Make some functions static.
[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_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_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_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_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 Positive on success, negative on errors. Possible errors include:
180 * any errors from para_open() or para_write().
181 *
182 * \sa para_open(), para_write().
183 */
184 int para_write_file(const char *filename, const void *buf, size_t size)
185 {
186 int ret, fd;
187
188 ret = para_open(filename, O_WRONLY | O_CREAT | O_EXCL, 0644);
189 if (ret < 0)
190 return ret;
191 fd = ret;
192 ret = write_all(fd, buf, size);
193 if (ret < 0)
194 goto out;
195 ret = 1;
196 out:
197 close(fd);
198 return ret;
199 }
200
201 static int append_file(const char *filename, char *header, size_t header_size,
202 char *data, size_t data_size, uint32_t *new_pos)
203 {
204 int ret, fd;
205
206 // DEBUG_LOG("appending %zu + %zu bytes\n", header_size, data_size);
207 ret = para_open(filename, O_WRONLY | O_CREAT | O_APPEND, 0644);
208 if (ret < 0)
209 return ret;
210 fd = ret;
211 if (header && header_size) {
212 ret = write_all(fd, header, header_size);
213 if (ret < 0)
214 goto out;
215 }
216 ret = write_all(fd, data, data_size);
217 if (ret < 0)
218 goto out;
219 if (new_pos) {
220 off_t offset = 0;
221 ret = __lseek(fd, &offset, SEEK_END);
222 if (ret < 0)
223 goto out;
224 // DEBUG_LOG("new file size: " FMT_OFF_T "\n", offset);
225 *new_pos = offset;
226 }
227 ret = 1;
228 out:
229 close(fd);
230 return ret;
231 }
232
233 /**
234 * Traverse the given directory recursively.
235 *
236 * \param dirname The directory to traverse.
237 * \param func The function to call for each entry.
238 * \param private_data Pointer to an arbitrary data structure.
239 *
240 * For each regular file under \a dirname, the supplied function \a func is
241 * called. The full path of the regular file and the \a private_data pointer
242 * are passed to \a func. Directories for which the calling process has no
243 * permissions to change to are silently ignored.
244 *
245 * \return Standard.
246 */
247 int for_each_file_in_dir(const char *dirname,
248 int (*func)(const char *, void *), void *private_data)
249 {
250 DIR *dir;
251 struct dirent *entry;
252 int cwd_fd, ret2, ret = para_opendir(dirname, &dir, &cwd_fd);
253
254 if (ret < 0)
255 return ret == -ERRNO_TO_ERROR(EACCES)? 1 : ret;
256 /* scan cwd recursively */
257 while ((entry = readdir(dir))) {
258 mode_t m;
259 char *tmp;
260 struct stat s;
261
262 if (!strcmp(entry->d_name, "."))
263 continue;
264 if (!strcmp(entry->d_name, ".."))
265 continue;
266 if (lstat(entry->d_name, &s) == -1)
267 continue;
268 m = s.st_mode;
269 if (!S_ISREG(m) && !S_ISDIR(m))
270 continue;
271 tmp = make_message("%s/%s", dirname, entry->d_name);
272 ret = -ERRNO_TO_ERROR(ENOMEM);
273 if (!tmp)
274 goto out;
275 if (!S_ISDIR(m)) {
276 ret = func(tmp, private_data);
277 free(tmp);
278 if (ret < 0)
279 goto out;
280 continue;
281 }
282 /* directory */
283 ret = for_each_file_in_dir(tmp, func, private_data);
284 free(tmp);
285 if (ret < 0)
286 goto out;
287 }
288 ret = 1;
289 out:
290 closedir(dir);
291 ret2 = para_fchdir(cwd_fd);
292 if (ret2 < 0 && ret >= 0)
293 ret = ret2;
294 close(cwd_fd);
295 return ret;
296 }
297
298 static int verify_name(const char *name)
299 {
300 if (!name)
301 return -E_BAD_NAME;
302 if (!*name)
303 return -E_BAD_NAME;
304 if (strchr(name, '/'))
305 return -E_BAD_NAME;
306 if (!strcmp(name, ".."))
307 return -E_BAD_NAME;
308 if (!strcmp(name, "."))
309 return -E_BAD_NAME;
310 return 1;
311 }
312
313 /**
314 * Compare two osl objects pointing to unsigned integers of 32 bit size.
315 *
316 * \param obj1 Pointer to the first integer.
317 * \param obj2 Pointer to the second integer.
318 *
319 * \return The values required for an osl compare function.
320 *
321 * \sa osl_compare_func, osl_hash_compare().
322 */
323 int uint32_compare(const struct osl_object *obj1, const struct osl_object *obj2)
324 {
325 uint32_t d1 = read_u32((const char *)obj1->data);
326 uint32_t d2 = read_u32((const char *)obj2->data);
327
328 if (d1 < d2)
329 return 1;
330 if (d1 > d2)
331 return -1;
332 return 0;
333 }
334
335 /**
336 * Compare two osl objects pointing to hash values.
337 *
338 * \param obj1 Pointer to the first hash object.
339 * \param obj2 Pointer to the second hash object.
340 *
341 * \return The values required for an osl compare function.
342 *
343 * \sa osl_compare_func, uint32_compare().
344 */
345 int osl_hash_compare(const struct osl_object *obj1, const struct osl_object *obj2)
346 {
347 return hash_compare((HASH_TYPE *)obj1->data, (HASH_TYPE *)obj2->data);
348 }
349
350 static char *disk_storage_dirname(const struct osl_table *t, unsigned col_num,
351 const char *ds_name)
352 {
353 char *dirname, *column_name = column_filename(t, col_num);
354
355 if (!column_name)
356 return NULL;
357 if (!(t->desc->flags & OSL_LARGE_TABLE))
358 return column_name;
359 dirname = make_message("%s/%.2s", column_name, ds_name);
360 free(column_name);
361 return dirname;
362 }
363
364 static char *disk_storage_name_of_object(const struct osl_table *t,
365 const struct osl_object *obj)
366 {
367 HASH_TYPE hash[HASH_SIZE];
368 hash_object(obj, hash);
369 return disk_storage_name_of_hash(t, hash);
370 }
371
372 static int disk_storage_name_of_row(const struct osl_table *t,
373 const struct osl_row *row, char **name)
374 {
375 struct osl_object obj;
376 int ret = osl_get_object(t, row, t->disk_storage_name_column, &obj);
377
378 if (ret < 0)
379 return ret;
380 *name = disk_storage_name_of_object(t, &obj);
381 if (*name)
382 return 1;
383 return -ERRNO_TO_ERROR(ENOMEM);
384 }
385
386 static void column_name_hash(const char *col_name, HASH_TYPE *hash)
387 {
388 hash_function(col_name, strlen(col_name), hash);
389 }
390
391 static int init_column_descriptions(struct osl_table *t)
392 {
393 int i, j, ret;
394 const struct osl_column_description *cd;
395
396 ret = -E_BAD_TABLE_DESC;
397 ret = verify_name(t->desc->name);
398 if (ret < 0)
399 goto err;
400 ret = -E_BAD_DB_DIR;
401 if (!t->desc->dir && (t->num_disk_storage_columns || t->num_mapped_columns))
402 goto err;
403 /* the size of the index header without column descriptions */
404 t->index_header_size = IDX_COLUMN_DESCRIPTIONS;
405 FOR_EACH_COLUMN(i, t->desc, cd) {
406 struct osl_column *col = t->columns + i;
407 if (cd->storage_flags & OSL_RBTREE) {
408 if (!cd->compare_function)
409 return -E_NO_COMPARE_FUNC;
410 }
411 if (cd->storage_type == OSL_NO_STORAGE)
412 continue;
413 ret = -E_NO_COLUMN_NAME;
414 if (!cd->name || !cd->name[0])
415 goto err;
416 ret = verify_name(cd->name);
417 if (ret < 0)
418 goto err;
419 t->index_header_size += index_column_description_size(cd->name);
420 column_name_hash(cd->name, col->name_hash);
421 ret = -E_DUPLICATE_COL_NAME;
422 for (j = i + 1; j < t->desc->num_columns; j++) {
423 const char *name2 = get_column_description(t->desc,
424 j)->name;
425 if (cd->name && name2 && !strcmp(cd->name, name2))
426 goto err;
427 }
428 }
429 return 1;
430 err:
431 return ret;
432 }
433
434 /**
435 * Initialize a struct table from given table description.
436 *
437 * \param desc The description of the osl table.
438 * \param table_ptr Result is returned here.
439 *
440 * This function performs several sanity checks on \p desc and returns if any
441 * of these tests fail. On success, a struct \p osl_table is allocated and
442 * initialized with data derived from \p desc.
443 *
444 * \return Positive on success, negative on errors. Possible errors include: \p
445 * E_BAD_TABLE_DESC, \p E_NO_COLUMN_DESC, \p E_NO_COLUMNS, \p
446 * E_BAD_STORAGE_TYPE, \p E_BAD_STORAGE_FLAGS, \p E_BAD_STORAGE_SIZE, \p
447 * E_NO_UNIQUE_RBTREE_COLUMN, \p E_NO_RBTREE_COL.
448 *
449 * \sa struct osl_table.
450 */
451 int init_table_structure(const struct osl_table_description *desc,
452 struct osl_table **table_ptr)
453 {
454 const struct osl_column_description *cd;
455 struct osl_table *t = calloc(1, sizeof(*t));
456 int i, ret = -ERRNO_TO_ERROR(ENOMEM), have_disk_storage_name_column = 0;
457
458 if (!t)
459 return ret;
460 ret = -E_BAD_TABLE_DESC;
461 if (!desc)
462 goto err;
463 DEBUG_LOG("creating table structure for '%s' from table "
464 "description\n", desc->name);
465 ret = -E_NO_COLUMN_DESC;
466 if (!desc->column_descriptions)
467 goto err;
468 ret = -E_NO_COLUMNS;
469 if (!desc->num_columns)
470 goto err;
471 ret = -ERRNO_TO_ERROR(ENOMEM);
472 t->columns = calloc(desc->num_columns, sizeof(struct osl_column));
473 if (!t->columns)
474 goto err;
475 t->desc = desc;
476 FOR_EACH_COLUMN(i, t->desc, cd) {
477 enum osl_storage_type st = cd->storage_type;
478 enum osl_storage_flags sf = cd->storage_flags;
479 struct osl_column *col = &t->columns[i];
480
481 ret = -E_BAD_STORAGE_TYPE;
482 if (st != OSL_MAPPED_STORAGE && st != OSL_DISK_STORAGE
483 && st != OSL_NO_STORAGE)
484 goto err;
485 ret = -E_BAD_STORAGE_FLAGS;
486 if (st == OSL_DISK_STORAGE && sf & OSL_RBTREE)
487 goto err;
488 ret = -E_BAD_STORAGE_SIZE;
489 if (sf & OSL_FIXED_SIZE && !cd->data_size)
490 goto err;
491 switch (st) {
492 case OSL_DISK_STORAGE:
493 t->num_disk_storage_columns++;
494 break;
495 case OSL_MAPPED_STORAGE:
496 t->num_mapped_columns++;
497 col->index_offset = t->row_index_size;
498 t->row_index_size += 8;
499 break;
500 case OSL_NO_STORAGE:
501 col->volatile_num = t->num_volatile_columns;
502 t->num_volatile_columns++;
503 break;
504 }
505 if (sf & OSL_RBTREE) {
506 col->rbtree_num = t->num_rbtrees;
507 t->num_rbtrees++;
508 if ((sf & OSL_UNIQUE) && (st == OSL_MAPPED_STORAGE)) {
509 if (!have_disk_storage_name_column)
510 t->disk_storage_name_column = i;
511 have_disk_storage_name_column = 1;
512 }
513 }
514 }
515 ret = -E_NO_UNIQUE_RBTREE_COLUMN;
516 if (t->num_disk_storage_columns && !have_disk_storage_name_column)
517 goto err;
518 ret = -E_NO_RBTREE_COL;
519 if (!t->num_rbtrees)
520 goto err;
521 /* success */
522 DEBUG_LOG("OK. Index entry size: %u\n", t->row_index_size);
523 ret = init_column_descriptions(t);
524 if (ret < 0)
525 goto err;
526 *table_ptr = t;
527 return 1;
528 err:
529 free(t->columns);
530 free(t);
531 return ret;
532 }
533
534 /**
535 * Read the table description from index header.
536 *
537 * \param map The memory mapping of the index file.
538 * \param desc The values found in the index header are returned here.
539 *
540 * Read the index header, check for the paraslash magic string and the table version number.
541 * Read all information stored in the index header into \a desc.
542 *
543 * \return Positive on success, negative on errors.
544 *
545 * \sa struct osl_table_description, osl_create_table.
546 */
547 int read_table_desc(struct osl_object *map, struct osl_table_description *desc)
548 {
549 char *buf = map->data;
550 uint8_t version;
551 uint16_t header_size;
552 int ret, i;
553 unsigned offset;
554 struct osl_column_description *cd;
555
556 if (map->size < MIN_INDEX_HEADER_SIZE(1))
557 return -E_SHORT_TABLE;
558 if (strncmp(buf + IDX_PARA_MAGIC, PARA_MAGIC, strlen(PARA_MAGIC)))
559 return -E_NO_MAGIC;
560 version = read_u8(buf + IDX_VERSION);
561 if (version < MIN_TABLE_VERSION || version > MAX_TABLE_VERSION)
562 return -E_VERSION_MISMATCH;
563 desc->flags = read_u8(buf + IDX_TABLE_FLAGS);
564 desc->num_columns = read_u16(buf + IDX_NUM_COLUMNS);
565 DEBUG_LOG("%u columns\n", desc->num_columns);
566 if (!desc->num_columns)
567 return -E_NO_COLUMNS;
568 header_size = read_u16(buf + IDX_HEADER_SIZE);
569 if (map->size < header_size)
570 return -E_BAD_SIZE;
571 desc->column_descriptions = calloc(desc->num_columns,
572 sizeof(struct osl_column_description));
573 if (!desc->column_descriptions)
574 return -ERRNO_TO_ERROR(ENOMEM);
575 offset = IDX_COLUMN_DESCRIPTIONS;
576 FOR_EACH_COLUMN(i, desc, cd) {
577 char *null_byte;
578
579 ret = -E_SHORT_TABLE;
580 if (map->size < offset + MIN_IDX_COLUMN_DESCRIPTION_SIZE) {
581 ERROR_LOG("map size = %zu < %u = offset + min desc size\n",
582 map->size, offset + MIN_IDX_COLUMN_DESCRIPTION_SIZE);
583 goto err;
584 }
585 cd->storage_type = read_u16(buf + offset + IDX_CD_STORAGE_TYPE);
586 cd->storage_flags = read_u16(buf + offset +
587 IDX_CD_STORAGE_FLAGS);
588 cd->data_size = read_u32(buf + offset + IDX_CD_DATA_SIZE);
589 null_byte = memchr(buf + offset + IDX_CD_NAME, '\0',
590 map->size - offset - IDX_CD_NAME);
591 ret = -E_INDEX_CORRUPTION;
592 if (!null_byte)
593 goto err;
594 ret = -ERRNO_TO_ERROR(ENOMEM);
595 cd->name = strdup(buf + offset + IDX_CD_NAME);
596 if (!cd->name)
597 goto err;
598 offset += index_column_description_size(cd->name);
599 }
600 if (offset != header_size) {
601 ret = -E_INDEX_CORRUPTION;
602 ERROR_LOG("real header size = %u != %u = stored header size\n",
603 offset, header_size);
604 goto err;
605 }
606 return 1;
607 err:
608 FOR_EACH_COLUMN(i, desc, cd)
609 free(cd->name);
610 return ret;
611 }
612
613 /*
614 * check whether the table description given by \p t->desc matches the on-disk
615 * table structure stored in the index of \a t.
616 */
617 static int compare_table_descriptions(struct osl_table *t)
618 {
619 int i, ret;
620 struct osl_table_description desc;
621 const struct osl_column_description *cd1, *cd2;
622
623 /* read the on-disk structure into desc */
624 ret = read_table_desc(&t->index_map, &desc);
625 if (ret < 0)
626 return ret;
627 ret = -E_BAD_TABLE_FLAGS;
628 if (desc.flags != t->desc->flags)
629 goto out;
630 ret = -E_BAD_COLUMN_NUM;
631 if (desc.num_columns > t->desc->num_columns)
632 goto out;
633 if (desc.num_columns < t->desc->num_columns) {
634 struct osl_column_description *cd;
635 unsigned diff = t->desc->num_columns - desc.num_columns;
636 INFO_LOG("extending table by %u volatile columns\n", diff);
637 ret = -ERRNO_TO_ERROR(ENOMEM);
638 desc.column_descriptions = realloc(desc.column_descriptions,
639 t->desc->num_columns * sizeof(struct osl_column_description));
640 if (!desc.column_descriptions)
641 goto out;
642 for (i = desc.num_columns; i < t->desc->num_columns; i++) {
643 cd = get_column_description(&desc, i);
644 cd->storage_type = OSL_NO_STORAGE;
645 cd->name = NULL;
646 }
647 desc.num_columns += diff;
648 }
649 FOR_EACH_COLUMN(i, t->desc, cd1) {
650 cd2 = get_column_description(&desc, i);
651 ret = -E_BAD_STORAGE_TYPE;
652 if (cd1->storage_type != cd2->storage_type)
653 goto out;
654 if (cd1->storage_type == OSL_NO_STORAGE)
655 continue;
656 ret = -E_BAD_STORAGE_FLAGS;
657 if (cd1->storage_flags != cd2->storage_flags) {
658 ERROR_LOG("sf1 = %u != %u = sf2\n",
659 cd1->storage_flags, cd2->storage_flags);
660 goto out;
661 }
662 ret = -E_BAD_DATA_SIZE;
663 if (cd1->storage_flags & OSL_FIXED_SIZE)
664 if (cd1->data_size != cd2->data_size)
665 goto out;
666 ret = -E_BAD_COLUMN_NAME;
667 if (strcmp(cd1->name, cd2->name))
668 goto out;
669 }
670 DEBUG_LOG("table description of '%s' matches on-disk data, good\n",
671 t->desc->name);
672 ret = 1;
673 out:
674 FOR_EACH_COLUMN(i, &desc, cd1)
675 free(cd1->name);
676 free(desc.column_descriptions);
677 return ret;
678 }
679
680 static int create_table_index(struct osl_table *t)
681 {
682 char *buf, *filename;
683 int i, ret;
684 size_t size = t->index_header_size;
685 const struct osl_column_description *cd;
686 unsigned offset;
687
688 INFO_LOG("creating %zu byte index for table %s\n", size,
689 t->desc->name);
690 buf = calloc(1, size);
691 if (!buf)
692 return -ERRNO_TO_ERROR(ENOMEM);
693 sprintf(buf + IDX_PARA_MAGIC, "%s", PARA_MAGIC);
694 write_u8(buf + IDX_TABLE_FLAGS, t->desc->flags);
695 write_u8(buf + IDX_DIRTY_FLAG, 0);
696 write_u8(buf + IDX_VERSION, CURRENT_TABLE_VERSION);
697 write_u16(buf + IDX_NUM_COLUMNS, t->num_mapped_columns + t->num_disk_storage_columns);
698 write_u16(buf + IDX_HEADER_SIZE, t->index_header_size);
699 offset = IDX_COLUMN_DESCRIPTIONS;
700 FOR_EACH_COLUMN(i, t->desc, cd) {
701 /* no need to store info about volatile storage */
702 if (cd->storage_type == OSL_NO_STORAGE)
703 continue;
704 write_u16(buf + offset + IDX_CD_STORAGE_TYPE,
705 cd->storage_type);
706 write_u16(buf + offset + IDX_CD_STORAGE_FLAGS,
707 cd->storage_flags);
708 if (cd->storage_flags & OSL_FIXED_SIZE)
709 write_u32(buf + offset + IDX_CD_DATA_SIZE,
710 cd->data_size);
711 strcpy(buf + offset + IDX_CD_NAME, cd->name);
712 offset += index_column_description_size(cd->name);
713 }
714 assert(offset = size);
715 filename = index_filename(t->desc);
716 if (filename)
717 ret = para_write_file(filename, buf, size);
718 else
719 ret = -ERRNO_TO_ERROR(ENOMEM);
720 free(buf);
721 free(filename);
722 return ret;
723 }
724
725 /**
726 * Create a new osl table.
727 *
728 * \param desc Pointer to the table description.
729 *
730 * \return Standard.
731 */
732 int osl_create_table(const struct osl_table_description *desc)
733 {
734 const struct osl_column_description *cd;
735 char *table_dir = NULL, *filename;
736 struct osl_table *t;
737 int i, ret = init_table_structure(desc, &t);
738
739 if (ret < 0)
740 return ret;
741 INFO_LOG("creating %s\n", desc->name);
742 FOR_EACH_COLUMN(i, t->desc, cd) {
743 if (cd->storage_type == OSL_NO_STORAGE)
744 continue;
745 if (!table_dir) {
746 ret = para_mkdir(desc->dir, 0777);
747 if (ret < 0 && !is_errno(-ret, EEXIST))
748 goto out;
749 table_dir = make_message("%s/%s", desc->dir,
750 desc->name);
751 ret = -ERRNO_TO_ERROR(ENOMEM);
752 if (!table_dir)
753 goto out;
754 ret = para_mkdir(table_dir, 0777);
755 if (ret < 0)
756 goto out;
757 }
758 ret = -ERRNO_TO_ERROR(ENOMEM);
759 filename = column_filename(t, i);
760 if (!filename)
761 goto out;
762 INFO_LOG("filename: %s\n", filename);
763 if (cd->storage_type == OSL_MAPPED_STORAGE) {
764 ret = para_open(filename, O_RDWR | O_CREAT | O_EXCL,
765 0644);
766 free(filename);
767 if (ret < 0)
768 goto out;
769 close(ret);
770 continue;
771 }
772 /* DISK STORAGE */
773 ret = para_mkdir(filename, 0777);
774 free(filename);
775 if (ret < 0)
776 goto out;
777 }
778 if (t->num_mapped_columns) {
779 ret = create_table_index(t);
780 if (ret < 0)
781 goto out;
782 }
783 ret = 1;
784 out:
785 free(table_dir);
786 free(t->columns);
787 free(t);
788 return ret;
789 }
790
791 static int table_is_dirty(struct osl_table *t)
792 {
793 char *buf = (char *)t->index_map.data + IDX_DIRTY_FLAG;
794 uint8_t dirty = read_u8(buf) & 0x1;
795 return !!dirty;
796 }
797
798 static void mark_table_dirty(struct osl_table *t)
799 {
800 char *buf = (char *)t->index_map.data + IDX_DIRTY_FLAG;
801 write_u8(buf, read_u8(buf) | 1);
802 }
803
804 static void mark_table_clean(struct osl_table *t)
805 {
806 char *buf = (char *)t->index_map.data + IDX_DIRTY_FLAG;
807 write_u8(buf, read_u8(buf) & 0xfe);
808 }
809
810 static void unmap_column(struct osl_table *t, unsigned col_num)
811 {
812 struct osl_object map = t->columns[col_num].data_map;
813 int ret;
814 if (!map.data)
815 return;
816 ret = para_munmap(map.data, map.size);
817 assert(ret > 0);
818 map.data = NULL;
819 }
820
821 /**
822 * Unmap all mapped files of an osl table.
823 *
824 * \param t Pointer to a mapped table.
825 * \param flags Options for unmapping.
826 *
827 * \return Positive on success, negative on errors.
828 *
829 * \sa map_table(), enum osl_close_flags, para_munmap().
830 */
831 int unmap_table(struct osl_table *t, enum osl_close_flags flags)
832 {
833 unsigned i;
834 const struct osl_column_description *cd;
835 int ret;
836
837 if (!t->num_mapped_columns) /* can this ever happen? */
838 return 1;
839 DEBUG_LOG("unmapping table '%s'\n", t->desc->name);
840 if (!t->index_map.data)
841 return -E_NOT_MAPPED;
842 if (flags & OSL_MARK_CLEAN)
843 mark_table_clean(t);
844 ret = para_munmap(t->index_map.data, t->index_map.size);
845 if (ret < 0)
846 return ret;
847 t->index_map.data = NULL;
848 if (!t->num_rows)
849 return 1;
850 FOR_EACH_MAPPED_COLUMN(i, t, cd)
851 unmap_column(t, i);
852 return 1;
853 }
854
855 static int map_column(struct osl_table *t, unsigned col_num)
856 {
857 struct stat statbuf;
858 char *filename = column_filename(t, col_num);
859 int ret = -E_STAT;
860
861 if (!filename)
862 return -ERRNO_TO_ERROR(ENOMEM);
863 if (stat(filename, &statbuf) < 0) {
864 free(filename);
865 return ret;
866 }
867 if (!(S_IFREG & statbuf.st_mode)) {
868 free(filename);
869 return ret;
870 }
871 ret = mmap_full_file(filename, O_RDWR,
872 &t->columns[col_num].data_map.data,
873 &t->columns[col_num].data_map.size,
874 NULL);
875 free(filename);
876 return ret;
877 }
878
879 /**
880 * Map the index file and all columns of type \p OSL_MAPPED_STORAGE into memory.
881 *
882 * \param t Pointer to an initialized table structure.
883 * \param flags Mapping options.
884 *
885 * \return Negative return value on errors; on success the number of rows
886 * (including invalid rows) is returned.
887 *
888 * \sa unmap_table(), enum map_table_flags, osl_open_table(), mmap(2).
889 */
890 int map_table(struct osl_table *t, enum map_table_flags flags)
891 {
892 char *filename;
893 const struct osl_column_description *cd;
894 int i = 0, ret, num_rows = 0;
895
896 if (!t->num_mapped_columns)
897 return 0;
898 if (t->index_map.data)
899 return -E_ALREADY_MAPPED;
900 filename = index_filename(t->desc);
901 if (!filename)
902 return -ERRNO_TO_ERROR(ENOMEM);
903 DEBUG_LOG("mapping table '%s' (index: %s)\n", t->desc->name, filename);
904 ret = mmap_full_file(filename, flags & MAP_TBL_FL_MAP_RDONLY?
905 O_RDONLY : O_RDWR, &t->index_map.data, &t->index_map.size, NULL);
906 free(filename);
907 if (ret < 0)
908 return ret;
909 if (flags & MAP_TBL_FL_VERIFY_INDEX) {
910 ret = compare_table_descriptions(t);
911 if (ret < 0)
912 goto err;
913 }
914 ret = -E_BUSY;
915 if (!(flags & MAP_TBL_FL_IGNORE_DIRTY)) {
916 if (table_is_dirty(t)) {
917 ERROR_LOG("%s is dirty\n", t->desc->name);
918 goto err;
919 }
920 }
921 mark_table_dirty(t);
922 num_rows = table_num_rows(t);
923 if (!num_rows)
924 return num_rows;
925 /* map data files */
926 FOR_EACH_MAPPED_COLUMN(i, t, cd) {
927 ret = map_column(t, i);
928 if (ret < 0)
929 goto err;
930 }
931 return num_rows;
932 err: /* unmap what is already mapped */
933 for (i--; i >= 0; i--) {
934 struct osl_object map = t->columns[i].data_map;
935 para_munmap(map.data, map.size);
936 map.data = NULL;
937 }
938 para_munmap(t->index_map.data, t->index_map.size);
939 t->index_map.data = NULL;
940 return ret;
941 }
942
943 /**
944 * Retrieve a mapped object by row and column number.
945 *
946 * \param t Pointer to an open osl table.
947 * \param col_num Number of the mapped column containing the object to retrieve.
948 * \param row_num Number of the row containing the object to retrieve.
949 * \param obj The result is returned here.
950 *
951 * It is considered an error if \a col_num does not refer to a column
952 * of storage type \p OSL_MAPPED_STORAGE.
953 *
954 * \return Positive on success, negative on errors. Possible errors include:
955 * \p E_BAD_ROW_NUM, \p E_INVALID_OBJECT.
956 *
957 * \sa osl_storage_type.
958 */
959 int get_mapped_object(const struct osl_table *t, unsigned col_num,
960 uint32_t row_num, struct osl_object *obj)
961 {
962 struct osl_column *col = &t->columns[col_num];
963 uint32_t offset;
964 char *header;
965 char *cell_index;
966 int ret;
967
968 if (t->num_rows <= row_num)
969 return -E_BAD_ROW_NUM;
970 ret = get_cell_index(t, row_num, col_num, &cell_index);
971 if (ret < 0)
972 return ret;
973 offset = read_u32(cell_index);
974 obj->size = read_u32(cell_index + 4) - 1;
975 header = col->data_map.data + offset;
976 obj->data = header + 1;
977 if (read_u8(header) == 0xff) {
978 ERROR_LOG("col %u, size %zu, offset %u\n", col_num,
979 obj->size, offset);
980 return -E_INVALID_OBJECT;
981 }
982 return 1;
983 }
984
985 static int search_rbtree(const struct osl_object *obj,
986 const struct osl_table *t, unsigned col_num,
987 struct rb_node **result, struct rb_node ***rb_link)
988 {
989 struct osl_column *col = &t->columns[col_num];
990 struct rb_node **new = &col->rbtree.rb_node, *parent = NULL;
991 const struct osl_column_description *cd =
992 get_column_description(t->desc, col_num);
993 enum osl_storage_type st = cd->storage_type;
994 while (*new) {
995 struct osl_row *this_row = get_row_pointer(*new,
996 col->rbtree_num);
997 int ret;
998 struct osl_object this_obj;
999 parent = *new;
1000 if (st == OSL_MAPPED_STORAGE) {
1001 ret = get_mapped_object(t, col_num, this_row->num,
1002 &this_obj);
1003 if (ret < 0)
1004 return ret;
1005 } else
1006 this_obj = this_row->volatile_objects[col->volatile_num];
1007 ret = cd->compare_function(obj, &this_obj);
1008 if (!ret) {
1009 if (result)
1010 *result = get_rb_node_pointer(this_row,
1011 col->rbtree_num);
1012 return 1;
1013 }
1014 if (ret < 0)
1015 new = &((*new)->rb_left);
1016 else
1017 new = &((*new)->rb_right);
1018 }
1019 if (result)
1020 *result = parent;
1021 if (rb_link)
1022 *rb_link = new;
1023 return -E_RB_KEY_NOT_FOUND;
1024 }
1025
1026 static int insert_rbtree(struct osl_table *t, unsigned col_num,
1027 const struct osl_row *row, const struct osl_object *obj)
1028 {
1029 struct rb_node *parent, **rb_link;
1030 unsigned rbtree_num;
1031 struct rb_node *n;
1032 int ret = search_rbtree(obj, t, col_num, &parent, &rb_link);
1033
1034 if (ret > 0)
1035 return -E_RB_KEY_EXISTS;
1036 rbtree_num = t->columns[col_num].rbtree_num;
1037 n = get_rb_node_pointer(row, rbtree_num);
1038 rb_link_node(n, parent, rb_link);
1039 rb_insert_color(n, &t->columns[col_num].rbtree);
1040 return 1;
1041 }
1042
1043 static void remove_rb_node(struct osl_table *t, unsigned col_num,
1044 const struct osl_row *row)
1045 {
1046 struct osl_column *col = &t->columns[col_num];
1047 const struct osl_column_description *cd =
1048 get_column_description(t->desc, col_num);
1049 enum osl_storage_flags sf = cd->storage_flags;
1050 struct rb_node *victim, *splice_out_node, *tmp;
1051 if (!(sf & OSL_RBTREE))
1052 return;
1053 /*
1054 * Which node is removed/spliced out actually depends on how many
1055 * children the victim node has: If it has no children, it gets
1056 * deleted. If it has one child, it gets spliced out. If it has two
1057 * children, its successor (which has at most a right child) gets
1058 * spliced out.
1059 */
1060 victim = get_rb_node_pointer(row, col->rbtree_num);
1061 if (victim->rb_left && victim->rb_right)
1062 splice_out_node = rb_next(victim);
1063 else
1064 splice_out_node = victim;
1065 /* Go up to the root and decrement the size of each node in the path. */
1066 for (tmp = splice_out_node; tmp; tmp = rb_parent(tmp))
1067 tmp->size--;
1068 rb_erase(victim, &col->rbtree);
1069 }
1070
1071 static int add_row_to_rbtrees(struct osl_table *t, uint32_t row_num,
1072 struct osl_object *volatile_objs, struct osl_row **row_ptr)
1073 {
1074 unsigned i;
1075 int ret;
1076 struct osl_row *row = allocate_row(t->num_rbtrees);
1077 const struct osl_column_description *cd;
1078
1079 if (!row)
1080 return -ERRNO_TO_ERROR(ENOMEM);
1081 row->num = row_num;
1082 row->volatile_objects = volatile_objs;
1083 FOR_EACH_RBTREE_COLUMN(i, t, cd) {
1084 if (cd->storage_type == OSL_MAPPED_STORAGE) {
1085 struct osl_object obj;
1086 ret = get_mapped_object(t, i, row_num, &obj);
1087 if (ret < 0)
1088 goto err;
1089 ret = insert_rbtree(t, i, row, &obj);
1090 } else { /* volatile */
1091 const struct osl_object *obj
1092 = volatile_objs + t->columns[i].volatile_num;
1093 ret = insert_rbtree(t, i, row, obj);
1094 }
1095 if (ret < 0)
1096 goto err;
1097 }
1098 if (row_ptr)
1099 *row_ptr = row;
1100 return 1;
1101 err: /* rollback changes, i.e. remove added entries from rbtrees */
1102 while (i)
1103 remove_rb_node(t, i--, row);
1104 free(row);
1105 return ret;
1106 }
1107
1108 static void free_volatile_objects(const struct osl_table *t,
1109 enum osl_close_flags flags)
1110 {
1111 int i, j;
1112 struct rb_node *n;
1113 struct osl_column *rb_col;
1114 const struct osl_column_description *cd;
1115
1116 if (!t->num_volatile_columns)
1117 return;
1118 /* find the first rbtree column (any will do) */
1119 FOR_EACH_RBTREE_COLUMN(i, t, cd)
1120 break;
1121 rb_col = t->columns + i;
1122 /* walk that rbtree and free all volatile objects */
1123 for (n = rb_first(&rb_col->rbtree); n; n = rb_next(n)) {
1124 struct osl_row *r = get_row_pointer(n, rb_col->rbtree_num);
1125 if (flags & OSL_FREE_VOLATILE)
1126 FOR_EACH_VOLATILE_COLUMN(j, t, cd) {
1127 if (cd->storage_flags & OSL_DONT_FREE)
1128 continue;
1129 free(r->volatile_objects[
1130 t->columns[j].volatile_num].data);
1131 }
1132 // for (j = 0; j < t->num_volatile_columns; j++)
1133 // free(r->volatile_objects[j].data);
1134 free(r->volatile_objects);
1135 }
1136 }
1137
1138 /**
1139 * Erase all rbtree nodes and free resources.
1140 *
1141 * \param t Pointer to an open osl table.
1142 *
1143 * This function is called by osl_close_table().
1144 */
1145 void clear_rbtrees(struct osl_table *t)
1146 {
1147 const struct osl_column_description *cd;
1148 unsigned i, rbtrees_cleared = 0;
1149
1150 FOR_EACH_RBTREE_COLUMN(i, t, cd) {
1151 struct osl_column *col = &t->columns[i];
1152 struct rb_node *n;
1153 rbtrees_cleared++;
1154 for (n = rb_first(&col->rbtree); n;) {
1155 struct osl_row *r;
1156 rb_erase(n, &col->rbtree);
1157 if (rbtrees_cleared == t->num_rbtrees) {
1158 r = get_row_pointer(n, col->rbtree_num);
1159 n = rb_next(n);
1160 free(r);
1161 } else
1162 n = rb_next(n);
1163 }
1164 }
1165
1166 }
1167
1168 /**
1169 * Close an osl table.
1170 *
1171 * \param t Pointer to the table to be closed.
1172 * \param flags Options for what should be cleaned up.
1173 *
1174 * If osl_open_table() succeeds, the resulting table pointer must later be
1175 * passed to this function in order to flush all changes to the file system and
1176 * to free the resources that were allocated by osl_open_table().
1177 *
1178 * \return Positive on success, negative on errors. Possible errors: \p E_BAD_TABLE,
1179 * errors returned by unmap_table().
1180 *
1181 * \sa osl_open_table(), unmap_table().
1182 */
1183 int osl_close_table(struct osl_table *t, enum osl_close_flags flags)
1184 {
1185 int ret;
1186
1187 if (!t)
1188 return -E_BAD_TABLE;
1189 free_volatile_objects(t, flags);
1190 clear_rbtrees(t);
1191 ret = unmap_table(t, flags);
1192 if (ret < 0)
1193 ERROR_LOG("unmap_table failed: %d\n", ret);
1194 free(t->columns);
1195 free(t);
1196 return ret;
1197 }
1198
1199 /**
1200 * Find out whether the given row number corresponds to an invalid row.
1201 *
1202 * \param t Pointer to the osl table.
1203 * \param row_num The number of the row in question.
1204 *
1205 * By definition, a row is considered invalid if all its index entries
1206 * are invalid.
1207 *
1208 * \return Positive if \a row_num corresponds to an invalid row,
1209 * zero if it corresponds to a valid row, negative on errors.
1210 */
1211 int row_is_invalid(struct osl_table *t, uint32_t row_num)
1212 {
1213 char *row_index;
1214 int i, ret = get_row_index(t, row_num, &row_index);
1215
1216 if (ret < 0)
1217 return ret;
1218 for (i = 0; i < t->row_index_size; i++) {
1219 if ((unsigned char)row_index[i] != 0xff)
1220 return 0;
1221 }
1222 INFO_LOG("row %d is invalid\n", row_num);
1223 return 1;
1224 }
1225
1226 /**
1227 * Invalidate a row of an osl table.
1228 *
1229 * \param t Pointer to an open osl table.
1230 * \param row_num Number of the row to mark as invalid.
1231 *
1232 * This function marks each mapped object in the index entry of \a row as
1233 * invalid.
1234 *
1235 * \return Positive on success, negative on errors.
1236 */
1237 int mark_row_invalid(struct osl_table *t, uint32_t row_num)
1238 {
1239 char *row_index;
1240 int ret = get_row_index(t, row_num, &row_index);
1241
1242 if (ret < 0)
1243 return ret;
1244 INFO_LOG("marking row %d as invalid\n", row_num);
1245 memset(row_index, 0xff, t->row_index_size);
1246 return 1;
1247 }
1248
1249 /**
1250 * Initialize all rbtrees and compute number of invalid rows.
1251 *
1252 * \param t The table containing the rbtrees to be initialized.
1253 *
1254 * \return Positive on success, negative on errors.
1255 */
1256 int init_rbtrees(struct osl_table *t)
1257 {
1258 int i, ret;
1259 const struct osl_column_description *cd;
1260
1261 /* create rbtrees */
1262 FOR_EACH_RBTREE_COLUMN(i, t, cd)
1263 t->columns[i].rbtree = RB_ROOT;
1264 /* add valid rows to rbtrees */
1265 t->num_invalid_rows = 0;
1266 for (i = 0; i < t->num_rows; i++) {
1267 ret = row_is_invalid(t, i);
1268 if (ret < 0)
1269 return ret;
1270 if (ret) {
1271 t->num_invalid_rows++;
1272 continue;
1273 }
1274 ret = add_row_to_rbtrees(t, i, NULL, NULL);
1275 if (ret < 0)
1276 return ret;
1277 }
1278 return 1;
1279 }
1280
1281 /**
1282 * Open an osl table.
1283 *
1284 * Each osl table must be opened before its data can be accessed.
1285 *
1286 * \param table_desc Describes the table to be opened.
1287 * \param result Contains a pointer to the open table on success.
1288 *
1289 * The table description given by \a desc should coincide with the
1290 * description used at creation time.
1291 *
1292 * \return Standard.
1293 */
1294 int osl_open_table(const struct osl_table_description *table_desc,
1295 struct osl_table **result)
1296 {
1297 int i, ret;
1298 struct osl_table *t;
1299 const struct osl_column_description *cd;
1300
1301 INFO_LOG("opening table %s\n", table_desc->name);
1302 ret = init_table_structure(table_desc, &t);
1303 if (ret < 0)
1304 return ret;
1305 FOR_EACH_DISK_STORAGE_COLUMN(i, t, cd) {
1306 struct stat statbuf;
1307 char *dirname = column_filename(t, i);
1308
1309 ret = -ERRNO_TO_ERROR(ENOMEM);
1310 if (!dirname)
1311 goto err;
1312 /* check if directory exists */
1313 ret = stat(dirname, &statbuf);
1314 free(dirname);
1315 if (ret < 0) {
1316 ret = -ERRNO_TO_ERROR(errno);
1317 goto err;
1318 }
1319 ret = -ERRNO_TO_ERROR(ENOTDIR);
1320 if (!S_ISDIR(statbuf.st_mode))
1321 goto err;
1322 }
1323 ret = map_table(t, MAP_TBL_FL_VERIFY_INDEX);
1324 if (ret < 0)
1325 goto err;
1326 t->num_rows = ret;
1327 DEBUG_LOG("num rows: %d\n", t->num_rows);
1328 ret = init_rbtrees(t);
1329 if (ret < 0) {
1330 osl_close_table(t, OSL_MARK_CLEAN); /* ignore further errors */
1331 return ret;
1332 }
1333 *result = t;
1334 return 1;
1335 err:
1336 free(t->columns);
1337 free(t);
1338 return ret;
1339 }
1340
1341 static int create_disk_storage_object_dir(const struct osl_table *t,
1342 unsigned col_num, const char *ds_name)
1343 {
1344 char *dirname;
1345 int ret;
1346
1347 if (!(t->desc->flags & OSL_LARGE_TABLE))
1348 return 1;
1349 dirname = disk_storage_dirname(t, col_num, ds_name);
1350 if (!dirname)
1351 return -ERRNO_TO_ERROR(ENOMEM);
1352 ret = para_mkdir(dirname, 0777);
1353 free(dirname);
1354 if (ret < 0 && !is_errno(-ret, EEXIST))
1355 return ret;
1356 return 1;
1357 }
1358
1359 static int write_disk_storage_file(const struct osl_table *t, unsigned col_num,
1360 const struct osl_object *obj, const char *ds_name)
1361 {
1362 int ret;
1363 char *filename;
1364
1365 ret = create_disk_storage_object_dir(t, col_num, ds_name);
1366 if (ret < 0)
1367 return ret;
1368 filename = disk_storage_path(t, col_num, ds_name);
1369 if (!filename)
1370 return -ERRNO_TO_ERROR(ENOMEM);
1371 ret = para_write_file(filename, obj->data, obj->size);
1372 free(filename);
1373 return ret;
1374 }
1375
1376 static int append_map_file(const struct osl_table *t, unsigned col_num,
1377 const struct osl_object *obj, uint32_t *new_size)
1378 {
1379 char *filename = column_filename(t, col_num);
1380 int ret;
1381 char header = 0; /* zero means valid object */
1382
1383 if (!filename)
1384 return -ERRNO_TO_ERROR(ENOMEM);
1385 ret = append_file(filename, &header, 1, obj->data, obj->size,
1386 new_size);
1387 free(filename);
1388 return ret;
1389 }
1390
1391 static int append_row_index(const struct osl_table *t, char *row_index)
1392 {
1393 char *filename;
1394 int ret;
1395
1396 if (!t->num_mapped_columns)
1397 return 1;
1398 filename = index_filename(t->desc);
1399 if (!filename)
1400 return -ERRNO_TO_ERROR(ENOMEM);
1401 ret = append_file(filename, NULL, 0, row_index,
1402 t->row_index_size, NULL);
1403 free(filename);
1404 return ret;
1405 }
1406
1407 /**
1408 * A wrapper for truncate(2)
1409 *
1410 * \param path Name of the regular file to truncate
1411 * \param size Number of bytes to \b shave \b off
1412 *
1413 * Truncate the regular file named by \a path by \a size bytes.
1414 *
1415 * \return Positive on success, negative on errors. Possible errors include: \p
1416 * E_STAT, \p E_BAD_SIZE, \p E_TRUNC.
1417 *
1418 * \sa truncate(2)
1419 */
1420 int para_truncate(const char *path, off_t size)
1421 {
1422 int ret;
1423 struct stat statbuf;
1424
1425 ret = -E_STAT;
1426 if (stat(path, &statbuf) < 0)
1427 goto out;
1428 ret = -E_BAD_SIZE;
1429 if (statbuf.st_size < size)
1430 goto out;
1431 ret = -E_TRUNC;
1432 if (truncate(path, statbuf.st_size - size) < 0)
1433 goto out;
1434 ret = 1;
1435 out:
1436 return ret;
1437 }
1438
1439 static int truncate_mapped_file(const struct osl_table *t, unsigned col_num,
1440 off_t size)
1441 {
1442 int ret;
1443 char *filename = column_filename(t, col_num);
1444
1445 if (!filename)
1446 return -ERRNO_TO_ERROR(ENOMEM);
1447 ret = para_truncate(filename, size);
1448 free(filename);
1449 return ret;
1450 }
1451
1452 static int delete_disk_storage_file(const struct osl_table *t, unsigned col_num,
1453 const char *ds_name)
1454 {
1455 char *dirname, *filename = disk_storage_path(t, col_num, ds_name);
1456 int ret, err;
1457
1458 if (!filename)
1459 return -ERRNO_TO_ERROR(ENOMEM);
1460 ret = unlink(filename);
1461 err = errno;
1462 free(filename);
1463 if (ret < 0)
1464 return -ERRNO_TO_ERROR(err);
1465 if (!(t->desc->flags & OSL_LARGE_TABLE))
1466 return 1;
1467 dirname = disk_storage_dirname(t, col_num, ds_name);
1468 if (!dirname)
1469 return -ERRNO_TO_ERROR(ENOMEM);
1470 rmdir(dirname);
1471 free(dirname);
1472 return 1;
1473 }
1474
1475 /**
1476 * Add a new row to an osl table and retrieve this row.
1477 *
1478 * \param t Pointer to an open osl table.
1479 * \param objects Array of objects to be added.
1480 * \param row Result pointer.
1481 *
1482 * The \a objects parameter must point to an array containing one object per
1483 * column. The order of the objects in the array is given by the table
1484 * description of \a table. Several sanity checks are performed during object
1485 * insertion and the function returns without modifying the table if any of
1486 * these tests fail. In fact, it is atomic in the sense that it either
1487 * succeeds or leaves the table unchanged (i.e. either all or none of the
1488 * objects are added to the table).
1489 *
1490 * It is considered an error if an object is added to a column with associated
1491 * rbtree if this object is equal to an object already contained in that column
1492 * (i.e. the compare function for the column's rbtree returns zero).
1493 *
1494 * Possible errors include: \p E_RB_KEY_EXISTS, \p E_BAD_DATA_SIZE.
1495 *
1496 * \return Positive on success, negative on errors.
1497 *
1498 * \sa struct osl_table_description, osl_compare_func, osl_add_row().
1499 */
1500 int osl_add_and_get_row(struct osl_table *t, struct osl_object *objects,
1501 struct osl_row **row)
1502 {
1503 int i, ret;
1504 char *ds_name = NULL;
1505 struct rb_node **rb_parents = NULL, ***rb_links = NULL;
1506 char *new_row_index = NULL;
1507 struct osl_object *volatile_objs = NULL;
1508 const struct osl_column_description *cd;
1509
1510 if (!t)
1511 return -E_BAD_TABLE;
1512 rb_parents = malloc(t->num_rbtrees * sizeof(struct rn_node*));
1513 if (!rb_parents)
1514 return -ERRNO_TO_ERROR(ENOMEM);
1515 rb_links = malloc(t->num_rbtrees * sizeof(struct rn_node**));
1516 if (!rb_links) {
1517 free(rb_parents);
1518 return -ERRNO_TO_ERROR(ENOMEM);
1519 }
1520 if (t->num_mapped_columns) {
1521 new_row_index = malloc(t->row_index_size);
1522 if (!new_row_index) {
1523 free(rb_links);
1524 free(rb_parents);
1525 return -ERRNO_TO_ERROR(ENOMEM);
1526 }
1527 }
1528 /* pass 1: sanity checks */
1529 // DEBUG_LOG("sanity tests: %p:%p\n", objects[0].data,
1530 // objects[1].data);
1531 FOR_EACH_COLUMN(i, t->desc, cd) {
1532 enum osl_storage_type st = cd->storage_type;
1533 enum osl_storage_flags sf = cd->storage_flags;
1534
1535 // ret = -E_NULL_OBJECT;
1536 // if (!objects[i])
1537 // goto out;
1538 if (st == OSL_DISK_STORAGE)
1539 continue;
1540 if (sf & OSL_RBTREE) {
1541 unsigned rbtree_num = t->columns[i].rbtree_num;
1542 ret = -E_RB_KEY_EXISTS;
1543 // DEBUG_LOG("checking whether %p exists\n",
1544 // objects[i].data);
1545 if (search_rbtree(objects + i, t, i,
1546 &rb_parents[rbtree_num],
1547 &rb_links[rbtree_num]) > 0)
1548 goto out;
1549 }
1550 if (sf & OSL_FIXED_SIZE) {
1551 // DEBUG_LOG("fixed size. need: %zu, have: %d\n",
1552 // objects[i].size, cd->data_size);
1553 ret = -E_BAD_DATA_SIZE;
1554 if (objects[i].size != cd->data_size)
1555 goto out;
1556 }
1557 }
1558 if (t->num_disk_storage_columns) {
1559 ds_name = disk_storage_name_of_object(t,
1560 &objects[t->disk_storage_name_column]);
1561 ret = -ERRNO_TO_ERROR(ENOMEM);
1562 if (!ds_name)
1563 goto out;
1564 }
1565 ret = unmap_table(t, OSL_MARK_CLEAN);
1566 if (ret < 0)
1567 goto out;
1568 // DEBUG_LOG("sanity tests passed%s\n", "");
1569 /* pass 2: create data files, append map data */
1570 FOR_EACH_COLUMN(i, t->desc, cd) {
1571 enum osl_storage_type st = cd->storage_type;
1572 if (st == OSL_NO_STORAGE)
1573 continue;
1574 if (st == OSL_MAPPED_STORAGE) {
1575 uint32_t new_size;
1576 struct osl_column *col = &t->columns[i];
1577 // DEBUG_LOG("appending object of size %zu\n",
1578 // objects[i].size);
1579 ret = append_map_file(t, i, objects + i, &new_size);
1580 if (ret < 0)
1581 goto rollback;
1582 update_cell_index(new_row_index, col, new_size,
1583 objects[i].size);
1584 continue;
1585 }
1586 /* DISK_STORAGE */
1587 ret = write_disk_storage_file(t, i, objects + i, ds_name);
1588 if (ret < 0)
1589 goto rollback;
1590 }
1591 ret = append_row_index(t, new_row_index);
1592 if (ret < 0)
1593 goto rollback;
1594 ret = map_table(t, MAP_TBL_FL_VERIFY_INDEX);
1595 if (ret < 0) { /* truncate index and rollback changes */
1596 char *filename = index_filename(t->desc);
1597 if (filename)
1598 para_truncate(filename, t->row_index_size);
1599 free(filename);
1600 goto rollback;
1601 }
1602 /* pass 3: add entry to rbtrees */
1603 if (t->num_volatile_columns) {
1604 ret = -ERRNO_TO_ERROR(ENOMEM);
1605 volatile_objs = calloc(t->num_volatile_columns,
1606 sizeof(struct osl_object));
1607 if (!volatile_objs)
1608 goto out;
1609 FOR_EACH_VOLATILE_COLUMN(i, t, cd)
1610 volatile_objs[t->columns[i].volatile_num] = objects[i];
1611 }
1612 t->num_rows++;
1613 // DEBUG_LOG("adding new entry as row #%d\n", t->num_rows - 1);
1614 ret = add_row_to_rbtrees(t, t->num_rows - 1, volatile_objs, row);
1615 if (ret < 0)
1616 goto out;
1617 // DEBUG_LOG("added new entry as row #%d\n", t->num_rows - 1);
1618 ret = 1;
1619 goto out;
1620 rollback: /* rollback all changes made, ignore further errors */
1621 for (i--; i >= 0; i--) {
1622 cd = get_column_description(t->desc, i);
1623 enum osl_storage_type st = cd->storage_type;
1624 if (st == OSL_NO_STORAGE)
1625 continue;
1626
1627 if (st == OSL_MAPPED_STORAGE)
1628 truncate_mapped_file(t, i, objects[i].size);
1629 else /* disk storage */
1630 delete_disk_storage_file(t, i, ds_name);
1631 }
1632 /* ignore error and return previous error value */
1633 map_table(t, MAP_TBL_FL_VERIFY_INDEX);
1634 out:
1635 free(new_row_index);
1636 free(ds_name);
1637 free(rb_parents);
1638 free(rb_links);
1639 return ret;
1640 }
1641
1642 /**
1643 * Add a new row to an osl table.
1644 *
1645 * \param t Same meaning as osl_add_and_get_row().
1646 * \param objects Same meaning as osl_add_and_get_row().
1647 *
1648 * \return The return value of the underlying call to osl_add_and_get_row().
1649 *
1650 * This is equivalent to osl_add_and_get_row(t, objects, NULL).
1651 */
1652 int osl_add_row(struct osl_table *t, struct osl_object *objects)
1653 {
1654 return osl_add_and_get_row(t, objects, NULL);
1655 }
1656
1657 /**
1658 * Retrieve an object identified by row and column
1659 *
1660 * \param t Pointer to an open osl table.
1661 * \param r Pointer to the row.
1662 * \param col_num The column number.
1663 * \param object The result pointer.
1664 *
1665 * The column determined by \a col_num must be of type \p OSL_MAPPED_STORAGE
1666 * or \p OSL_NO_STORAGE, i.e. no disk storage objects may be retrieved by this
1667 * function.
1668 *
1669 * \return Positive if object was found, negative on errors. Possible errors
1670 * include: \p E_BAD_TABLE, \p E_BAD_STORAGE_TYPE.
1671 *
1672 * \sa osl_storage_type, osl_open_disk_object().
1673 */
1674 int osl_get_object(const struct osl_table *t, const struct osl_row *r,
1675 unsigned col_num, struct osl_object *object)
1676 {
1677 const struct osl_column_description *cd;
1678
1679 if (!t)
1680 return -E_BAD_TABLE;
1681 cd = get_column_description(t->desc, col_num);
1682 /* col must not be disk storage */
1683 if (cd->storage_type == OSL_DISK_STORAGE)
1684 return -E_BAD_STORAGE_TYPE;
1685 if (cd->storage_type == OSL_MAPPED_STORAGE)
1686 return get_mapped_object(t, col_num, r->num, object);
1687 /* volatile */
1688 *object = r->volatile_objects[t->columns[col_num].volatile_num];
1689 return 1;
1690 }
1691
1692 static int mark_mapped_object_invalid(const struct osl_table *t,
1693 uint32_t row_num, unsigned col_num)
1694 {
1695 struct osl_object obj;
1696 char *p;
1697 int ret = get_mapped_object(t, col_num, row_num, &obj);
1698
1699 if (ret < 0)
1700 return ret;
1701 p = obj.data;
1702 p--;
1703 *p = 0xff;
1704 return 1;
1705 }
1706
1707 /**
1708 * Delete a row from an osl table.
1709 *
1710 * \param t Pointer to an open osl table.
1711 * \param row Pointer to the row to delete.
1712 *
1713 * This removes all disk storage objects, removes all rbtree nodes, and frees
1714 * all volatile objects belonging to the given row. For mapped columns, the
1715 * data is merely marked invalid and may be pruned from time to time by
1716 * para_fsck.
1717 *
1718 * \return Positive on success, negative on errors. Possible errors include:
1719 * \p E_BAD_TABLE, errors returned by osl_get_object().
1720 */
1721 int osl_del_row(struct osl_table *t, struct osl_row *row)
1722 {
1723 struct osl_row *r = row;
1724 int i, ret;
1725 const struct osl_column_description *cd;
1726
1727 if (!t)
1728 return -E_BAD_TABLE;
1729 INFO_LOG("deleting row %p\n", row);
1730
1731 if (t->num_disk_storage_columns) {
1732 char *ds_name;
1733 ret = disk_storage_name_of_row(t, r, &ds_name);
1734 if (ret < 0)
1735 goto out;
1736 FOR_EACH_DISK_STORAGE_COLUMN(i, t, cd)
1737 delete_disk_storage_file(t, i, ds_name);
1738 free(ds_name);
1739 }
1740 FOR_EACH_COLUMN(i, t->desc, cd) {
1741 struct osl_column *col = t->columns + i;
1742 enum osl_storage_type st = cd->storage_type;
1743 remove_rb_node(t, i, r);
1744 if (st == OSL_MAPPED_STORAGE) {
1745 mark_mapped_object_invalid(t, r->num, i);
1746 continue;
1747 }
1748 if (st == OSL_NO_STORAGE && !(cd->storage_flags & OSL_DONT_FREE))
1749 free(r->volatile_objects[col->volatile_num].data);
1750 }
1751 if (t->num_mapped_columns) {
1752 ret = mark_row_invalid(t, r->num);
1753 if (ret < 0)
1754 goto out;
1755 t->num_invalid_rows++;
1756 } else
1757 t->num_rows--;
1758 ret = 1;
1759 out:
1760 free(r->volatile_objects);
1761 free(r);
1762 return ret;
1763 }
1764
1765 /* test if column has an rbtree */
1766 static int check_rbtree_col(const struct osl_table *t, unsigned col_num,
1767 struct osl_column **col)
1768 {
1769 if (!t)
1770 return -E_BAD_TABLE;
1771 if (!(get_column_description(t->desc, col_num)->storage_flags & OSL_RBTREE))
1772 return -E_BAD_STORAGE_FLAGS;
1773 *col = t->columns + col_num;
1774 return 1;
1775 }
1776
1777 /**
1778 * Get the row that contains the given object.
1779 *
1780 * \param t Pointer to an open osl table.
1781 * \param col_num The number of the column to be searched.
1782 * \param obj The object to be looked up.
1783 * \param result Points to the row containing \a obj.
1784 *
1785 * Lookup \a obj in \a t and return the row containing \a obj. The column
1786 * specified by \a col_num must have an associated rbtree.
1787 *
1788 * \return Positive on success, negative on errors. If an error occurred, \a
1789 * result is set to \p NULL. Possible errors include: \p E_BAD_TABLE, \p
1790 * E_BAD_STORAGE_FLAGS, errors returned by get_mapped_object(), \p
1791 * E_RB_KEY_NOT_FOUND.
1792 *
1793 * \sa osl_storage_flags
1794 */
1795 int osl_get_row(const struct osl_table *t, unsigned col_num,
1796 const struct osl_object *obj, struct osl_row **result)
1797 {
1798 int ret;
1799 struct rb_node *node;
1800 struct osl_row *row;
1801 struct osl_column *col;
1802
1803 *result = NULL;
1804 ret = check_rbtree_col(t, col_num, &col);
1805 if (ret < 0)
1806 return ret;
1807 ret = search_rbtree(obj, t, col_num, &node, NULL);
1808 if (ret < 0)
1809 return ret;
1810 row = get_row_pointer(node, t->columns[col_num].rbtree_num);
1811 *result = row;
1812 return 1;
1813 }
1814
1815 static int rbtree_loop(struct osl_column *col, void *private_data,
1816 osl_rbtree_loop_func *func)
1817 {
1818 struct rb_node *n, *tmp;
1819
1820 /* this for-loop is safe against removal of an entry */
1821 for (n = rb_first(&col->rbtree), tmp = n? rb_next(n) : NULL;
1822 n;
1823 n = tmp, tmp = tmp? rb_next(tmp) : NULL) {
1824 struct osl_row *r = get_row_pointer(n, col->rbtree_num);
1825 int ret = func(r, private_data);
1826 if (ret < 0)
1827 return ret;
1828 }
1829 return 1;
1830 }
1831
1832 static int rbtree_loop_reverse(struct osl_column *col, void *private_data,
1833 osl_rbtree_loop_func *func)
1834 {
1835 struct rb_node *n, *tmp;
1836
1837 /* safe against removal of an entry */
1838 for (n = rb_last(&col->rbtree), tmp = n? rb_prev(n) : NULL;
1839 n;
1840 n = tmp, tmp = tmp? rb_prev(tmp) : NULL) {
1841 struct osl_row *r = get_row_pointer(n, col->rbtree_num);
1842 int ret = func(r, private_data);
1843 if (ret < 0)
1844 return ret;
1845 }
1846 return 1;
1847 }
1848
1849 /**
1850 * Loop over all nodes in an rbtree.
1851 *
1852 * \param t Pointer to an open osl table.
1853 * \param col_num The column to use for iterating over the elements.
1854 * \param private_data Pointer that gets passed to \a func.
1855 * \param func The function to be called for each node in the rbtree.
1856 *
1857 * This function does an in-order walk of the rbtree associated with \a
1858 * col_num. It is an error if the \p OSL_RBTREE flag is not set for this
1859 * column. For each node in the rbtree, the given function \a func is called
1860 * with two pointers as arguments: The first osl_row* argument points to the
1861 * row that contains the object corresponding to the rbtree node currently
1862 * traversed, and the \a private_data pointer is passed verbatim to \a func as the
1863 * second argument. The loop terminates either if \a func returns a negative
1864 * value, or if all nodes of the tree have been visited.
1865 *
1866 *
1867 * \return Positive on success, negative on errors. If the termination of the
1868 * loop was caused by \a func returning a negative value, this value is
1869 * returned.
1870 *
1871 * \sa osl_storage_flags, osl_rbtree_loop_reverse(), osl_compare_func.
1872 */
1873 int osl_rbtree_loop(const struct osl_table *t, unsigned col_num,
1874 void *private_data, osl_rbtree_loop_func *func)
1875 {
1876 struct osl_column *col;
1877
1878 int ret = check_rbtree_col(t, col_num, &col);
1879 if (ret < 0)
1880 return ret;
1881 return rbtree_loop(col, private_data, func);
1882 }
1883
1884 /**
1885 * Loop over all nodes in an rbtree in reverse order.
1886 *
1887 * \param t Identical meaning as in \p osl_rbtree_loop().
1888 * \param col_num Identical meaning as in \p osl_rbtree_loop().
1889 * \param private_data Identical meaning as in \p osl_rbtree_loop().
1890 * \param func Identical meaning as in \p osl_rbtree_loop().
1891 *
1892 * This function is identical to \p osl_rbtree_loop(), the only difference
1893 * is that the tree is walked in reverse order.
1894 *
1895 * \return The same return value as \p osl_rbtree_loop().
1896 *
1897 * \sa osl_rbtree_loop().
1898 */
1899 int osl_rbtree_loop_reverse(const struct osl_table *t, unsigned col_num,
1900 void *private_data, osl_rbtree_loop_func *func)
1901 {
1902 struct osl_column *col;
1903
1904 int ret = check_rbtree_col(t, col_num, &col);
1905 if (ret < 0)
1906 return ret;
1907 return rbtree_loop_reverse(col, private_data, func);
1908 }
1909
1910 /* TODO: Rollback changes on errors */
1911 static int rename_disk_storage_objects(struct osl_table *t,
1912 struct osl_object *old_obj, struct osl_object *new_obj)
1913 {
1914 int i, ret;
1915 const struct osl_column_description *cd;
1916 char *old_ds_name, *new_ds_name;
1917
1918 if (!t->num_disk_storage_columns)
1919 return 1; /* nothing to do */
1920 if (old_obj->size == new_obj->size && !memcmp(new_obj->data,
1921 old_obj->data, new_obj->size))
1922 return 1; /* object did not change */
1923 old_ds_name = disk_storage_name_of_object(t, old_obj);
1924 new_ds_name = disk_storage_name_of_object(t, new_obj);
1925 ret = -ERRNO_TO_ERROR(ENOMEM);
1926 if (!old_ds_name || ! new_ds_name)
1927 goto out;
1928
1929 FOR_EACH_DISK_STORAGE_COLUMN(i, t, cd) {
1930 char *old_filename, *new_filename;
1931 ret = create_disk_storage_object_dir(t, i, new_ds_name);
1932 if (ret < 0)
1933 goto out;
1934 old_filename = disk_storage_path(t, i, old_ds_name);
1935 new_filename = disk_storage_path(t, i, new_ds_name);
1936 if (!old_filename || !new_filename)
1937 ret = -ERRNO_TO_ERROR(ENOMEM);
1938 else
1939 ret = para_rename(old_filename, new_filename);
1940 free(old_filename);
1941 free(new_filename);
1942 if (ret < 0)
1943 goto out;
1944 }
1945 ret = 1;
1946 out:
1947 free(old_ds_name);
1948 free(new_ds_name);
1949 return ret;
1950
1951 }
1952
1953 /**
1954 * Change an object in an osl table.
1955 *
1956 * \param t Pointer to an open osl table.
1957 * \param r Pointer to the row containing the object to be updated.
1958 * \param col_num Number of the column containing the object to be updated.
1959 * \param obj Pointer to the replacement object.
1960 *
1961 * This function gets rid of all references to the old object. This includes
1962 * removal of the rbtree node in case there is an rbtree associated with \a
1963 * col_num. It then inserts \a obj into the table and the rbtree if necessary.
1964 *
1965 * If the \p OSL_RBTREE flag is set for \a col_num, you \b MUST call this
1966 * function in order to change the contents of an object, even for volatile or
1967 * mapped columns of constant size (which may be updated directly if \p
1968 * OSL_RBTREE is not set). Otherwise the rbtree might become corrupted.
1969 *
1970 * \return Standard
1971 */
1972 int osl_update_object(struct osl_table *t, const struct osl_row *r,
1973 unsigned col_num, struct osl_object *obj)
1974 {
1975 struct osl_column *col;
1976 const struct osl_column_description *cd;
1977 int ret;
1978
1979 if (!t)
1980 return -E_BAD_TABLE;
1981 col = &t->columns[col_num];
1982 cd = get_column_description(t->desc, col_num);
1983 DEBUG_LOG("updating column %u of %s\n", col_num, t->desc->name);
1984 if (cd->storage_flags & OSL_RBTREE) {
1985 if (search_rbtree(obj, t, col_num, NULL, NULL) > 0)
1986 return -E_RB_KEY_EXISTS;
1987 }
1988 if (cd->storage_flags & OSL_FIXED_SIZE) {
1989 if (obj->size != cd->data_size)
1990 return -E_BAD_DATA_SIZE;
1991 }
1992 remove_rb_node(t, col_num, r);
1993 if (cd->storage_type == OSL_NO_STORAGE) { /* TODO: If fixed size, reuse object? */
1994 free(r->volatile_objects[col->volatile_num].data);
1995 r->volatile_objects[col->volatile_num] = *obj;
1996 } else if (cd->storage_type == OSL_DISK_STORAGE) {
1997 char *ds_name;
1998 ret = disk_storage_name_of_row(t, r, &ds_name);
1999 if (ret < 0)
2000 return ret;
2001 ret = delete_disk_storage_file(t, col_num, ds_name);
2002 if (ret < 0 && !is_errno(-ret, ENOENT)) {
2003 free(ds_name);
2004 return ret;
2005 }
2006 ret = write_disk_storage_file(t, col_num, obj, ds_name);
2007 free(ds_name);
2008 if (ret < 0)
2009 return ret;
2010 } else { /* mapped storage */
2011 struct osl_object old_obj;
2012 ret = get_mapped_object(t, col_num, r->num, &old_obj);
2013 if (ret < 0)
2014 return ret;
2015 /*
2016 * If the updated column is the disk storage name column, the
2017 * disk storage name changes, so we have to rename all disk
2018 * storage objects accordingly.
2019 */
2020 if (col_num == t->disk_storage_name_column) {
2021 ret = rename_disk_storage_objects(t, &old_obj, obj);
2022 if (ret < 0)
2023 return ret;
2024 }
2025 if (cd->storage_flags & OSL_FIXED_SIZE)
2026 memcpy(old_obj.data, obj->data, cd->data_size);
2027 else { /* TODO: if the size doesn't change, use old space */
2028 uint32_t new_data_map_size;
2029 char *row_index;
2030 ret = get_row_index(t, r->num, &row_index);
2031 if (ret < 0)
2032 return ret;
2033 ret = mark_mapped_object_invalid(t, r->num, col_num);
2034 if (ret < 0)
2035 return ret;
2036 unmap_column(t, col_num);
2037 ret = append_map_file(t, col_num, obj,
2038 &new_data_map_size);
2039 if (ret < 0)
2040 return ret;
2041 ret = map_column(t, col_num);
2042 if (ret < 0)
2043 return ret;
2044 update_cell_index(row_index, col, new_data_map_size,
2045 obj->size);
2046 }
2047 }
2048 if (cd->storage_flags & OSL_RBTREE) {
2049 ret = insert_rbtree(t, col_num, r, obj);
2050 if (ret < 0)
2051 return ret;
2052 }
2053 return 1;
2054 }
2055
2056 /**
2057 * Retrieve an object of type \p OSL_DISK_STORAGE by row and column.
2058 *
2059 * \param t Pointer to an open osl table.
2060 * \param r Pointer to the row containing the object.
2061 * \param col_num The column number.
2062 * \param obj Points to the result upon successful return.
2063 *
2064 * For columns of type \p OSL_DISK_STORAGE, this function must be used to
2065 * retrieve one of its containing objects. Afterwards, osl_close_disk_object()
2066 * must be called in order to deallocate the resources.
2067 *
2068 * \return Positive on success, negative on errors. Possible errors include:
2069 * \p E_BAD_TABLE, \p E_BAD_STORAGE_TYPE, errors returned by osl_get_object().
2070 *
2071 * \sa osl_get_object(), osl_storage_type, osl_close_disk_object().
2072 */
2073 int osl_open_disk_object(const struct osl_table *t, const struct osl_row *r,
2074 unsigned col_num, struct osl_object *obj)
2075 {
2076 const struct osl_column_description *cd;
2077 char *ds_name, *filename;
2078 int ret;
2079
2080 if (!t)
2081 return -E_BAD_TABLE;
2082 cd = get_column_description(t->desc, col_num);
2083 if (cd->storage_type != OSL_DISK_STORAGE)
2084 return -E_BAD_STORAGE_TYPE;
2085
2086 ret = disk_storage_name_of_row(t, r, &ds_name);
2087 if (ret < 0)
2088 return ret;
2089 filename = disk_storage_path(t, col_num, ds_name);
2090 free(ds_name);
2091 if (!filename)
2092 return -ERRNO_TO_ERROR(ENOMEM);
2093 DEBUG_LOG("filename: %s\n", filename);
2094 ret = mmap_full_file(filename, O_RDONLY, &obj->data, &obj->size, NULL);
2095 free(filename);
2096 return ret;
2097 }
2098
2099 /**
2100 * Free resources that were allocated during osl_open_disk_object().
2101 *
2102 * \param obj Pointer to the object previously returned by open_disk_object().
2103 *
2104 * \return The return value of the underlying call to para_munmap().
2105 *
2106 * \sa para_munmap().
2107 */
2108 int osl_close_disk_object(struct osl_object *obj)
2109 {
2110 return para_munmap(obj->data, obj->size);
2111 }
2112
2113 /**
2114 * Get the number of rows of the given table.
2115 *
2116 * \param t Pointer to an open osl table.
2117 * \param num_rows Result is returned here.
2118 *
2119 * The number of rows returned via \a num_rows excluding any invalid rows.
2120 *
2121 * \return Positive on success, \p -E_BAD_TABLE if \a t is \p NULL.
2122 */
2123 int osl_get_num_rows(const struct osl_table *t, unsigned *num_rows)
2124 {
2125 if (!t)
2126 return -E_BAD_TABLE;
2127 assert(t->num_rows >= t->num_invalid_rows);
2128 *num_rows = t->num_rows - t->num_invalid_rows;
2129 return 1;
2130 }
2131
2132 /**
2133 * Get the rank of a row.
2134 *
2135 * \param t An open osl table.
2136 * \param r The row to get the rank of.
2137 * \param col_num The number of an rbtree column.
2138 * \param rank Result pointer.
2139 *
2140 * The rank is, by definition, the position of the row in the linear order
2141 * determined by an in-order tree walk of the rbtree associated with column
2142 * number \a col_num of \a table.
2143 *
2144 * \return Positive on success, negative on errors.
2145 *
2146 * \sa osl_get_nth_row().
2147 */
2148 int osl_get_rank(const struct osl_table *t, struct osl_row *r,
2149 unsigned col_num, unsigned *rank)
2150 {
2151 struct osl_object obj;
2152 struct osl_column *col;
2153 struct rb_node *node;
2154 int ret = check_rbtree_col(t, col_num, &col);
2155
2156 if (ret < 0)
2157 return ret;
2158 ret = osl_get_object(t, r, col_num, &obj);
2159 if (ret < 0)
2160 return ret;
2161 ret = search_rbtree(&obj, t, col_num, &node, NULL);
2162 if (ret < 0)
2163 return ret;
2164 ret = rb_rank(node, rank);
2165 if (ret < 0)
2166 return -E_BAD_ROW;
2167 return 1;
2168 }
2169
2170 /**
2171 * Get the row with n-th greatest value.
2172 *
2173 * \param t Pointer to an open osl table.
2174 * \param col_num The column number.
2175 * \param n The rank of the desired row.
2176 * \param result Row is returned here.
2177 *
2178 * Retrieve the n-th order statistic with respect to the compare function
2179 * of the rbtree column \a col_num. In other words, get that row with
2180 * \a n th greatest value in column \a col_num. It's an error if
2181 * \a col_num is not a rbtree column, or if \a n is larger than the
2182 * number of rows in the table.
2183 *
2184 * \return Positive on success, negative on errors. Possible errors:
2185 * \p E_BAD_TABLE, \p E_BAD_STORAGE_FLAGS, \p E_RB_KEY_NOT_FOUND.
2186 *
2187 * \sa osl_storage_flags, osl_compare_func, osl_get_row(),
2188 * osl_rbtree_last_row(), osl_rbtree_first_row(), osl_get_rank().
2189 */
2190 int osl_get_nth_row(const struct osl_table *t, unsigned col_num,
2191 unsigned n, struct osl_row **result)
2192 {
2193 struct osl_column *col;
2194 struct rb_node *node;
2195 unsigned num_rows;
2196 int ret;
2197
2198 if (n == 0)
2199 return -E_RB_KEY_NOT_FOUND;
2200 ret = osl_get_num_rows(t, &num_rows);
2201 if (ret < 0)
2202 return ret;
2203 if (n > num_rows)
2204 return -E_RB_KEY_NOT_FOUND;
2205 ret = check_rbtree_col(t, col_num, &col);
2206 if (ret < 0)
2207 return ret;
2208 node = rb_nth(col->rbtree.rb_node, n);
2209 if (!node)
2210 return -E_RB_KEY_NOT_FOUND;
2211 *result = get_row_pointer(node, col->rbtree_num);
2212 return 1;
2213 }
2214
2215 /**
2216 * Get the row corresponding to the smallest rbtree node of a column.
2217 *
2218 * \param t An open rbtree table.
2219 * \param col_num The number of the rbtree column.
2220 * \param result A pointer to the first row is returned here.
2221 *
2222 * The rbtree node of the smallest object (with respect to the corresponding
2223 * compare function) is selected and the row containing this object is
2224 * returned. It is an error if \a col_num refers to a column without an
2225 * associated rbtree.
2226 *
2227 * \return Positive on success, negative on errors.
2228 *
2229 * \sa osl_get_nth_row(), osl_rbtree_last_row().
2230 */
2231 int osl_rbtree_first_row(const struct osl_table *t, unsigned col_num,
2232 struct osl_row **result)
2233 {
2234 return osl_get_nth_row(t, col_num, 1, result);
2235 }
2236
2237 /**
2238 * Get the row corresponding to the greatest rbtree node of a column.
2239 *
2240 * \param t The same meaning as in \p osl_rbtree_first_row().
2241 * \param col_num The same meaning as in \p osl_rbtree_first_row().
2242 * \param result The same meaning as in \p osl_rbtree_first_row().
2243 *
2244 * This function works just like osl_rbtree_first_row(), the only difference
2245 * is that the row containing the greatest rather than the smallest object is
2246 * returned.
2247 *
2248 * \return Positive on success, negative on errors.
2249 *
2250 * \sa osl_get_nth_row(), osl_rbtree_first_row().
2251 */
2252 int osl_rbtree_last_row(const struct osl_table *t, unsigned col_num,
2253 struct osl_row **result)
2254 {
2255 unsigned num_rows;
2256 int ret = osl_get_num_rows(t, &num_rows);
2257
2258 if (ret < 0)
2259 return ret;
2260 return osl_get_nth_row(t, col_num, num_rows, result);
2261 }