Generate osl.h from osl.h.in.
[osl.git] / osl.c
1 /*
2 * Copyright (C) 2007-2008 Andre Noll <maan@systemlinux.org>
3 *
4 * Licensed under the GPL v2. For licencing details see COPYING.
5 */
6
7 /** \file osl.c Object storage layer functions. */
8 #include <dirent.h> /* readdir() */
9 #include <assert.h>
10
11
12 #include "log.h"
13 #include "error.h"
14 #include "fd.h"
15 #include "list.h"
16 #include "osl_core.h"
17
18 /**
19 * Allocate a sufficiently large string and print into it.
20 *
21 * \param fmt A usual format string.
22 *
23 * Produce output according to \p fmt. No artificial bound on the length of the
24 * resulting string is imposed.
25 *
26 * \return This function either returns a pointer to a string that must be
27 * freed by the caller or \p NULL if memory allocation failed.
28 *
29 * \sa printf(3).
30 */
31 static __must_check __printf_1_2 __malloc char *make_message(const char *fmt, ...)
32 {
33 int n;
34 size_t size = 100;
35 char *p = malloc(size);
36
37 if (!p)
38 return NULL;
39 while (1) {
40 char *q;
41 va_list ap;
42 /* Try to print in the allocated space. */
43 va_start(ap, fmt);
44 n = vsnprintf(p, size, fmt, ap);
45 va_end(ap);
46 /* If that worked, return the string. */
47 if (n > -1 && n < size)
48 break;
49 /* Else try again with more space. */
50 if (n > -1) /* glibc 2.1 */
51 size = n + 1; /* precisely what is needed */
52 else /* glibc 2.0 */
53 size *= 2; /* twice the old size */
54 q = realloc(p, size);
55 if (!q) {
56 free(p);
57 return NULL;
58 }
59 }
60 return p;
61 }
62
63 /**
64 * The log function.
65 *
66 * \param ll Loglevel.
67 * \param fmt Usual format string.
68 *
69 * All XXX_LOG() macros use this function.
70 */
71 __printf_2_3 void __log(int ll, const char* fmt,...)
72 {
73 va_list argp;
74 FILE *outfd;
75 struct tm *tm;
76 time_t t1;
77 char str[255] = "";
78
79 if (ll < 2)
80 return;
81 outfd = stderr;
82 time(&t1);
83 tm = localtime(&t1);
84 strftime(str, sizeof(str), "%b %d %H:%M:%S", tm);
85 fprintf(outfd, "%s ", str);
86 va_start(argp, fmt);
87 vfprintf(outfd, fmt, argp);
88 va_end(argp);
89 }
90
91 /**
92 * A wrapper for lseek(2).
93 *
94 * \param fd The file descriptor whose offset is to be to repositioned.
95 * \param offset A value-result parameter.
96 * \param whence Usual repositioning directive.
97 *
98 * Reposition the offset of the file descriptor \a fd to the argument \a offset
99 * according to the directive \a whence. Upon successful return, \a offset
100 * contains the resulting offset location as measured in bytes from the
101 * beginning of the file.
102 *
103 * \return Positive on success. Otherwise, the function returns \p -E_OSL_LSEEK.
104 *
105 * \sa lseek(2).
106 */
107 static int __lseek(int fd, off_t *offset, int whence)
108 {
109 *offset = lseek(fd, *offset, whence);
110 int ret = -E_OSL_LSEEK;
111 if (*offset == -1)
112 return ret;
113 return 1;
114 }
115
116 /**
117 * Wrapper for the write system call.
118 *
119 * \param fd The file descriptor to write to.
120 * \param buf The buffer to write.
121 * \param size The length of \a buf in bytes.
122 *
123 * This function writes out the given buffer and retries if an interrupt
124 * occurred during the write.
125 *
126 * \return On success, the number of bytes written is returned, otherwise, the
127 * function returns \p -E_OSL_WRITE.
128 *
129 * \sa write(2).
130 */
131 static ssize_t __write(int fd, const void *buf, size_t size)
132 {
133 ssize_t ret;
134
135 for (;;) {
136 ret = write(fd, buf, size);
137 if ((ret < 0) && (errno == EAGAIN || errno == EINTR))
138 continue;
139 return ret >= 0? ret : -E_OSL_WRITE;
140 }
141 }
142
143 /**
144 * Write the whole buffer to a file descriptor.
145 *
146 * \param fd The file descriptor to write to.
147 * \param buf The buffer to write.
148 * \param size The length of \a buf in bytes.
149 *
150 * This function writes the given buffer and continues on short writes and
151 * when interrupted by a signal.
152 *
153 * \return Positive on success, negative on errors. Possible errors: any
154 * errors returned by para_write().
155 *
156 * \sa para_write().
157 */
158 static ssize_t write_all(int fd, const void *buf, size_t size)
159 {
160 // DEBUG_LOG("writing %zu bytes\n", size);
161 const char *b = buf;
162 while (size) {
163 ssize_t ret = __write(fd, b, size);
164 // DEBUG_LOG("ret: %zd\n", ret);
165 if (ret < 0)
166 return ret;
167 b += ret;
168 size -= ret;
169 }
170 return 1;
171 }
172 /**
173 * Open a file, write the given buffer and close the file.
174 *
175 * \param filename Full path to the file to open.
176 * \param buf The buffer to write to the file.
177 * \param size The size of \a buf.
178 *
179 * \return Standard.
180 */
181 static int write_file(const char *filename, const void *buf, size_t size)
182 {
183 int ret, fd;
184
185 ret = osl_open(filename, O_WRONLY | O_CREAT | O_EXCL, 0644);
186 if (ret < 0)
187 return ret;
188 fd = ret;
189 ret = write_all(fd, buf, size);
190 if (ret < 0)
191 goto out;
192 ret = 1;
193 out:
194 close(fd);
195 return ret;
196 }
197
198 static int append_file(const char *filename, char *header, size_t header_size,
199 char *data, size_t data_size, uint32_t *new_pos)
200 {
201 int ret, fd;
202
203 // DEBUG_LOG("appending %zu + %zu bytes\n", header_size, data_size);
204 ret = osl_open(filename, O_WRONLY | O_CREAT | O_APPEND, 0644);
205 if (ret < 0)
206 return ret;
207 fd = ret;
208 if (header && header_size) {
209 ret = write_all(fd, header, header_size);
210 if (ret < 0)
211 goto out;
212 }
213 ret = write_all(fd, data, data_size);
214 if (ret < 0)
215 goto out;
216 if (new_pos) {
217 off_t offset = 0;
218 ret = __lseek(fd, &offset, SEEK_END);
219 if (ret < 0)
220 goto out;
221 // DEBUG_LOG("new file size: " FMT_OFF_T "\n", offset);
222 *new_pos = offset;
223 }
224 ret = 1;
225 out:
226 close(fd);
227 return ret;
228 }
229
230 static int verify_name(const char *name)
231 {
232 if (!name)
233 return -E_OSL_BAD_NAME;
234 if (!*name)
235 return -E_OSL_BAD_NAME;
236 if (strchr(name, '/'))
237 return -E_OSL_BAD_NAME;
238 if (!strcmp(name, ".."))
239 return -E_OSL_BAD_NAME;
240 if (!strcmp(name, "."))
241 return -E_OSL_BAD_NAME;
242 return 1;
243 }
244
245 /**
246 * Compare two osl objects pointing to unsigned integers of 32 bit size.
247 *
248 * \param obj1 Pointer to the first integer.
249 * \param obj2 Pointer to the second integer.
250 *
251 * \return The values required for an osl compare function.
252 *
253 * \sa osl_compare_func, osl_hash_compare().
254 */
255 int uint32_compare(const struct osl_object *obj1, const struct osl_object *obj2)
256 {
257 uint32_t d1 = read_u32((const char *)obj1->data);
258 uint32_t d2 = read_u32((const char *)obj2->data);
259
260 if (d1 < d2)
261 return 1;
262 if (d1 > d2)
263 return -1;
264 return 0;
265 }
266
267 /**
268 * Compare two osl objects pointing to hash values.
269 *
270 * \param obj1 Pointer to the first hash object.
271 * \param obj2 Pointer to the second hash object.
272 *
273 * \return The values required for an osl compare function.
274 *
275 * \sa osl_compare_func, uint32_compare().
276 */
277 int osl_hash_compare(const struct osl_object *obj1, const struct osl_object *obj2)
278 {
279 return hash_compare((HASH_TYPE *)obj1->data, (HASH_TYPE *)obj2->data);
280 }
281
282 static char *disk_storage_dirname(const struct osl_table *t, unsigned col_num,
283 const char *ds_name)
284 {
285 char *dirname, *column_name = column_filename(t, col_num);
286
287 if (!column_name)
288 return NULL;
289 if (!(t->desc->flags & OSL_LARGE_TABLE))
290 return column_name;
291 dirname = make_message("%s/%.2s", column_name, ds_name);
292 free(column_name);
293 return dirname;
294 }
295
296 static char *disk_storage_name_of_object(const struct osl_table *t,
297 const struct osl_object *obj)
298 {
299 HASH_TYPE hash[HASH_SIZE];
300 hash_object(obj, hash);
301 return disk_storage_name_of_hash(t, hash);
302 }
303
304 static int disk_storage_name_of_row(const struct osl_table *t,
305 const struct osl_row *row, char **name)
306 {
307 struct osl_object obj;
308 int ret = osl_get_object(t, row, t->disk_storage_name_column, &obj);
309
310 if (ret < 0)
311 return ret;
312 *name = disk_storage_name_of_object(t, &obj);
313 if (*name)
314 return 1;
315 return -ERRNO_TO_ERROR(ENOMEM);
316 }
317
318 static void column_name_hash(const char *col_name, HASH_TYPE *hash)
319 {
320 hash_function(col_name, strlen(col_name), hash);
321 }
322
323 static int init_column_descriptions(struct osl_table *t)
324 {
325 int i, j, ret;
326 const struct osl_column_description *cd;
327
328 ret = -E_OSL_BAD_TABLE_DESC;
329 ret = verify_name(t->desc->name);
330 if (ret < 0)
331 goto err;
332 ret = -E_OSL_BAD_DB_DIR;
333 if (!t->desc->dir && (t->num_disk_storage_columns || t->num_mapped_columns))
334 goto err;
335 /* the size of the index header without column descriptions */
336 t->index_header_size = IDX_COLUMN_DESCRIPTIONS;
337 FOR_EACH_COLUMN(i, t->desc, cd) {
338 struct osl_column *col = t->columns + i;
339 if (cd->storage_flags & OSL_RBTREE) {
340 if (!cd->compare_function)
341 return -E_OSL_NO_COMPARE_FUNC;
342 }
343 if (cd->storage_type == OSL_NO_STORAGE)
344 continue;
345 ret = -E_OSL_NO_COLUMN_NAME;
346 if (!cd->name || !cd->name[0])
347 goto err;
348 ret = verify_name(cd->name);
349 if (ret < 0)
350 goto err;
351 t->index_header_size += index_column_description_size(cd->name);
352 column_name_hash(cd->name, col->name_hash);
353 ret = -E_OSL_DUPLICATE_COL_NAME;
354 for (j = i + 1; j < t->desc->num_columns; j++) {
355 const char *name2 = get_column_description(t->desc,
356 j)->name;
357 if (cd->name && name2 && !strcmp(cd->name, name2))
358 goto err;
359 }
360 }
361 return 1;
362 err:
363 return ret;
364 }
365
366 /**
367 * Initialize a struct table from given table description.
368 *
369 * \param desc The description of the osl table.
370 * \param table_ptr Result is returned here.
371 *
372 * This function performs several sanity checks on \p desc and returns if any
373 * of these tests fail. On success, a struct \p osl_table is allocated and
374 * initialized with data derived from \p desc.
375 *
376 * \return Standard.
377 *
378 * \sa struct osl_table.
379 */
380 int init_table_structure(const struct osl_table_description *desc,
381 struct osl_table **table_ptr)
382 {
383 const struct osl_column_description *cd;
384 struct osl_table *t = calloc(1, sizeof(*t));
385 int i, ret = -ERRNO_TO_ERROR(ENOMEM), have_disk_storage_name_column = 0;
386
387 if (!t)
388 return ret;
389 ret = -E_OSL_BAD_TABLE_DESC;
390 if (!desc)
391 goto err;
392 DEBUG_LOG("creating table structure for '%s' from table "
393 "description\n", desc->name);
394 ret = -E_OSL_NO_COLUMN_DESC;
395 if (!desc->column_descriptions)
396 goto err;
397 ret = -E_OSL_NO_COLUMNS;
398 if (!desc->num_columns)
399 goto err;
400 ret = -ERRNO_TO_ERROR(ENOMEM);
401 t->columns = calloc(desc->num_columns, sizeof(struct osl_column));
402 if (!t->columns)
403 goto err;
404 t->desc = desc;
405 FOR_EACH_COLUMN(i, t->desc, cd) {
406 enum osl_storage_type st = cd->storage_type;
407 enum osl_storage_flags sf = cd->storage_flags;
408 struct osl_column *col = &t->columns[i];
409
410 ret = -E_OSL_BAD_STORAGE_TYPE;
411 if (st != OSL_MAPPED_STORAGE && st != OSL_DISK_STORAGE
412 && st != OSL_NO_STORAGE)
413 goto err;
414 ret = -E_OSL_BAD_STORAGE_FLAGS;
415 if (st == OSL_DISK_STORAGE && sf & OSL_RBTREE)
416 goto err;
417 ret = -E_OSL_BAD_STORAGE_SIZE;
418 if (sf & OSL_FIXED_SIZE && !cd->data_size)
419 goto err;
420 switch (st) {
421 case OSL_DISK_STORAGE:
422 t->num_disk_storage_columns++;
423 break;
424 case OSL_MAPPED_STORAGE:
425 t->num_mapped_columns++;
426 col->index_offset = t->row_index_size;
427 t->row_index_size += 8;
428 break;
429 case OSL_NO_STORAGE:
430 col->volatile_num = t->num_volatile_columns;
431 t->num_volatile_columns++;
432 break;
433 }
434 if (sf & OSL_RBTREE) {
435 col->rbtree_num = t->num_rbtrees;
436 t->num_rbtrees++;
437 if ((sf & OSL_UNIQUE) && (st == OSL_MAPPED_STORAGE)) {
438 if (!have_disk_storage_name_column)
439 t->disk_storage_name_column = i;
440 have_disk_storage_name_column = 1;
441 }
442 }
443 }
444 ret = -E_OSL_NO_UNIQUE_RBTREE_COLUMN;
445 if (t->num_disk_storage_columns && !have_disk_storage_name_column)
446 goto err;
447 ret = -E_OSL_NO_RBTREE_COL;
448 if (!t->num_rbtrees)
449 goto err;
450 /* success */
451 DEBUG_LOG("OK. Index entry size: %u\n", t->row_index_size);
452 ret = init_column_descriptions(t);
453 if (ret < 0)
454 goto err;
455 *table_ptr = t;
456 return 1;
457 err:
458 free(t->columns);
459 free(t);
460 return ret;
461 }
462
463 /**
464 * Read the table description from index header.
465 *
466 * \param map The memory mapping of the index file.
467 * \param desc The values found in the index header are returned here.
468 *
469 * Read the index header, check for the paraslash magic string and the table version number.
470 * Read all information stored in the index header into \a desc.
471 *
472 * \return Standard.
473 *
474 * \sa struct osl_table_description, osl_create_table.
475 */
476 int read_table_desc(struct osl_object *map, struct osl_table_description *desc)
477 {
478 char *buf = map->data;
479 uint8_t version;
480 uint16_t header_size;
481 int ret, i;
482 unsigned offset;
483 struct osl_column_description *cd;
484
485 if (map->size < MIN_INDEX_HEADER_SIZE(1))
486 return -E_OSL_SHORT_TABLE;
487 if (strncmp(buf + IDX_PARA_MAGIC, PARA_MAGIC, strlen(PARA_MAGIC)))
488 return -E_OSL_NO_MAGIC;
489 version = read_u8(buf + IDX_VERSION);
490 if (version < MIN_TABLE_VERSION || version > MAX_TABLE_VERSION)
491 return -E_OSL_VERSION_MISMATCH;
492 desc->flags = read_u8(buf + IDX_TABLE_FLAGS);
493 desc->num_columns = read_u16(buf + IDX_NUM_COLUMNS);
494 DEBUG_LOG("%u columns\n", desc->num_columns);
495 if (!desc->num_columns)
496 return -E_OSL_NO_COLUMNS;
497 header_size = read_u16(buf + IDX_HEADER_SIZE);
498 if (map->size < header_size)
499 return -E_OSL_BAD_SIZE;
500 desc->column_descriptions = calloc(desc->num_columns,
501 sizeof(struct osl_column_description));
502 if (!desc->column_descriptions)
503 return -ERRNO_TO_ERROR(ENOMEM);
504 offset = IDX_COLUMN_DESCRIPTIONS;
505 FOR_EACH_COLUMN(i, desc, cd) {
506 char *null_byte;
507
508 ret = -E_OSL_SHORT_TABLE;
509 if (map->size < offset + MIN_IDX_COLUMN_DESCRIPTION_SIZE) {
510 ERROR_LOG("map size = %zu < %u = offset + min desc size\n",
511 map->size, offset + MIN_IDX_COLUMN_DESCRIPTION_SIZE);
512 goto err;
513 }
514 cd->storage_type = read_u16(buf + offset + IDX_CD_STORAGE_TYPE);
515 cd->storage_flags = read_u16(buf + offset +
516 IDX_CD_STORAGE_FLAGS);
517 cd->data_size = read_u32(buf + offset + IDX_CD_DATA_SIZE);
518 null_byte = memchr(buf + offset + IDX_CD_NAME, '\0',
519 map->size - offset - IDX_CD_NAME);
520 ret = -E_OSL_INDEX_CORRUPTION;
521 if (!null_byte)
522 goto err;
523 ret = -ERRNO_TO_ERROR(ENOMEM);
524 cd->name = strdup(buf + offset + IDX_CD_NAME);
525 if (!cd->name)
526 goto err;
527 offset += index_column_description_size(cd->name);
528 }
529 if (offset != header_size) {
530 ret = -E_OSL_INDEX_CORRUPTION;
531 ERROR_LOG("real header size = %u != %u = stored header size\n",
532 offset, header_size);
533 goto err;
534 }
535 return 1;
536 err:
537 FOR_EACH_COLUMN(i, desc, cd)
538 free(cd->name);
539 return ret;
540 }
541
542 /*
543 * check whether the table description given by \p t->desc matches the on-disk
544 * table structure stored in the index of \a t.
545 */
546 static int compare_table_descriptions(struct osl_table *t)
547 {
548 int i, ret;
549 struct osl_table_description desc;
550 const struct osl_column_description *cd1, *cd2;
551
552 /* read the on-disk structure into desc */
553 ret = read_table_desc(&t->index_map, &desc);
554 if (ret < 0)
555 return ret;
556 ret = -E_OSL_BAD_TABLE_FLAGS;
557 if (desc.flags != t->desc->flags)
558 goto out;
559 ret = -E_OSL_BAD_COLUMN_NUM;
560 if (desc.num_columns > t->desc->num_columns)
561 goto out;
562 if (desc.num_columns < t->desc->num_columns) {
563 struct osl_column_description *cd;
564 unsigned diff = t->desc->num_columns - desc.num_columns;
565 INFO_LOG("extending table by %u volatile columns\n", diff);
566 ret = -ERRNO_TO_ERROR(ENOMEM);
567 desc.column_descriptions = realloc(desc.column_descriptions,
568 t->desc->num_columns * sizeof(struct osl_column_description));
569 if (!desc.column_descriptions)
570 goto out;
571 for (i = desc.num_columns; i < t->desc->num_columns; i++) {
572 cd = get_column_description(&desc, i);
573 cd->storage_type = OSL_NO_STORAGE;
574 cd->name = NULL;
575 }
576 desc.num_columns += diff;
577 }
578 FOR_EACH_COLUMN(i, t->desc, cd1) {
579 cd2 = get_column_description(&desc, i);
580 ret = -E_OSL_BAD_STORAGE_TYPE;
581 if (cd1->storage_type != cd2->storage_type)
582 goto out;
583 if (cd1->storage_type == OSL_NO_STORAGE)
584 continue;
585 ret = -E_OSL_BAD_STORAGE_FLAGS;
586 if (cd1->storage_flags != cd2->storage_flags) {
587 ERROR_LOG("sf1 = %u != %u = sf2\n",
588 cd1->storage_flags, cd2->storage_flags);
589 goto out;
590 }
591 ret = -E_OSL_BAD_DATA_SIZE;
592 if (cd1->storage_flags & OSL_FIXED_SIZE)
593 if (cd1->data_size != cd2->data_size)
594 goto out;
595 ret = -E_OSL_BAD_COLUMN_NAME;
596 if (strcmp(cd1->name, cd2->name))
597 goto out;
598 }
599 DEBUG_LOG("table description of '%s' matches on-disk data, good\n",
600 t->desc->name);
601 ret = 1;
602 out:
603 FOR_EACH_COLUMN(i, &desc, cd1)
604 free(cd1->name);
605 free(desc.column_descriptions);
606 return ret;
607 }
608
609 static int create_table_index(struct osl_table *t)
610 {
611 char *buf, *filename;
612 int i, ret;
613 size_t size = t->index_header_size;
614 const struct osl_column_description *cd;
615 unsigned offset;
616
617 INFO_LOG("creating %zu byte index for table %s\n", size,
618 t->desc->name);
619 buf = calloc(1, size);
620 if (!buf)
621 return -ERRNO_TO_ERROR(ENOMEM);
622 sprintf(buf + IDX_PARA_MAGIC, "%s", PARA_MAGIC);
623 write_u8(buf + IDX_TABLE_FLAGS, t->desc->flags);
624 write_u8(buf + IDX_DIRTY_FLAG, 0);
625 write_u8(buf + IDX_VERSION, CURRENT_TABLE_VERSION);
626 write_u16(buf + IDX_NUM_COLUMNS, t->num_mapped_columns + t->num_disk_storage_columns);
627 write_u16(buf + IDX_HEADER_SIZE, t->index_header_size);
628 offset = IDX_COLUMN_DESCRIPTIONS;
629 FOR_EACH_COLUMN(i, t->desc, cd) {
630 /* no need to store info about volatile storage */
631 if (cd->storage_type == OSL_NO_STORAGE)
632 continue;
633 write_u16(buf + offset + IDX_CD_STORAGE_TYPE,
634 cd->storage_type);
635 write_u16(buf + offset + IDX_CD_STORAGE_FLAGS,
636 cd->storage_flags);
637 if (cd->storage_flags & OSL_FIXED_SIZE)
638 write_u32(buf + offset + IDX_CD_DATA_SIZE,
639 cd->data_size);
640 strcpy(buf + offset + IDX_CD_NAME, cd->name);
641 offset += index_column_description_size(cd->name);
642 }
643 assert(offset = size);
644 filename = index_filename(t->desc);
645 if (filename)
646 ret = write_file(filename, buf, size);
647 else
648 ret = -ERRNO_TO_ERROR(ENOMEM);
649 free(buf);
650 free(filename);
651 return ret;
652 }
653
654 /**
655 * Create a new osl table.
656 *
657 * \param desc Pointer to the table description.
658 *
659 * \return Standard.
660 */
661 __export int osl_create_table(const struct osl_table_description *desc)
662 {
663 const struct osl_column_description *cd;
664 char *table_dir = NULL, *filename;
665 struct osl_table *t;
666 int i, ret = init_table_structure(desc, &t);
667
668 if (ret < 0)
669 return ret;
670 INFO_LOG("creating %s\n", desc->name);
671 FOR_EACH_COLUMN(i, t->desc, cd) {
672 if (cd->storage_type == OSL_NO_STORAGE)
673 continue;
674 if (!table_dir) {
675 ret = para_mkdir(desc->dir, 0777);
676 if (ret < 0 && !is_errno(-ret, EEXIST))
677 goto out;
678 table_dir = make_message("%s/%s", desc->dir,
679 desc->name);
680 ret = -ERRNO_TO_ERROR(ENOMEM);
681 if (!table_dir)
682 goto out;
683 ret = para_mkdir(table_dir, 0777);
684 if (ret < 0)
685 goto out;
686 }
687 ret = -ERRNO_TO_ERROR(ENOMEM);
688 filename = column_filename(t, i);
689 if (!filename)
690 goto out;
691 INFO_LOG("filename: %s\n", filename);
692 if (cd->storage_type == OSL_MAPPED_STORAGE) {
693 ret = osl_open(filename, O_RDWR | O_CREAT | O_EXCL,
694 0644);
695 free(filename);
696 if (ret < 0)
697 goto out;
698 close(ret);
699 continue;
700 }
701 /* DISK STORAGE */
702 ret = para_mkdir(filename, 0777);
703 free(filename);
704 if (ret < 0)
705 goto out;
706 }
707 if (t->num_mapped_columns) {
708 ret = create_table_index(t);
709 if (ret < 0)
710 goto out;
711 }
712 ret = 1;
713 out:
714 free(table_dir);
715 free(t->columns);
716 free(t);
717 return ret;
718 }
719
720 static int table_is_dirty(struct osl_table *t)
721 {
722 char *buf = (char *)t->index_map.data + IDX_DIRTY_FLAG;
723 uint8_t dirty = read_u8(buf) & 0x1;
724 return !!dirty;
725 }
726
727 static void mark_table_dirty(struct osl_table *t)
728 {
729 char *buf = (char *)t->index_map.data + IDX_DIRTY_FLAG;
730 write_u8(buf, read_u8(buf) | 1);
731 }
732
733 static void mark_table_clean(struct osl_table *t)
734 {
735 char *buf = (char *)t->index_map.data + IDX_DIRTY_FLAG;
736 write_u8(buf, read_u8(buf) & 0xfe);
737 }
738
739 static void unmap_column(struct osl_table *t, unsigned col_num)
740 {
741 struct osl_object map = t->columns[col_num].data_map;
742 int ret;
743 if (!map.data)
744 return;
745 ret = para_munmap(map.data, map.size);
746 assert(ret > 0);
747 map.data = NULL;
748 }
749
750 /**
751 * Unmap all mapped files of an osl table.
752 *
753 * \param t Pointer to a mapped table.
754 * \param flags Options for unmapping.
755 *
756 * \return Positive on success, negative on errors.
757 *
758 * \sa map_table(), enum osl_close_flags, para_munmap().
759 */
760 int unmap_table(struct osl_table *t, enum osl_close_flags flags)
761 {
762 unsigned i;
763 const struct osl_column_description *cd;
764 int ret;
765
766 if (!t->num_mapped_columns) /* can this ever happen? */
767 return 1;
768 DEBUG_LOG("unmapping table '%s'\n", t->desc->name);
769 if (!t->index_map.data)
770 return -E_OSL_NOT_MAPPED;
771 if (flags & OSL_MARK_CLEAN)
772 mark_table_clean(t);
773 ret = para_munmap(t->index_map.data, t->index_map.size);
774 if (ret < 0)
775 return ret;
776 t->index_map.data = NULL;
777 if (!t->num_rows)
778 return 1;
779 FOR_EACH_MAPPED_COLUMN(i, t, cd)
780 unmap_column(t, i);
781 return 1;
782 }
783
784 static int map_column(struct osl_table *t, unsigned col_num)
785 {
786 struct stat statbuf;
787 char *filename = column_filename(t, col_num);
788 int ret = -E_OSL_STAT;
789
790 if (!filename)
791 return -ERRNO_TO_ERROR(ENOMEM);
792 if (stat(filename, &statbuf) < 0) {
793 free(filename);
794 return ret;
795 }
796 if (!(S_IFREG & statbuf.st_mode)) {
797 free(filename);
798 return ret;
799 }
800 ret = mmap_full_file(filename, O_RDWR,
801 &t->columns[col_num].data_map.data,
802 &t->columns[col_num].data_map.size,
803 NULL);
804 free(filename);
805 return ret;
806 }
807
808 /**
809 * Map the index file and all columns of type \p OSL_MAPPED_STORAGE into memory.
810 *
811 * \param t Pointer to an initialized table structure.
812 * \param flags Mapping options.
813 *
814 * \return Negative return value on errors; on success the number of rows
815 * (including invalid rows) is returned.
816 *
817 * \sa unmap_table(), enum map_table_flags, osl_open_table(), mmap(2).
818 */
819 int map_table(struct osl_table *t, enum map_table_flags flags)
820 {
821 char *filename;
822 const struct osl_column_description *cd;
823 int i = 0, ret, num_rows = 0;
824
825 if (!t->num_mapped_columns)
826 return 0;
827 if (t->index_map.data)
828 return -E_OSL_ALREADY_MAPPED;
829 filename = index_filename(t->desc);
830 if (!filename)
831 return -ERRNO_TO_ERROR(ENOMEM);
832 DEBUG_LOG("mapping table '%s' (index: %s)\n", t->desc->name, filename);
833 ret = mmap_full_file(filename, flags & MAP_TBL_FL_MAP_RDONLY?
834 O_RDONLY : O_RDWR, &t->index_map.data, &t->index_map.size, NULL);
835 free(filename);
836 if (ret < 0)
837 return ret;
838 if (flags & MAP_TBL_FL_VERIFY_INDEX) {
839 ret = compare_table_descriptions(t);
840 if (ret < 0)
841 goto err;
842 }
843 ret = -E_OSL_BUSY;
844 if (!(flags & MAP_TBL_FL_IGNORE_DIRTY)) {
845 if (table_is_dirty(t)) {
846 ERROR_LOG("%s is dirty\n", t->desc->name);
847 goto err;
848 }
849 }
850 mark_table_dirty(t);
851 num_rows = table_num_rows(t);
852 if (!num_rows)
853 return num_rows;
854 /* map data files */
855 FOR_EACH_MAPPED_COLUMN(i, t, cd) {
856 ret = map_column(t, i);
857 if (ret < 0)
858 goto err;
859 }
860 return num_rows;
861 err: /* unmap what is already mapped */
862 for (i--; i >= 0; i--) {
863 struct osl_object map = t->columns[i].data_map;
864 para_munmap(map.data, map.size);
865 map.data = NULL;
866 }
867 para_munmap(t->index_map.data, t->index_map.size);
868 t->index_map.data = NULL;
869 return ret;
870 }
871
872 /**
873 * Retrieve a mapped object by row and column number.
874 *
875 * \param t Pointer to an open osl table.
876 * \param col_num Number of the mapped column containing the object to retrieve.
877 * \param row_num Number of the row containing the object to retrieve.
878 * \param obj The result is returned here.
879 *
880 * It is considered an error if \a col_num does not refer to a column
881 * of storage type \p OSL_MAPPED_STORAGE.
882 *
883 * \return Standard.
884 *
885 * \sa osl_storage_type.
886 */
887 int get_mapped_object(const struct osl_table *t, unsigned col_num,
888 uint32_t row_num, struct osl_object *obj)
889 {
890 struct osl_column *col = &t->columns[col_num];
891 uint32_t offset;
892 char *header;
893 char *cell_index;
894 int ret;
895
896 if (t->num_rows <= row_num)
897 return -E_OSL_BAD_ROW_NUM;
898 ret = get_cell_index(t, row_num, col_num, &cell_index);
899 if (ret < 0)
900 return ret;
901 offset = read_u32(cell_index);
902 obj->size = read_u32(cell_index + 4) - 1;
903 header = col->data_map.data + offset;
904 obj->data = header + 1;
905 if (read_u8(header) == 0xff) {
906 ERROR_LOG("col %u, size %zu, offset %u\n", col_num,
907 obj->size, offset);
908 return -E_OSL_INVALID_OBJECT;
909 }
910 return 1;
911 }
912
913 static int search_rbtree(const struct osl_object *obj,
914 const struct osl_table *t, unsigned col_num,
915 struct rb_node **result, struct rb_node ***rb_link)
916 {
917 struct osl_column *col = &t->columns[col_num];
918 struct rb_node **new = &col->rbtree.rb_node, *parent = NULL;
919 const struct osl_column_description *cd =
920 get_column_description(t->desc, col_num);
921 enum osl_storage_type st = cd->storage_type;
922 while (*new) {
923 struct osl_row *this_row = get_row_pointer(*new,
924 col->rbtree_num);
925 int ret;
926 struct osl_object this_obj;
927 parent = *new;
928 if (st == OSL_MAPPED_STORAGE) {
929 ret = get_mapped_object(t, col_num, this_row->num,
930 &this_obj);
931 if (ret < 0)
932 return ret;
933 } else
934 this_obj = this_row->volatile_objects[col->volatile_num];
935 ret = cd->compare_function(obj, &this_obj);
936 if (!ret) {
937 if (result)
938 *result = get_rb_node_pointer(this_row,
939 col->rbtree_num);
940 return 1;
941 }
942 if (ret < 0)
943 new = &((*new)->rb_left);
944 else
945 new = &((*new)->rb_right);
946 }
947 if (result)
948 *result = parent;
949 if (rb_link)
950 *rb_link = new;
951 return -E_OSL_RB_KEY_NOT_FOUND;
952 }
953
954 static int insert_rbtree(struct osl_table *t, unsigned col_num,
955 const struct osl_row *row, const struct osl_object *obj)
956 {
957 struct rb_node *parent, **rb_link;
958 unsigned rbtree_num;
959 struct rb_node *n;
960 int ret = search_rbtree(obj, t, col_num, &parent, &rb_link);
961
962 if (ret > 0)
963 return -E_OSL_RB_KEY_EXISTS;
964 rbtree_num = t->columns[col_num].rbtree_num;
965 n = get_rb_node_pointer(row, rbtree_num);
966 rb_link_node(n, parent, rb_link);
967 rb_insert_color(n, &t->columns[col_num].rbtree);
968 return 1;
969 }
970
971 static void remove_rb_node(struct osl_table *t, unsigned col_num,
972 const struct osl_row *row)
973 {
974 struct osl_column *col = &t->columns[col_num];
975 const struct osl_column_description *cd =
976 get_column_description(t->desc, col_num);
977 enum osl_storage_flags sf = cd->storage_flags;
978 struct rb_node *victim, *splice_out_node, *tmp;
979 if (!(sf & OSL_RBTREE))
980 return;
981 /*
982 * Which node is removed/spliced out actually depends on how many
983 * children the victim node has: If it has no children, it gets
984 * deleted. If it has one child, it gets spliced out. If it has two
985 * children, its successor (which has at most a right child) gets
986 * spliced out.
987 */
988 victim = get_rb_node_pointer(row, col->rbtree_num);
989 if (victim->rb_left && victim->rb_right)
990 splice_out_node = rb_next(victim);
991 else
992 splice_out_node = victim;
993 /* Go up to the root and decrement the size of each node in the path. */
994 for (tmp = splice_out_node; tmp; tmp = rb_parent(tmp))
995 tmp->size--;
996 rb_erase(victim, &col->rbtree);
997 }
998
999 static int add_row_to_rbtrees(struct osl_table *t, uint32_t row_num,
1000 struct osl_object *volatile_objs, struct osl_row **row_ptr)
1001 {
1002 unsigned i;
1003 int ret;
1004 struct osl_row *row = allocate_row(t->num_rbtrees);
1005 const struct osl_column_description *cd;
1006
1007 if (!row)
1008 return -ERRNO_TO_ERROR(ENOMEM);
1009 row->num = row_num;
1010 row->volatile_objects = volatile_objs;
1011 FOR_EACH_RBTREE_COLUMN(i, t, cd) {
1012 if (cd->storage_type == OSL_MAPPED_STORAGE) {
1013 struct osl_object obj;
1014 ret = get_mapped_object(t, i, row_num, &obj);
1015 if (ret < 0)
1016 goto err;
1017 ret = insert_rbtree(t, i, row, &obj);
1018 } else { /* volatile */
1019 const struct osl_object *obj
1020 = volatile_objs + t->columns[i].volatile_num;
1021 ret = insert_rbtree(t, i, row, obj);
1022 }
1023 if (ret < 0)
1024 goto err;
1025 }
1026 if (row_ptr)
1027 *row_ptr = row;
1028 return 1;
1029 err: /* rollback changes, i.e. remove added entries from rbtrees */
1030 while (i)
1031 remove_rb_node(t, i--, row);
1032 free(row);
1033 return ret;
1034 }
1035
1036 static void free_volatile_objects(const struct osl_table *t,
1037 enum osl_close_flags flags)
1038 {
1039 int i, j;
1040 struct rb_node *n;
1041 struct osl_column *rb_col;
1042 const struct osl_column_description *cd;
1043
1044 if (!t->num_volatile_columns)
1045 return;
1046 /* find the first rbtree column (any will do) */
1047 FOR_EACH_RBTREE_COLUMN(i, t, cd)
1048 break;
1049 rb_col = t->columns + i;
1050 /* walk that rbtree and free all volatile objects */
1051 for (n = rb_first(&rb_col->rbtree); n; n = rb_next(n)) {
1052 struct osl_row *r = get_row_pointer(n, rb_col->rbtree_num);
1053 if (flags & OSL_FREE_VOLATILE)
1054 FOR_EACH_VOLATILE_COLUMN(j, t, cd) {
1055 if (cd->storage_flags & OSL_DONT_FREE)
1056 continue;
1057 free(r->volatile_objects[
1058 t->columns[j].volatile_num].data);
1059 }
1060 // for (j = 0; j < t->num_volatile_columns; j++)
1061 // free(r->volatile_objects[j].data);
1062 free(r->volatile_objects);
1063 }
1064 }
1065
1066 /**
1067 * Erase all rbtree nodes and free resources.
1068 *
1069 * \param t Pointer to an open osl table.
1070 *
1071 * This function is called by osl_close_table().
1072 */
1073 void clear_rbtrees(struct osl_table *t)
1074 {
1075 const struct osl_column_description *cd;
1076 unsigned i, rbtrees_cleared = 0;
1077
1078 FOR_EACH_RBTREE_COLUMN(i, t, cd) {
1079 struct osl_column *col = &t->columns[i];
1080 struct rb_node *n;
1081 rbtrees_cleared++;
1082 for (n = rb_first(&col->rbtree); n;) {
1083 struct osl_row *r;
1084 rb_erase(n, &col->rbtree);
1085 if (rbtrees_cleared == t->num_rbtrees) {
1086 r = get_row_pointer(n, col->rbtree_num);
1087 n = rb_next(n);
1088 free(r);
1089 } else
1090 n = rb_next(n);
1091 }
1092 }
1093
1094 }
1095
1096 /**
1097 * Close an osl table.
1098 *
1099 * \param t Pointer to the table to be closed.
1100 * \param flags Options for what should be cleaned up.
1101 *
1102 * If osl_open_table() succeeds, the resulting table pointer must later be
1103 * passed to this function in order to flush all changes to the file system and
1104 * to free the resources that were allocated by osl_open_table().
1105 *
1106 * \return Standard.
1107 *
1108 * \sa osl_open_table(), unmap_table().
1109 */
1110 __export int osl_close_table(struct osl_table *t, enum osl_close_flags flags)
1111 {
1112 int ret;
1113
1114 if (!t)
1115 return -E_OSL_BAD_TABLE;
1116 free_volatile_objects(t, flags);
1117 clear_rbtrees(t);
1118 ret = unmap_table(t, flags);
1119 if (ret < 0)
1120 ERROR_LOG("unmap_table failed: %d\n", ret);
1121 free(t->columns);
1122 free(t);
1123 return ret;
1124 }
1125
1126 /**
1127 * Find out whether the given row number corresponds to an invalid row.
1128 *
1129 * \param t Pointer to the osl table.
1130 * \param row_num The number of the row in question.
1131 *
1132 * By definition, a row is considered invalid if all its index entries
1133 * are invalid.
1134 *
1135 * \return Positive if \a row_num corresponds to an invalid row,
1136 * zero if it corresponds to a valid row, negative on errors.
1137 */
1138 int row_is_invalid(struct osl_table *t, uint32_t row_num)
1139 {
1140 char *row_index;
1141 int i, ret = get_row_index(t, row_num, &row_index);
1142
1143 if (ret < 0)
1144 return ret;
1145 for (i = 0; i < t->row_index_size; i++) {
1146 if ((unsigned char)row_index[i] != 0xff)
1147 return 0;
1148 }
1149 INFO_LOG("row %d is invalid\n", row_num);
1150 return 1;
1151 }
1152
1153 /**
1154 * Invalidate a row of an osl table.
1155 *
1156 * \param t Pointer to an open osl table.
1157 * \param row_num Number of the row to mark as invalid.
1158 *
1159 * This function marks each mapped object in the index entry of \a row as
1160 * invalid.
1161 *
1162 * \return Standard.
1163 */
1164 int mark_row_invalid(struct osl_table *t, uint32_t row_num)
1165 {
1166 char *row_index;
1167 int ret = get_row_index(t, row_num, &row_index);
1168
1169 if (ret < 0)
1170 return ret;
1171 INFO_LOG("marking row %d as invalid\n", row_num);
1172 memset(row_index, 0xff, t->row_index_size);
1173 return 1;
1174 }
1175
1176 /**
1177 * Initialize all rbtrees and compute number of invalid rows.
1178 *
1179 * \param t The table containing the rbtrees to be initialized.
1180 *
1181 * \return Standard.
1182 */
1183 int init_rbtrees(struct osl_table *t)
1184 {
1185 int i, ret;
1186 const struct osl_column_description *cd;
1187
1188 /* create rbtrees */
1189 FOR_EACH_RBTREE_COLUMN(i, t, cd)
1190 t->columns[i].rbtree = RB_ROOT;
1191 /* add valid rows to rbtrees */
1192 t->num_invalid_rows = 0;
1193 for (i = 0; i < t->num_rows; i++) {
1194 ret = row_is_invalid(t, i);
1195 if (ret < 0)
1196 return ret;
1197 if (ret) {
1198 t->num_invalid_rows++;
1199 continue;
1200 }
1201 ret = add_row_to_rbtrees(t, i, NULL, NULL);
1202 if (ret < 0)
1203 return ret;
1204 }
1205 return 1;
1206 }
1207
1208 /**
1209 * Open an osl table.
1210 *
1211 * Each osl table must be opened before its data can be accessed.
1212 *
1213 * \param table_desc Describes the table to be opened.
1214 * \param result Contains a pointer to the open table on success.
1215 *
1216 * The table description given by \a desc should coincide with the
1217 * description used at creation time.
1218 *
1219 * \return Standard.
1220 */
1221 __export int osl_open_table(const struct osl_table_description *table_desc,
1222 struct osl_table **result)
1223 {
1224 int i, ret;
1225 struct osl_table *t;
1226 const struct osl_column_description *cd;
1227
1228 INFO_LOG("opening table %s\n", table_desc->name);
1229 ret = init_table_structure(table_desc, &t);
1230 if (ret < 0)
1231 return ret;
1232 FOR_EACH_DISK_STORAGE_COLUMN(i, t, cd) {
1233 struct stat statbuf;
1234 char *dirname = column_filename(t, i);
1235
1236 ret = -ERRNO_TO_ERROR(ENOMEM);
1237 if (!dirname)
1238 goto err;
1239 /* check if directory exists */
1240 ret = stat(dirname, &statbuf);
1241 free(dirname);
1242 if (ret < 0) {
1243 ret = -ERRNO_TO_ERROR(errno);
1244 goto err;
1245 }
1246 ret = -ERRNO_TO_ERROR(ENOTDIR);
1247 if (!S_ISDIR(statbuf.st_mode))
1248 goto err;
1249 }
1250 ret = map_table(t, MAP_TBL_FL_VERIFY_INDEX);
1251 if (ret < 0)
1252 goto err;
1253 t->num_rows = ret;
1254 DEBUG_LOG("num rows: %d\n", t->num_rows);
1255 ret = init_rbtrees(t);
1256 if (ret < 0) {
1257 osl_close_table(t, OSL_MARK_CLEAN); /* ignore further errors */
1258 return ret;
1259 }
1260 *result = t;
1261 return 1;
1262 err:
1263 free(t->columns);
1264 free(t);
1265 return ret;
1266 }
1267
1268 static int create_disk_storage_object_dir(const struct osl_table *t,
1269 unsigned col_num, const char *ds_name)
1270 {
1271 char *dirname;
1272 int ret;
1273
1274 if (!(t->desc->flags & OSL_LARGE_TABLE))
1275 return 1;
1276 dirname = disk_storage_dirname(t, col_num, ds_name);
1277 if (!dirname)
1278 return -ERRNO_TO_ERROR(ENOMEM);
1279 ret = para_mkdir(dirname, 0777);
1280 free(dirname);
1281 if (ret < 0 && !is_errno(-ret, EEXIST))
1282 return ret;
1283 return 1;
1284 }
1285
1286 static int write_disk_storage_file(const struct osl_table *t, unsigned col_num,
1287 const struct osl_object *obj, const char *ds_name)
1288 {
1289 int ret;
1290 char *filename;
1291
1292 ret = create_disk_storage_object_dir(t, col_num, ds_name);
1293 if (ret < 0)
1294 return ret;
1295 filename = disk_storage_path(t, col_num, ds_name);
1296 if (!filename)
1297 return -ERRNO_TO_ERROR(ENOMEM);
1298 ret = write_file(filename, obj->data, obj->size);
1299 free(filename);
1300 return ret;
1301 }
1302
1303 static int append_map_file(const struct osl_table *t, unsigned col_num,
1304 const struct osl_object *obj, uint32_t *new_size)
1305 {
1306 char *filename = column_filename(t, col_num);
1307 int ret;
1308 char header = 0; /* zero means valid object */
1309
1310 if (!filename)
1311 return -ERRNO_TO_ERROR(ENOMEM);
1312 ret = append_file(filename, &header, 1, obj->data, obj->size,
1313 new_size);
1314 free(filename);
1315 return ret;
1316 }
1317
1318 static int append_row_index(const struct osl_table *t, char *row_index)
1319 {
1320 char *filename;
1321 int ret;
1322
1323 if (!t->num_mapped_columns)
1324 return 1;
1325 filename = index_filename(t->desc);
1326 if (!filename)
1327 return -ERRNO_TO_ERROR(ENOMEM);
1328 ret = append_file(filename, NULL, 0, row_index,
1329 t->row_index_size, NULL);
1330 free(filename);
1331 return ret;
1332 }
1333
1334 /**
1335 * A wrapper for truncate(2)
1336 *
1337 * \param path Name of the regular file to truncate
1338 * \param size Number of bytes to \b shave \b off
1339 *
1340 * Truncate the regular file named by \a path by \a size bytes.
1341 *
1342 * \return Standard.
1343 *
1344 * \sa truncate(2)
1345 */
1346 int para_truncate(const char *path, off_t size)
1347 {
1348 int ret;
1349 struct stat statbuf;
1350
1351 ret = -E_OSL_STAT;
1352 if (stat(path, &statbuf) < 0)
1353 goto out;
1354 ret = -E_OSL_BAD_SIZE;
1355 if (statbuf.st_size < size)
1356 goto out;
1357 ret = -E_OSL_TRUNC;
1358 if (truncate(path, statbuf.st_size - size) < 0)
1359 goto out;
1360 ret = 1;
1361 out:
1362 return ret;
1363 }
1364
1365 static int truncate_mapped_file(const struct osl_table *t, unsigned col_num,
1366 off_t size)
1367 {
1368 int ret;
1369 char *filename = column_filename(t, col_num);
1370
1371 if (!filename)
1372 return -ERRNO_TO_ERROR(ENOMEM);
1373 ret = para_truncate(filename, size);
1374 free(filename);
1375 return ret;
1376 }
1377
1378 static int delete_disk_storage_file(const struct osl_table *t, unsigned col_num,
1379 const char *ds_name)
1380 {
1381 char *dirname, *filename = disk_storage_path(t, col_num, ds_name);
1382 int ret, err;
1383
1384 if (!filename)
1385 return -ERRNO_TO_ERROR(ENOMEM);
1386 ret = unlink(filename);
1387 err = errno;
1388 free(filename);
1389 if (ret < 0)
1390 return -ERRNO_TO_ERROR(err);
1391 if (!(t->desc->flags & OSL_LARGE_TABLE))
1392 return 1;
1393 dirname = disk_storage_dirname(t, col_num, ds_name);
1394 if (!dirname)
1395 return -ERRNO_TO_ERROR(ENOMEM);
1396 rmdir(dirname);
1397 free(dirname);
1398 return 1;
1399 }
1400
1401 /**
1402 * Add a new row to an osl table and retrieve this row.
1403 *
1404 * \param t Pointer to an open osl table.
1405 * \param objects Array of objects to be added.
1406 * \param row Result pointer.
1407 *
1408 * The \a objects parameter must point to an array containing one object per
1409 * column. The order of the objects in the array is given by the table
1410 * description of \a table. Several sanity checks are performed during object
1411 * insertion and the function returns without modifying the table if any of
1412 * these tests fail. In fact, it is atomic in the sense that it either
1413 * succeeds or leaves the table unchanged (i.e. either all or none of the
1414 * objects are added to the table).
1415 *
1416 * It is considered an error if an object is added to a column with associated
1417 * rbtree if this object is equal to an object already contained in that column
1418 * (i.e. the compare function for the column's rbtree returns zero).
1419 *
1420 * \return Standard.
1421 *
1422 * \sa struct osl_table_description, osl_compare_func, osl_add_row().
1423 */
1424 __export int osl_add_and_get_row(struct osl_table *t, struct osl_object *objects,
1425 struct osl_row **row)
1426 {
1427 int i, ret;
1428 char *ds_name = NULL;
1429 struct rb_node **rb_parents = NULL, ***rb_links = NULL;
1430 char *new_row_index = NULL;
1431 struct osl_object *volatile_objs = NULL;
1432 const struct osl_column_description *cd;
1433
1434 if (!t)
1435 return -E_OSL_BAD_TABLE;
1436 rb_parents = malloc(t->num_rbtrees * sizeof(struct rn_node*));
1437 if (!rb_parents)
1438 return -ERRNO_TO_ERROR(ENOMEM);
1439 rb_links = malloc(t->num_rbtrees * sizeof(struct rn_node**));
1440 if (!rb_links) {
1441 free(rb_parents);
1442 return -ERRNO_TO_ERROR(ENOMEM);
1443 }
1444 if (t->num_mapped_columns) {
1445 new_row_index = malloc(t->row_index_size);
1446 if (!new_row_index) {
1447 free(rb_links);
1448 free(rb_parents);
1449 return -ERRNO_TO_ERROR(ENOMEM);
1450 }
1451 }
1452 /* pass 1: sanity checks */
1453 // DEBUG_LOG("sanity tests: %p:%p\n", objects[0].data,
1454 // objects[1].data);
1455 FOR_EACH_COLUMN(i, t->desc, cd) {
1456 enum osl_storage_type st = cd->storage_type;
1457 enum osl_storage_flags sf = cd->storage_flags;
1458
1459 // ret = -E_OSL_NULL_OBJECT;
1460 // if (!objects[i])
1461 // goto out;
1462 if (st == OSL_DISK_STORAGE)
1463 continue;
1464 if (sf & OSL_RBTREE) {
1465 unsigned rbtree_num = t->columns[i].rbtree_num;
1466 ret = -E_OSL_RB_KEY_EXISTS;
1467 // DEBUG_LOG("checking whether %p exists\n",
1468 // objects[i].data);
1469 if (search_rbtree(objects + i, t, i,
1470 &rb_parents[rbtree_num],
1471 &rb_links[rbtree_num]) > 0)
1472 goto out;
1473 }
1474 if (sf & OSL_FIXED_SIZE) {
1475 // DEBUG_LOG("fixed size. need: %zu, have: %d\n",
1476 // objects[i].size, cd->data_size);
1477 ret = -E_OSL_BAD_DATA_SIZE;
1478 if (objects[i].size != cd->data_size)
1479 goto out;
1480 }
1481 }
1482 if (t->num_disk_storage_columns) {
1483 ds_name = disk_storage_name_of_object(t,
1484 &objects[t->disk_storage_name_column]);
1485 ret = -ERRNO_TO_ERROR(ENOMEM);
1486 if (!ds_name)
1487 goto out;
1488 }
1489 ret = unmap_table(t, OSL_MARK_CLEAN);
1490 if (ret < 0)
1491 goto out;
1492 // DEBUG_LOG("sanity tests passed%s\n", "");
1493 /* pass 2: create data files, append map data */
1494 FOR_EACH_COLUMN(i, t->desc, cd) {
1495 enum osl_storage_type st = cd->storage_type;
1496 if (st == OSL_NO_STORAGE)
1497 continue;
1498 if (st == OSL_MAPPED_STORAGE) {
1499 uint32_t new_size;
1500 struct osl_column *col = &t->columns[i];
1501 // DEBUG_LOG("appending object of size %zu\n",
1502 // objects[i].size);
1503 ret = append_map_file(t, i, objects + i, &new_size);
1504 if (ret < 0)
1505 goto rollback;
1506 update_cell_index(new_row_index, col, new_size,
1507 objects[i].size);
1508 continue;
1509 }
1510 /* DISK_STORAGE */
1511 ret = write_disk_storage_file(t, i, objects + i, ds_name);
1512 if (ret < 0)
1513 goto rollback;
1514 }
1515 ret = append_row_index(t, new_row_index);
1516 if (ret < 0)
1517 goto rollback;
1518 ret = map_table(t, MAP_TBL_FL_VERIFY_INDEX);
1519 if (ret < 0) { /* truncate index and rollback changes */
1520 char *filename = index_filename(t->desc);
1521 if (filename)
1522 para_truncate(filename, t->row_index_size);
1523 free(filename);
1524 goto rollback;
1525 }
1526 /* pass 3: add entry to rbtrees */
1527 if (t->num_volatile_columns) {
1528 ret = -ERRNO_TO_ERROR(ENOMEM);
1529 volatile_objs = calloc(t->num_volatile_columns,
1530 sizeof(struct osl_object));
1531 if (!volatile_objs)
1532 goto out;
1533 FOR_EACH_VOLATILE_COLUMN(i, t, cd)
1534 volatile_objs[t->columns[i].volatile_num] = objects[i];
1535 }
1536 t->num_rows++;
1537 // DEBUG_LOG("adding new entry as row #%d\n", t->num_rows - 1);
1538 ret = add_row_to_rbtrees(t, t->num_rows - 1, volatile_objs, row);
1539 if (ret < 0)
1540 goto out;
1541 // DEBUG_LOG("added new entry as row #%d\n", t->num_rows - 1);
1542 ret = 1;
1543 goto out;
1544 rollback: /* rollback all changes made, ignore further errors */
1545 for (i--; i >= 0; i--) {
1546 cd = get_column_description(t->desc, i);
1547 enum osl_storage_type st = cd->storage_type;
1548 if (st == OSL_NO_STORAGE)
1549 continue;
1550
1551 if (st == OSL_MAPPED_STORAGE)
1552 truncate_mapped_file(t, i, objects[i].size);
1553 else /* disk storage */
1554 delete_disk_storage_file(t, i, ds_name);
1555 }
1556 /* ignore error and return previous error value */
1557 map_table(t, MAP_TBL_FL_VERIFY_INDEX);
1558 out:
1559 free(new_row_index);
1560 free(ds_name);
1561 free(rb_parents);
1562 free(rb_links);
1563 return ret;
1564 }
1565
1566 /**
1567 * Add a new row to an osl table.
1568 *
1569 * \param t Same meaning as osl_add_and_get_row().
1570 * \param objects Same meaning as osl_add_and_get_row().
1571 *
1572 * \return The return value of the underlying call to osl_add_and_get_row().
1573 *
1574 * This is equivalent to osl_add_and_get_row(t, objects, NULL).
1575 */
1576 __export int osl_add_row(struct osl_table *t, struct osl_object *objects)
1577 {
1578 return osl_add_and_get_row(t, objects, NULL);
1579 }
1580
1581 /**
1582 * Retrieve an object identified by row and column
1583 *
1584 * \param t Pointer to an open osl table.
1585 * \param r Pointer to the row.
1586 * \param col_num The column number.
1587 * \param object The result pointer.
1588 *
1589 * The column determined by \a col_num must be of type \p OSL_MAPPED_STORAGE
1590 * or \p OSL_NO_STORAGE, i.e. no disk storage objects may be retrieved by this
1591 * function.
1592 *
1593 * \return Standard.
1594 *
1595 * \sa osl_storage_type, osl_open_disk_object().
1596 */
1597 __export int osl_get_object(const struct osl_table *t, const struct osl_row *r,
1598 unsigned col_num, struct osl_object *object)
1599 {
1600 const struct osl_column_description *cd;
1601
1602 if (!t)
1603 return -E_OSL_BAD_TABLE;
1604 cd = get_column_description(t->desc, col_num);
1605 /* col must not be disk storage */
1606 if (cd->storage_type == OSL_DISK_STORAGE)
1607 return -E_OSL_BAD_STORAGE_TYPE;
1608 if (cd->storage_type == OSL_MAPPED_STORAGE)
1609 return get_mapped_object(t, col_num, r->num, object);
1610 /* volatile */
1611 *object = r->volatile_objects[t->columns[col_num].volatile_num];
1612 return 1;
1613 }
1614
1615 static int mark_mapped_object_invalid(const struct osl_table *t,
1616 uint32_t row_num, unsigned col_num)
1617 {
1618 struct osl_object obj;
1619 char *p;
1620 int ret = get_mapped_object(t, col_num, row_num, &obj);
1621
1622 if (ret < 0)
1623 return ret;
1624 p = obj.data;
1625 p--;
1626 *p = 0xff;
1627 return 1;
1628 }
1629
1630 /**
1631 * Delete a row from an osl table.
1632 *
1633 * \param t Pointer to an open osl table.
1634 * \param row Pointer to the row to delete.
1635 *
1636 * This removes all disk storage objects, removes all rbtree nodes, and frees
1637 * all volatile objects belonging to the given row. For mapped columns, the
1638 * data is merely marked invalid and may be pruned from time to time by
1639 * para_fsck.
1640 *
1641 * \return Standard.
1642 */
1643 __export int osl_del_row(struct osl_table *t, struct osl_row *row)
1644 {
1645 struct osl_row *r = row;
1646 int i, ret;
1647 const struct osl_column_description *cd;
1648
1649 if (!t)
1650 return -E_OSL_BAD_TABLE;
1651 INFO_LOG("deleting row %p\n", row);
1652
1653 if (t->num_disk_storage_columns) {
1654 char *ds_name;
1655 ret = disk_storage_name_of_row(t, r, &ds_name);
1656 if (ret < 0)
1657 goto out;
1658 FOR_EACH_DISK_STORAGE_COLUMN(i, t, cd)
1659 delete_disk_storage_file(t, i, ds_name);
1660 free(ds_name);
1661 }
1662 FOR_EACH_COLUMN(i, t->desc, cd) {
1663 struct osl_column *col = t->columns + i;
1664 enum osl_storage_type st = cd->storage_type;
1665 remove_rb_node(t, i, r);
1666 if (st == OSL_MAPPED_STORAGE) {
1667 mark_mapped_object_invalid(t, r->num, i);
1668 continue;
1669 }
1670 if (st == OSL_NO_STORAGE && !(cd->storage_flags & OSL_DONT_FREE))
1671 free(r->volatile_objects[col->volatile_num].data);
1672 }
1673 if (t->num_mapped_columns) {
1674 ret = mark_row_invalid(t, r->num);
1675 if (ret < 0)
1676 goto out;
1677 t->num_invalid_rows++;
1678 } else
1679 t->num_rows--;
1680 ret = 1;
1681 out:
1682 free(r->volatile_objects);
1683 free(r);
1684 return ret;
1685 }
1686
1687 /* test if column has an rbtree */
1688 static int check_rbtree_col(const struct osl_table *t, unsigned col_num,
1689 struct osl_column **col)
1690 {
1691 if (!t)
1692 return -E_OSL_BAD_TABLE;
1693 if (!(get_column_description(t->desc, col_num)->storage_flags & OSL_RBTREE))
1694 return -E_OSL_BAD_STORAGE_FLAGS;
1695 *col = t->columns + col_num;
1696 return 1;
1697 }
1698
1699 /**
1700 * Get the row that contains the given object.
1701 *
1702 * \param t Pointer to an open osl table.
1703 * \param col_num The number of the column to be searched.
1704 * \param obj The object to be looked up.
1705 * \param result Points to the row containing \a obj.
1706 *
1707 * Lookup \a obj in \a t and return the row containing \a obj. The column
1708 * specified by \a col_num must have an associated rbtree.
1709 *
1710 * \return Standard.
1711 *
1712 * \sa osl_storage_flags
1713 */
1714 __export int osl_get_row(const struct osl_table *t, unsigned col_num,
1715 const struct osl_object *obj, struct osl_row **result)
1716 {
1717 int ret;
1718 struct rb_node *node;
1719 struct osl_row *row;
1720 struct osl_column *col;
1721
1722 *result = NULL;
1723 ret = check_rbtree_col(t, col_num, &col);
1724 if (ret < 0)
1725 return ret;
1726 ret = search_rbtree(obj, t, col_num, &node, NULL);
1727 if (ret < 0)
1728 return ret;
1729 row = get_row_pointer(node, t->columns[col_num].rbtree_num);
1730 *result = row;
1731 return 1;
1732 }
1733
1734 static int rbtree_loop(struct osl_column *col, void *private_data,
1735 osl_rbtree_loop_func *func)
1736 {
1737 struct rb_node *n, *tmp;
1738
1739 /* this for-loop is safe against removal of an entry */
1740 for (n = rb_first(&col->rbtree), tmp = n? rb_next(n) : NULL;
1741 n;
1742 n = tmp, tmp = tmp? rb_next(tmp) : NULL) {
1743 struct osl_row *r = get_row_pointer(n, col->rbtree_num);
1744 int ret = func(r, private_data);
1745 if (ret < 0)
1746 return ret;
1747 }
1748 return 1;
1749 }
1750
1751 static int rbtree_loop_reverse(struct osl_column *col, void *private_data,
1752 osl_rbtree_loop_func *func)
1753 {
1754 struct rb_node *n, *tmp;
1755
1756 /* safe against removal of an entry */
1757 for (n = rb_last(&col->rbtree), tmp = n? rb_prev(n) : NULL;
1758 n;
1759 n = tmp, tmp = tmp? rb_prev(tmp) : NULL) {
1760 struct osl_row *r = get_row_pointer(n, col->rbtree_num);
1761 int ret = func(r, private_data);
1762 if (ret < 0)
1763 return ret;
1764 }
1765 return 1;
1766 }
1767
1768 /**
1769 * Loop over all nodes in an rbtree.
1770 *
1771 * \param t Pointer to an open osl table.
1772 * \param col_num The column to use for iterating over the elements.
1773 * \param private_data Pointer that gets passed to \a func.
1774 * \param func The function to be called for each node in the rbtree.
1775 *
1776 * This function does an in-order walk of the rbtree associated with \a
1777 * col_num. It is an error if the \p OSL_RBTREE flag is not set for this
1778 * column. For each node in the rbtree, the given function \a func is called
1779 * with two pointers as arguments: The first osl_row* argument points to the
1780 * row that contains the object corresponding to the rbtree node currently
1781 * traversed, and the \a private_data pointer is passed verbatim to \a func as the
1782 * second argument. The loop terminates either if \a func returns a negative
1783 * value, or if all nodes of the tree have been visited.
1784 *
1785 *
1786 * \return Standard. If the termination of the loop was caused by \a func
1787 * returning a negative value, this value is returned.
1788 *
1789 * \sa osl_storage_flags, osl_rbtree_loop_reverse(), osl_compare_func.
1790 */
1791 __export int osl_rbtree_loop(const struct osl_table *t, unsigned col_num,
1792 void *private_data, osl_rbtree_loop_func *func)
1793 {
1794 struct osl_column *col;
1795
1796 int ret = check_rbtree_col(t, col_num, &col);
1797 if (ret < 0)
1798 return ret;
1799 return rbtree_loop(col, private_data, func);
1800 }
1801
1802 /**
1803 * Loop over all nodes in an rbtree in reverse order.
1804 *
1805 * \param t Identical meaning as in \p osl_rbtree_loop().
1806 * \param col_num Identical meaning as in \p osl_rbtree_loop().
1807 * \param private_data Identical meaning as in \p osl_rbtree_loop().
1808 * \param func Identical meaning as in \p osl_rbtree_loop().
1809 *
1810 * This function is identical to \p osl_rbtree_loop(), the only difference
1811 * is that the tree is walked in reverse order.
1812 *
1813 * \return The same return value as \p osl_rbtree_loop().
1814 *
1815 * \sa osl_rbtree_loop().
1816 */
1817 __export int osl_rbtree_loop_reverse(const struct osl_table *t, unsigned col_num,
1818 void *private_data, osl_rbtree_loop_func *func)
1819 {
1820 struct osl_column *col;
1821
1822 int ret = check_rbtree_col(t, col_num, &col);
1823 if (ret < 0)
1824 return ret;
1825 return rbtree_loop_reverse(col, private_data, func);
1826 }
1827
1828 /* TODO: Rollback changes on errors */
1829 static int rename_disk_storage_objects(struct osl_table *t,
1830 struct osl_object *old_obj, struct osl_object *new_obj)
1831 {
1832 int i, ret;
1833 const struct osl_column_description *cd;
1834 char *old_ds_name, *new_ds_name;
1835
1836 if (!t->num_disk_storage_columns)
1837 return 1; /* nothing to do */
1838 if (old_obj->size == new_obj->size && !memcmp(new_obj->data,
1839 old_obj->data, new_obj->size))
1840 return 1; /* object did not change */
1841 old_ds_name = disk_storage_name_of_object(t, old_obj);
1842 new_ds_name = disk_storage_name_of_object(t, new_obj);
1843 ret = -ERRNO_TO_ERROR(ENOMEM);
1844 if (!old_ds_name || ! new_ds_name)
1845 goto out;
1846
1847 FOR_EACH_DISK_STORAGE_COLUMN(i, t, cd) {
1848 char *old_filename, *new_filename;
1849 ret = create_disk_storage_object_dir(t, i, new_ds_name);
1850 if (ret < 0)
1851 goto out;
1852 old_filename = disk_storage_path(t, i, old_ds_name);
1853 new_filename = disk_storage_path(t, i, new_ds_name);
1854 if (!old_filename || !new_filename)
1855 ret = -ERRNO_TO_ERROR(ENOMEM);
1856 else
1857 ret = para_rename(old_filename, new_filename);
1858 free(old_filename);
1859 free(new_filename);
1860 if (ret < 0)
1861 goto out;
1862 }
1863 ret = 1;
1864 out:
1865 free(old_ds_name);
1866 free(new_ds_name);
1867 return ret;
1868
1869 }
1870
1871 /**
1872 * Change an object in an osl table.
1873 *
1874 * \param t Pointer to an open osl table.
1875 * \param r Pointer to the row containing the object to be updated.
1876 * \param col_num Number of the column containing the object to be updated.
1877 * \param obj Pointer to the replacement object.
1878 *
1879 * This function gets rid of all references to the old object. This includes
1880 * removal of the rbtree node in case there is an rbtree associated with \a
1881 * col_num. It then inserts \a obj into the table and the rbtree if necessary.
1882 *
1883 * If the \p OSL_RBTREE flag is set for \a col_num, you \b MUST call this
1884 * function in order to change the contents of an object, even for volatile or
1885 * mapped columns of constant size (which may be updated directly if \p
1886 * OSL_RBTREE is not set). Otherwise the rbtree might become corrupted.
1887 *
1888 * \return Standard
1889 */
1890 __export int osl_update_object(struct osl_table *t, const struct osl_row *r,
1891 unsigned col_num, struct osl_object *obj)
1892 {
1893 struct osl_column *col;
1894 const struct osl_column_description *cd;
1895 int ret;
1896
1897 if (!t)
1898 return -E_OSL_BAD_TABLE;
1899 col = &t->columns[col_num];
1900 cd = get_column_description(t->desc, col_num);
1901 DEBUG_LOG("updating column %u of %s\n", col_num, t->desc->name);
1902 if (cd->storage_flags & OSL_RBTREE) {
1903 if (search_rbtree(obj, t, col_num, NULL, NULL) > 0)
1904 return -E_OSL_RB_KEY_EXISTS;
1905 }
1906 if (cd->storage_flags & OSL_FIXED_SIZE) {
1907 if (obj->size != cd->data_size)
1908 return -E_OSL_BAD_DATA_SIZE;
1909 }
1910 remove_rb_node(t, col_num, r);
1911 if (cd->storage_type == OSL_NO_STORAGE) { /* TODO: If fixed size, reuse object? */
1912 free(r->volatile_objects[col->volatile_num].data);
1913 r->volatile_objects[col->volatile_num] = *obj;
1914 } else if (cd->storage_type == OSL_DISK_STORAGE) {
1915 char *ds_name;
1916 ret = disk_storage_name_of_row(t, r, &ds_name);
1917 if (ret < 0)
1918 return ret;
1919 ret = delete_disk_storage_file(t, col_num, ds_name);
1920 if (ret < 0 && !is_errno(-ret, ENOENT)) {
1921 free(ds_name);
1922 return ret;
1923 }
1924 ret = write_disk_storage_file(t, col_num, obj, ds_name);
1925 free(ds_name);
1926 if (ret < 0)
1927 return ret;
1928 } else { /* mapped storage */
1929 struct osl_object old_obj;
1930 ret = get_mapped_object(t, col_num, r->num, &old_obj);
1931 if (ret < 0)
1932 return ret;
1933 /*
1934 * If the updated column is the disk storage name column, the
1935 * disk storage name changes, so we have to rename all disk
1936 * storage objects accordingly.
1937 */
1938 if (col_num == t->disk_storage_name_column) {
1939 ret = rename_disk_storage_objects(t, &old_obj, obj);
1940 if (ret < 0)
1941 return ret;
1942 }
1943 if (cd->storage_flags & OSL_FIXED_SIZE)
1944 memcpy(old_obj.data, obj->data, cd->data_size);
1945 else { /* TODO: if the size doesn't change, use old space */
1946 uint32_t new_data_map_size;
1947 char *row_index;
1948 ret = get_row_index(t, r->num, &row_index);
1949 if (ret < 0)
1950 return ret;
1951 ret = mark_mapped_object_invalid(t, r->num, col_num);
1952 if (ret < 0)
1953 return ret;
1954 unmap_column(t, col_num);
1955 ret = append_map_file(t, col_num, obj,
1956 &new_data_map_size);
1957 if (ret < 0)
1958 return ret;
1959 ret = map_column(t, col_num);
1960 if (ret < 0)
1961 return ret;
1962 update_cell_index(row_index, col, new_data_map_size,
1963 obj->size);
1964 }
1965 }
1966 if (cd->storage_flags & OSL_RBTREE) {
1967 ret = insert_rbtree(t, col_num, r, obj);
1968 if (ret < 0)
1969 return ret;
1970 }
1971 return 1;
1972 }
1973
1974 /**
1975 * Retrieve an object of type \p OSL_DISK_STORAGE by row and column.
1976 *
1977 * \param t Pointer to an open osl table.
1978 * \param r Pointer to the row containing the object.
1979 * \param col_num The column number.
1980 * \param obj Points to the result upon successful return.
1981 *
1982 * For columns of type \p OSL_DISK_STORAGE, this function must be used to
1983 * retrieve one of its containing objects. Afterwards, osl_close_disk_object()
1984 * must be called in order to deallocate the resources.
1985 *
1986 * \return Standard.
1987 *
1988 * \sa osl_get_object(), osl_storage_type, osl_close_disk_object().
1989 */
1990 __export int osl_open_disk_object(const struct osl_table *t, const struct osl_row *r,
1991 unsigned col_num, struct osl_object *obj)
1992 {
1993 const struct osl_column_description *cd;
1994 char *ds_name, *filename;
1995 int ret;
1996
1997 if (!t)
1998 return -E_OSL_BAD_TABLE;
1999 cd = get_column_description(t->desc, col_num);
2000 if (cd->storage_type != OSL_DISK_STORAGE)
2001 return -E_OSL_BAD_STORAGE_TYPE;
2002
2003 ret = disk_storage_name_of_row(t, r, &ds_name);
2004 if (ret < 0)
2005 return ret;
2006 filename = disk_storage_path(t, col_num, ds_name);
2007 free(ds_name);
2008 if (!filename)
2009 return -ERRNO_TO_ERROR(ENOMEM);
2010 DEBUG_LOG("filename: %s\n", filename);
2011 ret = mmap_full_file(filename, O_RDONLY, &obj->data, &obj->size, NULL);
2012 free(filename);
2013 return ret;
2014 }
2015
2016 /**
2017 * Free resources that were allocated during osl_open_disk_object().
2018 *
2019 * \param obj Pointer to the object previously returned by open_disk_object().
2020 *
2021 * \return The return value of the underlying call to para_munmap().
2022 *
2023 * \sa para_munmap().
2024 */
2025 __export int osl_close_disk_object(struct osl_object *obj)
2026 {
2027 return para_munmap(obj->data, obj->size);
2028 }
2029
2030 /**
2031 * Get the number of rows of the given table.
2032 *
2033 * \param t Pointer to an open osl table.
2034 * \param num_rows Result is returned here.
2035 *
2036 * The number of rows returned via \a num_rows excluding any invalid rows.
2037 *
2038 * \return Positive on success, \p -E_OSL_BAD_TABLE if \a t is \p NULL.
2039 */
2040 __export int osl_get_num_rows(const struct osl_table *t, unsigned *num_rows)
2041 {
2042 if (!t)
2043 return -E_OSL_BAD_TABLE;
2044 assert(t->num_rows >= t->num_invalid_rows);
2045 *num_rows = t->num_rows - t->num_invalid_rows;
2046 return 1;
2047 }
2048
2049 /**
2050 * Get the rank of a row.
2051 *
2052 * \param t An open osl table.
2053 * \param r The row to get the rank of.
2054 * \param col_num The number of an rbtree column.
2055 * \param rank Result pointer.
2056 *
2057 * The rank is, by definition, the position of the row in the linear order
2058 * determined by an in-order tree walk of the rbtree associated with column
2059 * number \a col_num of \a table.
2060 *
2061 * \return Standard.
2062 *
2063 * \sa osl_get_nth_row().
2064 */
2065 __export int osl_get_rank(const struct osl_table *t, struct osl_row *r,
2066 unsigned col_num, unsigned *rank)
2067 {
2068 struct osl_object obj;
2069 struct osl_column *col;
2070 struct rb_node *node;
2071 int ret = check_rbtree_col(t, col_num, &col);
2072
2073 if (ret < 0)
2074 return ret;
2075 ret = osl_get_object(t, r, col_num, &obj);
2076 if (ret < 0)
2077 return ret;
2078 ret = search_rbtree(&obj, t, col_num, &node, NULL);
2079 if (ret < 0)
2080 return ret;
2081 ret = rb_rank(node, rank);
2082 if (ret < 0)
2083 return -E_OSL_BAD_ROW;
2084 return 1;
2085 }
2086
2087 /**
2088 * Get the row with n-th greatest value.
2089 *
2090 * \param t Pointer to an open osl table.
2091 * \param col_num The column number.
2092 * \param n The rank of the desired row.
2093 * \param result Row is returned here.
2094 *
2095 * Retrieve the n-th order statistic with respect to the compare function
2096 * of the rbtree column \a col_num. In other words, get that row with
2097 * \a n th greatest value in column \a col_num. It's an error if
2098 * \a col_num is not a rbtree column, or if \a n is larger than the
2099 * number of rows in the table.
2100 *
2101 * \return Standard.
2102 *
2103 * \sa osl_storage_flags, osl_compare_func, osl_get_row(),
2104 * osl_rbtree_last_row(), osl_rbtree_first_row(), osl_get_rank().
2105 */
2106 __export int osl_get_nth_row(const struct osl_table *t, unsigned col_num,
2107 unsigned n, struct osl_row **result)
2108 {
2109 struct osl_column *col;
2110 struct rb_node *node;
2111 unsigned num_rows;
2112 int ret;
2113
2114 if (n == 0)
2115 return -E_OSL_RB_KEY_NOT_FOUND;
2116 ret = osl_get_num_rows(t, &num_rows);
2117 if (ret < 0)
2118 return ret;
2119 if (n > num_rows)
2120 return -E_OSL_RB_KEY_NOT_FOUND;
2121 ret = check_rbtree_col(t, col_num, &col);
2122 if (ret < 0)
2123 return ret;
2124 node = rb_nth(col->rbtree.rb_node, n);
2125 if (!node)
2126 return -E_OSL_RB_KEY_NOT_FOUND;
2127 *result = get_row_pointer(node, col->rbtree_num);
2128 return 1;
2129 }
2130
2131 /**
2132 * Get the row corresponding to the smallest rbtree node of a column.
2133 *
2134 * \param t An open rbtree table.
2135 * \param col_num The number of the rbtree column.
2136 * \param result A pointer to the first row is returned here.
2137 *
2138 * The rbtree node of the smallest object (with respect to the corresponding
2139 * compare function) is selected and the row containing this object is
2140 * returned. It is an error if \a col_num refers to a column without an
2141 * associated rbtree.
2142 *
2143 * \return Standard.
2144 *
2145 * \sa osl_get_nth_row(), osl_rbtree_last_row().
2146 */
2147 __export int osl_rbtree_first_row(const struct osl_table *t, unsigned col_num,
2148 struct osl_row **result)
2149 {
2150 return osl_get_nth_row(t, col_num, 1, result);
2151 }
2152
2153 /**
2154 * Get the row corresponding to the greatest rbtree node of a column.
2155 *
2156 * \param t The same meaning as in \p osl_rbtree_first_row().
2157 * \param col_num The same meaning as in \p osl_rbtree_first_row().
2158 * \param result The same meaning as in \p osl_rbtree_first_row().
2159 *
2160 * This function works just like osl_rbtree_first_row(), the only difference
2161 * is that the row containing the greatest rather than the smallest object is
2162 * returned.
2163 *
2164 * \return Standard.
2165 *
2166 * \sa osl_get_nth_row(), osl_rbtree_first_row().
2167 */
2168 __export int osl_rbtree_last_row(const struct osl_table *t, unsigned col_num,
2169 struct osl_row **result)
2170 {
2171 unsigned num_rows;
2172 int ret = osl_get_num_rows(t, &num_rows);
2173
2174 if (ret < 0)
2175 return ret;
2176 return osl_get_nth_row(t, col_num, num_rows, result);
2177 }