Files
zeal/src/search/iterative_deepening.rs

97 lines
2.2 KiB
Rust

use std::io;
use crate::{
board::game::Game,
evaluation::{MAX_SCORE, MIN_SCORE},
interface::uci::{write_response, Response},
movegen::r#move::Move,
};
use super::{
negamax,
time::{hard_limit, TimeInfo},
};
pub fn iterative_deepening(
game: &mut Game,
max_depth: u8,
time_info: &TimeInfo,
) -> anyhow::Result<Option<Move>> {
let mut best_move = None;
for depth in 1..=max_depth {
if hard_limit(time_info.instant, time_info.time, time_info.inc) {
return Ok(best_move);
}
let mut nodes = 0;
let score = negamax::negamax(game, MIN_SCORE, MAX_SCORE, depth, 0, time_info, &mut nodes);
if score.is_err() {
break;
}
best_move = game.tt.lookup(game.hash).and_then(|entry| entry.mv);
write_response(
&mut io::stdout(),
&log_depth_results(
depth,
time_info.instant.elapsed().as_millis() as u64,
nodes,
time_info.nps(nodes),
score?,
best_move,
),
)?;
}
Ok(best_move)
}
fn log_depth_results(
depth: u8,
seconds: u64,
nodes: u64,
nps: u64,
best_score: i32,
best_move: Option<Move>,
) -> Response {
Response::Info(format!(
"info depth {} seconds {} nodes {} nps {} eval {} bestmove {}",
depth,
seconds,
nodes,
nps,
best_score,
best_move.expect("No best move found")
))
}
#[cfg(test)]
mod tests {
use crate::{
board::fen::from_fen,
movegen::attack_generator::init_attacks,
search::{iterative_deepening, time::TimeInfo, INC, MAX_DEPTH, TIME},
};
const FEN: &str = "1r2k2r/2P1pq1p/2npb3/1p3ppP/p3P3/P2B1Q2/1P1PNPP1/R3K2R w KQk g6 0 1";
#[test]
fn test_iterative_deepening() -> anyhow::Result<()> {
init_attacks();
let mut game = from_fen(FEN).unwrap();
let instant = std::time::Instant::now();
iterative_deepening::iterative_deepening(
&mut game,
MAX_DEPTH,
&TimeInfo::new(instant, TIME, INC),
)?;
dbg!(instant.elapsed());
Ok(())
}
}