# -*- coding: utf-8 -*- # # This file is part of the python-chess library. # Copyright (C) 2012-2017 Niklas Fiekas # # This program is free software: you can redistribute it and/or modify # it under the terms of the GNU General Public License as published by # the Free Software Foundation, either version 3 of the License, or # (at your option) any later version. # # This program is distributed in the hope that it will be useful, # but WITHOUT ANY WARRANTY; without even the implied warranty of # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the # GNU General Public License for more details. # # You should have received a copy of the GNU General Public License # along with this program. If not, see . import chess import collections import mmap import os import struct import sys import threading UINT64_BE = struct.Struct(">Q") UINT32 = struct.Struct("I") USHORT = struct.Struct("> 3) | (square << 3)) & 63 LOWER = [ 28, 0, 1, 2, 3, 4, 5, 6, 0, 29, 7, 8, 9, 10, 11, 12, 1, 7, 30, 13, 14, 15, 16, 17, 2, 8, 13, 31, 18, 19, 20, 21, 3, 9, 14, 18, 32, 22, 23, 24, 4, 10, 15, 19, 22, 33, 25, 26, 5, 11, 16, 20, 23, 25, 34, 27, 6, 12, 17, 21, 24, 26, 27, 35, ] DIAG = [ 0, 0, 0, 0, 0, 0, 0, 8, 0, 1, 0, 0, 0, 0, 9, 0, 0, 0, 2, 0, 0, 10, 0, 0, 0, 0, 0, 3, 11, 0, 0, 0, 0, 0, 0, 12, 4, 0, 0, 0, 0, 0, 13, 0, 0, 5, 0, 0, 0, 14, 0, 0, 0, 0, 6, 0, 15, 0, 0, 0, 0, 0, 0, 7, ] FLAP = [ 0, 0, 0, 0, 0, 0, 0, 0, 0, 6, 12, 18, 18, 12, 6, 0, 1, 7, 13, 19, 19, 13, 7, 1, 2, 8, 14, 20, 20, 14, 8, 2, 3, 9, 15, 21, 21, 15, 9, 3, 4, 10, 16, 22, 22, 16, 10, 4, 5, 11, 17, 23, 23, 17, 11, 5, 0, 0, 0, 0, 0, 0, 0, 0, ] PTWIST = [ 0, 0, 0, 0, 0, 0, 0, 0, 47, 35, 23, 11, 10, 22, 34, 46, 45, 33, 21, 9, 8, 20, 32, 44, 43, 31, 19, 7, 6, 18, 30, 42, 41, 29, 17, 5, 4, 16, 28, 40, 39, 27, 15, 3, 2, 14, 26, 38, 37, 25, 13, 1, 0, 12, 24, 36, 0, 0, 0, 0, 0, 0, 0, 0, ] INVFLAP = [ 8, 16, 24, 32, 40, 48, 9, 17, 25, 33, 41, 49, 10, 18, 26, 34, 42, 50, 11, 19, 27, 35, 43, 51, ] FILE_TO_FILE = [0, 1, 2, 3, 3, 2, 1, 0] KK_IDX = [[ -1, -1, -1, 0, 1, 2, 3, 4, -1, -1, -1, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, ], [ 58, -1, -1, -1, 59, 60, 61, 62, 63, -1, -1, -1, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, ], [ 116, 117, -1, -1, -1, 118, 119, 120, 121, 122, -1, -1, -1, 123, 124, 125, 126, 127, 128, 129, 130, 131, 132, 133, 134, 135, 136, 137, 138, 139, 140, 141, 142, 143, 144, 145, 146, 147, 148, 149, 150, 151, 152, 153, 154, 155, 156, 157, 158, 159, 160, 161, 162, 163, 164, 165, 166, 167, 168, 169, 170, 171, 172, 173, ], [ 174, -1, -1, -1, 175, 176, 177, 178, 179, -1, -1, -1, 180, 181, 182, 183, 184, -1, -1, -1, 185, 186, 187, 188, 189, 190, 191, 192, 193, 194, 195, 196, 197, 198, 199, 200, 201, 202, 203, 204, 205, 206, 207, 208, 209, 210, 211, 212, 213, 214, 215, 216, 217, 218, 219, 220, 221, 222, 223, 224, 225, 226, 227, 228, ], [ 229, 230, -1, -1, -1, 231, 232, 233, 234, 235, -1, -1, -1, 236, 237, 238, 239, 240, -1, -1, -1, 241, 242, 243, 244, 245, 246, 247, 248, 249, 250, 251, 252, 253, 254, 255, 256, 257, 258, 259, 260, 261, 262, 263, 264, 265, 266, 267, 268, 269, 270, 271, 272, 273, 274, 275, 276, 277, 278, 279, 280, 281, 282, 283, ], [ 284, 285, 286, 287, 288, 289, 290, 291, 292, 293, -1, -1, -1, 294, 295, 296, 297, 298, -1, -1, -1, 299, 300, 301, 302, 303, -1, -1, -1, 304, 305, 306, 307, 308, 309, 310, 311, 312, 313, 314, 315, 316, 317, 318, 319, 320, 321, 322, 323, 324, 325, 326, 327, 328, 329, 330, 331, 332, 333, 334, 335, 336, 337, 338, ], [ -1, -1, 339, 340, 341, 342, 343, 344, -1, -1, 345, 346, 347, 348, 349, 350, -1, -1, 441, 351, 352, 353, 354, 355, -1, -1, -1, 442, 356, 357, 358, 359, -1, -1, -1, -1, 443, 360, 361, 362, -1, -1, -1, -1, -1, 444, 363, 364, -1, -1, -1, -1, -1, -1, 445, 365, -1, -1, -1, -1, -1, -1, -1, 446, ], [ -1, -1, -1, 366, 367, 368, 369, 370, -1, -1, -1, 371, 372, 373, 374, 375, -1, -1, -1, 376, 377, 378, 379, 380, -1, -1, -1, 447, 381, 382, 383, 384, -1, -1, -1, -1, 448, 385, 386, 387, -1, -1, -1, -1, -1, 449, 388, 389, -1, -1, -1, -1, -1, -1, 450, 390, -1, -1, -1, -1, -1, -1, -1, 451, ], [ 452, 391, 392, 393, 394, 395, 396, 397, -1, -1, -1, -1, 398, 399, 400, 401, -1, -1, -1, -1, 402, 403, 404, 405, -1, -1, -1, -1, 406, 407, 408, 409, -1, -1, -1, -1, 453, 410, 411, 412, -1, -1, -1, -1, -1, 454, 413, 414, -1, -1, -1, -1, -1, -1, 455, 415, -1, -1, -1, -1, -1, -1, -1, 456, ], [ 457, 416, 417, 418, 419, 420, 421, 422, -1, 458, 423, 424, 425, 426, 427, 428, -1, -1, -1, -1, -1, 429, 430, 431, -1, -1, -1, -1, -1, 432, 433, 434, -1, -1, -1, -1, -1, 435, 436, 437, -1, -1, -1, -1, -1, 459, 438, 439, -1, -1, -1, -1, -1, -1, 460, 440, -1, -1, -1, -1, -1, -1, -1, 461, ]] PP_IDX = [[ 0, -1, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, -1, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, ], [ 62, -1, -1, 63, 64, 65, -1, 66, -1, 67, 68, 69, 70, 71, 72, -1, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 96, -1, 97, 98, 99, 100, 101, 102, 103, -1, 104, 105, 106, 107, 108, 109, -1, 110, -1, 111, 112, 113, 114, -1, 115, ], [ 116, -1, -1, -1, 117, -1, -1, 118, -1, 119, 120, 121, 122, 123, 124, -1, -1, 125, 126, 127, 128, 129, 130, -1, 131, 132, 133, 134, 135, 136, 137, 138, -1, 139, 140, 141, 142, 143, 144, 145, -1, 146, 147, 148, 149, 150, 151, -1, -1, 152, 153, 154, 155, 156, 157, -1, 158, -1, -1, 159, 160, -1, -1, 161, ], [ 162, -1, -1, -1, -1, -1, -1, 163, -1, 164, -1, 165, 166, 167, 168, -1, -1, 169, 170, 171, 172, 173, 174, -1, -1, 175, 176, 177, 178, 179, 180, -1, -1, 181, 182, 183, 184, 185, 186, -1, -1, -1, 187, 188, 189, 190, 191, -1, -1, 192, 193, 194, 195, 196, 197, -1, 198, -1, -1, -1, -1, -1, -1, 199, ], [ 200, -1, -1, -1, -1, -1, -1, 201, -1, 202, -1, -1, 203, -1, 204, -1, -1, -1, 205, 206, 207, 208, -1, -1, -1, 209, 210, 211, 212, 213, 214, -1, -1, -1, 215, 216, 217, 218, 219, -1, -1, -1, 220, 221, 222, 223, -1, -1, -1, 224, -1, 225, 226, -1, 227, -1, 228, -1, -1, -1, -1, -1, -1, 229, ], [ 230, -1, -1, -1, -1, -1, -1, 231, -1, 232, -1, -1, -1, -1, 233, -1, -1, -1, 234, -1, 235, 236, -1, -1, -1, -1, 237, 238, 239, 240, -1, -1, -1, -1, -1, 241, 242, 243, -1, -1, -1, -1, 244, 245, 246, 247, -1, -1, -1, 248, -1, -1, -1, -1, 249, -1, 250, -1, -1, -1, -1, -1, -1, 251, ], [ -1, -1, -1, -1, -1, -1, -1, 259, -1, 252, -1, -1, -1, -1, 260, -1, -1, -1, 253, -1, -1, 261, -1, -1, -1, -1, -1, 254, 262, -1, -1, -1, -1, -1, -1, -1, 255, -1, -1, -1, -1, -1, -1, -1, -1, 256, -1, -1, -1, -1, -1, -1, -1, -1, 257, -1, -1, -1, -1, -1, -1, -1, -1, 258, ], [ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 268, -1, -1, -1, 263, -1, -1, 269, -1, -1, -1, -1, -1, 264, 270, -1, -1, -1, -1, -1, -1, -1, 265, -1, -1, -1, -1, -1, -1, -1, -1, 266, -1, -1, -1, -1, -1, -1, -1, -1, 267, -1, -1, -1, -1, -1, -1, -1, -1, -1, ], [ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 274, -1, -1, -1, -1, -1, 271, 275, -1, -1, -1, -1, -1, -1, -1, 272, -1, -1, -1, -1, -1, -1, -1, -1, 273, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, ], [ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 277, -1, -1, -1, -1, -1, -1, -1, 276, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1 ]] def test45(sq): return chess.BB_SQUARES[sq] & (chess.BB_A5 | chess.BB_A6 | chess.BB_A7 | chess.BB_B5 | chess.BB_B6 | chess.BB_C5) MTWIST = [ 15, 63, 55, 47, 40, 48, 56, 12, 62, 11, 39, 31, 24, 32, 8, 57, 54, 38, 7, 23, 16, 4, 33, 49, 46, 30, 22, 3, 0, 17, 25, 41, 45, 29, 21, 2, 1, 18, 26, 42, 53, 37, 6, 20, 19, 5, 34, 50, 61, 10, 36, 28, 27, 35, 9, 58, 14, 60, 52, 44, 43, 51, 59, 13, ] BINOMIAL = [] for i in range(5): BINOMIAL.append([]) for j in range(64): f = j l = 1 for k in range(1, i + 1): f *= j - k l *= k + 1 BINOMIAL[i].append(f // l) PAWNIDX = [[0 for _ in range(24)] for _ in range(5)] PFACTOR = [[0 for _ in range(4)] for _ in range(5)] for i in range(5): j = 0 s = 0 while j < 6: PAWNIDX[i][j] = s s += 1 if i == 0 else BINOMIAL[i - 1][PTWIST[INVFLAP[j]]] j += 1 PFACTOR[i][0] = s s = 0 while j < 12: PAWNIDX[i][j] = s s += 1 if i == 0 else BINOMIAL[i - 1][PTWIST[INVFLAP[j]]] j += 1 PFACTOR[i][1] = s s = 0 while j < 18: PAWNIDX[i][j] = s s += 1 if i == 0 else BINOMIAL[i - 1][PTWIST[INVFLAP[j]]] j += 1 PFACTOR[i][2] = s s = 0 while j < 24: PAWNIDX[i][j] = s s += 1 if i == 0 else BINOMIAL[i - 1][PTWIST[INVFLAP[j]]] j += 1 PFACTOR[i][3] = s MULTIDX = [[0 for _ in range(10)] for _ in range(5)] MFACTOR = [0 for _ in range(5)] for i in range(5): s = 0 for j in range(10): MULTIDX[i][j] = s s += 1 if i == 0 else BINOMIAL[i - 1][MTWIST[INVTRIANGLE[j]]] MFACTOR[i] = s WDL_TO_MAP = [1, 3, 0, 2, 0] PA_FLAGS = [8, 0, 0, 0, 4] WDL_TO_DTZ = [-1, -101, 0, 101, 1] PCHR = ["K", "Q", "R", "B", "N", "P"] def filenames(one_king=True): if not one_king: for filename in all_dependencies(["PPPPPvP", "PPPPvPP", "PPPvPPP"], one_king=False): yield filename return for i in range(1, 6): yield "K%cvK" % (PCHR[i], ) for i in range(1, 6): for j in range(i, 6): yield "K%cvK%c" % (PCHR[i], PCHR[j]) for i in range(1, 6): for j in range(i, 6): yield "K%c%cvK" % (PCHR[i], PCHR[j]) for i in range(1, 6): for j in range(i, 6): for k in range(1, 6): yield "K%c%cvK%c" % (PCHR[i], PCHR[j], PCHR[k]) for i in range(1, 6): for j in range(i, 6): for k in range(j, 6): yield "K%c%c%cvK" % (PCHR[i], PCHR[j], PCHR[k]) for i in range(1, 6): for j in range(i, 6): for k in range(i, 6): for l in range(j if i == k else k, 6): yield "K%c%cvK%c%c" % (PCHR[i], PCHR[j], PCHR[k], PCHR[l]) for i in range(1, 6): for j in range(i, 6): for k in range(j, 6): for l in range(1, 6): yield "K%c%c%cvK%c" % (PCHR[i], PCHR[j], PCHR[k], PCHR[l]) for i in range(1, 6): for j in range(i, 6): for k in range(j, 6): for l in range(k, 6): yield "K%c%c%c%cvK" % (PCHR[i], PCHR[j], PCHR[k], PCHR[l]) def normalize_filename(filename, mirror=False): w, b = filename.split("v", 1) w = "".join(sorted(w, key=PCHR.index)) b = "".join(sorted(b, key=PCHR.index)) if mirror ^ ((len(w), [PCHR.index(c) for c in b]) < (len(b), [PCHR.index(c) for c in w])): return b + "v" + w else: return w + "v" + b def _dependencies(filename, one_king=True): for p in PCHR: if p == "K" and one_king: continue w, b = filename.split("v", 1) # Promotions. if p != "P" and "P" in w: yield normalize_filename(w.replace("P", p, 1) + "v" + b) if p != "P" and "P" in b: yield normalize_filename(w + "v" + b.replace("P", p, 1)) # Captures. w, b = filename.split("v", 1) if p in w and len(w) > 1: yield normalize_filename(w.replace(p, "", 1) + "v" + b) if p in b and len(b) > 1: yield normalize_filename(w + "v" + b.replace(p, "", 1)) def dependencies(filename, one_king=True): closed = set() if one_king: closed.add("KvK") for dependency in _dependencies(filename, one_king): if dependency not in closed and len(dependency) > 2: yield dependency closed.add(dependency) def all_dependencies(targets, one_king=True): closed = set() if one_king: closed.add("KvK") open_list = [normalize_filename(filename) for filename in targets] while open_list: filename = open_list.pop() if filename in closed: continue yield filename closed.add(filename) open_list.extend(_dependencies(filename, one_king)) def calc_key(board, mirror=False): w = board.occupied_co[chess.WHITE ^ mirror] b = board.occupied_co[chess.BLACK ^ mirror] return "".join([ "K" * chess.popcount(board.kings & w), "Q" * chess.popcount(board.queens & w), "R" * chess.popcount(board.rooks & w), "B" * chess.popcount(board.bishops & w), "N" * chess.popcount(board.knights & w), "P" * chess.popcount(board.pawns & w), "v", "K" * chess.popcount(board.kings & b), "Q" * chess.popcount(board.queens & b), "R" * chess.popcount(board.rooks & b), "B" * chess.popcount(board.bishops & b), "N" * chess.popcount(board.knights & b), "P" * chess.popcount(board.pawns & b), ]) def recalc_key(pieces, mirror=False): # Some endgames are stored with a different key than their filename # indicates: http://talkchess.com/forum/viewtopic.php?p=695509#695509 w = 8 if mirror else 0 b = 0 if mirror else 8 return "".join([ "K" * pieces.count(6 ^ w), "Q" * pieces.count(5 ^ w), "R" * pieces.count(4 ^ w), "B" * pieces.count(3 ^ w), "N" * pieces.count(2 ^ w), "P" * pieces.count(1 ^ w), "v", "K" * pieces.count(6 ^ b), "Q" * pieces.count(5 ^ b), "R" * pieces.count(4 ^ b), "B" * pieces.count(3 ^ b), "N" * pieces.count(2 ^ b), "P" * pieces.count(1 ^ b), ]) def subfactor(k, n): f = n l = 1 for i in range(1, k): f *= n - i l *= i + 1 return f // l def dtz_before_zeroing(wdl): return ((wdl > 0) - (wdl < 0)) * (1 if abs(wdl) == 2 else 101) class MissingTableError(KeyError): """Can not probe position because a required table is missing.""" pass class PairsData(object): def __init__(self): self.indextable = None self.sizetable = None self.data = None self.offset = None self.symlen = None self.sympat = None self.blocksize = None self.idxbits = None self.min_len = None self.base = None class PawnFileData(object): def __init__(self): self.precomp = {} self.factor = {} self.pieces = {} self.norm = {} class PawnFileDataDtz(object): def __init__(self): self.precomp = None self.factor = None self.pieces = None self.norm = None class Table(object): def __init__(self, directory, filename, variant): self.directory = directory self.filename = filename self.variant = variant self.fd = None self.data = None self.key = normalize_filename(filename) self.mirrored_key = normalize_filename(filename, mirror=True) self.symmetric = self.key == self.mirrored_key # Leave the v out of the filename to get the number of pieces. self.num = len(filename) - 1 self.has_pawns = "P" in filename black_part, white_part = filename.split("v") if self.has_pawns: self.pawns = {} self.pawns[0] = white_part.count("P") self.pawns[1] = black_part.count("P") if self.pawns[1] > 0 and (self.pawns[0] == 0 or self.pawns[1] < self.pawns[0]): self.pawns[0], self.pawns[1] = self.pawns[1], self.pawns[0] else: j = 0 for piece_type in PCHR: if black_part.count(piece_type) == 1: j += 1 if white_part.count(piece_type) == 1: j += 1 if j >= 3: self.enc_type = 0 elif j == 2: self.enc_type = 2 else: # only for suicide j = 16 for _ in range(16): for piece_type in PCHR: if 1 < black_part.count(piece_type) < j: j = black_part.count(piece_type) if 1 < white_part.count(piece_type) < j: j = white_part.count(piece_type) self.enc_type = 1 + j def init_mmap(self): # Open fd. if self.fd is None: path = os.path.join(self.directory, self.filename) + self.suffix self.fd = os.open(path, os.O_RDONLY | os.O_BINARY if hasattr(os, "O_BINARY") else os.O_RDONLY) # Open mmap. if self.data is None: self.data = mmap.mmap(self.fd, 0, access=mmap.ACCESS_READ) # Micro optimizations for read_ubyte. if sys.version_info >= (3, ): self.read_ubyte = self.data.__getitem__ else: def read_ubyte(data_ptr): return ord(self.data[data_ptr]) self.read_ubyte = read_ubyte def check_magic(self, magic): return all(self.read_ubyte(i) == m for i, m in enumerate(magic)) def setup_pairs(self, data_ptr, tb_size, size_idx, wdl): d = PairsData() self._flags = self.read_ubyte(data_ptr) if self.read_ubyte(data_ptr) & 0x80: d.idxbits = 0 if wdl: d.min_len = self.read_ubyte(data_ptr + 1) else: # http://www.talkchess.com/forum/viewtopic.php?p=698093#698093 d.min_len = 1 if self.variant.captures_compulsory else 0 self._next = data_ptr + 2 self.size[size_idx + 0] = 0 self.size[size_idx + 1] = 0 self.size[size_idx + 2] = 0 return d d.blocksize = self.read_ubyte(data_ptr + 1) d.idxbits = self.read_ubyte(data_ptr + 2) real_num_blocks = self.read_uint32(data_ptr + 4) num_blocks = real_num_blocks + self.read_ubyte(data_ptr + 3) max_len = self.read_ubyte(data_ptr + 8) min_len = self.read_ubyte(data_ptr + 9) h = max_len - min_len + 1 num_syms = self.read_ushort(data_ptr + 10 + 2 * h) d.offset = data_ptr + 10 d.symlen = [0 for _ in range(h * 8 + num_syms)] d.sympat = data_ptr + 12 + 2 * h d.min_len = min_len self._next = data_ptr + 12 + 2 * h + 3 * num_syms + (num_syms & 1) num_indices = (tb_size + (1 << d.idxbits) - 1) >> d.idxbits self.size[size_idx + 0] = 6 * num_indices self.size[size_idx + 1] = 2 * num_blocks self.size[size_idx + 2] = (1 << d.blocksize) * real_num_blocks tmp = [0 for _ in range(num_syms)] for i in range(num_syms): if not tmp[i]: self.calc_symlen(d, i, tmp) d.base = [0 for _ in range(h)] d.base[h - 1] = 0 for i in range(h - 2, -1, -1): d.base[i] = (d.base[i + 1] + self.read_ushort(d.offset + i * 2) - self.read_ushort(d.offset + i * 2 + 2)) // 2 for i in range(h): d.base[i] <<= 64 - (min_len + i) d.offset -= 2 * d.min_len return d def set_norm_piece(self, norm, pieces): if self.enc_type == 0: norm[0] = 3 elif self.enc_type == 2: norm[0] = 2 else: norm[0] = self.enc_type - 1 i = norm[0] while i < self.num: j = i while j < self.num and pieces[j] == pieces[i]: norm[i] += 1 j += 1 i += norm[i] def calc_factors_piece(self, factor, order, norm): if not self.variant.connected_kings: PIVFAC = [31332, 28056, 462] else: PIVFAC = [31332, 0, 518, 278] n = 64 - norm[0] f = 1 i = norm[0] k = 0 while i < self.num or k == order: if k == order: factor[0] = f if self.enc_type < 4: f *= PIVFAC[self.enc_type] else: f *= MFACTOR[self.enc_type - 2] else: factor[i] = f f *= subfactor(norm[i], n) n -= norm[i] i += norm[i] k += 1 return f def calc_factors_pawn(self, factor, order, order2, norm, f): i = norm[0] if order2 < 0x0f: i += norm[i] n = 64 - i fac = 1 k = 0 while i < self.num or k in [order, order2]: if k == order: factor[0] = fac fac *= PFACTOR[norm[0] - 1][f] elif k == order2: factor[norm[0]] = fac fac *= subfactor(norm[norm[0]], 48 - norm[0]) else: factor[i] = fac fac *= subfactor(norm[i], n) n -= norm[i] i += norm[i] k += 1 return fac def set_norm_pawn(self, norm, pieces): norm[0] = self.pawns[0] if self.pawns[1]: norm[self.pawns[0]] = self.pawns[1] i = self.pawns[0] + self.pawns[1] while i < self.num: j = i while j < self.num and pieces[j] == pieces[i]: norm[i] += 1 j += 1 i += norm[i] def calc_symlen(self, d, s, tmp): w = d.sympat + 3 * s s2 = (self.read_ubyte(w + 2) << 4) | (self.read_ubyte(w + 1) >> 4) if s2 == 0x0fff: d.symlen[s] = 0 else: s1 = ((self.read_ubyte(w + 1) & 0xf) << 8) | self.read_ubyte(w) if not tmp[s1]: self.calc_symlen(d, s1, tmp) if not tmp[s2]: self.calc_symlen(d, s2, tmp) d.symlen[s] = d.symlen[s1] + d.symlen[s2] + 1 tmp[s] = 1 def pawn_file(self, pos): for i in range(1, self.pawns[0]): if FLAP[pos[0]] > FLAP[pos[i]]: pos[0], pos[i] = pos[i], pos[0] return FILE_TO_FILE[pos[0] & 0x07] def encode_piece(self, norm, pos, factor): n = self.num if self.enc_type < 3: if pos[0] & 0x04: for i in range(n): pos[i] ^= 0x07 if pos[0] & 0x20: for i in range(n): pos[i] ^= 0x38 for i in range(n): if offdiag(pos[i]): break if i < (3 if self.enc_type == 0 else 2) and offdiag(pos[i]) > 0: for i in range(n): pos[i] = flipdiag(pos[i]) if self.enc_type == 0: # 111 i = int(pos[1] > pos[0]) j = int(pos[2] > pos[0]) + int(pos[2] > pos[1]) if offdiag(pos[0]): idx = TRIANGLE[pos[0]] * 63 * 62 + (pos[1] - i) * 62 + (pos[2] - j) elif offdiag(pos[1]): idx = 6 * 63 * 62 + DIAG[pos[0]] * 28 * 62 + LOWER[pos[1]] * 62 + pos[2] - j elif offdiag(pos[2]): idx = 6 * 63 * 62 + 4 * 28 * 62 + (DIAG[pos[0]]) * 7 * 28 + (DIAG[pos[1]] - i) * 28 + LOWER[pos[2]] else: idx = 6 * 63 * 62 + 4 * 28 * 62 + 4 * 7 * 28 + (DIAG[pos[0]] * 7 * 6) + (DIAG[pos[1]] - i) * 6 + (DIAG[pos[2]] - j) i = 3 elif self.enc_type == 2: # K2 if not self.variant.connected_kings: idx = KK_IDX[TRIANGLE[pos[0]]][pos[1]] else: i = pos[1] > pos[0] if offdiag(pos[0]): idx = TRIANGLE[pos[0]] * 63 + (pos[1] - i) elif offdiag(pos[1]): idx = 6 * 63 + DIAG[pos[0]] * 28 + LOWER[pos[1]] else: idx = 6 * 63 + 4 * 28 + (DIAG[pos[0]]) * 7 + (DIAG[pos[1]] - i) i = 2 elif self.enc_type == 3: # 2, e.g. KKvK if TRIANGLE[pos[0]] > TRIANGLE[pos[1]]: pos[0], pos[1] = pos[1], pos[0] if pos[0] & 0x04: for i in range(n): pos[i] ^= 0x07 if pos[0] & 0x20: for i in range(n): pos[i] ^= 0x38 if offdiag(pos[0]) > 0 or (offdiag(pos[0]) == 0 and offdiag(pos[1]) > 0): for i in range(n): pos[i] = flipdiag(pos[i]) if test45(pos[1]) and TRIANGLE[pos[0]] == TRIANGLE[pos[1]]: pos[0], pos[1] = pos[1], pos[0] for i in range(n): pos[i] = flipdiag(pos[i] ^ 0x38) idx = PP_IDX[TRIANGLE[pos[0]]][pos[1]] i = 2 else: # 3 and higher, e.g. KKKvK and KKKKvK for i in range(1, norm[0]): if TRIANGLE[pos[0]] > TRIANGLE[pos[i]]: pos[0], pos[i] = pos[i], pos[0] if pos[0] & 0x04: for i in range(n): pos[i] ^= 0x07 if pos[0] & 0x20: for i in range(n): pos[i] ^= 0x38 if offdiag(pos[0]) > 0: for i in range(n): pos[i] = flipdiag(pos[i]) for i in range(1, norm[0]): for j in range(i + 1, norm[0]): if MTWIST[pos[i]] > MTWIST[pos[j]]: pos[i], pos[j] = pos[j], pos[i] idx = MULTIDX[norm[0] - 1][TRIANGLE[pos[0]]] i = 1 while i < norm[0]: idx += BINOMIAL[i - 1][MTWIST[pos[i]]] i += 1 idx *= factor[0] while i < n: t = norm[i] for j in range(i, i + t): for k in range(j + 1, i + t): # Swap. if pos[j] > pos[k]: pos[j], pos[k] = pos[k], pos[j] s = 0 for m in range(i, i + t): p = pos[m] j = 0 for l in range(i): j += int(p > pos[l]) s += BINOMIAL[m - i][p - j] idx += s * factor[i] i += t return idx def encode_pawn(self, norm, pos, factor): n = self.num if pos[0] & 0x04: for i in range(n): pos[i] ^= 0x07 for i in range(1, self.pawns[0]): for j in range(i + 1, self.pawns[0]): if PTWIST[pos[i]] < PTWIST[pos[j]]: pos[i], pos[j] = pos[j], pos[i] t = self.pawns[0] - 1 idx = PAWNIDX[t][FLAP[pos[0]]] for i in range(t, 0, -1): idx += BINOMIAL[t - i][PTWIST[pos[i]]] idx *= factor[0] # Remaining pawns. i = self.pawns[0] t = i + self.pawns[1] if t > i: for j in range(i, t): for k in range(j + 1, t): if pos[j] > pos[k]: pos[j], pos[k] = pos[k], pos[j] s = 0 for m in range(i, t): p = pos[m] j = 0 for k in range(i): j += int(p > pos[k]) s += BINOMIAL[m - i][p - j - 8] idx += s * factor[i] i = t while i < n: t = norm[i] for j in range(i, i + t): for k in range(j + 1, i + t): if pos[j] > pos[k]: pos[j], pos[k] = pos[k], pos[j] s = 0 for m in range(i, i + t): p = pos[m] j = 0 for k in range(i): j += int(p > pos[k]) s += BINOMIAL[m - i][p - j] idx += s * factor[i] i += t return idx def decompress_pairs(self, d, idx): if not d.idxbits: return d.min_len mainidx = idx >> d.idxbits litidx = (idx & (1 << d.idxbits) - 1) - (1 << (d.idxbits - 1)) block = self.read_uint32(d.indextable + 6 * mainidx) idx_offset = self.read_ushort(d.indextable + 6 * mainidx + 4) litidx += idx_offset if litidx < 0: while litidx < 0: block -= 1 litidx += self.read_ushort(d.sizetable + 2 * block) + 1 else: while litidx > self.read_ushort(d.sizetable + 2 * block): litidx -= self.read_ushort(d.sizetable + 2 * block) + 1 block += 1 ptr = d.data + (block << d.blocksize) m = d.min_len base_idx = -m symlen_idx = 0 code = self.read_uint64_be(ptr) ptr += 2 * 4 bitcnt = 0 # Number of empty bits in code while True: l = m while code < d.base[base_idx + l]: l += 1 sym = self.read_ushort(d.offset + l * 2) sym += (code - d.base[base_idx + l]) >> (64 - l) if litidx < d.symlen[symlen_idx + sym] + 1: break litidx -= d.symlen[symlen_idx + sym] + 1 code <<= l bitcnt += l if bitcnt >= 32: bitcnt -= 32 code |= self.read_uint32_be(ptr) << bitcnt ptr += 4 # Cut off at 64bit. code &= 0xffffffffffffffff sympat = d.sympat while d.symlen[symlen_idx + sym]: w = sympat + 3 * sym s1 = ((self.read_ubyte(w + 1) & 0xf) << 8) | self.read_ubyte(w) if litidx < d.symlen[symlen_idx + s1] + 1: sym = s1 else: litidx -= d.symlen[symlen_idx + s1] + 1 sym = (self.read_ubyte(w + 2) << 4) | (self.read_ubyte(w + 1) >> 4) return self.read_ubyte(sympat + 3 * sym) def read_uint64_be(self, data_ptr): return UINT64_BE.unpack_from(self.data, data_ptr)[0] def read_uint32(self, data_ptr): return UINT32.unpack_from(self.data, data_ptr)[0] def read_uint32_be(self, data_ptr): return UINT32_BE.unpack_from(self.data, data_ptr)[0] def read_ushort(self, data_ptr): return USHORT.unpack_from(self.data, data_ptr)[0] def close(self): if self.data is not None: self.data.close() if self.fd is not None: try: os.close(self.fd) except OSError: pass self.data = None self.fd = None def __enter__(self): return self def __exit__(self, exc_type, exc_value, traceback): self.close() class WdlTable(Table): def __init__(self, directory, filename, variant=chess.Board, suffix=None): super(WdlTable, self).__init__(directory, filename, variant) self.suffix = suffix or variant.tbw_suffix self.initialized = False self.lock = threading.Lock() def init_table_wdl(self): with self.lock: self.init_mmap() if self.initialized: return assert self.check_magic(self.variant.tbw_magic) or ( not self.has_pawns and self.variant.pawnless_tbw_magic and self.check_magic(self.variant.pawnless_tbw_magic)) self.tb_size = [0 for _ in range(8)] self.size = [0 for _ in range(8 * 3)] # Used if there are only pieces. self.precomp = {} self.pieces = {} self.factor = {} self.factor[0] = [0, 0, 0, 0, 0, 0] # White self.factor[1] = [0, 0, 0, 0, 0, 0] # Black self.norm = {} self.norm[0] = [0 for _ in range(self.num)] # White self.norm[1] = [0 for _ in range(self.num)] # Black # Used if there are pawns. self.files = [PawnFileData() for _ in range(4)] self._next = None self._flags = None self.flags = None split = self.read_ubyte(4) & 0x01 files = 4 if self.read_ubyte(4) & 0x02 else 1 data_ptr = 5 if not self.has_pawns: self.setup_pieces_piece(data_ptr) data_ptr += self.num + 1 data_ptr += data_ptr & 0x01 self.precomp[0] = self.setup_pairs(data_ptr, self.tb_size[0], 0, True) data_ptr = self._next if split: self.precomp[1] = self.setup_pairs(data_ptr, self.tb_size[1], 3, True) data_ptr = self._next else: self.precomp[1] = None self.precomp[0].indextable = data_ptr data_ptr += self.size[0] if split: self.precomp[1].indextable = data_ptr data_ptr += self.size[3] self.precomp[0].sizetable = data_ptr data_ptr += self.size[1] if split: self.precomp[1].sizetable = data_ptr data_ptr += self.size[4] data_ptr = (data_ptr + 0x3f) & ~0x3f self.precomp[0].data = data_ptr data_ptr += self.size[2] if split: data_ptr = (data_ptr + 0x3f) & ~0x3f self.precomp[1].data = data_ptr self.key = recalc_key(self.pieces[0]) self.mirrored_key = recalc_key(self.pieces[0], mirror=True) else: s = 1 + int(self.pawns[1] > 0) for f in range(4): self.setup_pieces_pawn(data_ptr, 2 * f, f) data_ptr += self.num + s data_ptr += data_ptr & 0x01 for f in range(files): self.files[f].precomp[0] = self.setup_pairs(data_ptr, self.tb_size[2 * f], 6 * f, True) data_ptr = self._next if split: self.files[f].precomp[1] = self.setup_pairs(data_ptr, self.tb_size[2 * f + 1], 6 * f + 3, True) data_ptr = self._next else: self.files[f].precomp[1] = None for f in range(files): self.files[f].precomp[0].indextable = data_ptr data_ptr += self.size[6 * f] if split: self.files[f].precomp[1].indextable = data_ptr data_ptr += self.size[6 * f + 3] for f in range(files): self.files[f].precomp[0].sizetable = data_ptr data_ptr += self.size[6 * f + 1] if split: self.files[f].precomp[1].sizetable = data_ptr data_ptr += self.size[6 * f + 4] for f in range(files): data_ptr = (data_ptr + 0x3f) & ~0x3f self.files[f].precomp[0].data = data_ptr data_ptr += self.size[6 * f + 2] if split: data_ptr = (data_ptr + 0x3f) & ~0x3f self.files[f].precomp[1].data = data_ptr data_ptr += self.size[6 * f + 5] self.initialized = True def setup_pieces_pawn(self, p_data, p_tb_size, f): j = 1 + int(self.pawns[1] > 0) order = self.read_ubyte(p_data) & 0x0f order2 = self.read_ubyte(p_data + 1) & 0x0f if self.pawns[1] else 0x0f self.files[f].pieces[0] = [self.read_ubyte(p_data + i + j) & 0x0f for i in range(self.num)] self.files[f].norm[0] = [0 for _ in range(self.num)] self.set_norm_pawn(self.files[f].norm[0], self.files[f].pieces[0]) self.files[f].factor[0] = [0, 0, 0, 0, 0, 0] self.tb_size[p_tb_size] = self.calc_factors_pawn(self.files[f].factor[0], order, order2, self.files[f].norm[0], f) order = self.read_ubyte(p_data) >> 4 order2 = self.read_ubyte(p_data + 1) >> 4 if self.pawns[1] else 0x0f self.files[f].pieces[1] = [self.read_ubyte(p_data + i + j) >> 4 for i in range(self.num)] self.files[f].norm[1] = [0 for _ in range(self.num)] self.set_norm_pawn(self.files[f].norm[1], self.files[f].pieces[1]) self.files[f].factor[1] = [0, 0, 0, 0, 0, 0] self.tb_size[p_tb_size + 1] = self.calc_factors_pawn(self.files[f].factor[1], order, order2, self.files[f].norm[1], f) def setup_pieces_piece(self, p_data): self.pieces[0] = [self.read_ubyte(p_data + i + 1) & 0x0f for i in range(self.num)] order = self.read_ubyte(p_data) & 0x0f self.set_norm_piece(self.norm[0], self.pieces[0]) self.tb_size[0] = self.calc_factors_piece(self.factor[0], order, self.norm[0]) self.pieces[1] = [self.read_ubyte(p_data + i + 1) >> 4 for i in range(self.num)] order = self.read_ubyte(p_data) >> 4 self.set_norm_piece(self.norm[1], self.pieces[1]) self.tb_size[1] = self.calc_factors_piece(self.factor[1], order, self.norm[1]) def probe_wdl_table(self, board): self.init_table_wdl() key = calc_key(board) if not self.symmetric: if key != self.key: cmirror = 8 mirror = 0x38 bside = int(board.turn == chess.WHITE) else: cmirror = mirror = 0 bside = int(board.turn != chess.WHITE) else: cmirror = 0 if board.turn == chess.WHITE else 8 mirror = 0 if board.turn == chess.WHITE else 0x38 bside = 0 if not self.has_pawns: p = [0, 0, 0, 0, 0, 0] i = 0 while i < self.num: piece_type = self.pieces[bside][i] & 0x07 color = (self.pieces[bside][i] ^ cmirror) >> 3 bb = board.pieces_mask(piece_type, chess.WHITE if color == 0 else chess.BLACK) for square in chess.scan_forward(bb): p[i] = square i += 1 idx = self.encode_piece(self.norm[bside], p, self.factor[bside]) res = self.decompress_pairs(self.precomp[bside], idx) else: p = [0, 0, 0, 0, 0, 0] i = 0 k = self.files[0].pieces[0][0] ^ cmirror color = k >> 3 piece_type = k & 0x07 bb = board.pieces_mask(piece_type, chess.WHITE if color == 0 else chess.BLACK) for square in chess.scan_forward(bb): p[i] = square ^ mirror i += 1 f = self.pawn_file(p) pc = self.files[f].pieces[bside] while i < self.num: color = (pc[i] ^ cmirror) >> 3 piece_type = pc[i] & 0x07 bb = board.pieces_mask(piece_type, chess.WHITE if color == 0 else chess.BLACK) for square in chess.scan_forward(bb): p[i] = square ^ mirror i += 1 idx = self.encode_pawn(self.files[f].norm[bside], p, self.files[f].factor[bside]) res = self.decompress_pairs(self.files[f].precomp[bside], idx) return res - 2 def close(self): with self.lock: super(WdlTable, self).close() class DtzTable(Table): def __init__(self, directory, filename, variant=chess.Board, suffix=None): super(DtzTable, self).__init__(directory, filename, variant) self.suffix = suffix or variant.tbz_suffix self.initialized = False self.lock = threading.Lock() def init_table_dtz(self): with self.lock: self.init_mmap() if self.initialized: return assert self.check_magic(self.variant.tbz_magic) or ( not self.has_pawns and self.variant.pawnless_tbz_magic and self.check_magic(self.variant.pawnless_tbz_magic)) self.factor = [0, 0, 0, 0, 0, 0] self.norm = [0 for _ in range(self.num)] self.tb_size = [0, 0, 0, 0] self.size = [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0] self.files = [PawnFileDataDtz() for f in range(4)] files = 4 if self.read_ubyte(4) & 0x02 else 1 p_data = 5 if not self.has_pawns: self.map_idx = [0, 0, 0, 0] self.setup_pieces_piece_dtz(p_data, 0) p_data += self.num + 1 p_data += p_data & 0x01 self.precomp = self.setup_pairs(p_data, self.tb_size[0], 0, False) self.flags = self._flags p_data = self._next self.p_map = p_data if self.flags & 2: for i in range(4): self.map_idx[i] = p_data + 1 - self.p_map p_data += 1 + self.read_ubyte(p_data) p_data += p_data & 0x01 self.precomp.indextable = p_data p_data += self.size[0] self.precomp.sizetable = p_data p_data += self.size[1] p_data = (p_data + 0x3f) & ~0x3f self.precomp.data = p_data p_data += self.size[2] self.key = recalc_key(self.pieces) self.mirrored_key = recalc_key(self.pieces, mirror=True) else: s = 1 + int(self.pawns[1] > 0) for f in range(4): self.setup_pieces_pawn_dtz(p_data, f, f) p_data += self.num + s p_data += p_data & 0x01 self.flags = [] for f in range(files): self.files[f].precomp = self.setup_pairs(p_data, self.tb_size[f], 3 * f, False) p_data = self._next self.flags.append(self._flags) self.map_idx = [] self.p_map = p_data for f in range(files): self.map_idx.append([]) if self.flags[f] & 2: for i in range(4): self.map_idx[-1].append(p_data + 1 - self.p_map) p_data += 1 + self.read_ubyte(p_data) p_data += p_data & 0x01 for f in range(files): self.files[f].precomp.indextable = p_data p_data += self.size[3 * f] for f in range(files): self.files[f].precomp.sizetable = p_data p_data += self.size[3 * f + 1] for f in range(files): p_data = (p_data + 0x3f) & ~0x3f self.files[f].precomp.data = p_data p_data += self.size[3 * f + 2] self.initialized = True def probe_dtz_table(self, board, wdl): self.init_table_dtz() key = calc_key(board) if not self.symmetric: if key != self.key: cmirror = 8 mirror = 0x38 bside = int(board.turn == chess.WHITE) else: cmirror = mirror = 0 bside = int(board.turn != chess.WHITE) else: cmirror = 0 if board.turn == chess.WHITE else 8 mirror = 0 if board.turn == chess.WHITE else 0x38 bside = 0 if not self.has_pawns: if (self.flags & 1) != bside and not self.symmetric: return 0, -1 pc = self.pieces p = [0, 0, 0, 0, 0, 0] i = 0 while i < self.num: piece_type = pc[i] & 0x07 color = (pc[i] ^ cmirror) >> 3 bb = board.pieces_mask(piece_type, chess.WHITE if color == 0 else chess.BLACK) for square in chess.scan_forward(bb): p[i] = square i += 1 idx = self.encode_piece(self.norm, p, self.factor) res = self.decompress_pairs(self.precomp, idx) if self.flags & 2: res = self.read_ubyte(self.p_map + self.map_idx[WDL_TO_MAP[wdl + 2]] + res) if (not (self.flags & PA_FLAGS[wdl + 2])) or (wdl & 1): res *= 2 else: k = self.files[0].pieces[0] ^ cmirror piece_type = k & 0x07 color = k >> 3 bb = board.pieces_mask(piece_type, chess.WHITE if color == 0 else chess.BLACK) i = 0 p = [0, 0, 0, 0, 0, 0] for square in chess.scan_forward(bb): p[i] = square ^ mirror i += 1 f = self.pawn_file(p) if self.flags[f] & 1 != bside: return 0, -1 pc = self.files[f].pieces while i < self.num: piece_type = pc[i] & 0x07 color = (pc[i] ^ cmirror) >> 3 bb = board.pieces_mask(piece_type, chess.WHITE if color == 0 else chess.BLACK) for square in chess.scan_forward(bb): p[i] = square ^ mirror i += 1 idx = self.encode_pawn(self.files[f].norm, p, self.files[f].factor) res = self.decompress_pairs(self.files[f].precomp, idx) if self.flags[f] & 2: res = self.read_ubyte(self.p_map + self.map_idx[f][WDL_TO_MAP[wdl + 2]] + res) if (not (self.flags[f] & PA_FLAGS[wdl + 2])) or (wdl & 1): res *= 2 return res, 1 def setup_pieces_piece_dtz(self, p_data, p_tb_size): self.pieces = [self.read_ubyte(p_data + i + 1) & 0x0f for i in range(self.num)] order = self.read_ubyte(p_data) & 0x0f self.set_norm_piece(self.norm, self.pieces) self.tb_size[p_tb_size] = self.calc_factors_piece(self.factor, order, self.norm) def setup_pieces_pawn_dtz(self, p_data, p_tb_size, f): j = 1 + int(self.pawns[1] > 0) order = self.read_ubyte(p_data) & 0x0f order2 = self.read_ubyte(p_data + 1) & 0x0f if self.pawns[1] else 0x0f self.files[f].pieces = [self.read_ubyte(p_data + i + j) & 0x0f for i in range(self.num)] self.files[f].norm = [0 for _ in range(self.num)] self.set_norm_pawn(self.files[f].norm, self.files[f].pieces) self.files[f].factor = [0, 0, 0, 0, 0, 0] self.tb_size[p_tb_size] = self.calc_factors_pawn(self.files[f].factor, order, order2, self.files[f].norm, f) def close(self): with self.lock: super(DtzTable, self).close() class Tablebases(object): """ Manages a collection of tablebase files for probing. If *max_fds* is not ``None``, will at most use *max_fds* open file descriptors at any given time. The least recently used tables are closed, if nescessary. """ def __init__(self, max_fds=128, VariantBoard=chess.Board): self.variant = VariantBoard self.max_fds = max_fds self.lru = collections.deque() self.wdl = {} self.dtz = {} def _bump_lru(self, table): if self.max_fds is None: return try: self.lru.remove(table) self.lru.appendleft(table) except ValueError: self.lru.appendleft(table) if len(self.lru) > self.max_fds: self.lru.pop().close() def _open_table(self, hashtable, directory, filename, Table, suffix, pawnless_suffix): if os.path.isfile(os.path.join(directory, filename) + suffix): table = Table(directory, filename, self.variant, suffix) elif "P" not in filename and pawnless_suffix and os.path.isfile(os.path.join(directory, filename) + pawnless_suffix): table = Table(directory, filename, self.variant, pawnless_suffix) else: return 0 if table.key in hashtable: hashtable[table.key].close() hashtable[table.key] = table hashtable[table.mirrored_key] = table return 1 def open_directory(self, directory, load_wdl=True, load_dtz=True): """ Loads tables from a directory. By default all available tables with the correct file names (e.g. WDL files like ``KQvKN.rtbw`` and DTZ files like ``KRBvK.rtbz``) are loaded. Returns the number of successfully openened and loaded tablebase files. """ num = 0 directory = os.path.abspath(directory) if not os.path.isdir(directory): raise IOError("not a directory: {0}".format(repr(directory))) for filename in filenames(one_king=self.variant.one_king): if load_wdl: num += self._open_table(self.wdl, directory, filename, WdlTable, self.variant.tbw_suffix, self.variant.pawnless_tbw_suffix) if load_dtz: num += self._open_table(self.dtz, directory, filename, DtzTable, self.variant.tbz_suffix, self.variant.pawnless_tbz_suffix) return num def probe_wdl_table(self, board): if self.variant.one_king: # Test for KvK. if board.kings == board.occupied: return 0 else: # Test for suicide game end. if board.is_variant_win(): return 2 elif board.is_variant_draw(): return 0 key = calc_key(board) try: table = self.wdl[key] except KeyError: raise MissingTableError("did not find wdl table {0}".format(key)) self._bump_lru(table) return table.probe_wdl_table(board) def probe_ab(self, board, alpha, beta, threats=False): if self.variant.captures_compulsory: if board.is_variant_win(): return 2, 2 elif board.is_variant_loss(): return -2, 2 elif board.is_variant_draw(): return 0, 2 return self.sprobe_ab(board, alpha, beta, threats) # Generate non-ep captures. for move in board.generate_legal_moves(to_mask=board.occupied_co[not board.turn]): board.push(move) try: v_plus, _ = self.probe_ab(board, -beta, -alpha) v = -v_plus finally: board.pop() if v > alpha: if v >= beta: return v, 2 alpha = v v = self.probe_wdl_table(board) if alpha >= v: return alpha, 1 + int(alpha > 0) else: return v, 1 def sprobe_ab(self, board, alpha, beta, threats=False): if chess.popcount(board.occupied_co[not board.turn]) > 1: v, captures_found = self.sprobe_capts(board, alpha, beta) if captures_found: return v, 2 else: if any(board.generate_legal_captures()): return -2, 2 threats_found = False if threats or chess.popcount(board.occupied) >= 6: for threat in board.generate_legal_moves(~board.pawns): board.push(threat) try: v_plus, captures_found = self.sprobe_capts(board, -beta, -alpha) v = -v_plus finally: board.pop() if captures_found and v > alpha: threats_found = True alpha = v if alpha >= beta: return v, 3 v = self.probe_wdl_table(board) if v > alpha: return v, 1 else: return alpha, 3 if threats_found else 1 def sprobe_capts(self, board, alpha, beta): captures_found = False for move in board.generate_legal_captures(): captures_found = True board.push(move) try: v_plus, _ = self.sprobe_ab(board, -beta, -alpha) v = -v_plus finally: board.pop() alpha = max(v, alpha) if alpha >= beta: break return alpha, captures_found def probe_wdl(self, board): """ Probes WDL tables for win/draw/loss-information. Probing is thread-safe when done with different *board* objects and if *board* objects are not modified during probing. Returns ``2`` if the side to move is winning, ``0`` if the position is a draw and ``-2`` if the side to move is losing. Returns ``1`` in case of a cursed win and ``-1`` in case of a blessed loss. Mate can be forced but the position can be drawn due to the fifty-move rule. >>> import chess >>> import chess.syzygy >>> >>> with chess.syzygy.open_tablebases("data/syzygy/regular") as tablebases: ... board = chess.Board("8/2K5/4B3/3N4/8/8/4k3/8 b - - 0 1") ... print(tablebases.probe_wdl(board)) ... -2 :raises: :exc:`KeyError` (or specifically :exc:`chess.syzygy.MissingTableError`) if the probe fails. Use :func:`~chess.syzygy.Tablebases.get_wdl()` if you prefer to get ``None`` instead of an exception. """ # Positions with castling rights are not in the tablebase. if board.castling_rights: raise KeyError("syzygy tables do not contain positions with castling rights: {0}".format(board.fen())) # Validate piece count. if chess.popcount(board.occupied) > 6: raise KeyError("syzygy tables support up to 6 pieces, not {0}: {1}".format(chess.popcount(board.occupied), board.fen())) # Probe. v, _ = self.probe_ab(board, -2, 2) # If en passant is not possible, we are done. if not board.ep_square or self.variant.captures_compulsory: return v # Now handle en passant. v1 = -3 # Look at all legal en passant captures. for move in board.generate_legal_ep(): board.push(move) try: v0_plus, _ = self.probe_ab(board, -2, 2) v0 = -v0_plus finally: board.pop() if v0 > v1: v1 = v0 if v1 > -3: if v1 >= v: v = v1 elif v == 0: # If there is not at least one legal non-en-passant move we are # forced to play the losing en passant cature. if all(board.is_en_passant(move) for move in board.generate_legal_moves()): v = v1 return v def get_wdl(self, board, default=None): try: return self.probe_wdl(board) except KeyError: return default def probe_dtz_table(self, board, wdl): key = calc_key(board) try: table = self.dtz[key] except KeyError: raise MissingTableError("did not find dtz table {0}".format(key)) self._bump_lru(table) return table.probe_dtz_table(board, wdl) def probe_dtz_no_ep(self, board): wdl, success = self.probe_ab(board, -2, 2, threats=True) if wdl == 0: return 0 if success == 2 or not board.occupied_co[board.turn] & ~board.pawns: return dtz_before_zeroing(wdl) if wdl > 0: # The position is a win or a cursed win by a threat move. if success == 3: return 2 if wdl == 2 else 101 # Generate all legal non-capturing pawn moves. for move in board.generate_legal_moves(board.pawns, ~board.occupied): if board.is_capture(move): # En passant. continue board.push(move) try: v = -self.probe_wdl(board) finally: board.pop() if v == wdl: return 1 if v == 2 else 101 dtz, success = self.probe_dtz_table(board, wdl) if success >= 0: return dtz_before_zeroing(wdl) + (dtz if wdl > 0 else -dtz) if wdl > 0: best = 0xffff for move in board.generate_legal_moves(~board.pawns, ~board.occupied): board.push(move) try: v = -self.probe_dtz(board) finally: board.pop() if v > 0 and v + 1 < best: best = v + 1 return best else: best = -1 for move in board.generate_legal_moves(): board.push(move) try: if board.halfmove_clock == 0: if wdl == -2: v = -1 else: v, success = self.probe_ab(board, 1, 2, threats=True) v = 0 if v == 2 else -101 else: v = -self.probe_dtz(board) - 1 finally: board.pop() if v < best: best = v return best def probe_dtz(self, board): """ Probes DTZ tables for distance to zero information. Both DTZ and WDL tables are required in order to probe for DTZ. Returns a positive value if the side to move is winning, ``0`` if the position is a draw and a negative value if the side to move is losing. More precisely: +-----+------------------+--------------------------------------------+ | WDL | DTZ | | +=====+==================+============================================+ | -2 | -100 <= n <= -1 | Unconditional loss (assuming 50-move | | | | counter is zero), where a zeroing move can | | | | be forced in -n plies. | +-----+------------------+--------------------------------------------+ | -1 | n < -100 | Loss, but draw under the 50-move rule. | | | | A zeroing move can be forced in -n plies | | | | or -n - 100 plies (if a later phase is | | | | responsible for the blessed loss). | +-----+------------------+--------------------------------------------+ | 0 | 0 | Draw. | +-----+------------------+--------------------------------------------+ | 1 | 100 < n | Win, but draw under the 50-move rule. | | | | A zeroing move can be forced in n plies or | | | | n - 100 plies (if a later phase is | | | | responsible for the cursed win). | +-----+------------------+--------------------------------------------+ | 2 | 1 <= n <= 100 | Unconditional win (assuming 50-move | | | | counter is zero), where a zeroing move can | | | | be forced in n plies. | +-----+------------------+--------------------------------------------+ The return value can be off by one: a return value -n can mean a loss in n + 1 plies and a return value +n can mean a win in n + 1 plies. This is guaranteed not to happen for positions exactly on the edge of the 50-move rule, so that this never impacts results of practical play. Minmaxing the DTZ values guarantees winning a won position (and drawing a drawn position), because it makes progress keeping the win in hand. However the lines are not always the most straightforward ways to win. Engines like Stockfish calculate themselves, checking with DTZ, but only play according to DTZ if they can not manage on their own. >>> import chess >>> import chess.syzygy >>> >>> with chess.syzygy.open_tablebases("data/syzygy/regular") as tablebases: ... board = chess.Board("8/2K5/4B3/3N4/8/8/4k3/8 b - - 0 1") ... print(tablebases.probe_dtz(board)) ... -53 Probing is thread-safe when done with different *board* objects and if *board* objects are not modified during probing. :raises: :exc:`KeyError` (or specifically :exc:`chess.syzygy.MissingTableError`) if the probe fails. Use :func:`~chess.syzygy.Tablebases.get_dtz()` if you prefer to get ``None`` instead of an exception. """ v = self.probe_dtz_no_ep(board) if not board.ep_square or self.variant.captures_compulsory: return v v1 = -3 # Generate all en-passant moves. for move in board.generate_legal_ep(): board.push(move) try: v0_plus, _ = self.probe_ab(board, -2, 2) v0 = -v0_plus finally: board.pop() if v0 > v1: v1 = v0 if v1 > -3: v1 = WDL_TO_DTZ[v1 + 2] if v < -100: if v1 >= 0: v = v1 elif v < 0: if v1 >= 0 or v1 < -100: v = v1 elif v > 100: if v1 > 0: v = v1 elif v > 0: if v1 == 1: v = v1 elif v1 >= 0: v = v1 else: if all(board.is_en_passant(move) for move in board.generate_legal_moves()): v = v1 return v def get_dtz(self, board, default=None): try: return self.probe_dtz(board) except KeyError: return default def close(self): """Closes all loaded tables.""" while self.wdl: _, wdl = self.wdl.popitem() wdl.close() while self.dtz: _, dtz = self.dtz.popitem() dtz.close() self.lru.clear() def __enter__(self): return self def __exit__(self, exc_type, exc_value, traceback): self.close() def open_tablebases(directory, load_wdl=True, load_dtz=True, max_fds=128, VariantBoard=chess.Board): """ Opens a collection of tablebases for probing. See :class:`~chess.syzygy.Tablebases`. .. note:: Generally probing requires tablebase files for the specific material composition, **as well as** tablebase files with less pieces. This is important because 6-piece and 5-piece files are often distributed seperately, but are both required for 6-piece positions. Use :func:`~chess.syzygy.Tablebases.open_directory()` to load tablebases from additional directories. """ tables = Tablebases(max_fds=max_fds, VariantBoard=VariantBoard) tables.open_directory(directory, load_wdl=load_wdl, load_dtz=load_dtz) return tables