uct/tree.c

   1 #include <assert.h>
   2 #include <math.h>
   3 #include <stddef.h>
   4 #include <stdio.h>
   5 #include <stdlib.h>
   6 #include <string.h>
   7
   8 #include "board.h"
   9 #include "debug.h"
  10 #include "engine.h"
  11 #include "move.h"
  12 #include "playout.h"
  13 #include "uct/internal.h"
  14 #include "uct/tree.h"
  15
  16
  17 static struct tree_node *
  18 tree_init_node(struct tree *t, coord_t coord, int depth)
  19 {
  20         struct tree_node *n = calloc(1, sizeof(*n));
  21         n->coord = coord;
  22         n->depth = depth;
  23         if (depth > t->max_depth)
  24                 t->max_depth = depth;
  25         return n;
  26 }
  27
  28 struct tree *
  29 tree_init(struct board *board, enum stone color)
  30 {
  31         struct tree *t = calloc(1, sizeof(*t));
  32         t->board = board;
  33         /* The root PASS move is only virtual, we never play it. */
  34         t->root = tree_init_node(t, pass, 0);
  35         t->root_symmetry = board->symmetry;
  36         return t;
  37 }
  38
  39
  40 static void
  41 tree_done_node(struct tree *t, struct tree_node *n)
  42 {
  43         struct tree_node *ni = n->children;
  44         while (ni) {
  45                 struct tree_node *nj = ni->sibling;
  46                 tree_done_node(t, ni);
  47                 ni = nj;
  48         }
  49         free(n);
  50 }
  51
  52 void
  53 tree_done(struct tree *t)
  54 {
  55         tree_done_node(t, t->root);
  56         free(t);
  57 }
  58
  59
  60 static void
  61 tree_node_dump(struct tree *tree, struct tree_node *node, int l, int thres)
  62 {
  63         for (int i = 0; i < l; i++) fputc(' ', stderr);
  64         int children = 0;
  65         for (struct tree_node *ni = node->children; ni; ni = ni->sibling)
  66                 children++;
  67         fprintf(stderr, "[%s] %f (%d/%d playouts [prior %d/%d amaf %d/%d]; hints %x; %d children)\n", coord2sstr(node->coord, tree->board), node->u.value, node->u.wins, node->u.playouts, node->prior.wins, node->prior.playouts, node->amaf.wins, node->amaf.playouts, node->hints, children);
  68
  69         /* Print nodes sorted by #playouts. */
  70
  71         struct tree_node *nbox[1000]; int nboxl = 0;
  72         for (struct tree_node *ni = node->children; ni; ni = ni->sibling)
  73                 if (ni->u.playouts > thres)
  74                         nbox[nboxl++] = ni;
  75
  76         while (true) {
  77                 int best = -1;
  78                 for (int i = 0; i < nboxl; i++)
  79                         if (nbox[i] && (best < 0 || nbox[i]->u.playouts > nbox[best]->u.playouts))
  80                                 best = i;
  81                 if (best < 0)
  82                         break;
  83                 tree_node_dump(tree, nbox[best], l + 1, thres);
  84                 nbox[best] = NULL;
  85         }
  86 }
  87
  88 void
  89 tree_dump(struct tree *tree, int thres)
  90 {
  91         tree_node_dump(tree, tree->root, 0, thres);
  92 }
  93
  94
  95 static char *
  96 tree_book_name(struct board *b)
  97 {
  98         static char buf[256];
  99         sprintf(buf, "uctbook-%d-%02.01f.pachitree", b->size - 2, b->komi);
 100         return buf;
 101 }
 102
 103 static void
 104 tree_node_save(FILE *f, struct tree_node *node, int thres)
 105 {
 106         fputc(1, f);
 107         fwrite(((void *) node) + offsetof(struct tree_node, depth),
 108                sizeof(struct tree_node) - offsetof(struct tree_node, depth),
 109                1, f);
 110
 111         if (node->u.playouts >= thres)
 112                 for (struct tree_node *ni = node->children; ni; ni = ni->sibling)
 113                         tree_node_save(f, ni, thres);
 114
 115         fputc(0, f);
 116 }
 117
 118 void
 119 tree_save(struct tree *tree, struct board *b, int thres)
 120 {
 121         char *filename = tree_book_name(b);
 122         FILE *f = fopen(filename, "wb");
 123         if (!f) {
 124                 perror("fopen");
 125                 return;
 126         }
 127         tree_node_save(f, tree->root, thres);
 128         fputc(0, f);
 129         fclose(f);
 130 }
 131
 132
 133 void
 134 tree_node_load(FILE *f, struct tree_node *node, int *num, bool invert)
 135 {
 136         (*num)++;
 137
 138         fread(((void *) node) + offsetof(struct tree_node, depth),
 139                sizeof(struct tree_node) - offsetof(struct tree_node, depth),
 140                1, f);
 141
 142         if (invert) {
 143                 node->u.wins = node->u.playouts - node->u.wins;
 144                 node->u.value = 1 - node->u.value;
 145                 node->amaf.wins = node->amaf.playouts - node->amaf.wins;
 146                 node->amaf.value = 1 - node->amaf.value;
 147                 node->prior.wins = node->prior.playouts - node->prior.wins;
 148                 node->prior.value = 1 - node->prior.value;
 149         }
 150
 151         struct tree_node *ni = NULL, *ni_prev = NULL;
 152         while (fgetc(f)) {
 153                 ni_prev = ni; ni = calloc(1, sizeof(*ni));
 154                 if (!node->children)
 155                         node->children = ni;
 156                 else
 157                         ni_prev->sibling = ni;
 158                 ni->parent = node;
 159                 tree_node_load(f, ni, num, invert);
 160         }
 161 }
 162
 163 void
 164 tree_load(struct tree *tree, struct board *b, enum stone color)
 165 {
 166         char *filename = tree_book_name(b);
 167         FILE *f = fopen(filename, "rb");
 168         if (!f)
 169                 return;
 170
 171         fprintf(stderr, "Loading opening book %s...\n", filename);
 172
 173         int num = 0;
 174         if (fgetc(f))
 175                 tree_node_load(f, tree->root, &num, color != S_BLACK);
 176         fprintf(stderr, "Loaded %d nodes.\n", num);
 177
 178         fclose(f);
 179 }
 180
 181
 182 /* Tree symmetry: When possible, we will localize the tree to a single part
 183  * of the board in tree_expand_node() and possibly flip along symmetry axes
 184  * to another part of the board in tree_promote_at(). We follow b->symmetry
 185  * guidelines here. */
 186
 187
 188 void
 189 tree_expand_node(struct tree *t, struct tree_node *node, struct board *b, enum stone color, int radar, struct uct_policy *policy, int parity)
 190 {
 191         struct tree_node *ni = tree_init_node(t, pass, node->depth + 1);
 192         ni->parent = node; node->children = ni;
 193
 194         /* The loop considers only the symmetry playground. */
 195         if (UDEBUGL(6)) {
 196                 fprintf(stderr, "expanding %s within [%d,%d],[%d,%d] %d-%d\n",
 197                                 coord2sstr(node->coord, b),
 198                                 b->symmetry.x1, b->symmetry.y1,
 199                                 b->symmetry.x2, b->symmetry.y2,
 200                                 b->symmetry.type, b->symmetry.d);
 201         }
 202         for (int i = b->symmetry.x1; i <= b->symmetry.x2; i++) {
 203                 for (int j = b->symmetry.y1; j <= b->symmetry.y2; j++) {
 204                         if (b->symmetry.d) {
 205                                 int x = b->symmetry.type == SYM_DIAG_DOWN ? board_size(b) - 1 - i : i;
 206                                 if (x > j) {
 207                                         if (UDEBUGL(7))
 208                                                 fprintf(stderr, "drop %d,%d\n", i, j);
 209                                         continue;
 210                                 }
 211                         }
 212
 213                         coord_t c = coord_xy_otf(i, j, t->board);
 214                         if (board_at(b, c) != S_NONE)
 215                                 continue;
 216                         /* This looks very useful on large boards - weeds out huge amount of crufty moves. */
 217                         if (b->hash /* not empty board */ && radar && !board_stone_radar(b, c, radar))
 218                                 continue;
 219
 220                         struct tree_node *nj = tree_init_node(t, c, node->depth + 1);
 221                         nj->parent = node; ni->sibling = nj; ni = nj;
 222
 223                         if (policy->prior)
 224                                 policy->prior(policy, t, ni, b, color, parity);
 225                 }
 226         }
 227 }
 228
 229
 230 static coord_t
 231 flip_coord(struct board *b, coord_t c,
 232            bool flip_horiz, bool flip_vert, int flip_diag)
 233 {
 234         int x = coord_x(c, b), y = coord_y(c, b);
 235         if (flip_diag) {
 236                 int z = x; x = y; y = z;
 237         }
 238         if (flip_horiz) {
 239                 x = board_size(b) - 1 - x;
 240         }
 241         if (flip_vert) {
 242                 y = board_size(b) - 1 - y;
 243         }
 244         return coord_xy_otf(x, y, b);
 245 }
 246
 247 static void
 248 tree_fix_node_symmetry(struct board *b, struct tree_node *node,
 249                        bool flip_horiz, bool flip_vert, int flip_diag)
 250 {
 251         node->coord = flip_coord(b, node->coord, flip_horiz, flip_vert, flip_diag);
 252
 253         for (struct tree_node *ni = node->children; ni; ni = ni->sibling)
 254                 tree_fix_node_symmetry(b, ni, flip_horiz, flip_vert, flip_diag);
 255 }
 256
 257 static void
 258 tree_fix_symmetry(struct tree *tree, struct board *b, coord_t c)
 259 {
 260         struct board_symmetry *s = &tree->root_symmetry;
 261         int cx = coord_x(c, b), cy = coord_y(c, b);
 262
 263         /* playground   X->h->v->d normalization
 264          * :::..        .d...
 265          * .::..        v....
 266          * ..:..        .....
 267          * .....        h...X
 268          * .....        .....  */
 269         bool flip_horiz = cx < s->x1 || cx > s->x2;
 270         bool flip_vert = cy < s->y1 || cy > s->y2;
 271
 272         bool flip_diag = 0;
 273         if (s->d) {
 274                 bool dir = (s->type == SYM_DIAG_DOWN);
 275                 int x = dir ^ flip_horiz ^ flip_vert ? board_size(b) - 1 - cx : cx;
 276                 if (flip_vert ? x < cy : x > cy) {
 277                         flip_diag = 1;
 278                 }
 279         }
 280
 281         if (UDEBUGL(4)) {
 282                 fprintf(stderr, "%s will flip %d %d %d -> %s, sym %d (%d) -> %d (%d)\n",
 283                         coord2sstr(c, b), flip_horiz, flip_vert, flip_diag,
 284                         coord2sstr(flip_coord(b, c, flip_horiz, flip_vert, flip_diag), b),
 285                         s->type, s->d, b->symmetry.type, b->symmetry.d);
 286         }
 287         tree_fix_node_symmetry(b, tree->root, flip_horiz, flip_vert, flip_diag);
 288 }
 289
 290
 291 static void
 292 tree_unlink_node(struct tree_node *node)
 293 {
 294         struct tree_node *ni = node->parent;
 295         if (ni->children == node) {
 296                 ni->children = node->sibling;
 297         } else {
 298                 ni = ni->children;
 299                 while (ni->sibling != node)
 300                         ni = ni->sibling;
 301                 ni->sibling = node->sibling;
 302         }
 303 }
 304
 305 void
 306 tree_delete_node(struct tree *tree, struct tree_node *node)
 307 {
 308         tree_unlink_node(node);
 309         tree_done_node(tree, node);
 310 }
 311
 312 void
 313 tree_promote_node(struct tree *tree, struct tree_node *node)
 314 {
 315         assert(node->parent == tree->root);
 316         tree_unlink_node(node);
 317         tree_done_node(tree, tree->root);
 318         tree->root = node;
 319         board_symmetry_update(tree->board, &tree->root_symmetry, node->coord);
 320         node->parent = NULL;
 321 }
 322
 323 bool
 324 tree_promote_at(struct tree *tree, struct board *b, coord_t c)
 325 {
 326         tree_fix_symmetry(tree, b, c);
 327
 328         for (struct tree_node *ni = tree->root->children; ni; ni = ni->sibling) {
 329                 if (ni->coord == c) {
 330                         tree_promote_node(tree, ni);
 331                         return true;
 332                 }
 333         }
 334         return false;
 335 }
 336
 337 bool
 338 tree_leaf_node(struct tree_node *node)
 339 {
 340         return !(node->children);
 341 }
 342
 343 void
 344 tree_update_node_value(struct tree_node *node, bool add_amaf)
 345 {
 346         node->u.value = (float)(node->u.wins + node->prior.wins + (add_amaf ? node->amaf.wins : 0))
 347                         / (node->u.playouts + node->prior.playouts + (add_amaf ? node->amaf.playouts : 0));
 348 #if 0
 349         { struct board b2; board_size(&b2) = 9+2;
 350         fprintf(stderr, "%s->%s %d/%d %d/%d %f\n", node->parent ? coord2sstr(node->parent->coord, &b2) : NULL, coord2sstr(node->coord, &b2), node->u.wins, node->u.playouts, node->prior.wins, node->prior.playouts, node->u.value); }
 351 #endif
 352 }