Fix some format string warnings on x86_64.
[paraslash.git] / osl.c
1 /*
2 * Copyright (C) 2007 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 "para.h"
9 #include "error.h"
10 #include "list.h"
11 #include "osl_core.h"
12 #include <dirent.h> /* readdir() */
13 #include <assert.h>
14
15 //#define FMT_OFF_T "%li"
16
17
18 /**
19 * A wrapper for lseek(2).
20 *
21 * \param fd The filedescriptor whose offset is to be to repositioned.
22 * \param offset A value-result parameter.
23 * \param whence Usual repositioning directive.
24 *
25 * Reposition the offset of the file descriptor \a fd to the argument \a offset
26 * according to the directive \a whence. Upon successful return, \a offset
27 * contains the resulting offset location as measured in bytes from the
28 * beginning of the file.
29 *
30 * \return Positive on success. Otherwise, the function returns \p -E_LSEEK.
31 *
32 * \sa lseek(2).
33 */
34 int para_lseek(int fd, off_t *offset, int whence)
35 {
36 *offset = lseek(fd, *offset, whence);
37 int ret = -E_LSEEK;
38 if (*offset == -1)
39 return ret;
40 return 1;
41 }
42
43 /**
44 * Waraper for the write system call.
45 *
46 * \param fd The file descriptor to write to.
47 * \param buf The buffer to write.
48 * \param size The length of \a buf in bytes.
49 *
50 * This function writes out the given bufffer and retries if an interrupt
51 * occured during the write.
52 *
53 * \return On success, the number of bytes written is returned, otherwise, the
54 * function returns \p -E_WRITE.
55 *
56 * \sa write(2).
57 */
58 ssize_t para_write(int fd, const void *buf, size_t size)
59 {
60 ssize_t ret;
61
62 for (;;) {
63 ret = write(fd, buf, size);
64 if ((ret < 0) && (errno == EAGAIN || errno == EINTR))
65 continue;
66 return ret >= 0? ret : -E_WRITE;
67 }
68 }
69
70 /**
71 * Write the whole buffer to a file descriptor.
72 *
73 * \param fd The file descriptor to write to.
74 * \param buf The buffer to write.
75 * \param size The length of \a buf in bytes.
76 *
77 * This function writes the given buffer and continues on short writes and
78 * when interrupted by a signal.
79 *
80 * \return Positive on success, negative on errors. Possible errors: any
81 * errors returned by para_write().
82 *
83 * \sa para_write().
84 */
85 ssize_t para_write_all(int fd, const void *buf, size_t size)
86 {
87 PARA_DEBUG_LOG("writing %zu bytes\n", size);
88 const char *b = buf;
89 while (size) {
90 ssize_t ret = para_write(fd, b, size);
91 PARA_DEBUG_LOG("ret: %zd\n", ret);
92 if (ret < 0)
93 return ret;
94 b += ret;
95 size -= ret;
96 }
97 return 1;
98 }
99 /**
100 * Wrapper for the open(2) system call.
101 *
102 * \param path The filename.
103 * \param flags The usual open(2) flags.
104 * \param mode Specifies the permissions to use.
105 *
106 * The mode parameter must be specified when O_CREAT is in the flags, and is ignored
107 * otherwise.
108 *
109 * \return Positive on success, negative on errors. Possible errors: \p
110 * E_EXIST, \p E_ISDIR, \p E_NOENT, \p E_OSL_PERM.
111 *
112 * \sa open(2).
113 */
114 int para_open(const char *path, int flags, mode_t mode)
115 {
116 PARA_DEBUG_LOG("opening %s\n", path);
117 int ret = open(path, flags, mode);
118
119 if (ret >= 0)
120 return ret;
121 switch (errno) {
122 case EEXIST:
123 ret = -E_EXIST;
124 break;
125 case EISDIR:
126 ret = -E_ISDIR;
127 break;
128 case ENOENT:
129 ret = -E_NOENT;
130 break;
131 case EPERM:
132 ret = -E_OSL_PERM;
133 break;
134 };
135 PARA_ERROR_LOG("failed to open %s: %s\n", path, strerror(errno));
136 return ret;
137 }
138
139 /**
140 * Open a file, write the given buffer and close the file.
141 *
142 * \param filename Full path to the file to open.
143 * \param buf The buffer to write to the file.
144 * \param size The size of \a buf.
145 *
146 * \return Positive on success, negative on errors. Possible errors include:
147 * any errors from para_open() or para_write().
148 *
149 * \sa para_open(), para_write().
150 */
151 int para_write_file(const char *filename, const void *buf, size_t size)
152 {
153 int ret, fd;
154
155 ret = para_open(filename, O_WRONLY | O_CREAT | O_EXCL, 0644);
156 if (ret < 0)
157 return ret;
158 fd = ret;
159 ret = para_write_all(fd, buf, size);
160 if (ret < 0)
161 goto out;
162 ret = 1;
163 out:
164 close(fd);
165 return ret;
166 }
167
168 static int append_file(const char *filename, char *header, size_t header_size,
169 char *data, size_t data_size, uint32_t *new_pos)
170 {
171 int ret, fd;
172
173 PARA_DEBUG_LOG("appending %zu + %zu bytes\n", header_size, data_size);
174 ret = para_open(filename, O_WRONLY | O_CREAT | O_APPEND, 0644);
175 if (ret < 0)
176 return ret;
177 fd = ret;
178 if (header && header_size) {
179 ret = para_write_all(fd, header, header_size);
180 if (ret < 0)
181 goto out;
182 }
183 ret = para_write_all(fd, data, data_size);
184 if (ret < 0)
185 goto out;
186 if (new_pos) {
187 off_t offset = 0;
188 ret = para_lseek(fd, &offset, SEEK_END);
189 if (ret < 0)
190 goto out;
191 // PARA_DEBUG_LOG("new file size: " FMT_OFF_T "\n", offset);
192 *new_pos = offset;
193 }
194 ret = 1;
195 out:
196 close(fd);
197 return ret;
198 }
199
200 /**
201 * Map a file into memory.
202 *
203 * \param path Name of the regular file to map.
204 * \param open_mode Either \p O_RDONLY or \p O_RDWR.
205 * \param obj On success, the mapping is returned here.
206 *
207 * \return Positive on success, negative on errors. Possible errors include: \p
208 * E_FSTAT, any errors returned by para_open(), \p E_EMPTY, \p E_MMAP.
209 *
210 * \sa para_open(), mmap(2).
211 */
212 int mmap_full_file(const char *path, int open_mode, struct osl_object *obj)
213 {
214 int fd, ret, mmap_prot, mmap_flags;
215 struct stat file_status;
216
217 if (open_mode == O_RDONLY) {
218 mmap_prot = PROT_READ;
219 mmap_flags = MAP_PRIVATE;
220 } else {
221 mmap_prot = PROT_READ | PROT_WRITE;
222 mmap_flags = MAP_SHARED;
223 }
224 ret = para_open(path, open_mode, 0);
225 if (ret < 0)
226 return ret;
227 fd = ret;
228 ret = -E_FSTAT;
229 if (fstat(fd, &file_status) < 0)
230 goto out;
231 obj->size = file_status.st_size;
232 ret = -E_EMPTY;
233 PARA_DEBUG_LOG("%s: size %zu\n", path, obj->size);
234 if (!obj->size)
235 goto out;
236 obj->data = mmap(NULL, obj->size, mmap_prot, mmap_flags, fd, 0);
237 if (obj->data == MAP_FAILED) {
238 obj->data = NULL;
239 ret = -E_MMAP;
240 goto out;
241 }
242 ret = 1;
243 out:
244 close(fd);
245 return ret;
246 }
247
248 /**
249 * Traverse the given directory recursively.
250 *
251 * \param dirname The directory to traverse.
252 * \param func The function to call for each entry.
253 * \param private_data Pointer to an arbitrary data structure.
254 *
255 * For each regular file in \a dirname, the supplied function \a func is
256 * called. The full path of the regular file and the \a private_data pointer
257 * are passed to \a func.
258 *
259 * \return On success, 1 is returned. Otherwise, this function returns a
260 * negative value which indicates the kind of the error.
261 */
262 int for_each_file_in_dir(const char *dirname,
263 int (*func)(const char *, const void *), const void *private_data)
264 {
265 DIR *dir = NULL;
266 struct dirent *entry;
267 /*
268 * Opening the current directory (".") and calling fchdir() to return
269 * is usually faster and more reliable than saving cwd in some buffer
270 * and calling chdir() afterwards (see man 3 getcwd).
271 */
272 int cwd_fd = open(".", O_RDONLY);
273 struct stat s;
274 int ret = -1;
275
276 // PARA_DEBUG_LOG("dirname: %s\n", dirname);
277 if (cwd_fd < 0)
278 return -E_OSL_GETCWD;
279 ret = -E_OSL_CHDIR;
280 if (chdir(dirname) < 0)
281 goto out;
282 ret = -E_OSL_OPENDIR;
283 dir = opendir(".");
284 if (!dir)
285 goto out;
286 /* scan cwd recursively */
287 while ((entry = readdir(dir))) {
288 mode_t m;
289 char *tmp;
290
291 if (!strcmp(entry->d_name, "."))
292 continue;
293 if (!strcmp(entry->d_name, ".."))
294 continue;
295 ret = -E_OSL_LSTAT;
296 if (lstat(entry->d_name, &s) == -1)
297 continue;
298 m = s.st_mode;
299 if (!S_ISREG(m) && !S_ISDIR(m))
300 continue;
301 tmp = make_message("%s/%s", dirname, entry->d_name);
302 if (!S_ISDIR(m)) {
303 ret = func(tmp, private_data);
304 free(tmp);
305 if (ret < 0)
306 goto out;
307 continue;
308 }
309 /* directory */
310 ret = for_each_file_in_dir(tmp, func, private_data);
311 free(tmp);
312 if (ret < 0)
313 goto out;
314 }
315 ret = 1;
316 out:
317 if (dir)
318 closedir(dir);
319 if (fchdir(cwd_fd) < 0 && ret >= 0)
320 ret = -E_OSL_CHDIR;
321 close(cwd_fd);
322 return ret;
323 }
324
325 int para_mkdir(const char *path, mode_t mode)
326 {
327 if (!mkdir(path, mode))
328 return 1;
329 if (errno == EEXIST)
330 return -E_EXIST;
331 if (errno == ENOSPC)
332 return -E_NOSPC;
333 if (errno == ENOTDIR)
334 return -E_NOTDIR;
335 if (errno == EPERM)
336 return E_OSL_PERM;
337 return -E_MKDIR;
338 }
339
340 static int verify_basename(const char *name)
341 {
342 if (!name)
343 return -E_BAD_BASENAME;
344 if (!*name)
345 return -E_BAD_BASENAME;
346 if (strchr(name, '/'))
347 return -E_BAD_BASENAME;
348 if (!strcmp(name, ".."))
349 return -E_BAD_BASENAME;
350 if (!strcmp(name, "."))
351 return -E_BAD_BASENAME;
352 return 1;
353 }
354
355 /**
356 * Compare two osl objects pointing to unsigned integers of 32 bit size.
357 *
358 * \param obj1 Pointer to the first integer.
359 * \param obj2 Pointer to the second integer.
360 *
361 * \return The values required for an osl compare function.
362 *
363 * \sa osl_compare_func, osl_hash_compare().
364 */
365 int uint32_compare(const struct osl_object *obj1, const struct osl_object *obj2)
366 {
367 uint32_t d1 = read_u32((const char *)obj1->data);
368 uint32_t d2 = read_u32((const char *)obj2->data);
369
370 if (d1 < d2)
371 return 1;
372 if (d1 > d2)
373 return -1;
374 return 0;
375 }
376
377 /**
378 * Compare two osl objects pointing to hash values.
379 *
380 * \param obj1 Pointer to the first hash object.
381 * \param obj2 Pointer to the second hash object.
382 *
383 * \return The values required for an osl compare function.
384 *
385 * \sa osl_compare_func, uint32_compare().
386 */
387 int osl_hash_compare(const struct osl_object *obj1, const struct osl_object *obj2)
388 {
389 return hash_compare((HASH_TYPE *)obj1->data, (HASH_TYPE *)obj2->data);
390 }
391
392 static char *disk_storage_dirname(const struct osl_table *t, unsigned col_num,
393 const char *ds_name)
394 {
395 char *dirname, *column_name = column_filename(t, col_num);
396
397 if (!(t->desc->flags & OSL_LARGE_TABLE))
398 return column_name;
399 dirname = make_message("%s/%.2s", column_name, ds_name);
400 free(column_name);
401 return dirname;
402 }
403
404 static char *disk_storage_name_of_object(const struct osl_table *t,
405 const struct osl_object *obj)
406 {
407 HASH_TYPE hash[HASH_SIZE];
408 hash_object(obj, hash);
409 return disk_storage_name_of_hash(t, hash);
410 }
411
412 static int disk_storage_name_of_row(const struct osl_table *t,
413 const struct osl_row *row, char **name)
414 {
415 struct osl_object obj;
416 int ret = osl_get_object(t, row, t->disk_storage_name_column, &obj);
417
418 if (ret < 0)
419 return ret;
420 *name = disk_storage_name_of_object(t, &obj);
421 return 1;
422 }
423
424 static void column_name_hash(const char *col_name, HASH_TYPE *hash)
425 {
426 return hash_function(col_name, strlen(col_name), hash);
427 }
428
429 static int init_column_descriptions(struct osl_table *t)
430 {
431 int i, j, ret;
432 const struct osl_column_description *cd;
433
434 ret = -E_BAD_TABLE_DESC;
435 ret = verify_basename(t->desc->name);
436 if (ret < 0)
437 goto err;
438 ret = -E_BAD_DB_DIR;
439 if (!t->desc->dir)
440 goto err;
441 /* the size of the index header without column descriptions */
442 t->index_header_size = IDX_COLUMN_DESCRIPTIONS;
443 FOR_EACH_COLUMN(i, t->desc, cd) {
444 struct osl_column *col = t->columns + i;
445 if (cd->storage_flags & OSL_RBTREE) {
446 if (!cd->compare_function)
447 return -E_NO_COMPARE_FUNC;
448 }
449 if (cd->storage_type == OSL_NO_STORAGE)
450 continue;
451 ret = -E_NO_COLUMN_NAME;
452 if (!cd->name || !cd->name[0])
453 goto err;
454 ret = verify_basename(cd->name);
455 if (ret < 0)
456 goto err;
457 t->index_header_size += index_column_description_size(cd->name);
458 column_name_hash(cd->name, col->name_hash);
459 ret = -E_DUPLICATE_COL_NAME;
460 for (j = i + 1; j < t->desc->num_columns; j++) {
461 const char *name2 = get_column_description(t->desc,
462 j)->name;
463 if (cd->name && name2 && !strcmp(cd->name, name2))
464 goto err;
465 }
466 }
467 return 1;
468 err:
469 return ret;
470 }
471
472 /**
473 * Initialize a struct table from given table description.
474 *
475 * \param desc The description of the osl table.
476 * \param table_ptr Result is returned here.
477 *
478 * This function performs several sanity checks on \p desc and returns if any
479 * of these tests fail. On success, a struct \p osl_table is allocated and
480 * initialized with data derived from \p desc.
481 *
482 * \return Positive on success, negative on errors. Possible errors include: \p
483 * E_BAD_TABLE_DESC, \p E_NO_COLUMN_DESC, \p E_NO_COLUMNS, \p
484 * E_BAD_STORAGE_TYPE, \p E_BAD_STORAGE_FLAGS, \p E_BAD_STORAGE_SIZE, \p
485 * E_NO_UNIQUE_RBTREE_COLUMN, \p E_NO_RBTREE_COL.
486 *
487 * \sa struct osl_table.
488 */
489 int init_table_structure(const struct osl_table_description *desc,
490 struct osl_table **table_ptr)
491 {
492 const struct osl_column_description *cd;
493 struct osl_table *t = para_calloc(sizeof(*t));
494 int i, ret = -E_BAD_TABLE_DESC, have_disk_storage_name_column = 0;
495
496 PARA_INFO_LOG("creating table structure for '%s' from table "
497 "description\n", desc->name);
498 if (!desc)
499 goto err;
500 ret = -E_NO_COLUMN_DESC;
501 if (!desc->column_descriptions)
502 goto err;
503 ret = -E_NO_COLUMNS;
504 if (!desc->num_columns)
505 goto err;
506 t->columns = para_calloc(desc->num_columns * sizeof(struct osl_column));
507 t->desc = desc;
508 FOR_EACH_COLUMN(i, t->desc, cd) {
509 enum osl_storage_type st = cd->storage_type;
510 enum osl_storage_flags sf = cd->storage_flags;
511 struct osl_column *col = &t->columns[i];
512
513 ret = -E_BAD_STORAGE_TYPE;
514 if (st != OSL_MAPPED_STORAGE && st != OSL_DISK_STORAGE
515 && st != OSL_NO_STORAGE)
516 goto err;
517 ret = -E_BAD_STORAGE_FLAGS;
518 if (st == OSL_DISK_STORAGE && sf & OSL_RBTREE)
519 goto err;
520 ret = -E_BAD_STORAGE_SIZE;
521 if (sf & OSL_FIXED_SIZE && !cd->data_size)
522 goto err;
523 switch (st) {
524 case OSL_DISK_STORAGE:
525 t->num_disk_storage_columns++;
526 break;
527 case OSL_MAPPED_STORAGE:
528 t->num_mapped_columns++;
529 col->index_offset = t->index_entry_size;
530 t->index_entry_size += 8;
531 break;
532 case OSL_NO_STORAGE:
533 col->volatile_num = t->num_volatile_columns;
534 t->num_volatile_columns++;
535 break;
536 }
537 if (sf & OSL_RBTREE) {
538 col->rbtree_num = t->num_rbtrees;
539 t->num_rbtrees++;
540 if ((sf & OSL_UNIQUE) && (st == OSL_MAPPED_STORAGE)) {
541 if (!have_disk_storage_name_column)
542 t->disk_storage_name_column = i;
543 have_disk_storage_name_column = 1;
544 }
545 }
546 }
547 ret = -E_NO_UNIQUE_RBTREE_COLUMN;
548 if (t->num_disk_storage_columns && !have_disk_storage_name_column)
549 goto err;
550 ret = -E_NO_RBTREE_COL;
551 if (!t->num_rbtrees)
552 goto err;
553 /* success */
554 PARA_INFO_LOG("OK. Index entry size: %u\n", t->index_entry_size);
555 ret = init_column_descriptions(t);
556 if (ret < 0)
557 goto err;
558 *table_ptr = t;
559 return 1;
560 err:
561 free(t->columns);
562 free(t);
563 return ret;
564 }
565
566 /**
567 * Read the table description from index header.
568 *
569 * \param map The memory mapping of the index file.
570 * \param desc The values found in the index header are returned here.
571 *
572 * Read the index header, check for the paraslash magic string and the table version number.
573 * Read all information stored in the index header into \a desc.
574 *
575 * \return Positive on success, negative on errors.
576 *
577 * \sa struct osl_table_description, osl_create_table.
578 */
579 int read_table_desc(struct osl_object *map, struct osl_table_description *desc)
580 {
581 char *buf = map->data;
582 uint8_t version;
583 uint16_t header_size;
584 int ret, i;
585 unsigned offset;
586 struct osl_column_description *cd;
587
588 if (map->size < MIN_INDEX_HEADER_SIZE(1))
589 return -E_SHORT_TABLE;
590 if (strncmp(buf + IDX_PARA_MAGIC, PARA_MAGIC, strlen(PARA_MAGIC)))
591 return -E_NO_MAGIC;
592 version = read_u8(buf + IDX_VERSION);
593 if (version < MIN_TABLE_VERSION || version > MAX_TABLE_VERSION)
594 return -E_VERSION_MISMATCH;
595 desc->num_columns = read_u8(buf + IDX_TABLE_FLAGS);
596 desc->flags = read_u8(buf + IDX_TABLE_FLAGS);
597 desc->num_columns = read_u16(buf + IDX_NUM_COLUMNS);
598 PARA_DEBUG_LOG("%u columns\n", desc->num_columns);
599 if (!desc->num_columns)
600 return -E_NO_COLUMNS;
601 header_size = read_u16(buf + IDX_HEADER_SIZE);
602 if (map->size < header_size)
603 return -E_BAD_SIZE;
604 desc->column_descriptions = para_calloc(desc->num_columns
605 * sizeof(struct osl_column_description));
606 offset = IDX_COLUMN_DESCRIPTIONS;
607 FOR_EACH_COLUMN(i, desc, cd) {
608 char *null_byte;
609
610 ret = -E_SHORT_TABLE;
611 if (map->size < offset + MIN_IDX_COLUMN_DESCRIPTION_SIZE) {
612 PARA_ERROR_LOG("map size = %zu < %u = offset + min desc size\n",
613 map->size, offset + MIN_IDX_COLUMN_DESCRIPTION_SIZE);
614 goto err;
615 }
616 cd->storage_type = read_u16(buf + offset + IDX_CD_STORAGE_TYPE);
617 cd->storage_flags = read_u16(buf + offset +
618 IDX_CD_STORAGE_FLAGS);
619 cd->data_size = read_u32(buf + offset + IDX_CD_DATA_SIZE);
620 null_byte = memchr(buf + offset + IDX_CD_NAME, '\0',
621 map->size - offset - IDX_CD_NAME);
622 ret = -E_INDEX_CORRUPTION;
623 if (!null_byte)
624 goto err;
625 cd->name = para_strdup(buf + offset + IDX_CD_NAME);
626 offset += index_column_description_size(cd->name);
627 }
628 if (offset != header_size) {
629 ret = -E_INDEX_CORRUPTION;
630 PARA_ERROR_LOG("real header size = %u != %u = stored header size\n",
631 offset, header_size);
632 goto err;
633 }
634 return 1;
635 err:
636 FOR_EACH_COLUMN(i, desc, cd)
637 free(cd->name);
638 return ret;
639 }
640
641 /*
642 * check whether the table description given by \p t->desc matches the on-disk
643 * table structure stored in the index of \a t.
644 */
645 static int compare_table_descriptions(struct osl_table *t)
646 {
647 int i, ret;
648 struct osl_table_description desc;
649 const struct osl_column_description *cd1, *cd2;
650
651 /* read the on-disk structure into desc */
652 ret = read_table_desc(&t->index_map, &desc);
653 if (ret < 0)
654 return ret;
655 ret = -E_BAD_TABLE_FLAGS;
656 if (desc.flags != t->desc->flags)
657 goto out;
658 ret = E_BAD_COLUMN_NUM;
659 if (desc.num_columns != t->desc->num_columns)
660 goto out;
661 FOR_EACH_COLUMN(i, t->desc, cd1) {
662 cd2 = get_column_description(&desc, i);
663 ret = -E_BAD_STORAGE_TYPE;
664 if (cd1->storage_type != cd2->storage_type)
665 goto out;
666 ret = -E_BAD_STORAGE_FLAGS;
667 if (cd1->storage_flags != cd2->storage_flags) {
668 PARA_ERROR_LOG("sf1 = %u != %u = sf2\n",
669 cd1->storage_flags, cd2->storage_flags);
670 goto out;
671 }
672 ret = -E_BAD_DATA_SIZE;
673 if (cd1->storage_flags & OSL_FIXED_SIZE)
674 if (cd1->data_size != cd2->data_size)
675 goto out;
676 ret = -E_BAD_COLUMN_NAME;
677 if (strcmp(cd1->name, cd2->name))
678 goto out;
679 }
680 PARA_INFO_LOG("table description of '%s' matches on-disk data, good\n",
681 t->desc->name);
682 ret = 1;
683 out:
684 FOR_EACH_COLUMN(i, &desc, cd1)
685 free(cd1->name);
686 free(desc.column_descriptions);
687 return ret;
688 }
689
690 static int create_table_index(struct osl_table *t)
691 {
692 char *buf, *filename;
693 int i, ret;
694 size_t size = t->index_header_size;
695 const struct osl_column_description *cd;
696 unsigned offset;
697
698 PARA_INFO_LOG("creating %zu byte index for table %s\n", size,
699 t->desc->name);
700 buf = para_calloc(size);
701 sprintf(buf + IDX_PARA_MAGIC, "%s", PARA_MAGIC);
702 write_u8(buf + IDX_TABLE_FLAGS, t->desc->flags);
703 write_u8(buf + IDX_DIRTY_FLAG, 0);
704 write_u8(buf + IDX_VERSION, CURRENT_TABLE_VERSION);
705 write_u16(buf + IDX_NUM_COLUMNS, t->desc->num_columns);
706 write_u16(buf + IDX_HEADER_SIZE, t->index_header_size);
707 offset = IDX_COLUMN_DESCRIPTIONS;
708 FOR_EACH_COLUMN(i, t->desc, cd) {
709 write_u16(buf + offset + IDX_CD_STORAGE_TYPE,
710 cd->storage_type);
711 write_u16(buf + offset + IDX_CD_STORAGE_FLAGS,
712 cd->storage_flags);
713 if (cd->storage_flags & OSL_FIXED_SIZE)
714 write_u32(buf + offset + IDX_CD_DATA_SIZE,
715 cd->data_size);
716 strcpy(buf + offset + IDX_CD_NAME, cd->name);
717 offset += index_column_description_size(cd->name);
718 }
719 assert(offset = size);
720 filename = index_filename(t->desc);
721 ret = para_write_file(filename, buf, size);
722 free(buf);
723 free(filename);
724 return ret;
725 }
726
727 /**
728 * Create a new osl table.
729 *
730 * \param desc Pointer to the table description.
731 *
732 * \return Positive on success, negative on errors. Possible errors include: \p
733 * E_BAD_TABLE_DESC, \p E_BAD_DB_DIR, \p E_BAD_BASENAME, \p E_NO_COMPARE_FUNC, \p
734 * E_NO_COLUMN_NAME, \p E_DUPLICATE_COL_NAME, \p E_MKDIR, any errors returned
735 * by para_open().
736 */
737 int osl_create_table(const struct osl_table_description *desc)
738 {
739 const struct osl_column_description *cd;
740 char *table_dir = NULL, *filename;
741 struct osl_table *t;
742 int i, ret = init_table_structure(desc, &t);
743
744 if (ret < 0)
745 return ret;
746 PARA_INFO_LOG("creating %s\n", desc->name);
747 FOR_EACH_COLUMN(i, t->desc, cd) {
748 if (cd->storage_type == OSL_NO_STORAGE)
749 continue;
750 if (!table_dir) {
751 ret = para_mkdir(desc->dir, 0777);
752 if (ret < 0 && ret != -E_EXIST)
753 goto out;
754 table_dir = make_message("%s/%s", desc->dir,
755 desc->name);
756 ret = para_mkdir(table_dir, 0777);
757 if (ret < 0)
758 goto out;
759 }
760 filename = column_filename(t, i);
761 PARA_INFO_LOG("filename: %s\n", filename);
762 if (cd->storage_type == OSL_MAPPED_STORAGE) {
763 ret = para_open(filename, O_RDWR | O_CREAT | O_EXCL,
764 0644);
765 free(filename);
766 if (ret < 0)
767 goto out;
768 close(ret);
769 continue;
770 }
771 /* DISK STORAGE */
772 ret = para_mkdir(filename, 0777);
773 free(filename);
774 if (ret < 0)
775 goto out;
776 }
777 if (t->num_mapped_columns) {
778 ret = create_table_index(t);
779 if (ret < 0)
780 goto out;
781 }
782 ret = 1;
783 out:
784 free(table_dir);
785 free(t->columns);
786 free(t);
787 return ret;
788 }
789
790 static int table_is_dirty(struct osl_table *t)
791 {
792 char *buf = (char *)t->index_map.data + IDX_DIRTY_FLAG;
793 uint8_t dirty = read_u8(buf) & 0x1;
794 return !!dirty;
795 }
796
797 static void mark_table_dirty(struct osl_table *t)
798 {
799 char *buf = (char *)t->index_map.data + IDX_DIRTY_FLAG;
800 write_u8(buf, read_u8(buf) | 1);
801 }
802
803 static void mark_table_clean(struct osl_table *t)
804 {
805 char *buf = (char *)t->index_map.data + IDX_DIRTY_FLAG;
806 write_u8(buf, read_u8(buf) & 0xfe);
807 }
808
809 /**
810 * Unmap all mapped files of an osl table.
811 *
812 * \param t Pointer to a mapped table.
813 * \param flags Options for unmapping.
814 *
815 * \return Positive on success, negative on errors. Possible errors include:
816 * E_NOT_MAPPED, E_MUNMAP.
817 *
818 * \sa map_table(), enum osl_close_flags, para_munmap().
819 */
820 int unmap_table(struct osl_table *t, enum osl_close_flags flags)
821 {
822 unsigned i;
823 const struct osl_column_description *cd;
824 int ret;
825
826 if (!t->num_mapped_columns) /* can this ever happen? */
827 return 1;
828 PARA_INFO_LOG("unmapping table '%s'\n", t->desc->name);
829 if (!t->index_map.data)
830 return -E_NOT_MAPPED;
831 if (flags & OSL_MARK_CLEAN)
832 mark_table_clean(t);
833 ret = para_munmap(t->index_map.data, t->index_map.size);
834 if (ret < 0)
835 return ret;
836 t->index_map.data = NULL;
837 if (!t->num_rows)
838 return 1;
839 FOR_EACH_MAPPED_COLUMN(i, t, cd) {
840 struct osl_object map = t->columns[i].data_map;
841 if (!map.data)
842 continue;
843 ret = para_munmap(map.data, map.size);
844 if (ret < 0)
845 return ret;
846 map.data = NULL;
847 }
848 return 1;
849 }
850
851 /**
852 * Map the index file and all columns of type \p OSL_MAPPED_STORAGE into memory.
853 *
854 * \param t Pointer to an initialized table structure.
855 * \param flags Mapping options.
856 *
857 * \return Negative return value on errors; on success the number of rows
858 * (including invalid rows) is returned.
859 *
860 * \sa unmap_table(), enum map_table_flags, osl_open_table(), mmap(2).
861 */
862 int map_table(struct osl_table *t, enum map_table_flags flags)
863 {
864 char *filename;
865 const struct osl_column_description *cd;
866 int i = 0, ret, num_rows = 0;
867
868 if (!t->num_mapped_columns)
869 return 0;
870 if (t->index_map.data)
871 return -E_ALREADY_MAPPED;
872 filename = index_filename(t->desc);
873 PARA_DEBUG_LOG("mapping table '%s' (index: %s)\n", t->desc->name, filename);
874 ret = mmap_full_file(filename, flags & MAP_TBL_FL_MAP_RDONLY?
875 O_RDONLY : O_RDWR, &t->index_map);
876 free(filename);
877 if (ret < 0)
878 return ret;
879 if (flags & MAP_TBL_FL_VERIFY_INDEX) {
880 ret = compare_table_descriptions(t);
881 if (ret < 0)
882 goto err;
883 }
884 ret = -E_BUSY;
885 if (!(flags & MAP_TBL_FL_IGNORE_DIRTY)) {
886 if (table_is_dirty(t)) {
887 PARA_ERROR_LOG("%s is dirty\n", t->desc->name);
888 goto err;
889 }
890 }
891 mark_table_dirty(t);
892 num_rows = table_num_rows(t);
893 if (!num_rows)
894 return num_rows;
895 /* map data files */
896 FOR_EACH_MAPPED_COLUMN(i, t, cd) {
897 struct stat statbuf;
898 filename = column_filename(t, i);
899 ret = -E_STAT;
900 if (stat(filename, &statbuf) < 0) {
901 free(filename);
902 goto err;
903 }
904 if (!(S_IFREG & statbuf.st_mode)) {
905 free(filename);
906 goto err;
907 }
908 ret = mmap_full_file(filename, O_RDWR,
909 &t->columns[i].data_map);
910 free(filename);
911 if (ret < 0)
912 goto err;
913 }
914 return num_rows;
915 err: /* unmap what is already mapped */
916 for (i--; i >= 0; i--) {
917 struct osl_object map = t->columns[i].data_map;
918 para_munmap(map.data, map.size);
919 map.data = NULL;
920 }
921 para_munmap(t->index_map.data, t->index_map.size);
922 t->index_map.data = NULL;
923 return ret;
924 }
925
926 /**
927 * Retrieve a mapped object by row and column number.
928 *
929 * \param t Pointer to an open osl table.
930 * \param col_num Number of the mapped column containing the object to retrieve.
931 * \param row_num Number of the row containing the object to retrieve.
932 * \param obj The result is returned here.
933 *
934 * It is considered an error if \a col_num does not refer to a column
935 * of storage type \p OSL_MAPPED_STORAGE.
936 *
937 * \return Positive on success, negative on errors. Possible errors include:
938 * \p E_BAD_ID, \p E_INVALID_OBJECT.
939 *
940 * \sa osl_storage_type.
941 */
942 int get_mapped_object(const struct osl_table *t, unsigned col_num,
943 uint32_t row_num, struct osl_object *obj)
944 {
945 struct osl_column *col = &t->columns[col_num];
946 uint32_t offset;
947 char *header;
948 char *index_entry;
949 int ret;
950
951 if (t->num_rows <= row_num)
952 return -E_BAD_ID;
953 ret = get_index_entry(t, row_num, col_num, &index_entry);
954 if (ret < 0)
955 return ret;
956 offset = read_u32(index_entry);
957 obj->size = read_u32(index_entry + 4) - 1;
958 PARA_DEBUG_LOG("index_entry: %p\n", index_entry);
959 header = col->data_map.data + offset;
960 obj->data = header + 1;
961 if (read_u8(header) == 0xff) {
962 PARA_ERROR_LOG("col %u, size %zu, offset %u\n", col_num,
963 obj->size, offset);
964 return -E_INVALID_OBJECT;
965 }
966 PARA_DEBUG_LOG("mapped obj row_num: %u, col %u, size: %zu\n", row_num,
967 col_num, obj->size);
968 return 1;
969 }
970
971 static int search_rbtree(const struct osl_object *obj,
972 const struct osl_table *t, unsigned col_num,
973 struct rb_node **result, struct rb_node ***rb_link)
974 {
975 struct osl_column *col = &t->columns[col_num];
976 struct rb_node **new = &col->rbtree.rb_node, *parent = NULL;
977 const struct osl_column_description *cd =
978 get_column_description(t->desc, col_num);
979 enum osl_storage_type st = cd->storage_type;
980 while (*new) {
981 struct osl_row *this_row = get_row_pointer(*new,
982 col->rbtree_num);
983 int ret;
984 struct osl_object this_obj;
985 parent = *new;
986 if (st == OSL_MAPPED_STORAGE) {
987 ret = get_mapped_object(t, col_num, this_row->id,
988 &this_obj);
989 if (ret < 0)
990 return ret;
991 } else
992 this_obj = this_row->volatile_objects[col->volatile_num];
993 ret = cd->compare_function(obj, &this_obj);
994 if (!ret) {
995 if (result)
996 *result = get_rb_node_pointer(this_row,
997 col->rbtree_num);
998 return 1;
999 }
1000 if (ret < 0)
1001 new = &((*new)->rb_left);
1002 else
1003 new = &((*new)->rb_right);
1004 }
1005 if (result)
1006 *result = parent;
1007 if (rb_link)
1008 *rb_link = new;
1009 return -E_RB_KEY_NOT_FOUND;
1010 }
1011
1012 static int insert_rbtree(struct osl_table *t, unsigned col_num,
1013 const struct osl_row *row, const struct osl_object *obj)
1014 {
1015 struct rb_node *parent, **rb_link;
1016 unsigned rbtree_num;
1017 struct rb_node *n;
1018 int ret = search_rbtree(obj, t, col_num, &parent, &rb_link);
1019
1020 if (ret > 0)
1021 return -E_RB_KEY_EXISTS;
1022 rbtree_num = t->columns[col_num].rbtree_num;
1023 n = get_rb_node_pointer(row, rbtree_num);
1024 rb_link_node(n, parent, rb_link);
1025 rb_insert_color(n, &t->columns[col_num].rbtree);
1026 return 1;
1027 }
1028
1029 static void remove_rb_node(struct osl_table *t, unsigned col_num,
1030 const struct osl_row *row)
1031 {
1032 struct osl_column *col = &t->columns[col_num];
1033 const struct osl_column_description *cd =
1034 get_column_description(t->desc, col_num);
1035 enum osl_storage_flags sf = cd->storage_flags;
1036 struct rb_node *victim, *splice_out_node, *tmp;
1037 if (!(sf & OSL_RBTREE))
1038 return;
1039 /*
1040 * Which node is removed/spliced out actually depends on how many
1041 * children the victim node has: If it has no children, it gets
1042 * deleted. If it has one child, it gets spliced out. If it has two
1043 * children, its successor (which has at most a right child) gets
1044 * spliced out.
1045 */
1046 victim = get_rb_node_pointer(row, col->rbtree_num);
1047 if (victim->rb_left && victim->rb_right)
1048 splice_out_node = rb_next(victim);
1049 else
1050 splice_out_node = victim;
1051 /* Go up to the root and decrement the size of each node in the path. */
1052 for (tmp = splice_out_node; tmp; tmp = rb_parent(tmp))
1053 tmp->size--;
1054 rb_erase(victim, &col->rbtree);
1055 }
1056
1057 static int add_row_to_rbtrees(struct osl_table *t, uint32_t id,
1058 struct osl_object *volatile_objs, struct osl_row **row_ptr)
1059 {
1060 unsigned i;
1061 int ret;
1062 struct osl_row *row = allocate_row(t->num_rbtrees);
1063 const struct osl_column_description *cd;
1064
1065 PARA_DEBUG_LOG("row: %p, id: %u\n", row, id);
1066 row->id = id;
1067 row->volatile_objects = volatile_objs;
1068 FOR_EACH_RBTREE_COLUMN(i, t, cd) {
1069 if (cd->storage_type == OSL_MAPPED_STORAGE) {
1070 struct osl_object obj;
1071 ret = get_mapped_object(t, i, id, &obj);
1072 if (ret < 0)
1073 goto err;
1074 ret = insert_rbtree(t, i, row, &obj);
1075 } else { /* volatile */
1076 const struct osl_object *obj
1077 = volatile_objs + t->columns[i].volatile_num;
1078 PARA_DEBUG_LOG("inserting %p\n", obj->data);
1079 ret = insert_rbtree(t, i, row, obj);
1080 }
1081 if (ret < 0)
1082 goto err;
1083 }
1084 if (row_ptr)
1085 *row_ptr = row;
1086 return 1;
1087 err: /* rollback changes, i.e. remove added entries from rbtrees */
1088 while (i)
1089 remove_rb_node(t, i--, row);
1090 free(row);
1091 return ret;
1092 }
1093
1094 static void free_volatile_objects(const struct osl_table *t,
1095 enum osl_close_flags flags)
1096 {
1097 int i, j;
1098 struct rb_node *n;
1099 struct osl_column *rb_col;
1100 const struct osl_column_description *cd;
1101
1102 if (!t->num_volatile_columns)
1103 return;
1104 /* find the first rbtree column (any will do) */
1105 FOR_EACH_RBTREE_COLUMN(i, t, cd)
1106 break;
1107 rb_col = t->columns + i;
1108 /* walk that rbtree and free all volatile objects */
1109 for (n = rb_first(&rb_col->rbtree); n; n = rb_next(n)) {
1110 struct osl_row *r = get_row_pointer(n, rb_col->rbtree_num);
1111 if (flags & OSL_FREE_VOLATILE)
1112 for (j = 0; j < t->num_volatile_columns; j++)
1113 free(r->volatile_objects[j].data);
1114 free(r->volatile_objects);
1115 }
1116 }
1117
1118 /**
1119 * Erase all rbtree nodes and free resources.
1120 *
1121 * \param t Pointer to an open osl table.
1122 *
1123 * This function is called by osl_close_table().
1124 */
1125 void clear_rbtrees(struct osl_table *t)
1126 {
1127 const struct osl_column_description *cd;
1128 unsigned i, rbtrees_cleared = 0;
1129
1130 FOR_EACH_RBTREE_COLUMN(i, t, cd) {
1131 struct osl_column *col = &t->columns[i];
1132 struct rb_node *n;
1133 rbtrees_cleared++;
1134 for (n = rb_first(&col->rbtree); n;) {
1135 struct osl_row *r;
1136 rb_erase(n, &col->rbtree);
1137 if (rbtrees_cleared == t->num_rbtrees) {
1138 r = get_row_pointer(n, col->rbtree_num);
1139 n = rb_next(n);
1140 free(r);
1141 } else
1142 n = rb_next(n);
1143 }
1144 }
1145
1146 }
1147
1148 /**
1149 * Close an osl table.
1150 *
1151 * \param t Pointer to the table to be closed.
1152 * \param flags Options for what should be cleaned up.
1153 *
1154 * If osl_open_table() succeeds, the resulting table pointer must later be
1155 * passed to this function in order to flush all changes to the filesystem and
1156 * to free the resources that were allocated by osl_open_table().
1157 *
1158 * \return Positive on success, negative on errors. Possible errors: \p E_BAD_TABLE,
1159 * errors returned by unmap_table().
1160 *
1161 * \sa osl_open_table(), unmap_table().
1162 */
1163 int osl_close_table(struct osl_table *t, enum osl_close_flags flags)
1164 {
1165 int ret;
1166
1167 if (!t)
1168 return -E_BAD_TABLE;
1169 free_volatile_objects(t, flags);
1170 clear_rbtrees(t);
1171 ret = unmap_table(t, flags);
1172 if (ret < 0)
1173 PARA_ERROR_LOG("unmap_table failed: %d\n", ret);
1174 free(t->columns);
1175 free(t);
1176 return ret;
1177 }
1178
1179 /**
1180 * Find out whether the given row number corresponds to an invalid row.
1181 *
1182 * \param t Pointer to the osl table.
1183 * \param row_num The number of the row in question.
1184 *
1185 * By definition, a row is considered invalid if all its index entries
1186 * are invalid.
1187 *
1188 * \return Positive if \a row_num corresponds to an invalid row,
1189 * zero if it corresponds to a valid row, negative on errors.
1190 */
1191 int row_is_invalid(struct osl_table *t, uint32_t row_num)
1192 {
1193 char *index_entry;
1194 int i, ret = get_index_entry_start(t, row_num, &index_entry);
1195
1196 if (ret < 0)
1197 return ret;
1198 for (i = 0; i < t->index_entry_size; i++) {
1199 if ((unsigned char)index_entry[i] != 0xff)
1200 return 0;
1201 }
1202 PARA_INFO_LOG("row %d is invalid\n", row_num);
1203 return 1;
1204 }
1205
1206 /**
1207 * Invalidate a row of an osl table.
1208 *
1209 * \param t Pointer to an open osl table.
1210 * \param row_num Number of the row to mark as invalid.
1211 *
1212 * This function marks each mapped object in the index entry of \a row as
1213 * invalid.
1214 *
1215 * \return Positive on success, negative on errors.
1216 */
1217 int mark_row_invalid(struct osl_table *t, uint32_t row_num)
1218 {
1219 char *index_entry;
1220 int i, ret = get_index_entry_start(t, row_num, &index_entry);
1221
1222 PARA_INFO_LOG("marking row %d as invalid\n", row_num);
1223 if (ret < 0)
1224 return ret;
1225 for (i = 0; i < t->index_entry_size; i++)
1226 index_entry[i] = 0xff;
1227 return 1;
1228 }
1229
1230 /**
1231 * Initialize all rbtrees and compute number of invalid rows.
1232 *
1233 * \param t The table containing the rbtrees to be initialized.
1234 *
1235 * \return Positive on success, negative on errors.
1236 */
1237 int init_rbtrees(struct osl_table *t)
1238 {
1239 int i, ret;
1240 const struct osl_column_description *cd;
1241
1242 /* create rbtrees */
1243 FOR_EACH_RBTREE_COLUMN(i, t, cd)
1244 t->columns[i].rbtree = RB_ROOT;
1245 /* add valid rows to rbtrees */
1246 t->num_invalid_rows = 0;
1247 for (i = 0; i < t->num_rows; i++) {
1248 ret = row_is_invalid(t, i);
1249 if (ret < 0)
1250 return ret;
1251 if (ret) {
1252 t->num_invalid_rows++;
1253 continue;
1254 }
1255 ret = add_row_to_rbtrees(t, i, NULL, NULL);
1256 if (ret < 0)
1257 return ret;
1258 }
1259 return 1;
1260 }
1261
1262 /**
1263 * Open an osl table.
1264 *
1265 * Each osl table must be opened before its data can be accessed.
1266 *
1267 * \param table_desc Describes the table to be opened.
1268 * \param result Contains a pointer to the open table on success.
1269 *
1270 * The table description given by \a desc should coincide with the
1271 * description used at creation time.
1272 *
1273 * \return Positive on success, negative on errors. Possible errors include:
1274 * errors returned by init_table_structure(), \p E_NOENT, \p E_STAT, \p \p
1275 * E_NOTDIR, \p E_BAD_TABLE_DESC, \p E_BAD_DB_DIR, \p E_NO_COMPARE_FUNC, \p
1276 * E_NO_COLUMN_NAME, errors returned by init_rbtrees().
1277 */
1278 int osl_open_table(const struct osl_table_description *table_desc,
1279 struct osl_table **result)
1280 {
1281 int i, ret;
1282 struct osl_table *t;
1283 const struct osl_column_description *cd;
1284
1285 PARA_INFO_LOG("opening table %s\n", table_desc->name);
1286 ret = init_table_structure(table_desc, &t);
1287 if (ret < 0)
1288 return ret;
1289 FOR_EACH_DISK_STORAGE_COLUMN(i, t, cd) {
1290 /* check if directory exists */
1291 char *dirname = column_filename(t, i);
1292 struct stat statbuf;
1293 ret = stat(dirname, &statbuf);
1294 free(dirname);
1295 if (ret < 0) {
1296 if (errno == ENOENT)
1297 ret = -E_NOENT;
1298 else
1299 ret = -E_STAT;
1300 goto err;
1301 }
1302 ret = -E_NOTDIR;
1303 if (!S_ISDIR(statbuf.st_mode))
1304 goto err;
1305 }
1306 ret = map_table(t, MAP_TBL_FL_VERIFY_INDEX);
1307 if (ret < 0)
1308 goto err;
1309 t->num_rows = ret;
1310 PARA_DEBUG_LOG("num rows: %d\n", t->num_rows);
1311 ret = init_rbtrees(t);
1312 if (ret < 0) {
1313 osl_close_table(t, OSL_MARK_CLEAN); /* ignore further errors */
1314 return ret;
1315 }
1316 *result = t;
1317 return 1;
1318 err:
1319 free(t->columns);
1320 free(t);
1321 return ret;
1322 }
1323
1324 static int create_disk_storage_object_dir(const struct osl_table *t,
1325 unsigned col_num, const char *ds_name)
1326 {
1327 char *dirname;
1328 int ret;
1329
1330 if (!(t->desc->flags & OSL_LARGE_TABLE))
1331 return 1;
1332 dirname = disk_storage_dirname(t, col_num, ds_name);
1333 ret = para_mkdir(dirname, 0777);
1334 free(dirname);
1335 if (ret < 0 && ret != -E_EXIST)
1336 return ret;
1337 return 1;
1338 }
1339
1340 static int write_disk_storage_file(const struct osl_table *t, unsigned col_num,
1341 const struct osl_object *obj, const char *ds_name)
1342 {
1343 int ret;
1344 char *filename;
1345
1346 ret = create_disk_storage_object_dir(t, col_num, ds_name);
1347 if (ret < 0)
1348 return ret;
1349 filename = disk_storage_path(t, col_num, ds_name);
1350 ret = para_write_file(filename, obj->data, obj->size);
1351 free(filename);
1352 return ret;
1353 }
1354
1355 static int append_map_file(const struct osl_table *t, unsigned col_num,
1356 const struct osl_object *obj, uint32_t *new_size)
1357 {
1358 char *filename = column_filename(t, col_num);
1359 int ret;
1360 char header = 0; /* zero means valid object */
1361
1362 PARA_DEBUG_LOG("appending %zu + 1 byte\n", obj->size);
1363 ret = append_file(filename, &header, 1, obj->data, obj->size,
1364 new_size);
1365 free(filename);
1366 return ret;
1367 }
1368
1369 static int append_index_entry(const struct osl_table *t, char *new_index_entry)
1370 {
1371 char *filename;
1372 int ret;
1373
1374 if (!t->num_mapped_columns)
1375 return 1;
1376 filename = index_filename(t->desc);
1377 PARA_DEBUG_LOG("appending %u bytes\n", t->index_entry_size);
1378 ret = append_file(filename, NULL, 0, new_index_entry,
1379 t->index_entry_size, NULL);
1380 free(filename);
1381 return ret;
1382 }
1383
1384 /**
1385 * A wrapper for truncate(2)
1386 *
1387 * \param path Name of the regular file to truncate
1388 * \param size Number of bytes to \b shave \b off
1389 *
1390 * Truncate the regular file named by \a path by \a size bytes.
1391 *
1392 * \return Positive on success, negative on errors. Possible errors include: \p
1393 * E_STAT, \p E_BAD_SIZE, \p E_TRUNC.
1394 *
1395 * \sa truncate(2)
1396 */
1397 int para_truncate(const char *path, off_t size)
1398 {
1399 int ret;
1400 struct stat statbuf;
1401
1402 ret = -E_STAT;
1403 if (stat(path, &statbuf) < 0)
1404 goto out;
1405 ret = -E_BAD_SIZE;
1406 if (statbuf.st_size < size)
1407 goto out;
1408 ret = -E_TRUNC;
1409 if (truncate(path, statbuf.st_size - size) < 0)
1410 goto out;
1411 ret = 1;
1412 out:
1413 return ret;
1414 }
1415
1416 static int truncate_mapped_file(const struct osl_table *t, unsigned col_num,
1417 off_t size)
1418 {
1419 char *filename = column_filename(t, col_num);
1420 int ret = para_truncate(filename, size);
1421 free(filename);
1422 return ret;
1423 }
1424
1425 static int delete_disk_storage_file(const struct osl_table *t, unsigned col_num,
1426 const char *ds_name)
1427 {
1428 char *dirname, *filename = disk_storage_path(t, col_num, ds_name);
1429 int ret = unlink(filename);
1430
1431 PARA_INFO_LOG("deleted %s\n", filename);
1432 free(filename);
1433 if (ret < 0) {
1434 if (errno == ENOENT)
1435 return -E_NOENT;
1436 return -E_UNLINK;
1437 }
1438 if (!(t->desc->flags & OSL_LARGE_TABLE))
1439 return 1;
1440 dirname = disk_storage_dirname(t, col_num, ds_name);
1441 rmdir(dirname);
1442 free(dirname);
1443 return 1;
1444 }
1445
1446 /**
1447 * Add a new row to an osl table and retrieve this row.
1448 *
1449 * \param t Pointer to an open osl table.
1450 * \param objects Array of objects to be added.
1451 * \param row Result pointer.
1452 *
1453 * The \a objects parameter must point to an array containing one object per
1454 * column. The order of the objects in the array is given by the table
1455 * description of \a table. Several sanity checks are performed during object
1456 * insertion and the function returns without modifying the table if any of
1457 * these tests fail. In fact, it is atomic in the sense that it either
1458 * succeeds or leaves the table unchanged (i.e. either all or none of the
1459 * objects are added to the table).
1460 *
1461 * It is considered an error if an object is added to a column with associated
1462 * rbtree if this object is equal to an object already contained in that column
1463 * (i.e. the compare function for the column's rbtree returns zero).
1464 *
1465 * Possible errors include: \p E_RB_KEY_EXISTS, \p E_BAD_DATA_SIZE.
1466 *
1467 * \return Positive on success, negative on errors.
1468 *
1469 * \sa struct osl_table_description, osl_compare_func, osl_add_row().
1470 */
1471 int osl_add_and_get_row(struct osl_table *t, struct osl_object *objects,
1472 struct osl_row **row)
1473 {
1474 int i, ret;
1475 char *ds_name = NULL;
1476 struct rb_node **rb_parents = NULL, ***rb_links = NULL;
1477 char *new_index_entry = NULL;
1478 struct osl_object *volatile_objs = NULL;
1479 const struct osl_column_description *cd;
1480
1481 if (!t)
1482 return -E_BAD_TABLE;
1483 rb_parents = para_malloc(t->num_rbtrees * sizeof(struct rn_node*));
1484 rb_links = para_malloc(t->num_rbtrees * sizeof(struct rn_node**));
1485 if (t->num_mapped_columns)
1486 new_index_entry = para_malloc(t->index_entry_size);
1487 /* pass 1: sanity checks */
1488 PARA_DEBUG_LOG("sanity tests: %p:%p\n", objects[0].data,
1489 objects[1].data);
1490 FOR_EACH_COLUMN(i, t->desc, cd) {
1491 enum osl_storage_type st = cd->storage_type;
1492 enum osl_storage_flags sf = cd->storage_flags;
1493
1494 // ret = -E_NULL_OBJECT;
1495 // if (!objects[i])
1496 // goto out;
1497 if (st == OSL_DISK_STORAGE)
1498 continue;
1499 if (sf & OSL_RBTREE) {
1500 unsigned rbtree_num = t->columns[i].rbtree_num;
1501 ret = -E_RB_KEY_EXISTS;
1502 PARA_DEBUG_LOG("checking whether %p exists\n",
1503 objects[i].data);
1504 if (search_rbtree(objects + i, t, i,
1505 &rb_parents[rbtree_num],
1506 &rb_links[rbtree_num]) > 0)
1507 goto out;
1508 }
1509 if (sf & OSL_FIXED_SIZE) {
1510 PARA_DEBUG_LOG("fixed size. need: %zu, have: %d\n",
1511 objects[i].size, cd->data_size);
1512 ret = -E_BAD_DATA_SIZE;
1513 if (objects[i].size != cd->data_size)
1514 goto out;
1515 }
1516 }
1517 if (t->num_disk_storage_columns)
1518 ds_name = disk_storage_name_of_object(t,
1519 &objects[t->disk_storage_name_column]);
1520 ret = unmap_table(t, OSL_MARK_CLEAN);
1521 if (ret < 0)
1522 goto out;
1523 PARA_DEBUG_LOG("sanity tests passed%s\n", "");
1524 /* pass 2: create data files, append map data */
1525 FOR_EACH_COLUMN(i, t->desc, cd) {
1526 enum osl_storage_type st = cd->storage_type;
1527 if (st == OSL_NO_STORAGE)
1528 continue;
1529 if (st == OSL_MAPPED_STORAGE) {
1530 uint32_t new_size;
1531 struct osl_column *col = &t->columns[i];
1532 PARA_DEBUG_LOG("appending object of size %zu\n",
1533 objects[i].size);
1534 ret = append_map_file(t, i, objects + i, &new_size);
1535 if (ret < 0)
1536 goto rollback;
1537 update_index_entry(new_index_entry, col, new_size,
1538 objects[i].size);
1539 continue;
1540 }
1541 /* DISK_STORAGE */
1542 ret = write_disk_storage_file(t, i, objects + i, ds_name);
1543 if (ret < 0)
1544 goto rollback;
1545 }
1546 ret = append_index_entry(t, new_index_entry);
1547 if (ret < 0)
1548 goto rollback;
1549 ret = map_table(t, MAP_TBL_FL_VERIFY_INDEX);
1550 if (ret < 0) { /* truncate index and rollback changes */
1551 char *filename = index_filename(t->desc);
1552 para_truncate(filename, t->index_entry_size);
1553 free(filename);
1554 goto rollback;
1555 }
1556 /* pass 3: add entry to rbtrees */
1557 if (t->num_volatile_columns) {
1558 volatile_objs = para_calloc(t->num_volatile_columns
1559 * sizeof(struct osl_object));
1560 FOR_EACH_VOLATILE_COLUMN(i, t, cd)
1561 volatile_objs[t->columns[i].volatile_num] = objects[i];
1562 }
1563 t->num_rows++;
1564 PARA_DEBUG_LOG("adding new entry as row #%d\n", t->num_rows - 1);
1565 ret = add_row_to_rbtrees(t, t->num_rows - 1, volatile_objs, row);
1566 if (ret < 0)
1567 goto out;
1568 PARA_DEBUG_LOG("added new entry as row #%d\n", t->num_rows - 1);
1569 ret = 1;
1570 goto out;
1571 rollback: /* rollback all changes made, ignore further errors */
1572 for (i--; i >= 0; i--) {
1573 cd = get_column_description(t->desc, i);
1574 enum osl_storage_type st = cd->storage_type;
1575 if (st == OSL_NO_STORAGE)
1576 continue;
1577
1578 if (st == OSL_MAPPED_STORAGE)
1579 truncate_mapped_file(t, i, objects[i].size);
1580 else /* disk storage */
1581 delete_disk_storage_file(t, i, ds_name);
1582 }
1583 /* ignore error and return previous error value */
1584 map_table(t, MAP_TBL_FL_VERIFY_INDEX);
1585 out:
1586 free(new_index_entry);
1587 free(ds_name);
1588 free(rb_parents);
1589 free(rb_links);
1590 return ret;
1591 }
1592
1593 /**
1594 * Add a new row to an osl table.
1595 *
1596 * \param t Same meaning as osl_add_and_get_row().
1597 * \param objects Same meaning as osl_add_and_get_row().
1598 *
1599 * \return The return value of the underlying call to osl_add_and_get_row().
1600 *
1601 * This is equivalent to osl_add_and_get_row(t, objects, NULL).
1602 */
1603 int osl_add_row(struct osl_table *t, struct osl_object *objects)
1604 {
1605 return osl_add_and_get_row(t, objects, NULL);
1606 }
1607
1608 /**
1609 * Retrieve an object identified by row and column
1610 *
1611 * \param t Pointer to an open osl table.
1612 * \param r Pointer to the row.
1613 * \param col_num The column number.
1614 * \param object The result pointer.
1615 *
1616 * The column determined by \a col_num must be of type \p OSL_MAPPED_STORAGE
1617 * or \p OSL_NO_STORAGE, i.e. no disk storage objects may be retrieved by this
1618 * function.
1619 *
1620 * \return Positive if object was found, negative on errors. Possible errors
1621 * include: \p E_BAD_TABLE, \p E_BAD_STORAGE_TYPE.
1622 *
1623 * \sa osl_storage_type, osl_open_disk_object().
1624 */
1625 int osl_get_object(const struct osl_table *t, const struct osl_row *r,
1626 unsigned col_num, struct osl_object *object)
1627 {
1628 const struct osl_column_description *cd;
1629
1630 if (!t)
1631 return -E_BAD_TABLE;
1632 cd = get_column_description(t->desc, col_num);
1633 /* col must not be disk storage */
1634 if (cd->storage_type == OSL_DISK_STORAGE)
1635 return -E_BAD_STORAGE_TYPE;
1636 if (cd->storage_type == OSL_MAPPED_STORAGE)
1637 return get_mapped_object(t, col_num, r->id, object);
1638 /* volatile */
1639 *object = r->volatile_objects[t->columns[col_num].volatile_num];
1640 return 1;
1641 }
1642
1643 static int mark_mapped_object_invalid(const struct osl_table *t, uint32_t id,
1644 unsigned col_num)
1645 {
1646 struct osl_object obj;
1647 char *p;
1648 int ret = get_mapped_object(t, col_num, id, &obj);
1649
1650 if (ret < 0)
1651 return ret;
1652 p = obj.data;
1653 p--;
1654 *p = 0xff;
1655 return 1;
1656 }
1657
1658 /**
1659 * Delete a row from an osl table.
1660 *
1661 * \param t Pointer to an open osl table.
1662 * \param row Pointer to the row to delete.
1663 *
1664 * This removes all disk storage objects, removes all rbtree nodes, and frees
1665 * all volatile objects belonging to the given row. For mapped columns, the
1666 * data is merely marked invalid and may be pruned from time to time by
1667 * para_fsck.
1668 *
1669 * \return Positive on success, negative on errors. Possible errors include:
1670 * \p E_BAD_TABLE, errors returned by osl_get_object().
1671 */
1672 int osl_del_row(struct osl_table *t, struct osl_row *row)
1673 {
1674 struct osl_row *r = row;
1675 int i, ret;
1676 const struct osl_column_description *cd;
1677
1678 if (!t)
1679 return -E_BAD_TABLE;
1680 PARA_INFO_LOG("deleting row %p\n", row);
1681
1682 if (t->num_disk_storage_columns) {
1683 char *ds_name;
1684 ret = disk_storage_name_of_row(t, r, &ds_name);
1685 if (ret < 0)
1686 goto out;
1687 FOR_EACH_DISK_STORAGE_COLUMN(i, t, cd)
1688 delete_disk_storage_file(t, i, ds_name);
1689 free(ds_name);
1690 }
1691 FOR_EACH_COLUMN(i, t->desc, cd) {
1692 struct osl_column *col = t->columns + i;
1693 enum osl_storage_type st = cd->storage_type;
1694 remove_rb_node(t, i, r);
1695 if (st == OSL_MAPPED_STORAGE) {
1696 mark_mapped_object_invalid(t, r->id, i);
1697 continue;
1698 }
1699 if (st == OSL_NO_STORAGE)
1700 free(r->volatile_objects[col->volatile_num].data);
1701 }
1702 if (t->num_mapped_columns) {
1703 ret = mark_row_invalid(t, r->id);
1704 if (ret < 0)
1705 goto out;
1706 t->num_invalid_rows++;
1707 } else
1708 t->num_rows--;
1709 ret = 1;
1710 out:
1711 free(r->volatile_objects);
1712 free(r);
1713 return ret;
1714 }
1715
1716 /* test if column has an rbtree */
1717 static int check_rbtree_col(const struct osl_table *t, unsigned col_num,
1718 struct osl_column **col)
1719 {
1720 if (!t)
1721 return -E_BAD_TABLE;
1722 if (!(get_column_description(t->desc, col_num)->storage_flags & OSL_RBTREE))
1723 return -E_BAD_STORAGE_FLAGS;
1724 *col = t->columns + col_num;
1725 return 1;
1726 }
1727
1728 /**
1729 * Get the row that contains the given object.
1730 *
1731 * \param t Pointer to an open osl table.
1732 * \param col_num The number of the column to be searched.
1733 * \param obj The object to be looked up.
1734 * \param result Points to the row containing \a obj.
1735 *
1736 * Lookup \a obj in \a t and return the row containing \a obj. The column
1737 * specified by \a col_num must have an associated rbtree.
1738 *
1739 * \return Positive on success, negative on errors. If an error occured, \a
1740 * result is set to \p NULL. Possible errors include: \p E_BAD_TABLE, \p
1741 * E_BAD_STORAGE_FLAGS, errors returned by get_mapped_object(), \p
1742 * E_RB_KEY_NOT_FOUND.
1743 *
1744 * \sa osl_storage_flags
1745 */
1746 int osl_get_row(const struct osl_table *t, unsigned col_num,
1747 const struct osl_object *obj, struct osl_row **result)
1748 {
1749 int ret;
1750 struct rb_node *node;
1751 struct osl_row *row;
1752 struct osl_column *col;
1753
1754 *result = NULL;
1755 ret = check_rbtree_col(t, col_num, &col);
1756 if (ret < 0)
1757 return ret;
1758 ret = search_rbtree(obj, t, col_num, &node, NULL);
1759 if (ret < 0)
1760 return ret;
1761 row = get_row_pointer(node, t->columns[col_num].rbtree_num);
1762 *result = row;
1763 return 1;
1764 }
1765
1766 static int rbtree_loop(struct osl_column *col, void *private_data,
1767 osl_rbtree_loop_func *func)
1768 {
1769 struct rb_node *n;
1770
1771 for (n = rb_first(&col->rbtree); n; n = rb_next(n)) {
1772 struct osl_row *r = get_row_pointer(n, col->rbtree_num);
1773 int ret = func(r, private_data);
1774 if (ret < 0)
1775 return ret;
1776 }
1777 return 1;
1778 }
1779
1780 static int rbtree_loop_reverse(struct osl_column *col, void *private_data,
1781 osl_rbtree_loop_func *func)
1782 {
1783 struct rb_node *n;
1784
1785 for (n = rb_last(&col->rbtree); n; n = rb_prev(n)) {
1786 struct osl_row *r = get_row_pointer(n, col->rbtree_num);
1787 int ret = func(r, private_data);
1788 if (ret < 0)
1789 return ret;
1790 }
1791 return 1;
1792 }
1793
1794 /**
1795 * Loop over all nodes in an rbtree.
1796 *
1797 * \param t Pointer to an open osl table.
1798 * \param col_num The column to use for iterating over the elements.
1799 * \param private_data Pointer that gets passed to \a func.
1800 * \param func The function to be called for each node in the rbtree.
1801 *
1802 * This function does an in-order walk of the rbtree associated with \a
1803 * col_num. It is an error if the \p OSL_RBTREE flag is not set for this
1804 * column. For each node in the rbtree, the given function \a func is called
1805 * with two \p void* pointers as arguments: The first argument points to the
1806 * row that contains the object corresponding to the rbtree node currently
1807 * traversed, and the \a private_data pointer is passed to \a func as the
1808 * second argument. The loop terminates either if \a func returns a negative
1809 * value, or if all nodes of the tree have been visited.
1810 *
1811 *
1812 * \return Positive on success, negative on errors. If the termination of the
1813 * loop was caused by \a func returning a negative value, this value is
1814 * returned.
1815 *
1816 * \sa osl_storage_flags, osl_rbtree_loop_reverse(), osl_compare_func.
1817 */
1818 int osl_rbtree_loop(const struct osl_table *t, unsigned col_num,
1819 void *private_data, osl_rbtree_loop_func *func)
1820 {
1821 struct osl_column *col;
1822
1823 int ret = check_rbtree_col(t, col_num, &col);
1824 if (ret < 0)
1825 return ret;
1826 return rbtree_loop(col, private_data, func);
1827 }
1828
1829 /**
1830 * Loop over all nodes in an rbtree in reverse order.
1831 *
1832 * \param t Identical meaning as in \p osl_rbtree_loop().
1833 * \param col_num Identical meaning as in \p osl_rbtree_loop().
1834 * \param private_data Identical meaning as in \p osl_rbtree_loop().
1835 * \param func Identical meaning as in \p osl_rbtree_loop().
1836 *
1837 * This function is identical to \p osl_rbtree_loop(), the only difference
1838 * is that the tree is walked in reverse order.
1839 *
1840 * \return The same return value as \p osl_rbtree_loop().
1841 *
1842 * \sa osl_rbtree_loop().
1843 */
1844 int osl_rbtree_loop_reverse(const struct osl_table *t, unsigned col_num,
1845 void *private_data, osl_rbtree_loop_func *func)
1846 {
1847 struct osl_column *col;
1848
1849 int ret = check_rbtree_col(t, col_num, &col);
1850 if (ret < 0)
1851 return ret;
1852 return rbtree_loop_reverse(col, private_data, func);
1853 }
1854
1855 /* TODO: Rollback changes on errors */
1856 static int rename_disk_storage_objects(struct osl_table *t,
1857 struct osl_object *old_obj, struct osl_object *new_obj)
1858 {
1859 int i, ret;
1860 const struct osl_column_description *cd;
1861 char *old_ds_name, *new_ds_name;
1862
1863 if (!t->num_disk_storage_columns)
1864 return 1; /* nothing to do */
1865 if (old_obj->size == new_obj->size && !memcmp(new_obj->data,
1866 old_obj->data, new_obj->size))
1867 return 1; /* object did not change */
1868 old_ds_name = disk_storage_name_of_object(t, old_obj);
1869 new_ds_name = disk_storage_name_of_object(t, new_obj);
1870 FOR_EACH_DISK_STORAGE_COLUMN(i, t, cd) {
1871 char *old_filename, *new_filename;
1872 ret = create_disk_storage_object_dir(t, i, new_ds_name);
1873 if (ret < 0)
1874 goto out;
1875 old_filename = disk_storage_path(t, i, old_ds_name);
1876 new_filename = disk_storage_path(t, i, new_ds_name);
1877 ret = para_rename(old_filename, new_filename);
1878 free(old_filename);
1879 free(new_filename);
1880 if (ret < 0)
1881 goto out;
1882 }
1883 ret = 1;
1884 out:
1885 free(old_ds_name);
1886 free(new_ds_name);
1887 return ret;
1888
1889 }
1890
1891 /**
1892 * Change an object in an osl table.
1893 *
1894 * \param t Pointer to an open osl table.
1895 * \param r Pointer to the row containing the object to be updated.
1896 * \param col_num Number of the column containing the object to be updated.
1897 * \param obj Pointer to the replacement object.
1898 *
1899 * This function gets rid of all references to the old object. This includes
1900 * removal of the rbtree node in case there is an rbtree associated with \a
1901 * col_num. It then inserts \a obj into the table and the rbtree if neccessary.
1902 *
1903 * If the \p OSL_RBTREE flag is set for \a col_num, you \b MUST call this
1904 * function in order to change the contents of an object, even for volatile or
1905 * mapped columns of constant size (which may be updated directly if \p
1906 * OSL_RBTREE is not set). Otherwise the rbtree might become corrupted.
1907 *
1908 * \return Positive on success, negative on errors. Possible errors include: \p
1909 * E_BAD_TABLE, \p E_RB_KEY_EXISTS, \p E_BAD_SIZE, \p E_NOENT, \p E_UNLINK,
1910 * errors returned by para_write_file(), \p E_MKDIR.
1911 */
1912 int osl_update_object(struct osl_table *t, const struct osl_row *r,
1913 unsigned col_num, struct osl_object *obj)
1914 {
1915 struct osl_column *col;
1916 const struct osl_column_description *cd;
1917 int ret;
1918
1919 if (!t)
1920 return -E_BAD_TABLE;
1921 col = &t->columns[col_num];
1922 cd = get_column_description(t->desc, col_num);
1923 if (cd->storage_flags & OSL_RBTREE) {
1924 if (search_rbtree(obj, t, col_num, NULL, NULL) > 0)
1925 return -E_RB_KEY_EXISTS;
1926 }
1927 if (cd->storage_flags & OSL_FIXED_SIZE) {
1928 if (obj->size != cd->data_size)
1929 return -E_BAD_SIZE;
1930 }
1931 remove_rb_node(t, col_num, r);
1932 if (cd->storage_type == OSL_NO_STORAGE) { /* TODO: If fixed size, reuse object? */
1933 free(r->volatile_objects[col->volatile_num].data);
1934 r->volatile_objects[col->volatile_num] = *obj;
1935 } else if (cd->storage_type == OSL_DISK_STORAGE) {
1936 char *ds_name;
1937 ret = disk_storage_name_of_row(t, r, &ds_name);
1938 if (ret < 0)
1939 return ret;
1940 ret = delete_disk_storage_file(t, col_num, ds_name);
1941 if (ret < 0 && ret != -E_NOENT) {
1942 free(ds_name);
1943 return ret;
1944 }
1945 ret = write_disk_storage_file(t, col_num, obj, ds_name);
1946 free(ds_name);
1947 if (ret < 0)
1948 return ret;
1949 } else { /* mapped storage */
1950 struct osl_object old_obj;
1951 ret = get_mapped_object(t, col_num, r->id, &old_obj);
1952 if (ret < 0)
1953 return ret;
1954 /*
1955 * If the updated column is the disk storage name column, the
1956 * disk storage name changes, so we have to rename all disk
1957 * storage objects accordingly.
1958 */
1959 if (col_num == t->disk_storage_name_column) {
1960 ret = rename_disk_storage_objects(t, &old_obj, obj);
1961 if (ret < 0)
1962 return ret;
1963 }
1964 if (cd->storage_flags & OSL_FIXED_SIZE)
1965 memcpy(old_obj.data, obj->data, cd->data_size);
1966 else { /* TODO: if the size doesn't change, use old space */
1967 uint32_t new_data_map_size;
1968 char *index_entry;
1969 ret = get_index_entry_start(t, r->id, &index_entry);
1970 if (ret < 0)
1971 return ret;
1972 ret = mark_mapped_object_invalid(t, r->id, col_num);
1973 if (ret < 0)
1974 return ret;
1975 ret = append_map_file(t, col_num, obj,
1976 &new_data_map_size);
1977 if (ret < 0)
1978 return ret;
1979 update_index_entry(index_entry, col, new_data_map_size,
1980 obj->size);
1981 }
1982 }
1983 if (cd->storage_flags & OSL_RBTREE) {
1984 ret = insert_rbtree(t, col_num, r, obj);
1985 if (ret < 0)
1986 return ret;
1987 }
1988 return 1;
1989 }
1990
1991 /**
1992 * Retrieve an object of type \p OSL_DISK_STORAGE by row and column.
1993 *
1994 * \param t Pointer to an open osl table.
1995 * \param r Pointer to the row containing the object.
1996 * \param col_num The column number.
1997 * \param obj Points to the result upon successful return.
1998 *
1999 * For columns of type \p OSL_DISK_STORAGE, this function must be used to
2000 * retrieve one of its containing objects. Afterwards, osl_close_disk_object()
2001 * must be called in order to deallocate the resources.
2002 *
2003 * \return Positive on success, negative on errors. Possible errors include:
2004 * \p E_BAD_TABLE, \p E_BAD_STORAGE_TYPE, errors returned by osl_get_object().
2005 *
2006 * \sa osl_get_object(), osl_storage_type, osl_close_disk_object().
2007 */
2008 int osl_open_disk_object(const struct osl_table *t, const struct osl_row *r,
2009 unsigned col_num, struct osl_object *obj)
2010 {
2011 const struct osl_column_description *cd;
2012 char *ds_name, *filename;
2013 int ret;
2014
2015 if (!t)
2016 return -E_BAD_TABLE;
2017 cd = get_column_description(t->desc, col_num);
2018 if (cd->storage_type != OSL_DISK_STORAGE)
2019 return -E_BAD_STORAGE_TYPE;
2020
2021 ret = disk_storage_name_of_row(t, r, &ds_name);
2022 if (ret < 0)
2023 return ret;
2024 filename = disk_storage_path(t, col_num, ds_name);
2025 free(ds_name);
2026 PARA_DEBUG_LOG("filename: %s\n", filename);
2027 ret = mmap_full_file(filename, O_RDONLY, obj);
2028 free(filename);
2029 return ret;
2030 }
2031
2032 /**
2033 * Free resources that were allocated during osl_open_disk_object().
2034 *
2035 * \param obj Pointer to the object previously returned by open_disk_object().
2036 *
2037 * \return The return value of the underlying call to para_munmap().
2038 *
2039 * \sa para_munmap().
2040 */
2041 int osl_close_disk_object(struct osl_object *obj)
2042 {
2043 return para_munmap(obj->data, obj->size);
2044 }
2045
2046 /**
2047 * Get the number of rows of the given table.
2048 *
2049 * \param t Pointer to an open osl table.
2050 * \param num_rows Result is returned here.
2051 *
2052 * The number of rows returned via \a num_rows excluding any invalid rows.
2053 *
2054 * \return Positive on success, \p -E_BAD_TABLE if \a t is \p NULL.
2055 */
2056 int osl_get_num_rows(const struct osl_table *t, unsigned *num_rows)
2057 {
2058 if (!t)
2059 return -E_BAD_TABLE;
2060 assert(t->num_rows >= t->num_invalid_rows);
2061 *num_rows = t->num_rows - t->num_invalid_rows;
2062 return 1;
2063 }
2064
2065 /**
2066 * Get the rank of a row.
2067 *
2068 * \param t An open osl table.
2069 * \param r The row to get the rank of.
2070 * \param col_num The number of an rbtree column.
2071 * \param rank Result pointer.
2072 *
2073 * The rank is, by definition, the position of the row in the linear order
2074 * determined by an inorder tree walk of the rbtree associated with column
2075 * number \a col_num of \a table.
2076 *
2077 * \return Positive on success, negative on errors.
2078 *
2079 * \sa osl_get_nth_row().
2080 */
2081 int osl_get_rank(const struct osl_table *t, struct osl_row *r,
2082 unsigned col_num, unsigned *rank)
2083 {
2084 struct osl_object obj;
2085 struct osl_column *col;
2086 struct rb_node *node;
2087 int ret = check_rbtree_col(t, col_num, &col);
2088
2089 if (ret < 0)
2090 return ret;
2091 ret = osl_get_object(t, r, col_num, &obj);
2092 if (ret < 0)
2093 return ret;
2094 ret = search_rbtree(&obj, t, col_num, &node, NULL);
2095 if (ret < 0)
2096 return ret;
2097 ret = rb_rank(node, rank);
2098 if (ret < 0)
2099 return -E_BAD_ROW;
2100 return 1;
2101 }
2102
2103 /**
2104 * Get the row with n-th greatest value.
2105 *
2106 * \param t Pointer to an open osl table.
2107 * \param col_num The column number.
2108 * \param n The rank of the desired row.
2109 * \param result Row is returned here.
2110 *
2111 * Retrieve the n-th order statistic with respect to the compare function
2112 * of the rbtree column \a col_num. In other words, get that row with
2113 * \a n th greatest value in column \a col_num. It's an error if
2114 * \a col_num is not a rbtree column, or if \a n is larger than the
2115 * number of rows in the table.
2116 *
2117 * \return Positive on success, negative on errors. Possible errors:
2118 * \p E_BAD_TABLE, \p E_BAD_STORAGE_FLAGS, \p E_RB_KEY_NOT_FOUND.
2119 *
2120 * \sa osl_storage_flags, osl_compare_func, osl_get_row(),
2121 * osl_rbtree_last_row(), osl_rbtree_first_row(), osl_get_rank().
2122 */
2123 int osl_get_nth_row(const struct osl_table *t, unsigned col_num,
2124 unsigned n, struct osl_row **result)
2125 {
2126 struct osl_column *col;
2127 struct rb_node *node;
2128 int ret = check_rbtree_col(t, col_num, &col);
2129
2130 if (ret < 0)
2131 return ret;
2132 node = rb_nth(col->rbtree.rb_node, n);
2133 if (!node)
2134 return -E_RB_KEY_NOT_FOUND;
2135 *result = get_row_pointer(node, col->rbtree_num);
2136 return 1;
2137 }
2138
2139 /**
2140 * Get the row corresponding to the smallest rbtree node of a column.
2141 *
2142 * \param t An open rbtree table.
2143 * \param col_num The number of the rbtree column.
2144 * \param result A pointer to the first row is returned here.
2145 *
2146 * The rbtree node of the smallest object (with respect to the corresponding
2147 * compare function) is selected and the row containing this object is
2148 * returned. It is an error if \a col_num refers to a column without an
2149 * associated rbtree.
2150 *
2151 * \return Positive on success, negative on errors.
2152 *
2153 * \sa osl_get_nth_row(), osl_rbtree_last_row().
2154 */
2155 int osl_rbtree_first_row(const struct osl_table *t, unsigned col_num,
2156 struct osl_row **result)
2157 {
2158 return osl_get_nth_row(t, col_num, 1, result);
2159 }
2160
2161 /**
2162 * Get the row corresponding to the greatest rbtree node of a column.
2163 *
2164 * \param t The same meaning as in \p osl_rbtree_first_row().
2165 * \param col_num The same meaning as in \p osl_rbtree_first_row().
2166 * \param result The same meaning as in \p osl_rbtree_first_row().
2167 *
2168 * This function works just like osl_rbtree_first_row(), the only difference
2169 * is that the row containing the greatest rather than the smallest object is
2170 * returned.
2171 *
2172 * \return Positive on success, negative on errors.
2173 *
2174 * \sa osl_get_nth_row(), osl_rbtree_first_row().
2175 */
2176 int osl_rbtree_last_row(const struct osl_table *t, unsigned col_num,
2177 struct osl_row **result)
2178 {
2179 unsigned num_rows;
2180 int ret = osl_get_num_rows(t, &num_rows);
2181
2182 if (ret < 0)
2183 return ret;
2184 return osl_get_nth_row(t, col_num, num_rows, result);
2185 }