Merge 92fe660 into 5761499

Cargo.toml

@@ -11,3 +11,11 @@ edition = "2018"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
+rand = "0.7.2"
+
+[dev-dependencies]
+criterion = "0.3.0"
+
+[[bench]]
+name = "benchmarks"
+harness = false

benches/benchmarks.rs

@@ -0,0 +1,77 @@
+#[macro_use]
+extern crate criterion;
+
+use criterion::black_box;
+use criterion::Criterion;
+
+use open_ttt_lib::ai;
+use open_ttt_lib::game;
+
+// Sequence of positions that results in a cats game.
+// The resulting game board is as follows:
+//  +---+---+---+
+//  | X | O | X |
+//  +---+---+---+
+//  | X | O | O |
+//  +---+---+---+
+//  | O | X | X |
+//  +---+---+---+
+// Note: for a particular game the X and O spots might be reversed.
+const CATS_GAME_POSITION_SEQUENCE: [game::Position; 9] = [
+    game::Position { row: 0, column: 0 },
+    game::Position { row: 0, column: 1 },
+    game::Position { row: 0, column: 2 },
+    game::Position { row: 1, column: 1 },
+    game::Position { row: 1, column: 0 },
+    game::Position { row: 1, column: 2 },
+    game::Position { row: 2, column: 1 },
+    game::Position { row: 2, column: 0 },
+    game::Position { row: 2, column: 2 },
+];
+
+// Plays a complete game that results in a cat's game.
+// The exercises the speed of the game's state machine and victory condition logic.
+fn complete_game_benchmark(c: &mut Criterion) {
+    let mut game = game::Game::new();
+
+    c.bench_function("Complete game resulting in cats game.", |b| {
+        b.iter(|| {
+            for position in CATS_GAME_POSITION_SEQUENCE.iter() {
+                game.do_move(black_box(*position)).unwrap();
+            }
+            game.start_next_game();
+        })
+    });
+}
+
+// Creates a perfect AI opponent then benchmarks for various numbers of free
+// spaces remaining.
+fn perfect_ai_moves_benchmarks(c: &mut Criterion) {
+    let mut game = game::Game::new();
+
+    let mistake_probability = 0.0;
+    let ai_opponent = ai::Opponent::new(mistake_probability);
+
+    // Loop through each position first benchmarking how long the AI takes to
+    // select a position, doing the actual move with the predetermined position
+    // so next time through the loop there are less free moves remaining.
+    for idx in 0..CATS_GAME_POSITION_SEQUENCE.len() - 1 {
+        let moves_remaining = game.free_positions().count();
+
+        c.bench_function(
+            &format!("Perfect AI with {} moves remaining", moves_remaining),
+            |b| b.iter(|| ai_opponent.get_move(&game)),
+        );
+
+        game.do_move(CATS_GAME_POSITION_SEQUENCE[idx]).unwrap();
+    }
+}
+
+criterion_group!(game_bench, complete_game_benchmark);
+
+criterion_group!(
+    name = perfect_ai_bench; 
+    config = Criterion::default().sample_size(10); 
+    targets = perfect_ai_moves_benchmarks);
+
+criterion_main!(game_bench, perfect_ai_bench);