pike.git/src/rbtree_low.h:5aad93d0f00ff6eaf5b329826eb84e35b67fc4b4

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 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 /* The lower level api for using rbtree. This is in a separate file * since it's quite macro heavy. * * Created 2001-04-27 by Martin Stjernholm * * $Id: rbtree_low.h,v 1.2 2002/08/15 14:49:25 marcus Exp $ */ #ifndef RBTREE_LOW_H #define RBTREE_LOW_H #include "rbtree.h" /* A sliced stack is used to track the way down in a tree, so we can * back up again easily while rebalancing it. The first slice is * allocated on the C stack. */ #define STACK_SLICE_SIZE 20 /* This is in the worst possible case enough for trees of size * 2^(20/2) = 1024 before allocating another slice, but in the typical * case it's enough for trees with up to about 2^(20-1) = 524288 * elements. */ struct rbstack_slice { #ifdef RB_STATS size_t depth, maxdepth; #endif struct rbstack_slice *up; struct rb_node_hdr *stack[STACK_SLICE_SIZE]; }; struct rbstack_ptr { struct rbstack_slice *slice; size_t ssp; /* Only zero when the stack is empty. */ }; void rbstack_push (struct rbstack_ptr *rbstack, struct rb_node_hdr *node); void rbstack_pop (struct rbstack_ptr *rbstack); void rbstack_up (struct rbstack_ptr *rbstack); void rbstack_up_to_root (struct rbstack_ptr *rbstack); void rbstack_free (struct rbstack_ptr *rbstack); void rbstack_insert (struct rbstack_ptr *top, struct rbstack_ptr *pos, struct rb_node_hdr *node); void rbstack_assign (struct rbstack_ptr *target, struct rbstack_ptr *source); void rbstack_copy (struct rbstack_ptr *target, struct rbstack_ptr *source); void rbstack_shift (struct rbstack_ptr rbstack, struct rb_node_hdr *oldbase, struct rb_node_hdr *newbase); #define RBSTACK_INIT(rbstack) \ struct rbstack_slice PIKE_CONCAT3 (_, rbstack, _top_) = { \ DO_IF_RB_STATS (0 COMMA 0 COMMA) \ NULL, \ {} \ }; \ struct rbstack_ptr rbstack = { \ (PIKE_CONCAT3 (_, rbstack, _top_).up = NULL, \ &PIKE_CONCAT3 (_, rbstack, _top_)), \ 0 \ } #define RBSTACK_PUSH(rbstack, node) do { \ if ((rbstack).ssp < STACK_SLICE_SIZE) { \ (rbstack).slice->stack[(rbstack).ssp++] = (node); \ } \ else rbstack_push (&(rbstack), node); \ DO_IF_RB_STATS ( \ if (++(rbstack).slice->depth > (rbstack).slice->maxdepth) \ (rbstack).slice->maxdepth = (rbstack).slice->depth; \ ); \ } while (0) #define RBSTACK_POP(rbstack, node) do { \ if ((rbstack).ssp) { \ (node) = (rbstack).slice->stack[--(rbstack).ssp]; \ DO_IF_RB_STATS ((rbstack).slice->depth--); \ if (!(rbstack).ssp && (rbstack).slice->up) \ rbstack_pop (&(rbstack)); \ } \ else (node) = NULL; \ } while (0) #define RBSTACK_POP_IGNORE(rbstack) do { \ if ((rbstack).ssp && !--(rbstack).ssp) { \ DO_IF_RB_STATS ((rbstack).slice->depth--); \ if ((rbstack).slice->up) \ rbstack_pop (&(rbstack)); \ } \ } while (0) #define RBSTACK_UP(rbstack, node) do { \ if ((rbstack).ssp) { \ (node) = (rbstack).slice->stack[--(rbstack).ssp]; \ if (!(rbstack).ssp && (rbstack).slice->up) \ rbstack_up (&(rbstack)); \ } \ else (node) = NULL; \ } while (0) #define RBSTACK_UP_IGNORE(rbstack) do { \ if ((rbstack).ssp && !--(rbstack).ssp && (rbstack).slice->up) \ rbstack_up (&(rbstack)); \ } while (0) #define RBSTACK_PEEK(rbstack) \ ((rbstack).ssp ? (rbstack).slice->stack[(rbstack).ssp - 1] : NULL) #define RBSTACK_POKE(rbstack, node) do { \ DO_IF_DEBUG (if (!(rbstack).ssp) Pike_fatal ("Using free stack pointer.\n")); \ (rbstack).slice->stack[(rbstack).ssp - 1] = (node); \ } while (0) #define RBSTACK_UP_TO_ROOT(rbstack, node) do { \ if ((rbstack).ssp) { \ rbstack_up_to_root (&(rbstack)); \ (node) = (rbstack).slice->stack[0]; \ } \ } while (0) #define RBSTACK_FREE(rbstack) do { \ if ((rbstack).ssp) { \ if ((rbstack).slice->up) rbstack_free (&(rbstack)); \ (rbstack).ssp = 0; \ } \ DO_IF_RB_STATS ( \ rb_num_tracks++; \ rb_track_depth += (rbstack).slice->maxdepth; \ if ((rbstack).slice->maxdepth > rb_max_depth) \ rb_max_depth = (rbstack).slice->maxdepth; \ (rbstack).slice->depth = (rbstack).slice->maxdepth = 0; \ ); \ } while (0) #define RBSTACK_FREE_SET_ROOT(rbstack, node) do { \ if ((rbstack).ssp) { \ if ((rbstack).slice->up) rbstack_free (&(rbstack)); \ (node) = (rbstack).slice->stack[0]; \ } \ DO_IF_RB_STATS ( \ rb_num_tracks++; \ rb_track_depth += (rbstack).slice->maxdepth; \ if ((rbstack).slice->maxdepth > rb_max_depth) \ rb_max_depth = (rbstack).slice->maxdepth; \ (rbstack).slice->depth = (rbstack).slice->maxdepth = 0; \ ); \ } while (0) void low_rb_init_root (struct rb_node_hdr *new_root); void low_rb_link_at_prev (struct rb_node_hdr **root, struct rbstack_ptr rbstack, struct rb_node_hdr *new); void low_rb_link_at_next (struct rb_node_hdr **root, struct rbstack_ptr rbstack, struct rb_node_hdr *new); struct rb_node_hdr *low_rb_unlink_with_move (struct rb_node_hdr **root, struct rbstack_ptr *rbstack_ptr, int keep_rbstack, size_t node_size); void low_rb_unlink_without_move (struct rb_node_hdr **root, struct rbstack_ptr *rbstack_ptr, int keep_rbstack); void low_rb_build_stack (struct rb_node_hdr *root, struct rb_node_hdr *node, struct rbstack_ptr *rbstack); #if defined (PIKE_DEBUG) || defined (TEST_MULTISET) typedef void dump_data_fn (struct rb_node_hdr *node, void *extra); void debug_dump_rb_tree (struct rb_node_hdr *root, dump_data_fn *dump_data, void *extra); void debug_dump_rbstack (struct rbstack_ptr rbstack, struct rbstack_ptr *pos); void debug_check_rb_tree (struct rb_node_hdr *root, dump_data_fn *dump_data, void *extra); void debug_check_rbstack (struct rb_node_hdr *root, struct rbstack_ptr rbstack); #endif /* Traverses the tree in depth-first order: * push Run when entering the node. Preceded by an enter_* label. * p_leaf Run when the prev pointer of the node isn't a subtree. * p_sub Run when the prev pointer of the node is a subtree. * between Run after the prev subtree has been recursed and before * the next subtree is examined. Preceded by a between_* * label. * n_leaf Run when the next pointer of the node isn't a subtree. * n_sub Run when the next pointer of the node is a subtree. * pop Run when leaving the node. Preceded by a leave_* label. */ #define LOW_RB_TRAVERSE(label, rbstack, node, push, p_leaf, p_sub, \ between, n_leaf, n_sub, pop) \ do { \ struct rb_node_hdr *rb_last_; \ DO_IF_RB_STATS (rb_num_traverses++); \ if (node) { \ PIKE_CONCAT (enter_, label): \ DO_IF_RB_STATS (rb_num_traverse_ops++); \ {push;} \ if ((node)->flags & RB_THREAD_PREV) \ {p_leaf;} \ else { \ {p_sub;} \ RBSTACK_PUSH (rbstack, node); \ (node) = (node)->prev; \ goto PIKE_CONCAT (enter_, label); \ } \ PIKE_CONCAT (between_, label): \ {between;} \ if ((node)->flags & RB_THREAD_NEXT) \ {n_leaf;} \ else { \ {n_sub;} \ RBSTACK_PUSH (rbstack, node); \ (node) = (node)->next; \ goto PIKE_CONCAT (enter_, label); \ } \ while (1) { \ PIKE_CONCAT (leave_, label): \ DO_IF_RB_STATS (rb_num_traverse_ops++); \ {pop;} \ rb_last_ = (node); \ RBSTACK_POP (rbstack, node); \ if (!(node)) break; \ if (rb_last_ == (node)->prev) \ goto PIKE_CONCAT (between_, label); \ } \ } \ } while (0) #define LOW_RB_DEBUG_TRAVERSE(label, rbstack, node, push, p_leaf, p_sub, \ between, n_leaf, n_sub, pop) \ do { \ size_t PIKE_CONCAT (depth_, label) = 0; \ LOW_RB_TRAVERSE( \ label, rbstack, node, \ fprintf (stderr, "%*s%p enter\n", \ PIKE_CONCAT (depth_, label)++, "", node); {push;}, \ fprintf (stderr, "%*s%p prev leaf\n", \ PIKE_CONCAT (depth_, label), "", node); {p_leaf;}, \ fprintf (stderr, "%*s%p prev subtree\n", \ PIKE_CONCAT (depth_, label), "", node); {p_sub;}, \ fprintf (stderr, "%*s%p between\n", \ PIKE_CONCAT (depth_, label) - 1, "", node); {between;}, \ fprintf (stderr, "%*s%p next leaf\n", \ PIKE_CONCAT (depth_, label), "", node); {n_leaf;}, \ fprintf (stderr, "%*s%p next subtree\n", \ PIKE_CONCAT (depth_, label), "", node); {n_sub;}, \ fprintf (stderr, "%*s%p leave\n", \ --PIKE_CONCAT (depth_, label), "", node); {pop;}); \ } while (0) /* The `cmp' code should set the variable cmp_res to the result of the * comparison between the key and the current node `node'. */ #define LOW_RB_FIND(node, cmp, got_lt, got_eq, got_gt) \ do { \ int cmp_res, found_eq_ = 0; \ DO_IF_RB_STATS ( \ size_t stat_depth_count_ = 0; \ rb_num_finds++; \ ); \ while (1) { \ DO_IF_DEBUG (if (!node) Pike_fatal ("Recursing into null node.\n")); \ DO_IF_RB_STATS ( \ if (++stat_depth_count_ > rb_max_depth) \ rb_max_depth = stat_depth_count_; \ rb_find_depth++; \ ); \ {cmp;} \ if (cmp_res < 0) \ if ((node)->flags & RB_THREAD_PREV) \ if (found_eq_) \ (node) = (node)->prev; \ else { \ {got_gt;} \ break; \ } \ else { \ (node) = (node)->prev; \ continue; \ } \ else \ if ((node)->flags & RB_THREAD_NEXT) \ if (!cmp_res) \ {} \ else { \ {got_lt;} \ break; \ } \ else { \ if (!cmp_res) found_eq_ = 1; \ (node) = (node)->next; \ continue; \ } \ {got_eq;} \ break; \ } \ } while (0) /* Variant of LOW_RB_FIND that assumes that `cmp' never returns 0. */ #define LOW_RB_FIND_NEQ(node, cmp, got_lt, got_gt) \ do { \ int cmp_res; \ DO_IF_RB_STATS ( \ size_t stat_depth_count_ = 0; \ rb_num_finds++; \ ); \ while (1) { \ DO_IF_DEBUG (if (!node) Pike_fatal ("Recursing into null node.\n")); \ DO_IF_RB_STATS ( \ if (++stat_depth_count_ > rb_max_depth) \ rb_max_depth = stat_depth_count_; \ rb_find_depth++; \ ); \ {cmp;} \ if (cmp_res < 0) { \ if ((node)->flags & RB_THREAD_PREV) { \ {got_gt;} \ break; \ } \ (node) = (node)->prev; \ } \ else { \ DO_IF_DEBUG (if (!cmp_res) Pike_fatal ("cmp_res 0 not expected.\n")); \ if ((node)->flags & RB_THREAD_NEXT) { \ {got_lt;} \ break; \ } \ (node) = (node)->next; \ } \ } \ } while (0) /* Tracks the way down a tree to a specific node and updates the stack * as necessary for low_rb_link_* and low_rb_unlink_*. */ #define LOW_RB_TRACK(rbstack, node, cmp, got_lt, got_eq, got_gt) \ do { \ DO_IF_DEBUG ( \ if (RBSTACK_PEEK (rbstack)) Pike_fatal ("The stack is not empty.\n"); \ ); \ DO_IF_RB_STATS (rb_num_finds--); \ LOW_RB_FIND ( \ node, \ { \ DO_IF_RB_STATS (rb_find_depth--); \ RBSTACK_PUSH (rbstack, node); \ {cmp;} \ }, \ got_lt, \ { \ while ((node) != RBSTACK_PEEK (rbstack)) \ RBSTACK_POP_IGNORE (rbstack); \ {got_eq;} \ }, got_gt); \ } while (0) #define LOW_RB_TRACK_NEQ(rbstack, node, cmp, got_lt, got_gt) \ do { \ DO_IF_DEBUG ( \ if (RBSTACK_PEEK (rbstack)) Pike_fatal ("The stack is not empty.\n"); \ ); \ DO_IF_RB_STATS (rb_num_finds--); \ LOW_RB_FIND_NEQ ( \ node, \ { \ DO_IF_RB_STATS (rb_find_depth--); \ RBSTACK_PUSH (rbstack, node); \ {cmp;} \ }, \ got_lt, got_gt); \ } while (0) /* Goes to the first node in a tree while keeping the stack updated. */ #define LOW_RB_TRACK_FIRST(rbstack, node) \ do { \ DO_IF_DEBUG ( \ if (RBSTACK_PEEK (rbstack)) Pike_fatal ("The stack is not empty.\n"); \ ); \ DO_IF_RB_STATS (rb_num_sidetracks++); \ if (node) { \ struct rb_node_hdr *rb_prev_ = node->prev; \ RBSTACK_PUSH (rbstack, node); \ DO_IF_RB_STATS (rb_num_sidetrack_ops++); \ while (rb_prev_) { \ RBSTACK_PUSH (rbstack, node = rb_prev_); \ DO_IF_RB_STATS (rb_num_sidetrack_ops++); \ rb_prev_ = node->prev; \ } \ } \ } while (0) /* Goes to the next node in order while keeping the stack updated. */ #define LOW_RB_TRACK_NEXT(rbstack, node) \ do { \ DO_IF_DEBUG ( \ if (node != RBSTACK_PEEK (rbstack)) \ Pike_fatal ("Given node is not on top of stack.\n"); \ ); \ DO_IF_RB_STATS (rb_num_sidetracks++); \ if (node->flags & RB_THREAD_NEXT) { \ struct rb_node_hdr *rb_next_ = node->next; \ while ((node = RBSTACK_PEEK (rbstack)) != rb_next_) { \ RBSTACK_POP_IGNORE (rbstack); \ DO_IF_RB_STATS (rb_num_sidetrack_ops++); \ } \ } \ else { \ node = node->next; \ while (1) { \ RBSTACK_PUSH (rbstack, node); \ DO_IF_RB_STATS (rb_num_sidetrack_ops++); \ if (node->flags & RB_THREAD_PREV) break; \ node = node->prev; \ } \ } \ } while (0) /* Goes to the previous node in order while keeping the stack updated. */ #define LOW_RB_TRACK_PREV(rbstack, node) \ do { \ DO_IF_DEBUG ( \ if (node != RBSTACK_PEEK (rbstack)) \ Pike_fatal ("Given node is not on top of stack.\n"); \ ); \ DO_IF_RB_STATS (rb_num_sidetracks++); \ if (node->flags & RB_THREAD_PREV) { \ struct rb_node_hdr *rb_prev_ = node->prev; \ while ((node = RBSTACK_PEEK (rbstack)) != rb_prev_) { \ RBSTACK_POP_IGNORE (rbstack); \ DO_IF_RB_STATS (rb_num_sidetrack_ops++); \ } \ } \ else { \ node = node->prev; \ while (1) { \ RBSTACK_PUSH (rbstack, node); \ DO_IF_RB_STATS (rb_num_sidetrack_ops++); \ if (node->flags & RB_THREAD_NEXT) break; \ node = node->next; \ } \ } \ } while (0) /* An alternative to rb_insert, which might or might not insert the * newly created node. This one compares nodes like LOW_RB_FIND and * will only run the code `insert' when a new node actually is to be * inserted, otherwise it runs the code `replace' on the matching * existing node. */ #define LOW_RB_INSERT(tree, node, cmp, insert, replace) \ do { \ int rb_ins_type_; \ RBSTACK_INIT (rbstack); \ if (((node) = *(tree))) { \ LOW_RB_TRACK ( \ rbstack, node, cmp, \ { \ rb_ins_type_ = 1; /* Got less - link at next. */ \ }, { \ rb_ins_type_ = 0; /* Got equal - replace. */ \ {replace;} \ RBSTACK_FREE (rbstack); \ }, { \ rb_ins_type_ = 2; /* Got greater - link at prev. */ \ }); \ } \ else rb_ins_type_ = 3; \ if (rb_ins_type_) { \ DO_IF_DEBUG ((node) = 0); \ {insert;} \ switch (rb_ins_type_) { \ case 1: low_rb_link_at_next ((tree), rbstack, (node)); break; \ case 2: low_rb_link_at_prev ((tree), rbstack, (node)); break; \ case 3: low_rb_init_root (*(tree) = (node)); break; \ } \ } \ } while (0) /* Merges the two trees a and b in linear time (no more, no less). The * operation argument describes the way to merge, like the one given * to merge() in array.c. cmp does the comparison between a and b to * cmp_res, copy_a and copy_b copy the nodes a and b resp, to * new_node. free_a and free_b free the nodes a and b resp. prep_a and * prep_b is run for every visited node in a and b resp, before any of * the other code blocks. * * The result in res is a list linked by the next pointers, and length * is set to the length of it. These are suitable for rb_make_tree. * * NB: It doesn't handle making duplicates of the same node, i.e. * PIKE_ARRAY_OP_A without PIKE_ARRAY_OP_SKIP_A. Not a problem since * none of the currently defined operations use that. */ #define LOW_RB_MERGE(label, a, b, res, length, operation, \ prep_a, prep_b, cmp, copy_a, free_a, copy_b, free_b) \ do { \ struct rb_node_hdr *new_node; \ int cmp_res, op_ = 0; /* Init only to avoid warnings. */ \ /* Traverse backwards so that the merge "gravitates" towards the */ \ /* end when duplicate entries are processed, e.g. */ \ /* (<1:1, 1:2>) | (<1:3>) produces (<1:1, 1:3>) and not */ \ /* (<1:3, 1:2>). */ \ \ a = rb_last (a); \ b = rb_last (b); \ res = 0; \ \ while (1) { \ /* A bit quirky code to avoid expanding the code blocks more */ \ /* than once. */ \ if (a) {prep_a;} \ if (b) { \ {prep_b;} \ if (a) { \ {cmp;} \ /* Result reversed due to backward direction. */ \ if (cmp_res > 0) \ op_ = operation >> 8; \ else if (cmp_res < 0) \ op_ = operation; \ else \ op_ = operation >> 4; \ } \ else if (operation & PIKE_ARRAY_OP_B) \ goto PIKE_CONCAT (label, _copy_b); \ else \ goto PIKE_CONCAT (label, _free_b); \ } \ else \ if (a) \ if (operation & (PIKE_ARRAY_OP_A << 8)) \ goto PIKE_CONCAT (label, _copy_a); \ else \ goto PIKE_CONCAT (label, _free_a); \ else \ break; \ \ if (op_ & PIKE_ARRAY_OP_B) { \ PIKE_CONCAT (label, _copy_b):; \ {copy_b;} \ new_node->next = res, res = new_node; \ length++; \ b = rb_prev (b); \ } \ else if (op_ & PIKE_ARRAY_OP_SKIP_B) { \ PIKE_CONCAT (label, _free_b):; \ new_node = rb_prev (b); \ {free_b;} \ b = new_node; \ } \ \ if (a) { \ if (op_ & PIKE_ARRAY_OP_A) { \ if (!(op_ & PIKE_ARRAY_OP_B)) { \ PIKE_CONCAT (label, _copy_a):; \ {copy_a;} \ new_node->next = res, res = new_node; \ length++; \ a = rb_prev (a); \ } \ } \ else if (op_ & PIKE_ARRAY_OP_SKIP_A) { \ PIKE_CONCAT (label, _free_a):; \ new_node = rb_prev (a); \ {free_a;} \ a = new_node; \ } \ } \ } \ } while (0) #endif /* RBTREE_H */

pike.git/ src/ rbtree_low.h > 5aad93d0f00ff6eaf5b329826eb84e35b67fc4b4 [Annotate]