Asterisk - The Open Source Telephony Project GIT-master-7921072
Functions
bt_seq.c File Reference
#include <sys/types.h>
#include <errno.h>
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include "../include/db.h"
#include "btree.h"
Include dependency graph for bt_seq.c:

Go to the source code of this file.

Functions

static int __bt_first (BTREE *t, const DBT *key, EPG *erval, int *exactp)
 
int __bt_seq (DB *dbp, DBT *key, DBT *data, u_int flags) const
 
static int __bt_seqadv (BTREE *t, EPG *ep, int flags)
 
static int __bt_seqset (BTREE *t, EPG *ep, DBT *key, int flags)
 
void __bt_setcur (BTREE *t, pgno_t pgno, u_int index)
 
static int __bt_first __P ((BTREE *, const DBT *, EPG *, int *))
 
static int __bt_seqset __P ((BTREE *, EPG *, DBT *, int))
 
static int __bt_seqadv __P ((BTREE *, EPG *, int))
 

Function Documentation

◆ __bt_first()

static int __bt_first ( BTREE *  t,
const DBT *  key,
EPG *  erval,
int *  exactp 
)
static

Definition at line 342 of file bt_seq.c.

347{
348 PAGE *h;
349 EPG *ep, save;
350 pgno_t pg;
351
352 /*
353 * Find any matching record; __bt_search pins the page.
354 *
355 * If it's an exact match and duplicates are possible, walk backwards
356 * in the tree until we find the first one. Otherwise, make sure it's
357 * a valid key (__bt_search may return an index just past the end of a
358 * page) and return it.
359 */
360 if ((ep = __bt_search(t, key, exactp)) == NULL)
361 return (RET_SPECIAL);
362 if (*exactp) {
363 if (F_ISSET(t, B_NODUPS)) {
364 *erval = *ep;
365 return (RET_SUCCESS);
366 }
367
368 /*
369 * Walk backwards, as long as the entry matches and there are
370 * keys left in the tree. Save a copy of each match in case
371 * we go too far.
372 */
373 save = *ep;
374 h = ep->page;
375 do {
376 if (save.page->pgno != ep->page->pgno) {
377 mpool_put(t->bt_mp, save.page, 0);
378 save = *ep;
379 } else
380 save.index = ep->index;
381
382 /*
383 * Don't unpin the page the last (or original) match
384 * was on, but make sure it's unpinned if an error
385 * occurs.
386 */
387 if (ep->index == 0) {
388 if (h->prevpg == P_INVALID)
389 break;
390 if (h->pgno != save.page->pgno)
391 mpool_put(t->bt_mp, h, 0);
392 if ((h = mpool_get(t->bt_mp,
393 h->prevpg, 0)) == NULL) {
394 if (h->pgno == save.page->pgno)
395 mpool_put(t->bt_mp,
396 save.page, 0);
397 return (RET_ERROR);
398 }
399 ep->page = h;
400 ep->index = NEXTINDEX(h);
401 }
402 --ep->index;
403 } while (__bt_cmp(t, key, ep) == 0);
404
405 /*
406 * Reach here with the last page that was looked at pinned,
407 * which may or may not be the same as the last (or original)
408 * match page. If it's not useful, release it.
409 */
410 if (h->pgno != save.page->pgno)
411 mpool_put(t->bt_mp, h, 0);
412
413 *erval = save;
414 return (RET_SUCCESS);
415 }
416
417 /* If at the end of a page, find the next entry. */
418 if (ep->index == NEXTINDEX(ep->page)) {
419 h = ep->page;
420 pg = h->nextpg;
421 mpool_put(t->bt_mp, h, 0);
422 if (pg == P_INVALID)
423 return (RET_SPECIAL);
424 if ((h = mpool_get(t->bt_mp, pg, 0)) == NULL)
425 return (RET_ERROR);
426 ep->index = 0;
427 ep->page = h;
428 }
429 *erval = *ep;
430 return (RET_SUCCESS);
431}
__bt_search
EPG * __bt_search(BTREE *t, const DBT *key, int *exactp)
Definition: bt_search.c:66
__bt_cmp
int __bt_cmp(BTREE *t, const DBT *k1, EPG *e)
Definition: bt_utils.c:153
F_ISSET
#define F_ISSET(p, f)
Definition: btree.h:42
B_NODUPS
#define B_NODUPS
Definition: btree.h:374
NEXTINDEX
#define NEXTINDEX(p)
Definition: btree.h:98
P_INVALID
#define P_INVALID
Definition: btree.h:63
RET_SUCCESS
#define RET_SUCCESS
Definition: db.h:52
RET_ERROR
#define RET_ERROR
Definition: db.h:51
RET_SPECIAL
#define RET_SPECIAL
Definition: db.h:53
pgno_t
u_int32_t pgno_t
Definition: db.h:78
mpool_get
void * mpool_get(MPOOL *mp, pgno_t pgno, u_int flags)
Definition: mpool.c:165
mpool_put
int mpool_put(MPOOL *mp, void *page, u_int flags)
Definition: mpool.c:251
NULL
#define NULL
Definition: resample.c:96
_btree::bt_mp
MPOOL * bt_mp
Definition: btree.h:313
_epg
Definition: btree.h:254
_epg::index
indx_t index
Definition: btree.h:256
_epg::page
PAGE * page
Definition: btree.h:255
_page
Definition: btree.h:75
_page::prevpg
pgno_t prevpg
Definition: btree.h:77
_page::pgno
pgno_t pgno
Definition: btree.h:76
_page::nextpg
pgno_t nextpg
Definition: btree.h:78

References __bt_cmp(), __bt_search(), B_NODUPS, _btree::bt_mp, F_ISSET, _epg::index, mpool_get(), mpool_put(), NEXTINDEX, _page::nextpg, NULL, P_INVALID, _epg::page, _page::pgno, _page::prevpg, RET_ERROR, RET_SPECIAL, and RET_SUCCESS.

Referenced by __bt_seqadv(), and __bt_seqset().

◆ __bt_seq()

int __bt_seq ( DB *  dbp,
DBT *  key,
DBT *  data,
u_int  flags 
) const

Definition at line 77 of file bt_seq.c.

81{
82 BTREE *t;
83 EPG e;
84 int status;
85
86 t = dbp->internal;
87
88 /* Toss any page pinned across calls. */
89 if (t->bt_pinned != NULL) {
90 mpool_put(t->bt_mp, t->bt_pinned, 0);
91 t->bt_pinned = NULL;
92 }
93
94 /*
95 * If scan uninitialized as yet, or starting at a specific record, set
96 * the scan to a specific key. Both __bt_seqset and __bt_seqadv pin
97 * the page the cursor references if they're successful.
98 */
99 switch (flags) {
100 case R_NEXT:
101 case R_PREV:
102 if (F_ISSET(&t->bt_cursor, CURS_INIT)) {
103 status = __bt_seqadv(t, &e, flags);
104 break;
105 }
106 /* FALLTHROUGH */
107 case R_FIRST:
108 case R_LAST:
109 case R_CURSOR:
110 status = __bt_seqset(t, &e, key, flags);
111 break;
112 default:
113 errno = EINVAL;
114 return (RET_ERROR);
115 }
116
117 if (status == RET_SUCCESS) {
118 __bt_setcur(t, e.page->pgno, e.index);
119
120 status =
121 __bt_ret(t, &e, key, &t->bt_rkey, data, &t->bt_rdata, 0);
122
123 /*
124 * If the user is doing concurrent access, we copied the
125 * key/data, toss the page.
126 */
127 if (F_ISSET(t, B_DB_LOCK))
128 mpool_put(t->bt_mp, e.page, 0);
129 else
130 t->bt_pinned = e.page;
131 }
132 return (status);
133}
status
jack_status_t status
Definition: app_jack.c:146
__bt_setcur
void __bt_setcur(BTREE *t, pgno_t pgno, u_int index)
Definition: bt_seq.c:443
__bt_seqset
static int __bt_seqset(BTREE *t, EPG *ep, DBT *key, int flags)
Definition: bt_seq.c:152
__bt_seqadv
static int __bt_seqadv(BTREE *t, EPG *ep, int flags)
Definition: bt_seq.c:240
__bt_ret
int __bt_ret(BTREE *t, EPG *e, DBT *key, DBT *rkey, DBT *data, DBT *rdata, int copy)
Definition: bt_utils.c:67
CURS_INIT
#define CURS_INIT
Definition: btree.h:291
B_DB_LOCK
#define B_DB_LOCK
Definition: btree.h:385
R_PREV
#define R_PREV
Definition: db.h:99
R_NEXT
#define R_NEXT
Definition: db.h:97
R_FIRST
#define R_FIRST
Definition: db.h:93
R_LAST
#define R_LAST
Definition: db.h:96
R_CURSOR
#define R_CURSOR
Definition: db.h:91
dbp
static DB * dbp
Definition: hsearch.c:49
errno
int errno
__db::internal
void * internal
Definition: db.h:137
_btree
Definition: btree.h:312
_btree::bt_cursor
CURSOR bt_cursor
Definition: btree.h:320
_btree::bt_rkey
DBT bt_rkey
Definition: btree.h:332
_btree::bt_pinned
PAGE * bt_pinned
Definition: btree.h:318
_btree::bt_rdata
DBT bt_rdata
Definition: btree.h:333

References __bt_ret(), __bt_seqadv(), __bt_seqset(), __bt_setcur(), B_DB_LOCK, _btree::bt_cursor, _btree::bt_mp, _btree::bt_pinned, _btree::bt_rdata, _btree::bt_rkey, CURS_INIT, dbp, errno, F_ISSET, _epg::index, __db::internal, mpool_put(), NULL, _epg::page, _page::pgno, R_CURSOR, R_FIRST, R_LAST, R_NEXT, R_PREV, RET_ERROR, RET_SUCCESS, and status.

Referenced by __bt_open().

◆ __bt_seqadv()

static int __bt_seqadv ( BTREE *  t,
EPG *  ep,
int  flags 
)
static

Definition at line 240 of file bt_seq.c.

244{
245 CURSOR *c;
246 PAGE *h;
247 indx_t index = 0;
248 pgno_t pg;
249 int exact;
250
251 /*
252 * There are a couple of states that we can be in. The cursor has
253 * been initialized by the time we get here, but that's all we know.
254 */
255 c = &t->bt_cursor;
256
257 /*
258 * The cursor was deleted where there weren't any duplicate records,
259 * so the key was saved. Find out where that key would go in the
260 * current tree. It doesn't matter if the returned key is an exact
261 * match or not -- if it's an exact match, the record was added after
262 * the delete so we can just return it. If not, as long as there's
263 * a record there, return it.
264 */
265 if (F_ISSET(c, CURS_ACQUIRE))
266 return (__bt_first(t, &c->key, ep, &exact));
267
268 /* Get the page referenced by the cursor. */
269 if ((h = mpool_get(t->bt_mp, c->pg.pgno, 0)) == NULL)
270 return (RET_ERROR);
271
272 /*
273 * Find the next/previous record in the tree and point the cursor at
274 * it. The cursor may not be moved until a new key has been found.
275 */
276 switch (flags) {
277 case R_NEXT: /* Next record. */
278 /*
279 * The cursor was deleted in duplicate records, and moved
280 * forward to a record that has yet to be returned. Clear
281 * that flag, and return the record.
282 */
283 if (F_ISSET(c, CURS_AFTER))
284 goto usecurrent;
285 index = c->pg.index;
286 if (++index == NEXTINDEX(h)) {
287 pg = h->nextpg;
288 mpool_put(t->bt_mp, h, 0);
289 if (pg == P_INVALID)
290 return (RET_SPECIAL);
291 if ((h = mpool_get(t->bt_mp, pg, 0)) == NULL)
292 return (RET_ERROR);
293 index = 0;
294 }
295 break;
296 case R_PREV: /* Previous record. */
297 /*
298 * The cursor was deleted in duplicate records, and moved
299 * backward to a record that has yet to be returned. Clear
300 * that flag, and return the record.
301 */
302 if (F_ISSET(c, CURS_BEFORE)) {
303usecurrent: F_CLR(c, CURS_AFTER | CURS_BEFORE);
304 ep->page = h;
305 ep->index = c->pg.index;
306 return (RET_SUCCESS);
307 }
308 index = c->pg.index;
309 if (index == 0) {
310 pg = h->prevpg;
311 mpool_put(t->bt_mp, h, 0);
312 if (pg == P_INVALID)
313 return (RET_SPECIAL);
314 if ((h = mpool_get(t->bt_mp, pg, 0)) == NULL)
315 return (RET_ERROR);
316 index = NEXTINDEX(h) - 1;
317 } else
318 --index;
319 break;
320 }
321
322 ep->page = h;
323 ep->index = index;
324 return (RET_SUCCESS);
325}
__bt_first
static int __bt_first(BTREE *t, const DBT *key, EPG *erval, int *exactp)
Definition: bt_seq.c:342
CURS_AFTER
#define CURS_AFTER
Definition: btree.h:289
CURS_ACQUIRE
#define CURS_ACQUIRE
Definition: btree.h:288
F_CLR
#define F_CLR(p, f)
Definition: btree.h:41
CURS_BEFORE
#define CURS_BEFORE
Definition: btree.h:290
indx_t
u_int16_t indx_t
Definition: db.h:80
_cursor
Definition: btree.h:283
c
static struct test_val c
Definition: test_linkedlists.c:48

References __bt_first(), _btree::bt_cursor, _btree::bt_mp, c, CURS_ACQUIRE, CURS_AFTER, CURS_BEFORE, F_CLR, F_ISSET, _epg::index, mpool_get(), mpool_put(), NEXTINDEX, _page::nextpg, NULL, P_INVALID, _epg::page, _page::prevpg, R_NEXT, R_PREV, RET_ERROR, RET_SPECIAL, and RET_SUCCESS.

Referenced by __bt_seq().

◆ __bt_seqset()

static int __bt_seqset ( BTREE *  t,
EPG *  ep,
DBT *  key,
int  flags 
)
static

Definition at line 152 of file bt_seq.c.

157{
158 PAGE *h;
159 pgno_t pg;
160 int exact;
161
162 /*
163 * Find the first, last or specific key in the tree and point the
164 * cursor at it. The cursor may not be moved until a new key has
165 * been found.
166 */
167 switch (flags) {
168 case R_CURSOR: /* Keyed scan. */
169 /*
170 * Find the first instance of the key or the smallest key
171 * which is greater than or equal to the specified key.
172 */
173 if (key->data == NULL || key->size == 0) {
174 errno = EINVAL;
175 return (RET_ERROR);
176 }
177 return (__bt_first(t, key, ep, &exact));
178 case R_FIRST: /* First record. */
179 case R_NEXT:
180 /* Walk down the left-hand side of the tree. */
181 for (pg = P_ROOT;;) {
182 if ((h = mpool_get(t->bt_mp, pg, 0)) == NULL)
183 return (RET_ERROR);
184
185 /* Check for an empty tree. */
186 if (NEXTINDEX(h) == 0) {
187 mpool_put(t->bt_mp, h, 0);
188 return (RET_SPECIAL);
189 }
190
191 if (h->flags & (P_BLEAF | P_RLEAF))
192 break;
193 pg = GETBINTERNAL(h, 0)->pgno;
194 mpool_put(t->bt_mp, h, 0);
195 }
196 ep->page = h;
197 ep->index = 0;
198 break;
199 case R_LAST: /* Last record. */
200 case R_PREV:
201 /* Walk down the right-hand side of the tree. */
202 for (pg = P_ROOT;;) {
203 if ((h = mpool_get(t->bt_mp, pg, 0)) == NULL)
204 return (RET_ERROR);
205
206 /* Check for an empty tree. */
207 if (NEXTINDEX(h) == 0) {
208 mpool_put(t->bt_mp, h, 0);
209 return (RET_SPECIAL);
210 }
211
212 if (h->flags & (P_BLEAF | P_RLEAF))
213 break;
214 pg = GETBINTERNAL(h, NEXTINDEX(h) - 1)->pgno;
215 mpool_put(t->bt_mp, h, 0);
216 }
217
218 ep->page = h;
219 ep->index = NEXTINDEX(h) - 1;
220 break;
221 }
222 return (RET_SUCCESS);
223}
P_RLEAF
#define P_RLEAF
Definition: btree.h:84
GETBINTERNAL
#define GETBINTERNAL(pg, indx)
Definition: btree.h:138
P_BLEAF
#define P_BLEAF
Definition: btree.h:81
P_ROOT
#define P_ROOT
Definition: btree.h:65
DBT::data
void * data
Definition: db.h:86
DBT::size
size_t size
Definition: db.h:87
_page::flags
u_int32_t flags
Definition: btree.h:87

References __bt_first(), _btree::bt_mp, DBT::data, errno, _page::flags, GETBINTERNAL, _epg::index, mpool_get(), mpool_put(), NEXTINDEX, NULL, P_BLEAF, P_RLEAF, P_ROOT, _epg::page, R_CURSOR, R_FIRST, R_LAST, R_NEXT, R_PREV, RET_ERROR, RET_SPECIAL, RET_SUCCESS, and DBT::size.

Referenced by __bt_seq().

◆ __bt_setcur()

void __bt_setcur ( BTREE *  t,
pgno_t  pgno,
u_int  index 
)

Definition at line 443 of file bt_seq.c.

447{
448 /* Lose any already deleted key. */
449 if (t->bt_cursor.key.data != NULL) {
450 free(t->bt_cursor.key.data);
451 t->bt_cursor.key.size = 0;
452 t->bt_cursor.key.data = NULL;
453 }
454 F_CLR(&t->bt_cursor, CURS_ACQUIRE | CURS_AFTER | CURS_BEFORE);
455
456 /* Update the cursor. */
457 t->bt_cursor.pg.pgno = pgno;
458 t->bt_cursor.pg.index = index;
459 F_SET(&t->bt_cursor, CURS_INIT);
460}
F_SET
#define F_SET(p, f)
Definition: btree.h:40
free
void free()
_cursor::pg
EPGNO pg
Definition: btree.h:284
_cursor::key
DBT key
Definition: btree.h:285
_epgno::pgno
pgno_t pgno
Definition: btree.h:250
_epgno::index
indx_t index
Definition: btree.h:251

References _btree::bt_cursor, CURS_ACQUIRE, CURS_AFTER, CURS_BEFORE, CURS_INIT, DBT::data, F_CLR, F_SET, free(), _epgno::index, _cursor::key, NULL, _cursor::pg, _epgno::pgno, and DBT::size.

Referenced by __bt_put(), and __bt_seq().

◆ __P() [1/3]

static int __bt_first __P ( (BTREE *, const DBT *, EPG *, int *)  )
static

◆ __P() [2/3]

static int __bt_seqset __P ( (BTREE *, EPG *, DBT *, int)  )
static

◆ __P() [3/3]

static int __bt_seqadv __P ( (BTREE *, EPG *, int)  )
static
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