Add support for probing the engine hash (requires gRPC-patched Stockfish).

[remoteglot] / www / js / hash-lookup.js

diff --git a/www/js/hash-lookup.js b/www/js/hash-lookup.js
new file mode 100644 (file)
index 0000000..d9499d0
--- /dev/null
+++ b/www/js/hash-lookup.js
@@ -0,0 +1,130 @@
+var grpc = require('grpc');
+var Chess = require(__dirname + '/chess.min.js').Chess;
+
+var PROTO_PATH = __dirname + '/hashprobe.proto';
+var hashprobe_proto = grpc.load(PROTO_PATH).hashprobe;
+
+// TODO: Make destination configurable.
+var client = new hashprobe_proto.HashProbe('localhost:50051', grpc.credentials.createInsecure());
+
+var handle_request = function(fen, response) {
+       client.probe({fen: fen}, function(err, probe_response) {
+               if (err) {
+                       response.writeHead(500, {});
+                       response.end();
+               } else {
+                       handle_response(fen, response, probe_response);
+               }
+       });
+}
+exports.handle_request = handle_request;
+
+var handle_response = function(fen, response, probe_response) {
+       var board = new Chess();
+
+       var lines = {};
+
+       var root = translate_line(board, fen, probe_response['root'], true);
+       for (var i = 0; i < probe_response['line'].length; ++i) {
+               var line = probe_response['line'][i];
+               var uci_move = line['move']['from_sq'] + line['move']['to_sq'] + line['move']['promotion'];
+               lines[uci_move] = translate_line(board, fen, line, false);
+       }
+
+       var text = JSON.stringify({
+               root: root,
+               lines: lines
+       });
+       var headers = {
+               'Content-Type': 'text/json; charset=utf-8'
+               //'Content-Length': text.length
+       };
+       response.writeHead(200, headers);
+       response.write(text);
+       response.end();
+}
+
+var translate_line = function(board, fen, line, pretty_score) {
+       var r = {};
+       board.load(fen);
+       var toplay = board.turn();
+
+       if (line['move'] && line['move']['from_sq']) {
+               r['pretty_move'] = board.move({ from: line['move']['from_sq'], to: line['move']['to_sq'], promotion: line['move']['promotion'] }).san;
+       } else {
+               r['pretty_move'] = '';
+       }
+       r['sort_key'] = r['pretty_move'];
+       if (!line['found']) {
+               r['pv_pretty'] = [];
+               r['score_sort_key'] = -100000000;
+               return r;
+       }
+       r['depth'] = line['depth'];
+
+       // Convert the PV.
+       var pv = [];
+       if (r['pretty_move']) {
+               pv.push(r['pretty_move']);
+       }
+       for (var j = 0; j < line['pv'].length; ++j) {
+               var move = line['pv'][j];
+               var decoded = board.move({ from: move['from_sq'], to: move['to_sq'], promotion: move['promotion'] });
+               if (decoded === null) {
+                       break;
+               }
+               pv.push(decoded.san);
+       }
+       r['pv_pretty'] = pv;
+
+       // Write out the pretty score.
+       // TODO: mates!
+       var score = pretty_score ? 'Score: ' : '';
+
+       if (line['bound'] === 'BOUND_UPPER') {
+               score += '≤\u00a0';
+       } else if (line['bound'] === 'BOUND_LOWER') {
+               score += '≥\u00a0';
+       }
+
+       var value = line['value']['score_cp'];
+       if (value > 0) {
+               score += '+' + (value / 100.0).toFixed(2);
+       } else if (value < 0) {
+               score += (value / 100.0).toFixed(2);
+       } else if (value == 0) {
+               score += '0.00';
+       } else {
+               score += '';
+       }
+       r['pretty_score'] = score;
+       r['score_sort_key'] = score_sort_key(line['value'], toplay === 'b') * 200 + r['depth'];
+
+       return r;
+}
+
+var score_sort_key = function(score, invert) {
+       if (score['score_type'] === 'SCORE_MATE') {
+               var mate = score['score_mate'];
+               var score;
+               if (mate > 0) {
+                       // Side to move mates
+                       score = 99999 - mate;
+               } else {
+                       // Side to move is getting mated (note the double negative for mate)
+                       score = -99999 - mate;
+               }
+               if (invert) {
+                       score = -score;
+               }
+               return score;
+       } else if (score['score_type'] === 'SCORE_CP') {
+               var score = score['score_cp'];
+               if (invert) {
+                       score = -score;
+               }
+               return score;
+       }
+
+       return null;
+}