1 | /* |
2 | * bt_iterator.c |
3 | * |
4 | * Copyright (C) 2013-2014 Aerospike, Inc. |
5 | * |
6 | * Portions may be licensed to Aerospike, Inc. under one or more contributor |
7 | * license agreements. |
8 | * |
9 | * This program is free software: you can redistribute it and/or modify it under |
10 | * the terms of the GNU Affero General Public License as published by the Free |
11 | * Software Foundation, either version 3 of the License, or (at your option) any |
12 | * later version. |
13 | * |
14 | * This program is distributed in the hope that it will be useful, but WITHOUT |
15 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS |
16 | * FOR A PARTICULAR PURPOSE. See the GNU Affero General Public License for more |
17 | * details. |
18 | * |
19 | * You should have received a copy of the GNU Affero General Public License |
20 | * along with this program. If not, see http://www.gnu.org/licenses/ |
21 | */ |
22 | /* |
23 | * This file implements Aerospike Index B-tree iterators. |
24 | */ |
25 | |
26 | #include <assert.h> |
27 | #include <float.h> |
28 | #include <stdio.h> |
29 | #include <stdlib.h> |
30 | #include <string.h> |
31 | #include <strings.h> |
32 | #include <sys/param.h> // For MAX() & MIN(). |
33 | |
34 | #include "ai_obj.h" |
35 | #include "bt_iterator.h" |
36 | #include "stream.h" |
37 | #include <citrusleaf/alloc.h> |
38 | |
39 | // HELPER_DEFINES HELPER_DEFINES HELPER_DEFINES HELPER_DEFINES HELPER_DEFINES |
40 | #define GET_NEW_CHILD(iter) \ |
41 | if (!iter->bln->child) { iter->bln->child = get_new_iter_child(iter); } |
42 | |
43 | #define SETITER8R(iter, btr, asc, l, lrev, n, nrev) \ |
44 | btSIter *siter = setIterator(iter, btr, asc ? l : lrev, asc ? n : nrev); |
45 | |
46 | #define CR8ITER8R(btr, asc, l, lrev, n, nrev) \ |
47 | btSIter *siter = createIterator(btr, asc ? l : lrev, asc ? n : nrev); |
48 | |
49 | bt_ll_n *get_new_iter_child(btIterator *iter) { //printf("get_newiterchild\n"); |
50 | assert(iter->num_nodes < MAX_BTREE_DEPTH); |
51 | bt_ll_n *nn = &(iter->nodes[iter->num_nodes]); |
52 | bzero(nn, sizeof(bt_ll_n)); |
53 | iter->num_nodes++; |
54 | return nn; |
55 | } |
56 | |
57 | void to_child(btIterator *iter, bt_n* self) { //printf("to_child\n"); |
58 | iter->depth++; |
59 | iter->bln->child->parent = iter->bln; |
60 | iter->bln->child->ik = 0; |
61 | iter->bln->child->in = 0; |
62 | iter->bln->child->self = self; |
63 | iter->bln = iter->bln->child; |
64 | } |
65 | static void toparentrecurse(btIterator *iter) { //printf("to_parent\n"); |
66 | if (!iter->bln->parent) { |
67 | iter->finished = 1; /* finished */ |
68 | return; |
69 | } |
70 | iter->depth--; |
71 | bt *btr = iter->btr; |
72 | void *child = KEYS(btr, iter->bln->self, iter->bln->ik); |
73 | iter->bln = iter->bln->parent; /* -> parent */ |
74 | void *parent = KEYS(btr, iter->bln->self, iter->bln->ik); |
75 | int x = btr->cmp(child, parent); |
76 | if (x > 0) { |
77 | if ((iter->bln->ik + 1) < iter->bln->self->n) iter->bln->ik++; |
78 | if ((iter->bln->in + 1) < iter->bln->self->n) iter->bln->in++; |
79 | else toparentrecurse(iter); |
80 | } |
81 | } |
82 | static void iter_leaf(btIterator *iter) { //printf("iter_leaf\n"); |
83 | if ((iter->bln->ik + 1) < iter->bln->self->n) iter->bln->ik++; |
84 | else toparentrecurse(iter); |
85 | } |
86 | static void tochildrecurse(btIterator *iter, bt_n* self) { |
87 | to_child(iter, self); |
88 | if (!iter->bln->self->leaf) { // depth-first |
89 | GET_NEW_CHILD(iter) |
90 | tochildrecurse(iter, NODES(iter->btr, iter->bln->self)[iter->bln->in]); |
91 | } |
92 | } |
93 | static void iter_node(btIterator *iter) { |
94 | if ((iter->bln->ik + 1) < iter->bln->self->n) iter->bln->ik++; |
95 | if ((iter->bln->in + 1) <= iter->bln->self->n) iter->bln->in++; |
96 | GET_NEW_CHILD(iter) |
97 | tochildrecurse(iter, NODES(iter->btr, iter->bln->self)[iter->bln->in]); |
98 | } |
99 | |
100 | static void *btNext(btSIter *siter, bt_n **rx, int *ri, bool asc) { |
101 | btIterator *iter = &(siter->x); |
102 | if (iter->finished) { |
103 | if (siter->scan) siter->missed = siter->nim; |
104 | return NULL; |
105 | } |
106 | if (asc) siter->missed = siter->nim; //Curr MISSED = LastLoop's NextIsMissed |
107 | bt_n *x = iter->bln->self; |
108 | if (rx) *rx = x; |
109 | int i = iter->bln->ik; |
110 | if (ri) *ri = i; |
111 | void *curr = KEYS(iter->btr, x, i); |
112 | siter->nim = getDR(iter->btr, x, i) ? 1 : 0; |
113 | if (iter->bln->self->leaf) (*iter->iLeaf)(iter); |
114 | else (*iter->iNode)(iter); |
115 | return curr; |
116 | } |
117 | |
118 | void to_child_rev(btIterator *iter, bt_n* self) { |
119 | iter->depth++; |
120 | iter->bln->child->parent = iter->bln; |
121 | iter->bln->child->ik = self->n - 1; |
122 | iter->bln->child->in = self->n; |
123 | iter->bln->child->self = self; |
124 | iter->bln = iter->bln->child; |
125 | } |
126 | static void tochildrecurserev(btIterator *iter, bt_n* self) { |
127 | to_child_rev(iter, self); |
128 | if (!iter->bln->self->leaf) { // depth-first |
129 | GET_NEW_CHILD(iter) |
130 | tochildrecurserev(iter, |
131 | NODES(iter->btr, iter->bln->self)[iter->bln->in]); |
132 | } |
133 | } |
134 | static void toparentrecurserev(btIterator *iter) { |
135 | if (!iter->bln->parent) { |
136 | iter->finished = 1; /* finished */ |
137 | return; |
138 | } |
139 | iter->depth--; |
140 | bt *btr = iter->btr; |
141 | void *child = KEYS(btr, iter->bln->self, iter->bln->ik); |
142 | iter->bln = iter->bln->parent; /* -> parent */ |
143 | void *parent = KEYS(btr, iter->bln->self, iter->bln->ik); |
144 | int x = btr->cmp(child, parent); |
145 | if (x < 0) { |
146 | if (iter->bln->ik) iter->bln->ik--; |
147 | if (iter->bln->in) iter->bln->in--; |
148 | else toparentrecurserev(iter); |
149 | } |
150 | if (iter->bln->in == iter->bln->self->n) iter->bln->in--; |
151 | } |
152 | static void iter_leaf_rev(btIterator *iter) { //printf("iter_leaf_rev\n"); |
153 | if (iter->bln->ik) iter->bln->ik--; |
154 | else toparentrecurserev(iter); |
155 | } |
156 | static void iter_node_rev(btIterator *iter) { |
157 | GET_NEW_CHILD(iter) |
158 | tochildrecurserev(iter, NODES(iter->btr, iter->bln->self)[iter->bln->in]); |
159 | } |
160 | |
161 | // INIT_ITERATOR INIT_ITERATOR INIT_ITERATOR INIT_ITERATOR INIT_ITERATOR |
162 | static void *setIter(bt *btr, bt_data_t bkey, btSIter *siter, ai_obj *alow, |
163 | bt_n **rx, int *ri, bool asc) { |
164 | btIterator *iter = &(siter->x); |
165 | int ret = bt_init_iterator(btr, bkey, iter, alow); |
166 | //printf("setIter: ret: %d\n", ret); |
167 | if (ret == II_FAIL) return NULL; |
168 | siter->empty = 0; |
169 | if (ret == II_L_MISS) { |
170 | siter->nim = siter->missed = 1; |
171 | return NULL; |
172 | } |
173 | else if (ret == II_MISS) siter->nim = siter->missed = 1; |
174 | else if (ret != II_OK) { /* range queries, find nearest match */ |
175 | int x = btr->cmp(bkey, KEYS(btr, iter->bln->self, iter->bln->ik)); |
176 | if (x > 0) { |
177 | if (ret == II_ONLY_RIGHT) { // off end of B-tree |
178 | siter->empty = 1; |
179 | return NULL; |
180 | } else { // II_LEAF_EXIT |
181 | //printf("setIter: [II_LEAF_EXIT\n"); //TODO needed? |
182 | return btNext(siter, rx, ri, asc); // find next |
183 | } |
184 | } |
185 | } |
186 | if (rx) *rx = iter->bln->self; |
187 | if (ri) *ri = iter->bln->ik; |
188 | return KEYS(iter->btr, iter->bln->self, iter->bln->ik); |
189 | } |
190 | static void init_iter(btIterator *iter, bt *btr, |
191 | iter_single *itl, iter_single *itn) { |
192 | iter->btr = btr; |
193 | iter->high = LONG_MIN; |
194 | iter->iLeaf = itl; |
195 | iter->iNode = itn; |
196 | iter->finished = 0; |
197 | iter->num_nodes = 0; |
198 | iter->bln = &(iter->nodes[0]); |
199 | iter->bln->ik = iter->bln->in = 0; |
200 | iter->num_nodes++; |
201 | iter->bln->self = btr->root; |
202 | iter->bln->parent = iter->bln->child = NULL; |
203 | iter->depth = 0; |
204 | } |
205 | |
206 | // AEROSPIKE MULTI_THREAD |
207 | static btSIter *newIter() { |
208 | btSIter *siter = cf_malloc(sizeof(btSIter)); |
209 | bzero(siter, sizeof(btSIter)); |
210 | return siter; |
211 | } |
212 | |
213 | static btSIter *getIterator() { |
214 | return newIter(); |
215 | } |
216 | |
217 | static void releaseIterator(btSIter *siter) { |
218 | if (siter) { |
219 | cf_free(siter); |
220 | } |
221 | return; |
222 | } |
223 | |
224 | static btSIter *createIterator(bt *btr, iter_single *itl, iter_single *itn) { |
225 | btSIter *siter = getIterator(); |
226 | siter->dofree = 1; |
227 | siter->missed = 0; |
228 | siter->nim = 0; |
229 | siter->empty = 1; |
230 | siter->scan = 0; |
231 | siter->ktype = btr->s.ktype; |
232 | init_ai_obj(&siter->key); |
233 | siter->be.key = &(siter->key); |
234 | siter->be.val = NULL; |
235 | init_iter(&siter->x, btr, itl, itn); |
236 | return siter; |
237 | } |
238 | //extra insertion |
239 | |
240 | static btSIter *setIterator(btSIter *iter, bt *btr, iter_single *itl, iter_single *itn) { |
241 | btSIter *siter = iter; |
242 | siter->dofree = 0; |
243 | siter->missed = 0; |
244 | siter->nim = 0; |
245 | siter->empty = 1; |
246 | siter->scan = 0; |
247 | siter->ktype = btr->s.ktype; |
248 | init_ai_obj(&siter->key); |
249 | siter->be.key = &(siter->key); |
250 | siter->be.val = NULL; |
251 | init_iter(&siter->x, btr, itl, itn); |
252 | return siter; |
253 | } |
254 | void btReleaseRangeIterator(btSIter *siter) { |
255 | if (!siter) return; |
256 | if (siter->dofree) { |
257 | releaseIterator(siter); |
258 | } |
259 | } |
260 | static void setHigh(btSIter *siter, ai_obj *high, col_type_t ktype) { |
261 | if (C_IS_L(ktype) || C_IS_G(ktype)) { |
262 | siter->x.high = high->l; |
263 | } |
264 | else if (C_IS_DG(ktype)) { |
265 | siter->x.highy = high->y; |
266 | } |
267 | } |
268 | |
269 | static bool streamToBTEntry(uchar *stream, btSIter *siter, bt_n *x, int i) { |
270 | if (!stream) return 0; |
271 | if (i < 0) i = 0; |
272 | convertStream2Key(stream, siter->be.key, siter->x.btr); |
273 | siter->be.val = parseStream(stream, siter->x.btr); |
274 | bool gost = IS_GHOST(siter->x.btr, siter->be.val); |
275 | if (gost) { |
276 | siter->missed = 1; // GHOST key |
277 | siter->nim = 0; |
278 | } |
279 | siter->be.dr = x ? getDR(siter->x.btr, x, i) : 0; |
280 | siter->be.stream = stream; |
281 | siter->be.x = x; |
282 | siter->be.i = i; //NOTE: used by bt_validate_dirty |
283 | //DUMP_STREAM_TO_BT_ENTRY |
284 | return 1; |
285 | } |
286 | btSIter *btGetRangeIter(bt *btr, ai_obj *alow, ai_obj *ahigh, bool asc) { |
287 | if (!btr->root || !btr->numkeys) return NULL; |
288 | btk_t btk; |
289 | bool med; |
290 | uint32 ksize; //bt_dumptree(btr, btr->ktype); |
291 | CR8ITER8R(btr, asc, iter_leaf, iter_leaf_rev, iter_node, iter_node_rev); |
292 | setHigh(siter, asc ? ahigh : alow, btr->s.ktype); |
293 | char *bkey = createBTKey(asc ? alow : ahigh, |
294 | &med, &ksize, btr, &btk); //D032 |
295 | if (!bkey) goto rangeiter_err; |
296 | bt_n *x = NULL; |
297 | int i = -1; |
298 | uchar *stream = setIter(btr, bkey, siter, asc ? alow : ahigh, &x, &i, asc); |
299 | destroyBTKey(bkey, med); /* DESTROYED 032 */ |
300 | if (!streamToBTEntry(stream, siter, x, i)) goto rangeiter_err; |
301 | return siter; |
302 | |
303 | rangeiter_err: |
304 | btReleaseRangeIterator(siter); |
305 | return NULL; |
306 | } |
307 | |
308 | |
309 | btSIter *btSetRangeIter(btSIter * iter, bt *btr, ai_obj *alow, ai_obj *ahigh, bool asc) { |
310 | if (!btr->root || !btr->numkeys) return NULL; |
311 | btk_t btk; |
312 | bool med; |
313 | uint32 ksize; //bt_dumptree(btr, btr->ktype); |
314 | SETITER8R(iter, btr, asc, iter_leaf, iter_leaf_rev, iter_node, iter_node_rev); |
315 | setHigh(siter, asc ? ahigh : alow, btr->s.ktype); |
316 | char *bkey = createBTKey(asc ? alow : ahigh, |
317 | &med, &ksize, btr, &btk); //D032 |
318 | if (!bkey) goto rangeiter_err; |
319 | bt_n *x = NULL; |
320 | int i = -1; |
321 | uchar *stream = setIter(btr, bkey, siter, asc ? alow : ahigh, &x, &i, asc); |
322 | destroyBTKey(bkey, med); /* DESTROYED 032 */ |
323 | if (!streamToBTEntry(stream, siter, x, i)) goto rangeiter_err; |
324 | return siter; |
325 | |
326 | rangeiter_err: |
327 | btReleaseRangeIterator(siter); |
328 | return NULL; |
329 | } |
330 | btEntry *btRangeNext(btSIter *siter, bool asc) { //printf("btRangeNext\n"); |
331 | //printf("btRangeNext: siter: %p\n", (void *)siter); |
332 | //if (siter) printf("btRangeNext: empty: %d\n", siter->empty); |
333 | if (!siter || siter->empty) return NULL; |
334 | bt_n *x = NULL; |
335 | int i = -1; |
336 | uchar *stream = btNext(siter, &x, &i, asc); |
337 | if (!streamToBTEntry(stream, siter, x, i)) return NULL; |
338 | if (C_IS_L(siter->ktype) || C_IS_G(siter->ktype)) { |
339 | long l = siter->key.l; |
340 | if (l == siter->x.high) siter->x.finished = 1; /* exact match */ |
341 | if (!asc) { |
342 | //printf("btRangeNext: DESC: l: %lu dr: %u\n", |
343 | // l, getDR(siter->x.btr, x, i)); |
344 | l += getDR(siter->x.btr, x, i); |
345 | } |
346 | bool over = asc ? (l > siter->x.high) : (l < siter->x.high); |
347 | if (over && siter->nim) { |
348 | siter->missed = 1; |
349 | } |
350 | //printf("btRangeNext: over: %d l: %lu high: %lu\n", |
351 | // over, l, siter->x.high); |
352 | return over ? NULL : &(siter->be); |
353 | } else if (C_IS_DG(siter->ktype)) { |
354 | uint160 yy = siter->key.y; |
355 | int ret = u160Cmp(&yy, &siter->x.highy); |
356 | if (!ret) siter->x.finished = 1; /* exact match */ |
357 | if (!asc) { //TODO is ENDIANness of memcpy() correct |
358 | uint32 low; |
359 | char *spot = ((char *)&yy) + 12; |
360 | memcpy(&low, spot, 4); |
361 | low += getDR(siter->x.btr, x, i); |
362 | memcpy(spot, &low, 4); |
363 | } |
364 | bool over = asc ? (ret > 0) : (ret < 0); |
365 | return over ? NULL : &(siter->be); |
366 | } else { |
367 | return NULL; |
368 | } |
369 | } |
370 | |
371 | // FULL_BTREE_ITERATOR FULL_BTREE_ITERATOR FULL_BTREE_ITERATOR |
372 | bool assignMinKey(bt *btr, ai_obj *akey) { //TODO combine w/ setIter() |
373 | void *e = bt_min(btr); |
374 | if (!e) return 0; // iter can be initialised |
375 | convertStream2Key(e, akey, btr); |
376 | return 1; // w/ this lookup |
377 | } |
378 | bool assignMaxKey(bt *btr, ai_obj *akey) { |
379 | void *e = bt_max(btr); |
380 | if (!e) return 0; |
381 | convertStream2Key(e, akey, btr); |
382 | return 1; |
383 | } |
384 | btSIter *btGetFullRangeIter(bt *btr, bool asc, cswc_t *w) { |
385 | cswc_t W; // used in setHigh() |
386 | if (!btr->root || !btr->numkeys) return NULL; |
387 | if (!w) w = &W; |
388 | ai_obj *aL = &w->wf.alow, *aH = &w->wf.ahigh; |
389 | if (!assignMinKey(btr, aL) || !assignMaxKey(btr, aH)) return NULL; |
390 | btk_t btk; |
391 | bool med; |
392 | uint32 ksize; |
393 | CR8ITER8R(btr, asc, iter_leaf, iter_leaf_rev, iter_node, iter_node_rev); |
394 | siter->scan = 1; |
395 | setHigh(siter, asc ? aH : aL, btr->s.ktype); |
396 | char *bkey = createBTKey(asc ? aL : aH, |
397 | &med, &ksize, btr, &btk); //DEST 030 |
398 | if (!bkey) goto frangeiter_err; |
399 | bt_n *x = NULL; |
400 | int i = -1; |
401 | uchar *stream = setIter(btr, bkey, siter, asc ? aL : aH, &x, &i, asc); |
402 | destroyBTKey(bkey, med); /* DESTROYED 030 */ |
403 | if (!stream && siter->missed) return siter;//IILMISS |
404 | if (!streamToBTEntry(stream, siter, x, i)) goto frangeiter_err; |
405 | if (btr->dirty_left) siter->missed = 1; // FULL means 100% FULL |
406 | return siter; |
407 | |
408 | frangeiter_err: |
409 | btReleaseRangeIterator(siter); |
410 | return NULL; |
411 | } |
412 | |
413 | btSIter *btSetFullRangeIter(btSIter *iter, bt *btr, bool asc, cswc_t *w) { |
414 | cswc_t W; // used in setHigh() |
415 | if (!btr->root || !btr->numkeys) return NULL; |
416 | if (!w) w = &W; |
417 | ai_obj *aL = &w->wf.alow, *aH = &w->wf.ahigh; |
418 | if (!assignMinKey(btr, aL) || !assignMaxKey(btr, aH)) return NULL; |
419 | btk_t btk; |
420 | bool med; |
421 | uint32 ksize; |
422 | SETITER8R(iter, btr, asc, iter_leaf, iter_leaf_rev, iter_node, iter_node_rev); |
423 | siter->scan = 1; |
424 | setHigh(siter, asc ? aH : aL, btr->s.ktype); |
425 | char *bkey = createBTKey(asc ? aL : aH, |
426 | &med, &ksize, btr, &btk); //DEST 030 |
427 | if (!bkey) goto frangeiter_err; |
428 | bt_n *x = NULL; |
429 | int i = -1; |
430 | uchar *stream = setIter(btr, bkey, siter, asc ? aL : aH, &x, &i, asc); |
431 | destroyBTKey(bkey, med); /* DESTROYED 030 */ |
432 | if (!stream && siter->missed) return siter;//IILMISS |
433 | if (!streamToBTEntry(stream, siter, x, i)) goto frangeiter_err; |
434 | if (btr->dirty_left) siter->missed = 1; // FULL means 100% FULL |
435 | return siter; |
436 | |
437 | frangeiter_err: |
438 | btReleaseRangeIterator(siter); |
439 | return NULL; |
440 | } |
441 | |
442 | typedef struct four_longs { |
443 | long cnt; |
444 | long ofst; |
445 | long diff; |
446 | long over; |
447 | } fol_t; |
448 | |
449 | #define INIT_ITER_BEENTRY(siter, btr, x, i) \ |
450 | { uchar *iistream = KEYS(btr, x, i); streamToBTEntry(iistream, siter, x, i); } |
451 | static bool btScionFind(btSIter *siter, bt_n *x, ulong ofst, bt *btr, bool asc, |
452 | cswc_t *w, long lim) { |
453 | int i = asc ? 0 : x->n; |
454 | int fin = asc ? x->n + 1 : -1; |
455 | while (i != fin) { |
456 | if (x->leaf) break; |
457 | uint32_t scion = NODES(btr, x)[i]->scion; |
458 | if (scion >= ofst) { |
459 | bool i_end_n = (i == siter->x.bln->self->n); |
460 | siter->x.bln->in = i; |
461 | siter->x.bln->ik = (i_end_n) ? i - 1 : i; |
462 | if (scion == ofst) { |
463 | if (!asc) { |
464 | siter->x.bln->in = siter->x.bln->ik = i - 1; |
465 | } |
466 | return 1; |
467 | } |
468 | siter->x.bln->child = get_new_iter_child(&siter->x); |
469 | to_child(&siter->x, NODES(btr, x)[i]); |
470 | bt_n *kid = NODES(btr, x)[i]; |
471 | if (!kid->leaf) { |
472 | btScionFind(siter, kid, ofst, btr, asc, w, lim); |
473 | return 1; |
474 | } else x = kid; |
475 | break; |
476 | } else ofst -= (scion + 1); // +1 for NODE itself |
477 | i = asc ? i + 1 : i - 1; // loop increment |
478 | } |
479 | // Now Find the rest of the OFFSET (respecting DRs) |
480 | uint32 n = siter->x.bln->self->n; |
481 | i = asc ? 0 : n - 1; |
482 | fin = asc ? MIN(ofst, n) : MAX(-1, (n - ofst)); |
483 | int last = asc ? n - 1 : 0; |
484 | ulong cnt = 0; |
485 | //TODO findminnode() is too inefficient -> needs to be a part of btr |
486 | bt_n *minx = findminnode(btr, btr->root); |
487 | int btdl = btr->dirty_left; |
488 | int dr = 0; |
489 | while (i != fin) { |
490 | dr = getDR(btr, x, i); |
491 | cnt += dr; |
492 | if (!i && x == minx) cnt += btdl; |
493 | if (cnt >= ofst) break; |
494 | cnt++; |
495 | i = asc ? i + 1 : i - 1; // loop increment |
496 | } |
497 | if (i == fin && i == last) { |
498 | if (cnt >= x->scion) return 0; |
499 | } |
500 | else if (cnt < ofst) return 0; //OFST 2big |
501 | siter->x.bln->ik = i; |
502 | INIT_ITER_BEENTRY(siter, btr, x, siter->x.bln->ik); |
503 | if (asc) { |
504 | if ((ofst + dr) != cnt) siter->missed = 1; |
505 | } |
506 | else { |
507 | if (!i && x == minx) { |
508 | if (ofst != (cnt - btdl)) siter->missed = 1; |
509 | } |
510 | else { |
511 | if (ofst != cnt) siter->missed = 1; |
512 | } |
513 | } |
514 | return 1; |
515 | } |
516 | btSIter *btGetFullXthIter(bt *btr, ulong oofst, bool asc, cswc_t *w, long lim) { |
517 | ulong ofst = oofst; |
518 | cswc_t W; // used in setHigh() |
519 | if (!btr->root || !btr->numkeys) return NULL; |
520 | if (!w) w = &W; |
521 | ai_obj *aL = &w->wf.alow, *aH = &w->wf.ahigh; |
522 | if (!assignMinKey(btr, aL) || !assignMaxKey(btr, aH)) return NULL; |
523 | CR8ITER8R(btr, asc, iter_leaf, iter_leaf_rev, iter_node, iter_node_rev); |
524 | setHigh(siter, asc ? aH : aL, btr->s.ktype); |
525 | if (btScionFind(siter, btr->root, ofst, btr, asc, w, lim)) siter->empty = 0; |
526 | return siter; |
527 | } |
528 | |