add divan benchmarks and CodSpeed workflow

.github/workflows/codspeed.yml

@@ -0,0 +1,37 @@
+name: CodSpeed
+
+on:
+  push:
+    branches:
+      - "main"
+  pull_request:
+  # `workflow_dispatch` allows CodSpeed to trigger backtest
+  # performance analysis in order to generate initial data.
+  workflow_dispatch:
+
+permissions:
+  contents: read
+  id-token: write
+
+jobs:
+  codspeed:
+    name: Run benchmarks
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v6
+
+      - name: Setup rust toolchain, cache and cargo-codspeed binary
+        uses: moonrepo/setup-rust@v0
+        with:
+          channel: stable
+          cache-target: release
+          bins: cargo-codspeed
+
+      - name: Build the benchmark target(s)
+        run: cargo codspeed build -m simulation
+
+      - name: Run the benchmarks
+        uses: CodSpeedHQ/action@v4
+        with:
+          mode: simulation
+          run: cargo codspeed run

Cargo.toml

@@ -16,3 +16,11 @@ name = "term_grid"
 
 [dependencies]
 ansi-width = "0.1.0"
+
+[dev-dependencies]
+divan = { version = "4.3.0", package = "codspeed-divan-compat" }
+
+[[bench]]
+name = "bench_grid"
+path = "benches/bench-grid.rs"
+harness = false

benches/bench-grid.rs

@@ -0,0 +1,76 @@
+// For the full copyright and license information, please view the LICENSE
+// file that was distributed with this source code.
+
+use std::hint::black_box;
+
+use divan::Bencher;
+use term_grid::{Direction, Filling, Grid, GridOptions};
+
+const CELL_COUNTS: [usize; 4] = [10, 100, 1_000, 10_000];
+
+fn generate_cells(n: usize) -> Vec<String> {
+    (0..n).map(|i| format!("file-{i:04}.txt")).collect()
+}
+
+#[divan::bench(args = CELL_COUNTS)]
+fn grid_top_to_bottom(bencher: Bencher, n: usize) {
+    let cells = generate_cells(n);
+    bencher.with_inputs(|| cells.clone()).bench_values(|cells| {
+        black_box(Grid::new(
+            cells,
+            GridOptions {
+                direction: Direction::TopToBottom,
+                filling: Filling::Spaces(2),
+                width: 80,
+            },
+        ))
+    });
+}
+
+#[divan::bench(args = CELL_COUNTS)]
+fn grid_left_to_right(bencher: Bencher, n: usize) {
+    let cells = generate_cells(n);
+    bencher.with_inputs(|| cells.clone()).bench_values(|cells| {
+        black_box(Grid::new(
+            cells,
+            GridOptions {
+                direction: Direction::LeftToRight,
+                filling: Filling::Spaces(2),
+                width: 80,
+            },
+        ))
+    });
+}
+
+#[divan::bench(args = CELL_COUNTS)]
+fn grid_display(bencher: Bencher, n: usize) {
+    let cells = generate_cells(n);
+    let grid = Grid::new(
+        cells,
+        GridOptions {
+            direction: Direction::TopToBottom,
+            filling: Filling::Spaces(2),
+            width: 80,
+        },
+    );
+    bencher.bench(|| black_box(grid.to_string()));
+}
+
+#[divan::bench(args = [20, 80, 160, 320])]
+fn grid_varying_width(bencher: Bencher, width: usize) {
+    let cells = generate_cells(500);
+    bencher.with_inputs(|| cells.clone()).bench_values(|cells| {
+        black_box(Grid::new(
+            cells,
+            GridOptions {
+                direction: Direction::TopToBottom,
+                filling: Filling::Spaces(2),
+                width,
+            },
+        ))
+    });
+}
+
+fn main() {
+    divan::main();
+}