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JoshHeaps.Net/JoshHeaps.Net/Services/Implementations/LearnedWeightsStore.cs
T

85 lines
3.3 KiB
C#

using JoshHeaps.Net.Models;
using JoshHeaps.Net.Services.Interfaces;
using Microsoft.Extensions.Options;
namespace JoshHeaps.Net.Services.Implementations;
/// <summary>
/// Managed facade over the native learned-weights model (see <see cref="ILearnedWeightsStore"/>).
/// On construction it points the native engine at the weights file; everything else delegates
/// to the shared native ABI in <see cref="CustomChessEngine"/>.
/// </summary>
public sealed class LearnedWeightsStore : ILearnedWeightsStore
{
private const int Pieces = 6; // Pawn..King
private const int Squares = 64;
private const int Features = 8; // mobility N/B/R/Q, passed, isolated, doubled, king safety
public string WeightsFilePath { get; }
public LearnedWeightsStore(IHostEnvironment env, IOptions<ChessEngineOptions> options, ILogger<LearnedWeightsStore> logger)
{
// Prefer the configured path (production points this outside the deploy dir); fall
// back to the content root for local dev.
var configured = options.Value.WeightsPath;
WeightsFilePath = string.IsNullOrWhiteSpace(configured)
? Path.Combine(env.ContentRootPath, "chess-data", "learned-weights.txt")
: configured;
// A missing/unwritable/misconfigured path must not take down the whole app — the
// learned engine just plays from a neutral table and can't persist training.
try
{
Directory.CreateDirectory(Path.GetDirectoryName(WeightsFilePath)!);
CustomChessEngine.NativeMethods.learned_load(WeightsFilePath);
}
catch (Exception ex)
{
logger.LogError(ex,
"Could not initialize the learned-weights store at {Path}. The learned engine will " +
"play from a neutral table and training will not persist. In production set " +
"ChessEngine:WeightsPath (env ChessEngine__WeightsPath) to a service-writable directory.",
WeightsFilePath);
}
}
public nint CreateTrainer() => CustomChessEngine.NativeMethods.trainer_create();
public void Record(nint trainer, string fen) =>
CustomChessEngine.NativeMethods.trainer_record(trainer, fen);
public void ApplyResult(nint trainer, PieceColor winner, double weight) =>
CustomChessEngine.NativeMethods.trainer_apply(trainer, winner == PieceColor.White ? 0 : 1, weight);
public void DestroyTrainer(nint trainer) =>
CustomChessEngine.NativeMethods.trainer_destroy(trainer);
public LearnedWeightsSnapshot Snapshot()
{
const int total = Pieces * Squares * 2 + Features;
var buffer = new int[total];
unsafe
{
fixed (int* p = buffer)
CustomChessEngine.NativeMethods.weights_snapshot(p, total);
}
var mg = new int[Pieces][];
var eg = new int[Pieces][];
for (int piece = 0; piece < Pieces; piece++)
{
mg[piece] = new int[Squares];
eg[piece] = new int[Squares];
Array.Copy(buffer, piece * Squares, mg[piece], 0, Squares);
Array.Copy(buffer, Pieces * Squares + piece * Squares, eg[piece], 0, Squares);
}
var features = new int[Features];
Array.Copy(buffer, Pieces * Squares * 2, features, 0, Features);
return new LearnedWeightsSnapshot(mg, eg, features);
}
}