reduce target latency

battlesnake/src/logic.rs

@@ -87,8 +87,20 @@ pub fn end(game: &Game, turn: i32, _board: &Board, you: &Battlesnake) {
 // move is called on every turn and returns your next move
 // Valid moves are "up", "down", "left", or "right"
 // See https://docs.battlesnake.com/api/example-move for available data
-pub fn get_move(game: &Game, turn: i32, board: &Board, you: &Battlesnake) -> Option<Action> {
-    let start = Instant::now();
+pub fn get_move(
+    game: &Game,
+    turn: i32,
+    board: &Board,
+    you: &Battlesnake,
+    start: &Instant,
+) -> Option<Action> {
+    let calc_start = Instant::now();
+    if calc_start - *start > Duration::from_millis(10) {
+        error!(
+            "The calculation was started long after the request ({}ms)",
+            (calc_start - *start).as_millis()
+        );
+    }
     let game_info = GAME_INFOS
         .lock()
         .ok()
@@ -115,7 +127,7 @@ pub fn get_move(game: &Game, turn: i32, board: &Board, you: &Battlesnake) -> Opt
     );
     let possible_actions = board.possible_actions().get(&game_info.my_token).cloned()?;
     if possible_actions.len() == 1 {
-        info!("Only one movement option exists. Skipping Tree evaluation");
+        info!("Only one movement option exists in turn {turn}. Skipping Tree evaluation");
         return possible_actions.first().map(|direction| Action {
             r#move: *direction,
             shout: None,
@@ -123,11 +135,11 @@ pub fn get_move(game: &Game, turn: i32, board: &Board, you: &Battlesnake) -> Opt
     }
 
     // do some latency compensation
-    let deadline = start
+    let deadline = *start
         + game_info.calculation_time.lock().map_or_else(
             |_| Duration::from_millis(u64::from(game.timeout) / 2),
             |mut guard| {
-                let target_latency = game.timeout * 3 / 4;
+                let target_latency = game.timeout / 2;
                 let latency = you.latency.parse().unwrap_or_else(|e| {
                     error!("Unable to parse latency: {e}");
                     target_latency

battlesnake/src/main.rs

@@ -6,7 +6,7 @@ use rocket::{
     fairing::AdHoc, get, http::Status, launch, post, routes, serde::json::Json, tokio::task,
 };
 use serde_json::Value;
-use std::env;
+use std::{env, time::Instant};
 
 #[get("/")]
 fn handle_index() -> Json<Value> {
@@ -27,12 +27,14 @@ fn handle_start(start_req: Json<GameState>) -> Status {
 
 #[post("/move", format = "json", data = "<move_req>")]
 async fn handle_move(move_req: Json<GameState>) -> Option<Json<Action>> {
+    let start = Instant::now();
     let response = task::spawn_blocking(move || {
         logic::get_move(
             &move_req.game,
             move_req.turn,
             &move_req.board,
             &move_req.you,
+            &start,
         )
     })
     .await