cell.fg.fg(),
-                       cell.bg.bg(),
-                       cell.symbol)
-                    .unwrap();
+                string.push_str(&format!("{}{}{}{}",
+                                         termion::cursor::Goto(x + 1, y + 1),
+                                         cell.fg.fg(),
+                                         cell.bg.bg(),
+                                         cell.symbol))
             }
         }
+        write!(self.stdout, "{}", string);
         self.stdout.flush().unwrap();
     }
     pub fn clear(&mut self) {

src/util.rs

@@ -3,9 +3,10 @@ use std::hash::{Hash, Hasher, BuildHasher};
 
 use layout::Rect;
 
-pub fn hash<T: Hash>(t: &T) -> u64 {
+pub fn hash<T: Hash>(t: &T, area: &Rect) -> u64 {
     let state = RandomState::new();
     let mut hasher = state.build_hasher();
     t.hash(&mut hasher);
+    area.hash(&mut hasher);
     hasher.finish()
 }

src/widgets/chart.rs

@@ -138,7 +138,6 @@ impl<'a> Widget<'a> for Chart<'a> {
 
         let margin_x = chart_area.x - area.x;
         let margin_y = chart_area.y - area.y;
-        // info!("{:?}", self.datasets[0].data[0]);
 
         for dataset in self.datasets {
             for &(x, y) in dataset.data.iter() {
@@ -150,7 +149,6 @@ impl<'a> Widget<'a> for Chart<'a> {
                          (self.y_axis.bounds[1] - self.y_axis.bounds[0]);
                 let dx = (self.x_axis.bounds[1] - x) * (chart_area.width - 1) as f64 /
                          (self.x_axis.bounds[1] - self.x_axis.bounds[0]);
-                info!("{} {}", dx, dy);
                 buf.update_cell(dx as u16 + margin_x, dy as u16 + margin_y, |c| {
                     c.symbol = symbols::DOT;
                     c.fg = dataset.color;