git.sesse.net Git - remoteglot/blob - server/hash-lookup.js

   1 var grpc = require('grpc');
   2 var Chess = require('../www/js/chess.min.js').Chess;
   3
   4 var PROTO_PATH = __dirname + '/hashprobe.proto';
   5 var hashprobe_proto = grpc.load(PROTO_PATH).hashprobe;
   6
   7 var board = new Chess();
   8
   9 var clients = [];
  10
  11 var init = function(servers) {
  12         for (var i = 0; i < servers.length; ++i) {
  13                 clients.push(new hashprobe_proto.HashProbe(servers[i], grpc.credentials.createInsecure()));
  14         }
  15 }
  16 exports.init = init;
  17
  18 var handle_request = function(fen, response) {
  19         if (fen === undefined || fen === null || fen === '' || !board.validate_fen(fen).valid) {
  20                 response.writeHead(400, {});
  21                 response.end();
  22                 return;
  23         }
  24
  25         var rpc_status = {
  26                 failed: false,
  27                 left: clients.length,
  28                 responses: [],
  29         }
  30         for (var i = 0; i < clients.length; ++i) {
  31                 clients[i].probe({fen: fen}, function(err, probe_response) {
  32                         if (err) {
  33                                 rpc_status.failed = true;
  34                         } else {
  35                                 rpc_status.responses.push(probe_response);
  36                         }
  37                         if (--rpc_status.left == 0) {
  38                                 // All probes have come back.
  39                                 if (rpc_status.failed) {
  40                                         response.writeHead(500, {});
  41                                         response.end();
  42                                 } else {
  43                                         handle_response(fen, response, rpc_status.responses);
  44                                 }
  45                         }
  46                 });
  47         }
  48 }
  49 exports.handle_request = handle_request;
  50
  51 var handle_response = function(fen, response, probe_responses) {
  52         var probe_response = reconcile_responses(probe_responses);
  53         var lines = {};
  54
  55         var root = translate_line(board, fen, probe_response['root']);
  56         for (var i = 0; i < probe_response['line'].length; ++i) {
  57                 var line = probe_response['line'][i];
  58                 var uci_move = line['move']['from_sq'] + line['move']['to_sq'] + line['move']['promotion'];
  59                 lines[uci_move] = translate_line(board, fen, line);
  60         }
  61
  62         var text = JSON.stringify({
  63                 root: root,
  64                 lines: lines
  65         });
  66         var headers = {
  67                 'Content-Type': 'text/json; charset=utf-8'
  68                 //'Content-Length': text.length
  69         };
  70         response.writeHead(200, headers);
  71         response.write(text);
  72         response.end();
  73 }
  74
  75 var reconcile_responses = function(probe_responses) {
  76         var probe_response = {};
  77
  78         // Select the root that has searched the deepest, plain and simple.
  79         probe_response['root'] = probe_responses[0]['root'];
  80         for (var i = 1; i < probe_responses.length; ++i) {
  81                 var root = probe_responses[i]['root'];
  82                 if (root['depth'] > probe_response['root']['depth']) {
  83                         probe_response['root'] = root;
  84                 }
  85         }
  86
  87         // Do the same ting for each move, combining on move.
  88         var moves = {};
  89         for (var i = 0; i < probe_responses.length; ++i) {
  90                 for (var j = 0; j < probe_responses[i]['line'].length; ++j) {
  91                         var line = probe_responses[i]['line'][j];
  92                         var uci_move = line['move']['from_sq'] + line['move']['to_sq'] + line['move']['promotion'];
  93
  94                         if (!moves[uci_move]) {
  95                                 moves[uci_move] = line;
  96                         } else {
  97                                 moves[uci_move] = reconcile_moves(line, moves[uci_move]);
  98                         }
  99                 }
 100         }
 101         probe_response['line'] = [];
 102         for (var move in moves) {
 103                 probe_response['line'].push(moves[move]);
 104         }
 105         return probe_response;
 106 }
 107
 108 var reconcile_moves = function(a, b) {
 109         // Prefer exact bounds, unless the depth is just so much higher.
 110         if (a['bound'] === 'BOUND_EXACT' &&
 111             b['bound'] !== 'BOUND_EXACT' &&
 112             a['depth'] + 10 >= b['depth']) {
 113                 return a;
 114         }
 115         if (b['bound'] === 'BOUND_EXACT' &&
 116             a['bound'] !== 'BOUND_EXACT' &&
 117             b['depth'] + 10 >= a['depth']) {
 118                 return b;
 119         }
 120
 121         if (a['depth'] > b['depth']) {
 122                 return a;
 123         } else {
 124                 return b;
 125         }
 126 }
 127
 128 var translate_line = function(board, fen, line) {
 129         var r = {};
 130         board.load(fen);
 131         var toplay = board.turn();
 132
 133         if (line['move'] && line['move']['from_sq']) {
 134                 var promo = line['move']['promotion'];
 135                 if (promo) {
 136                         r['move'] = board.move({ from: line['move']['from_sq'], to: line['move']['to_sq'], promotion: promo.toLowerCase() }).san;
 137                 } else {
 138                         r['move'] = board.move({ from: line['move']['from_sq'], to: line['move']['to_sq'] }).san;
 139                 }
 140         } else {
 141                 r['move'] = '';
 142         }
 143         if (!line['found']) {
 144                 r['pv'] = [];
 145                 return r;
 146         }
 147         r['depth'] = line['depth'];
 148
 149         // Convert the PV.
 150         var pv = [];
 151         if (r['move']) {
 152                 pv.push(r['move']);
 153         }
 154         for (var j = 0; j < line['pv'].length; ++j) {
 155                 var move = line['pv'][j];
 156                 var decoded = board.move({ from: move['from_sq'], to: move['to_sq'], promotion: move['promotion'] });
 157                 if (decoded === null) {
 158                         break;
 159                 }
 160                 pv.push(decoded.san);
 161         }
 162         r['pv'] = pv;
 163
 164         // Convert the score. Use the static eval if no search.
 165         var value = line['value'] || line['eval'];
 166         var score = null;
 167         if (value['score_type'] === 'SCORE_CP') {
 168                 score = ['cp', value['score_cp']];
 169         } else if (value['score_type'] === 'SCORE_MATE') {
 170                 score = ['m', value['score_mate']];
 171         }
 172         if (score) {
 173                 if (line['bound'] === 'BOUND_UPPER') {
 174                         score.push('≤');
 175                 } else if (line['bound'] === 'BOUND_LOWER') {
 176                         score.push('≥');
 177                 }
 178         }
 179
 180         r['score'] = score;
 181
 182         return r;
 183 }