osl.c for_each_file_in_dir(): Move struct stat to inner loop.
[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 /**
16 * A wrapper for lseek(2).
17 *
18 * \param fd The filedescriptor whose offset is to be to repositioned.
19 * \param offset A value-result parameter.
20 * \param whence Usual repositioning directive.
21 *
22 * Reposition the offset of the file descriptor \a fd to the argument \a offset
23 * according to the directive \a whence. Upon successful return, \a offset
24 * contains the resulting offset location as measured in bytes from the
25 * beginning of the file.
26 *
27 * \return Positive on success. Otherwise, the function returns \p -E_LSEEK.
28 *
29 * \sa lseek(2).
30 */
31 int para_lseek(int fd, off_t *offset, int whence)
32 {
33 *offset = lseek(fd, *offset, whence);
34 int ret = -E_LSEEK;
35 if (*offset == -1)
36 return ret;
37 return 1;
38 }
39
40 /**
41 * Wrapper for the write system call.
42 *
43 * \param fd The file descriptor to write to.
44 * \param buf The buffer to write.
45 * \param size The length of \a buf in bytes.
46 *
47 * This function writes out the given bufffer and retries if an interrupt
48 * occured during the write.
49 *
50 * \return On success, the number of bytes written is returned, otherwise, the
51 * function returns \p -E_WRITE.
52 *
53 * \sa write(2).
54 */
55 ssize_t para_write(int fd, const void *buf, size_t size)
56 {
57 ssize_t ret;
58
59 for (;;) {
60 ret = write(fd, buf, size);
61 if ((ret < 0) && (errno == EAGAIN || errno == EINTR))
62 continue;
63 return ret >= 0? ret : -E_WRITE;
64 }
65 }
66
67 /**
68 * Write the whole buffer to a file descriptor.
69 *
70 * \param fd The file descriptor to write to.
71 * \param buf The buffer to write.
72 * \param size The length of \a buf in bytes.
73 *
74 * This function writes the given buffer and continues on short writes and
75 * when interrupted by a signal.
76 *
77 * \return Positive on success, negative on errors. Possible errors: any
78 * errors returned by para_write().
79 *
80 * \sa para_write().
81 */
82 ssize_t para_write_all(int fd, const void *buf, size_t size)
83 {
84 // PARA_DEBUG_LOG("writing %zu bytes\n", size);
85 const char *b = buf;
86 while (size) {
87 ssize_t ret = para_write(fd, b, size);
88 // PARA_DEBUG_LOG("ret: %zd\n", ret);
89 if (ret < 0)
90 return ret;
91 b += ret;
92 size -= ret;
93 }
94 return 1;
95 }
96 /**
97 * Wrapper for the open(2) system call.
98 *
99 * \param path The filename.
100 * \param flags The usual open(2) flags.
101 * \param mode Specifies the permissions to use.
102 *
103 * The mode parameter must be specified when O_CREAT is in the flags, and is ignored
104 * otherwise.
105 *
106 * \return Positive on success, negative on errors. Possible errors: \p
107 * E_EXIST, \p E_ISDIR, \p E_NOENT, \p E_OSL_PERM.
108 *
109 * \sa open(2).
110 */
111 int para_open(const char *path, int flags, mode_t mode)
112 {
113 PARA_DEBUG_LOG("opening %s\n", path);
114 int ret = open(path, flags, mode);
115
116 if (ret >= 0)
117 return ret;
118 switch (errno) {
119 case EEXIST:
120 ret = -E_EXIST;
121 break;
122 case EISDIR:
123 ret = -E_ISDIR;
124 break;
125 case ENOENT:
126 ret = -E_NOENT;
127 break;
128 case EPERM:
129 ret = -E_OSL_PERM;
130 break;
131 };
132 PARA_ERROR_LOG("failed to open %s: %s\n", path, strerror(errno));
133 return ret;
134 }
135
136 /**
137 * Open a file, write the given buffer and close the file.
138 *
139 * \param filename Full path to the file to open.
140 * \param buf The buffer to write to the file.
141 * \param size The size of \a buf.
142 *
143 * \return Positive on success, negative on errors. Possible errors include:
144 * any errors from para_open() or para_write().
145 *
146 * \sa para_open(), para_write().
147 */
148 int para_write_file(const char *filename, const void *buf, size_t size)
149 {
150 int ret, fd;
151
152 ret = para_open(filename, O_WRONLY | O_CREAT | O_EXCL, 0644);
153 if (ret < 0)
154 return ret;
155 fd = ret;
156 ret = para_write_all(fd, buf, size);
157 if (ret < 0)
158 goto out;
159 ret = 1;
160 out:
161 close(fd);
162 return ret;
163 }
164
165 static int append_file(const char *filename, char *header, size_t header_size,
166 char *data, size_t data_size, uint32_t *new_pos)
167 {
168 int ret, fd;
169
170 // PARA_DEBUG_LOG("appending %zu + %zu bytes\n", header_size, data_size);
171 ret = para_open(filename, O_WRONLY | O_CREAT | O_APPEND, 0644);
172 if (ret < 0)
173 return ret;
174 fd = ret;
175 if (header && header_size) {
176 ret = para_write_all(fd, header, header_size);
177 if (ret < 0)
178 goto out;
179 }
180 ret = para_write_all(fd, data, data_size);
181 if (ret < 0)
182 goto out;
183 if (new_pos) {
184 off_t offset = 0;
185 ret = para_lseek(fd, &offset, SEEK_END);
186 if (ret < 0)
187 goto out;
188 // PARA_DEBUG_LOG("new file size: " FMT_OFF_T "\n", offset);
189 *new_pos = offset;
190 }
191 ret = 1;
192 out:
193 close(fd);
194 return ret;
195 }
196
197 /**
198 * Map a file into memory.
199 *
200 * \param path Name of the regular file to map.
201 * \param open_mode Either \p O_RDONLY or \p O_RDWR.
202 * \param obj On success, the mapping is returned here.
203 *
204 * \return Positive on success, negative on errors. Possible errors include: \p
205 * E_FSTAT, any errors returned by para_open(), \p E_EMPTY, \p E_MMAP.
206 *
207 * \sa para_open(), mmap(2).
208 */
209 int mmap_full_file(const char *path, int open_mode, struct osl_object *obj)
210 {
211 int fd, ret, mmap_prot, mmap_flags;
212 struct stat file_status;
213
214 if (open_mode == O_RDONLY) {
215 mmap_prot = PROT_READ;
216 mmap_flags = MAP_PRIVATE;
217 } else {
218 mmap_prot = PROT_READ | PROT_WRITE;
219 mmap_flags = MAP_SHARED;
220 }
221 ret = para_open(path, open_mode, 0);
222 if (ret < 0)
223 return ret;
224 fd = ret;
225 ret = -E_FSTAT;
226 if (fstat(fd, &file_status) < 0)
227 goto out;
228 obj->size = file_status.st_size;
229 ret = -E_EMPTY;
230 PARA_DEBUG_LOG("%s: size %zu\n", path, obj->size);
231 if (!obj->size)
232 goto out;
233 obj->data = mmap(NULL, obj->size, mmap_prot, mmap_flags, fd, 0);
234 if (obj->data == MAP_FAILED) {
235 obj->data = NULL;
236 ret = -E_MMAP;
237 goto out;
238 }
239 ret = 1;
240 out:
241 close(fd);
242 return ret;
243 }
244
245 /**
246 * Traverse the given directory recursively.
247 *
248 * \param dirname The directory to traverse.
249 * \param func The function to call for each entry.
250 * \param private_data Pointer to an arbitrary data structure.
251 *
252 * For each regular file in \a dirname, the supplied function \a func is
253 * called. The full path of the regular file and the \a private_data pointer
254 * are passed to \a func.
255 *
256 * \return On success, 1 is returned. Otherwise, this function returns a
257 * negative value which indicates the kind of the error.
258 */
259 int for_each_file_in_dir(const char *dirname,
260 int (*func)(const char *, const void *), const void *private_data)
261 {
262 DIR *dir = NULL;
263 struct dirent *entry;
264 /*
265 * Opening the current directory (".") and calling fchdir() to return
266 * is usually faster and more reliable than saving cwd in some buffer
267 * and calling chdir() afterwards (see man 3 getcwd).
268 */
269 int cwd_fd = open(".", O_RDONLY);
270 int ret = -1;
271
272 // PARA_DEBUG_LOG("dirname: %s\n", dirname);
273 if (cwd_fd < 0)
274 return -E_OSL_GETCWD;
275 ret = -E_OSL_CHDIR;
276 if (chdir(dirname) < 0)
277 goto out;
278 ret = -E_OSL_OPENDIR;
279 dir = opendir(".");
280 if (!dir)
281 goto out;
282 /* scan cwd recursively */
283 while ((entry = readdir(dir))) {
284 mode_t m;
285 char *tmp;
286 struct stat s;
287
288 if (!strcmp(entry->d_name, "."))
289 continue;
290 if (!strcmp(entry->d_name, ".."))
291 continue;
292 ret = -E_OSL_LSTAT;
293 if (lstat(entry->d_name, &s) == -1)
294 continue;
295 m = s.st_mode;
296 if (!S_ISREG(m) && !S_ISDIR(m))
297 continue;
298 tmp = make_message("%s/%s", dirname, entry->d_name);
299 if (!S_ISDIR(m)) {
300 ret = func(tmp, private_data);
301 free(tmp);
302 if (ret < 0)
303 goto out;
304 continue;
305 }
306 /* directory */
307 ret = for_each_file_in_dir(tmp, func, private_data);
308 free(tmp);
309 if (ret < 0)
310 goto out;
311 }
312 ret = 1;
313 out:
314 if (dir)
315 closedir(dir);
316 if (fchdir(cwd_fd) < 0 && ret >= 0)
317 ret = -E_OSL_CHDIR;
318 close(cwd_fd);
319 return ret;
320 }
321
322 int para_mkdir(const char *path, mode_t mode)
323 {
324 if (!mkdir(path, mode))
325 return 1;
326 if (errno == EEXIST)
327 return -E_EXIST;
328 if (errno == ENOSPC)
329 return -E_NOSPC;
330 if (errno == ENOTDIR)
331 return -E_NOTDIR;
332 if (errno == EPERM)
333 return E_OSL_PERM;
334 return -E_MKDIR;
335 }
336
337 static int verify_name(const char *name)
338 {
339 if (!name)
340 return -E_BAD_NAME;
341 if (!*name)
342 return -E_BAD_NAME;
343 if (strchr(name, '/'))
344 return -E_BAD_NAME;
345 if (!strcmp(name, ".."))
346 return -E_BAD_NAME;
347 if (!strcmp(name, "."))
348 return -E_BAD_NAME;
349 return 1;
350 }
351
352 /**
353 * Compare two osl objects pointing to unsigned integers of 32 bit size.
354 *
355 * \param obj1 Pointer to the first integer.
356 * \param obj2 Pointer to the second integer.
357 *
358 * \return The values required for an osl compare function.
359 *
360 * \sa osl_compare_func, osl_hash_compare().
361 */
362 int uint32_compare(const struct osl_object *obj1, const struct osl_object *obj2)
363 {
364 uint32_t d1 = read_u32((const char *)obj1->data);
365 uint32_t d2 = read_u32((const char *)obj2->data);
366
367 if (d1 < d2)
368 return 1;
369 if (d1 > d2)
370 return -1;
371 return 0;
372 }
373
374 /**
375 * Compare two osl objects pointing to hash values.
376 *
377 * \param obj1 Pointer to the first hash object.
378 * \param obj2 Pointer to the second hash object.
379 *
380 * \return The values required for an osl compare function.
381 *
382 * \sa osl_compare_func, uint32_compare().
383 */
384 int osl_hash_compare(const struct osl_object *obj1, const struct osl_object *obj2)
385 {
386 return hash_compare((HASH_TYPE *)obj1->data, (HASH_TYPE *)obj2->data);
387 }
388
389 static char *disk_storage_dirname(const struct osl_table *t, unsigned col_num,
390 const char *ds_name)
391 {
392 char *dirname, *column_name = column_filename(t, col_num);
393
394 if (!(t->desc->flags & OSL_LARGE_TABLE))
395 return column_name;
396 dirname = make_message("%s/%.2s", column_name, ds_name);
397 free(column_name);
398 return dirname;
399 }
400
401 static char *disk_storage_name_of_object(const struct osl_table *t,
402 const struct osl_object *obj)
403 {
404 HASH_TYPE hash[HASH_SIZE];
405 hash_object(obj, hash);
406 return disk_storage_name_of_hash(t, hash);
407 }
408
409 static int disk_storage_name_of_row(const struct osl_table *t,
410 const struct osl_row *row, char **name)
411 {
412 struct osl_object obj;
413 int ret = osl_get_object(t, row, t->disk_storage_name_column, &obj);
414
415 if (ret < 0)
416 return ret;
417 *name = disk_storage_name_of_object(t, &obj);
418 return 1;
419 }
420
421 static void column_name_hash(const char *col_name, HASH_TYPE *hash)
422 {
423 return hash_function(col_name, strlen(col_name), hash);
424 }
425
426 static int init_column_descriptions(struct osl_table *t)
427 {
428 int i, j, ret;
429 const struct osl_column_description *cd;
430
431 ret = -E_BAD_TABLE_DESC;
432 ret = verify_name(t->desc->name);
433 if (ret < 0)
434 goto err;
435 ret = -E_BAD_DB_DIR;
436 if (!t->desc->dir)
437 goto err;
438 /* the size of the index header without column descriptions */
439 t->index_header_size = IDX_COLUMN_DESCRIPTIONS;
440 FOR_EACH_COLUMN(i, t->desc, cd) {
441 struct osl_column *col = t->columns + i;
442 if (cd->storage_flags & OSL_RBTREE) {
443 if (!cd->compare_function)
444 return -E_NO_COMPARE_FUNC;
445 }
446 if (cd->storage_type == OSL_NO_STORAGE)
447 continue;
448 ret = -E_NO_COLUMN_NAME;
449 if (!cd->name || !cd->name[0])
450 goto err;
451 ret = verify_name(cd->name);
452 if (ret < 0)
453 goto err;
454 t->index_header_size += index_column_description_size(cd->name);
455 column_name_hash(cd->name, col->name_hash);
456 ret = -E_DUPLICATE_COL_NAME;
457 for (j = i + 1; j < t->desc->num_columns; j++) {
458 const char *name2 = get_column_description(t->desc,
459 j)->name;
460 if (cd->name && name2 && !strcmp(cd->name, name2))
461 goto err;
462 }
463 }
464 return 1;
465 err:
466 return ret;
467 }
468
469 /**
470 * Initialize a struct table from given table description.
471 *
472 * \param desc The description of the osl table.
473 * \param table_ptr Result is returned here.
474 *
475 * This function performs several sanity checks on \p desc and returns if any
476 * of these tests fail. On success, a struct \p osl_table is allocated and
477 * initialized with data derived from \p desc.
478 *
479 * \return Positive on success, negative on errors. Possible errors include: \p
480 * E_BAD_TABLE_DESC, \p E_NO_COLUMN_DESC, \p E_NO_COLUMNS, \p
481 * E_BAD_STORAGE_TYPE, \p E_BAD_STORAGE_FLAGS, \p E_BAD_STORAGE_SIZE, \p
482 * E_NO_UNIQUE_RBTREE_COLUMN, \p E_NO_RBTREE_COL.
483 *
484 * \sa struct osl_table.
485 */
486 int init_table_structure(const struct osl_table_description *desc,
487 struct osl_table **table_ptr)
488 {
489 const struct osl_column_description *cd;
490 struct osl_table *t = para_calloc(sizeof(*t));
491 int i, ret = -E_BAD_TABLE_DESC, have_disk_storage_name_column = 0;
492
493 if (!desc)
494 goto err;
495 PARA_DEBUG_LOG("creating table structure for '%s' from table "
496 "description\n", desc->name);
497 ret = -E_NO_COLUMN_DESC;
498 if (!desc->column_descriptions)
499 goto err;
500 ret = -E_NO_COLUMNS;
501 if (!desc->num_columns)
502 goto err;
503 t->columns = para_calloc(desc->num_columns * sizeof(struct osl_column));
504 t->desc = desc;
505 FOR_EACH_COLUMN(i, t->desc, cd) {
506 enum osl_storage_type st = cd->storage_type;
507 enum osl_storage_flags sf = cd->storage_flags;
508 struct osl_column *col = &t->columns[i];
509
510 ret = -E_BAD_STORAGE_TYPE;
511 if (st != OSL_MAPPED_STORAGE && st != OSL_DISK_STORAGE
512 && st != OSL_NO_STORAGE)
513 goto err;
514 ret = -E_BAD_STORAGE_FLAGS;
515 if (st == OSL_DISK_STORAGE && sf & OSL_RBTREE)
516 goto err;
517 ret = -E_BAD_STORAGE_SIZE;
518 if (sf & OSL_FIXED_SIZE && !cd->data_size)
519 goto err;
520 switch (st) {
521 case OSL_DISK_STORAGE:
522 t->num_disk_storage_columns++;
523 break;
524 case OSL_MAPPED_STORAGE:
525 t->num_mapped_columns++;
526 col->index_offset = t->row_index_size;
527 t->row_index_size += 8;
528 break;
529 case OSL_NO_STORAGE:
530 col->volatile_num = t->num_volatile_columns;
531 t->num_volatile_columns++;
532 break;
533 }
534 if (sf & OSL_RBTREE) {
535 col->rbtree_num = t->num_rbtrees;
536 t->num_rbtrees++;
537 if ((sf & OSL_UNIQUE) && (st == OSL_MAPPED_STORAGE)) {
538 if (!have_disk_storage_name_column)
539 t->disk_storage_name_column = i;
540 have_disk_storage_name_column = 1;
541 }
542 }
543 }
544 ret = -E_NO_UNIQUE_RBTREE_COLUMN;
545 if (t->num_disk_storage_columns && !have_disk_storage_name_column)
546 goto err;
547 ret = -E_NO_RBTREE_COL;
548 if (!t->num_rbtrees)
549 goto err;
550 /* success */
551 PARA_DEBUG_LOG("OK. Index entry size: %u\n", t->row_index_size);
552 ret = init_column_descriptions(t);
553 if (ret < 0)
554 goto err;
555 *table_ptr = t;
556 return 1;
557 err:
558 free(t->columns);
559 free(t);
560 return ret;
561 }
562
563 /**
564 * Read the table description from index header.
565 *
566 * \param map The memory mapping of the index file.
567 * \param desc The values found in the index header are returned here.
568 *
569 * Read the index header, check for the paraslash magic string and the table version number.
570 * Read all information stored in the index header into \a desc.
571 *
572 * \return Positive on success, negative on errors.
573 *
574 * \sa struct osl_table_description, osl_create_table.
575 */
576 int read_table_desc(struct osl_object *map, struct osl_table_description *desc)
577 {
578 char *buf = map->data;
579 uint8_t version;
580 uint16_t header_size;
581 int ret, i;
582 unsigned offset;
583 struct osl_column_description *cd;
584
585 if (map->size < MIN_INDEX_HEADER_SIZE(1))
586 return -E_SHORT_TABLE;
587 if (strncmp(buf + IDX_PARA_MAGIC, PARA_MAGIC, strlen(PARA_MAGIC)))
588 return -E_NO_MAGIC;
589 version = read_u8(buf + IDX_VERSION);
590 if (version < MIN_TABLE_VERSION || version > MAX_TABLE_VERSION)
591 return -E_VERSION_MISMATCH;
592 desc->num_columns = read_u8(buf + IDX_TABLE_FLAGS);
593 desc->flags = read_u8(buf + IDX_TABLE_FLAGS);
594 desc->num_columns = read_u16(buf + IDX_NUM_COLUMNS);
595 PARA_DEBUG_LOG("%u columns\n", desc->num_columns);
596 if (!desc->num_columns)
597 return -E_NO_COLUMNS;
598 header_size = read_u16(buf + IDX_HEADER_SIZE);
599 if (map->size < header_size)
600 return -E_BAD_SIZE;
601 desc->column_descriptions = para_calloc(desc->num_columns
602 * sizeof(struct osl_column_description));
603 offset = IDX_COLUMN_DESCRIPTIONS;
604 FOR_EACH_COLUMN(i, desc, cd) {
605 char *null_byte;
606
607 ret = -E_SHORT_TABLE;
608 if (map->size < offset + MIN_IDX_COLUMN_DESCRIPTION_SIZE) {
609 PARA_ERROR_LOG("map size = %zu < %u = offset + min desc size\n",
610 map->size, offset + MIN_IDX_COLUMN_DESCRIPTION_SIZE);
611 goto err;
612 }
613 cd->storage_type = read_u16(buf + offset + IDX_CD_STORAGE_TYPE);
614 cd->storage_flags = read_u16(buf + offset +
615 IDX_CD_STORAGE_FLAGS);
616 cd->data_size = read_u32(buf + offset + IDX_CD_DATA_SIZE);
617 null_byte = memchr(buf + offset + IDX_CD_NAME, '\0',
618 map->size - offset - IDX_CD_NAME);
619 ret = -E_INDEX_CORRUPTION;
620 if (!null_byte)
621 goto err;
622 cd->name = para_strdup(buf + offset + IDX_CD_NAME);
623 offset += index_column_description_size(cd->name);
624 }
625 if (offset != header_size) {
626 ret = -E_INDEX_CORRUPTION;
627 PARA_ERROR_LOG("real header size = %u != %u = stored header size\n",
628 offset, header_size);
629 goto err;
630 }
631 return 1;
632 err:
633 FOR_EACH_COLUMN(i, desc, cd)
634 free(cd->name);
635 return ret;
636 }
637
638 /*
639 * check whether the table description given by \p t->desc matches the on-disk
640 * table structure stored in the index of \a t.
641 */
642 static int compare_table_descriptions(struct osl_table *t)
643 {
644 int i, ret;
645 struct osl_table_description desc;
646 const struct osl_column_description *cd1, *cd2;
647
648 /* read the on-disk structure into desc */
649 ret = read_table_desc(&t->index_map, &desc);
650 if (ret < 0)
651 return ret;
652 ret = -E_BAD_TABLE_FLAGS;
653 if (desc.flags != t->desc->flags)
654 goto out;
655 ret = E_BAD_COLUMN_NUM;
656 if (desc.num_columns != t->desc->num_columns)
657 goto out;
658 FOR_EACH_COLUMN(i, t->desc, cd1) {
659 cd2 = get_column_description(&desc, i);
660 ret = -E_BAD_STORAGE_TYPE;
661 if (cd1->storage_type != cd2->storage_type)
662 goto out;
663 ret = -E_BAD_STORAGE_FLAGS;
664 if (cd1->storage_flags != cd2->storage_flags) {
665 PARA_ERROR_LOG("sf1 = %u != %u = sf2\n",
666 cd1->storage_flags, cd2->storage_flags);
667 goto out;
668 }
669 ret = -E_BAD_DATA_SIZE;
670 if (cd1->storage_flags & OSL_FIXED_SIZE)
671 if (cd1->data_size != cd2->data_size)
672 goto out;
673 ret = -E_BAD_COLUMN_NAME;
674 if (strcmp(cd1->name, cd2->name))
675 goto out;
676 }
677 PARA_DEBUG_LOG("table description of '%s' matches on-disk data, good\n",
678 t->desc->name);
679 ret = 1;
680 out:
681 FOR_EACH_COLUMN(i, &desc, cd1)
682 free(cd1->name);
683 free(desc.column_descriptions);
684 return ret;
685 }
686
687 static int create_table_index(struct osl_table *t)
688 {
689 char *buf, *filename;
690 int i, ret;
691 size_t size = t->index_header_size;
692 const struct osl_column_description *cd;
693 unsigned offset;
694
695 PARA_INFO_LOG("creating %zu byte index for table %s\n", size,
696 t->desc->name);
697 buf = para_calloc(size);
698 sprintf(buf + IDX_PARA_MAGIC, "%s", PARA_MAGIC);
699 write_u8(buf + IDX_TABLE_FLAGS, t->desc->flags);
700 write_u8(buf + IDX_DIRTY_FLAG, 0);
701 write_u8(buf + IDX_VERSION, CURRENT_TABLE_VERSION);
702 write_u16(buf + IDX_NUM_COLUMNS, t->desc->num_columns);
703 write_u16(buf + IDX_HEADER_SIZE, t->index_header_size);
704 offset = IDX_COLUMN_DESCRIPTIONS;
705 FOR_EACH_COLUMN(i, t->desc, cd) {
706 write_u16(buf + offset + IDX_CD_STORAGE_TYPE,
707 cd->storage_type);
708 write_u16(buf + offset + IDX_CD_STORAGE_FLAGS,
709 cd->storage_flags);
710 if (cd->storage_flags & OSL_FIXED_SIZE)
711 write_u32(buf + offset + IDX_CD_DATA_SIZE,
712 cd->data_size);
713 strcpy(buf + offset + IDX_CD_NAME, cd->name);
714 offset += index_column_description_size(cd->name);
715 }
716 assert(offset = size);
717 filename = index_filename(t->desc);
718 ret = para_write_file(filename, buf, size);
719 free(buf);
720 free(filename);
721 return ret;
722 }
723
724 /**
725 * Create a new osl table.
726 *
727 * \param desc Pointer to the table description.
728 *
729 * \return Positive on success, negative on errors. Possible errors include: \p
730 * E_BAD_TABLE_DESC, \p E_BAD_DB_DIR, \p E_BAD_NAME, \p E_NO_COMPARE_FUNC, \p
731 * E_NO_COLUMN_NAME, \p E_DUPLICATE_COL_NAME, \p E_MKDIR, any errors returned
732 * by para_open().
733 */
734 int osl_create_table(const struct osl_table_description *desc)
735 {
736 const struct osl_column_description *cd;
737 char *table_dir = NULL, *filename;
738 struct osl_table *t;
739 int i, ret = init_table_structure(desc, &t);
740
741 if (ret < 0)
742 return ret;
743 PARA_INFO_LOG("creating %s\n", desc->name);
744 FOR_EACH_COLUMN(i, t->desc, cd) {
745 if (cd->storage_type == OSL_NO_STORAGE)
746 continue;
747 if (!table_dir) {
748 ret = para_mkdir(desc->dir, 0777);
749 if (ret < 0 && ret != -E_EXIST)
750 goto out;
751 table_dir = make_message("%s/%s", desc->dir,
752 desc->name);
753 ret = para_mkdir(table_dir, 0777);
754 if (ret < 0)
755 goto out;
756 }
757 filename = column_filename(t, i);
758 PARA_INFO_LOG("filename: %s\n", filename);
759 if (cd->storage_type == OSL_MAPPED_STORAGE) {
760 ret = para_open(filename, O_RDWR | O_CREAT | O_EXCL,
761 0644);
762 free(filename);
763 if (ret < 0)
764 goto out;
765 close(ret);
766 continue;
767 }
768 /* DISK STORAGE */
769 ret = para_mkdir(filename, 0777);
770 free(filename);
771 if (ret < 0)
772 goto out;
773 }
774 if (t->num_mapped_columns) {
775 ret = create_table_index(t);
776 if (ret < 0)
777 goto out;
778 }
779 ret = 1;
780 out:
781 free(table_dir);
782 free(t->columns);
783 free(t);
784 return ret;
785 }
786
787 static int table_is_dirty(struct osl_table *t)
788 {
789 char *buf = (char *)t->index_map.data + IDX_DIRTY_FLAG;
790 uint8_t dirty = read_u8(buf) & 0x1;
791 return !!dirty;
792 }
793
794 static void mark_table_dirty(struct osl_table *t)
795 {
796 char *buf = (char *)t->index_map.data + IDX_DIRTY_FLAG;
797 write_u8(buf, read_u8(buf) | 1);
798 }
799
800 static void mark_table_clean(struct osl_table *t)
801 {
802 char *buf = (char *)t->index_map.data + IDX_DIRTY_FLAG;
803 write_u8(buf, read_u8(buf) & 0xfe);
804 }
805
806 static void unmap_column(struct osl_table *t, unsigned col_num)
807 {
808 struct osl_object map = t->columns[col_num].data_map;
809 int ret;
810 if (!map.data)
811 return;
812 ret = para_munmap(map.data, map.size);
813 assert(ret > 0);
814 map.data = NULL;
815 }
816
817 /**
818 * Unmap all mapped files of an osl table.
819 *
820 * \param t Pointer to a mapped table.
821 * \param flags Options for unmapping.
822 *
823 * \return Positive on success, negative on errors. Possible errors include:
824 * E_NOT_MAPPED, E_MUNMAP.
825 *
826 * \sa map_table(), enum osl_close_flags, para_munmap().
827 */
828 int unmap_table(struct osl_table *t, enum osl_close_flags flags)
829 {
830 unsigned i;
831 const struct osl_column_description *cd;
832 int ret;
833
834 if (!t->num_mapped_columns) /* can this ever happen? */
835 return 1;
836 PARA_DEBUG_LOG("unmapping table '%s'\n", t->desc->name);
837 if (!t->index_map.data)
838 return -E_NOT_MAPPED;
839 if (flags & OSL_MARK_CLEAN)
840 mark_table_clean(t);
841 ret = para_munmap(t->index_map.data, t->index_map.size);
842 if (ret < 0)
843 return ret;
844 t->index_map.data = NULL;
845 if (!t->num_rows)
846 return 1;
847 FOR_EACH_MAPPED_COLUMN(i, t, cd)
848 unmap_column(t, i);
849 return 1;
850 }
851
852 static int map_column(struct osl_table *t, unsigned col_num)
853 {
854 struct stat statbuf;
855 char *filename = column_filename(t, col_num);
856 int ret = -E_STAT;
857 if (stat(filename, &statbuf) < 0) {
858 free(filename);
859 return ret;
860 }
861 if (!(S_IFREG & statbuf.st_mode)) {
862 free(filename);
863 return ret;
864 }
865 ret = mmap_full_file(filename, O_RDWR,
866 &t->columns[col_num].data_map);
867 free(filename);
868 return ret;
869 }
870
871 /**
872 * Map the index file and all columns of type \p OSL_MAPPED_STORAGE into memory.
873 *
874 * \param t Pointer to an initialized table structure.
875 * \param flags Mapping options.
876 *
877 * \return Negative return value on errors; on success the number of rows
878 * (including invalid rows) is returned.
879 *
880 * \sa unmap_table(), enum map_table_flags, osl_open_table(), mmap(2).
881 */
882 int map_table(struct osl_table *t, enum map_table_flags flags)
883 {
884 char *filename;
885 const struct osl_column_description *cd;
886 int i = 0, ret, num_rows = 0;
887
888 if (!t->num_mapped_columns)
889 return 0;
890 if (t->index_map.data)
891 return -E_ALREADY_MAPPED;
892 filename = index_filename(t->desc);
893 PARA_DEBUG_LOG("mapping table '%s' (index: %s)\n", t->desc->name, filename);
894 ret = mmap_full_file(filename, flags & MAP_TBL_FL_MAP_RDONLY?
895 O_RDONLY : O_RDWR, &t->index_map);
896 free(filename);
897 if (ret < 0)
898 return ret;
899 if (flags & MAP_TBL_FL_VERIFY_INDEX) {
900 ret = compare_table_descriptions(t);
901 if (ret < 0)
902 goto err;
903 }
904 ret = -E_BUSY;
905 if (!(flags & MAP_TBL_FL_IGNORE_DIRTY)) {
906 if (table_is_dirty(t)) {
907 PARA_ERROR_LOG("%s is dirty\n", t->desc->name);
908 goto err;
909 }
910 }
911 mark_table_dirty(t);
912 num_rows = table_num_rows(t);
913 if (!num_rows)
914 return num_rows;
915 /* map data files */
916 FOR_EACH_MAPPED_COLUMN(i, t, cd) {
917 ret = map_column(t, i);
918 if (ret < 0)
919 goto err;
920 }
921 return num_rows;
922 err: /* unmap what is already mapped */
923 for (i--; i >= 0; i--) {
924 struct osl_object map = t->columns[i].data_map;
925 para_munmap(map.data, map.size);
926 map.data = NULL;
927 }
928 para_munmap(t->index_map.data, t->index_map.size);
929 t->index_map.data = NULL;
930 return ret;
931 }
932
933 /**
934 * Retrieve a mapped object by row and column number.
935 *
936 * \param t Pointer to an open osl table.
937 * \param col_num Number of the mapped column containing the object to retrieve.
938 * \param row_num Number of the row containing the object to retrieve.
939 * \param obj The result is returned here.
940 *
941 * It is considered an error if \a col_num does not refer to a column
942 * of storage type \p OSL_MAPPED_STORAGE.
943 *
944 * \return Positive on success, negative on errors. Possible errors include:
945 * \p E_BAD_ROW_NUM, \p E_INVALID_OBJECT.
946 *
947 * \sa osl_storage_type.
948 */
949 int get_mapped_object(const struct osl_table *t, unsigned col_num,
950 uint32_t row_num, struct osl_object *obj)
951 {
952 struct osl_column *col = &t->columns[col_num];
953 uint32_t offset;
954 char *header;
955 char *cell_index;
956 int ret;
957
958 if (t->num_rows <= row_num)
959 return -E_BAD_ROW_NUM;
960 ret = get_cell_index(t, row_num, col_num, &cell_index);
961 if (ret < 0)
962 return ret;
963 offset = read_u32(cell_index);
964 obj->size = read_u32(cell_index + 4) - 1;
965 header = col->data_map.data + offset;
966 obj->data = header + 1;
967 if (read_u8(header) == 0xff) {
968 PARA_ERROR_LOG("col %u, size %zu, offset %u\n", col_num,
969 obj->size, offset);
970 return -E_INVALID_OBJECT;
971 }
972 return 1;
973 }
974
975 static int search_rbtree(const struct osl_object *obj,
976 const struct osl_table *t, unsigned col_num,
977 struct rb_node **result, struct rb_node ***rb_link)
978 {
979 struct osl_column *col = &t->columns[col_num];
980 struct rb_node **new = &col->rbtree.rb_node, *parent = NULL;
981 const struct osl_column_description *cd =
982 get_column_description(t->desc, col_num);
983 enum osl_storage_type st = cd->storage_type;
984 while (*new) {
985 struct osl_row *this_row = get_row_pointer(*new,
986 col->rbtree_num);
987 int ret;
988 struct osl_object this_obj;
989 parent = *new;
990 if (st == OSL_MAPPED_STORAGE) {
991 ret = get_mapped_object(t, col_num, this_row->num,
992 &this_obj);
993 if (ret < 0)
994 return ret;
995 } else
996 this_obj = this_row->volatile_objects[col->volatile_num];
997 ret = cd->compare_function(obj, &this_obj);
998 if (!ret) {
999 if (result)
1000 *result = get_rb_node_pointer(this_row,
1001 col->rbtree_num);
1002 return 1;
1003 }
1004 if (ret < 0)
1005 new = &((*new)->rb_left);
1006 else
1007 new = &((*new)->rb_right);
1008 }
1009 if (result)
1010 *result = parent;
1011 if (rb_link)
1012 *rb_link = new;
1013 return -E_RB_KEY_NOT_FOUND;
1014 }
1015
1016 static int insert_rbtree(struct osl_table *t, unsigned col_num,
1017 const struct osl_row *row, const struct osl_object *obj)
1018 {
1019 struct rb_node *parent, **rb_link;
1020 unsigned rbtree_num;
1021 struct rb_node *n;
1022 int ret = search_rbtree(obj, t, col_num, &parent, &rb_link);
1023
1024 if (ret > 0)
1025 return -E_RB_KEY_EXISTS;
1026 rbtree_num = t->columns[col_num].rbtree_num;
1027 n = get_rb_node_pointer(row, rbtree_num);
1028 rb_link_node(n, parent, rb_link);
1029 rb_insert_color(n, &t->columns[col_num].rbtree);
1030 return 1;
1031 }
1032
1033 static void remove_rb_node(struct osl_table *t, unsigned col_num,
1034 const struct osl_row *row)
1035 {
1036 struct osl_column *col = &t->columns[col_num];
1037 const struct osl_column_description *cd =
1038 get_column_description(t->desc, col_num);
1039 enum osl_storage_flags sf = cd->storage_flags;
1040 struct rb_node *victim, *splice_out_node, *tmp;
1041 if (!(sf & OSL_RBTREE))
1042 return;
1043 /*
1044 * Which node is removed/spliced out actually depends on how many
1045 * children the victim node has: If it has no children, it gets
1046 * deleted. If it has one child, it gets spliced out. If it has two
1047 * children, its successor (which has at most a right child) gets
1048 * spliced out.
1049 */
1050 victim = get_rb_node_pointer(row, col->rbtree_num);
1051 if (victim->rb_left && victim->rb_right)
1052 splice_out_node = rb_next(victim);
1053 else
1054 splice_out_node = victim;
1055 /* Go up to the root and decrement the size of each node in the path. */
1056 for (tmp = splice_out_node; tmp; tmp = rb_parent(tmp))
1057 tmp->size--;
1058 rb_erase(victim, &col->rbtree);
1059 }
1060
1061 static int add_row_to_rbtrees(struct osl_table *t, uint32_t row_num,
1062 struct osl_object *volatile_objs, struct osl_row **row_ptr)
1063 {
1064 unsigned i;
1065 int ret;
1066 struct osl_row *row = allocate_row(t->num_rbtrees);
1067 const struct osl_column_description *cd;
1068
1069 row->num = row_num;
1070 row->volatile_objects = volatile_objs;
1071 FOR_EACH_RBTREE_COLUMN(i, t, cd) {
1072 if (cd->storage_type == OSL_MAPPED_STORAGE) {
1073 struct osl_object obj;
1074 ret = get_mapped_object(t, i, row_num, &obj);
1075 if (ret < 0)
1076 goto err;
1077 ret = insert_rbtree(t, i, row, &obj);
1078 } else { /* volatile */
1079 const struct osl_object *obj
1080 = volatile_objs + t->columns[i].volatile_num;
1081 ret = insert_rbtree(t, i, row, obj);
1082 }
1083 if (ret < 0)
1084 goto err;
1085 }
1086 if (row_ptr)
1087 *row_ptr = row;
1088 return 1;
1089 err: /* rollback changes, i.e. remove added entries from rbtrees */
1090 while (i)
1091 remove_rb_node(t, i--, row);
1092 free(row);
1093 return ret;
1094 }
1095
1096 static void free_volatile_objects(const struct osl_table *t,
1097 enum osl_close_flags flags)
1098 {
1099 int i, j;
1100 struct rb_node *n;
1101 struct osl_column *rb_col;
1102 const struct osl_column_description *cd;
1103
1104 if (!t->num_volatile_columns)
1105 return;
1106 /* find the first rbtree column (any will do) */
1107 FOR_EACH_RBTREE_COLUMN(i, t, cd)
1108 break;
1109 rb_col = t->columns + i;
1110 /* walk that rbtree and free all volatile objects */
1111 for (n = rb_first(&rb_col->rbtree); n; n = rb_next(n)) {
1112 struct osl_row *r = get_row_pointer(n, rb_col->rbtree_num);
1113 if (flags & OSL_FREE_VOLATILE)
1114 for (j = 0; j < t->num_volatile_columns; j++)
1115 free(r->volatile_objects[j].data);
1116 free(r->volatile_objects);
1117 }
1118 }
1119
1120 /**
1121 * Erase all rbtree nodes and free resources.
1122 *
1123 * \param t Pointer to an open osl table.
1124 *
1125 * This function is called by osl_close_table().
1126 */
1127 void clear_rbtrees(struct osl_table *t)
1128 {
1129 const struct osl_column_description *cd;
1130 unsigned i, rbtrees_cleared = 0;
1131
1132 FOR_EACH_RBTREE_COLUMN(i, t, cd) {
1133 struct osl_column *col = &t->columns[i];
1134 struct rb_node *n;
1135 rbtrees_cleared++;
1136 for (n = rb_first(&col->rbtree); n;) {
1137 struct osl_row *r;
1138 rb_erase(n, &col->rbtree);
1139 if (rbtrees_cleared == t->num_rbtrees) {
1140 r = get_row_pointer(n, col->rbtree_num);
1141 n = rb_next(n);
1142 free(r);
1143 } else
1144 n = rb_next(n);
1145 }
1146 }
1147
1148 }
1149
1150 /**
1151 * Close an osl table.
1152 *
1153 * \param t Pointer to the table to be closed.
1154 * \param flags Options for what should be cleaned up.
1155 *
1156 * If osl_open_table() succeeds, the resulting table pointer must later be
1157 * passed to this function in order to flush all changes to the filesystem and
1158 * to free the resources that were allocated by osl_open_table().
1159 *
1160 * \return Positive on success, negative on errors. Possible errors: \p E_BAD_TABLE,
1161 * errors returned by unmap_table().
1162 *
1163 * \sa osl_open_table(), unmap_table().
1164 */
1165 int osl_close_table(struct osl_table *t, enum osl_close_flags flags)
1166 {
1167 int ret;
1168
1169 if (!t)
1170 return -E_BAD_TABLE;
1171 free_volatile_objects(t, flags);
1172 clear_rbtrees(t);
1173 ret = unmap_table(t, flags);
1174 if (ret < 0)
1175 PARA_ERROR_LOG("unmap_table failed: %d\n", ret);
1176 free(t->columns);
1177 free(t);
1178 return ret;
1179 }
1180
1181 /**
1182 * Find out whether the given row number corresponds to an invalid row.
1183 *
1184 * \param t Pointer to the osl table.
1185 * \param row_num The number of the row in question.
1186 *
1187 * By definition, a row is considered invalid if all its index entries
1188 * are invalid.
1189 *
1190 * \return Positive if \a row_num corresponds to an invalid row,
1191 * zero if it corresponds to a valid row, negative on errors.
1192 */
1193 int row_is_invalid(struct osl_table *t, uint32_t row_num)
1194 {
1195 char *row_index;
1196 int i, ret = get_row_index(t, row_num, &row_index);
1197
1198 if (ret < 0)
1199 return ret;
1200 for (i = 0; i < t->row_index_size; i++) {
1201 if ((unsigned char)row_index[i] != 0xff)
1202 return 0;
1203 }
1204 PARA_INFO_LOG("row %d is invalid\n", row_num);
1205 return 1;
1206 }
1207
1208 /**
1209 * Invalidate a row of an osl table.
1210 *
1211 * \param t Pointer to an open osl table.
1212 * \param row_num Number of the row to mark as invalid.
1213 *
1214 * This function marks each mapped object in the index entry of \a row as
1215 * invalid.
1216 *
1217 * \return Positive on success, negative on errors.
1218 */
1219 int mark_row_invalid(struct osl_table *t, uint32_t row_num)
1220 {
1221 char *row_index;
1222 int ret = get_row_index(t, row_num, &row_index);
1223
1224 if (ret < 0)
1225 return ret;
1226 PARA_INFO_LOG("marking row %d as invalid\n", row_num);
1227 memset(row_index, 0xff, t->row_index_size);
1228 return 1;
1229 }
1230
1231 /**
1232 * Initialize all rbtrees and compute number of invalid rows.
1233 *
1234 * \param t The table containing the rbtrees to be initialized.
1235 *
1236 * \return Positive on success, negative on errors.
1237 */
1238 int init_rbtrees(struct osl_table *t)
1239 {
1240 int i, ret;
1241 const struct osl_column_description *cd;
1242
1243 /* create rbtrees */
1244 FOR_EACH_RBTREE_COLUMN(i, t, cd)
1245 t->columns[i].rbtree = RB_ROOT;
1246 /* add valid rows to rbtrees */
1247 t->num_invalid_rows = 0;
1248 for (i = 0; i < t->num_rows; i++) {
1249 ret = row_is_invalid(t, i);
1250 if (ret < 0)
1251 return ret;
1252 if (ret) {
1253 t->num_invalid_rows++;
1254 continue;
1255 }
1256 ret = add_row_to_rbtrees(t, i, NULL, NULL);
1257 if (ret < 0)
1258 return ret;
1259 }
1260 return 1;
1261 }
1262
1263 /**
1264 * Open an osl table.
1265 *
1266 * Each osl table must be opened before its data can be accessed.
1267 *
1268 * \param table_desc Describes the table to be opened.
1269 * \param result Contains a pointer to the open table on success.
1270 *
1271 * The table description given by \a desc should coincide with the
1272 * description used at creation time.
1273 *
1274 * \return Positive on success, negative on errors. Possible errors include:
1275 * errors returned by init_table_structure(), \p E_NOENT, \p E_STAT, \p \p
1276 * E_NOTDIR, \p E_BAD_TABLE_DESC, \p E_BAD_DB_DIR, \p E_NO_COMPARE_FUNC, \p
1277 * E_NO_COLUMN_NAME, errors returned by init_rbtrees().
1278 */
1279 int osl_open_table(const struct osl_table_description *table_desc,
1280 struct osl_table **result)
1281 {
1282 int i, ret;
1283 struct osl_table *t;
1284 const struct osl_column_description *cd;
1285
1286 PARA_INFO_LOG("opening table %s\n", table_desc->name);
1287 ret = init_table_structure(table_desc, &t);
1288 if (ret < 0)
1289 return ret;
1290 FOR_EACH_DISK_STORAGE_COLUMN(i, t, cd) {
1291 /* check if directory exists */
1292 char *dirname = column_filename(t, i);
1293 struct stat statbuf;
1294 ret = stat(dirname, &statbuf);
1295 free(dirname);
1296 if (ret < 0) {
1297 if (errno == ENOENT)
1298 ret = -E_NOENT;
1299 else
1300 ret = -E_STAT;
1301 goto err;
1302 }
1303 ret = -E_NOTDIR;
1304 if (!S_ISDIR(statbuf.st_mode))
1305 goto err;
1306 }
1307 ret = map_table(t, MAP_TBL_FL_VERIFY_INDEX);
1308 if (ret < 0)
1309 goto err;
1310 t->num_rows = ret;
1311 PARA_DEBUG_LOG("num rows: %d\n", t->num_rows);
1312 ret = init_rbtrees(t);
1313 if (ret < 0) {
1314 osl_close_table(t, OSL_MARK_CLEAN); /* ignore further errors */
1315 return ret;
1316 }
1317 *result = t;
1318 return 1;
1319 err:
1320 free(t->columns);
1321 free(t);
1322 return ret;
1323 }
1324
1325 static int create_disk_storage_object_dir(const struct osl_table *t,
1326 unsigned col_num, const char *ds_name)
1327 {
1328 char *dirname;
1329 int ret;
1330
1331 if (!(t->desc->flags & OSL_LARGE_TABLE))
1332 return 1;
1333 dirname = disk_storage_dirname(t, col_num, ds_name);
1334 ret = para_mkdir(dirname, 0777);
1335 free(dirname);
1336 if (ret < 0 && ret != -E_EXIST)
1337 return ret;
1338 return 1;
1339 }
1340
1341 static int write_disk_storage_file(const struct osl_table *t, unsigned col_num,
1342 const struct osl_object *obj, const char *ds_name)
1343 {
1344 int ret;
1345 char *filename;
1346
1347 ret = create_disk_storage_object_dir(t, col_num, ds_name);
1348 if (ret < 0)
1349 return ret;
1350 filename = disk_storage_path(t, col_num, ds_name);
1351 ret = para_write_file(filename, obj->data, obj->size);
1352 free(filename);
1353 return ret;
1354 }
1355
1356 static int append_map_file(const struct osl_table *t, unsigned col_num,
1357 const struct osl_object *obj, uint32_t *new_size)
1358 {
1359 char *filename = column_filename(t, col_num);
1360 int ret;
1361 char header = 0; /* zero means valid object */
1362
1363 // PARA_DEBUG_LOG("appending %zu + 1 byte\n", obj->size);
1364 ret = append_file(filename, &header, 1, obj->data, obj->size,
1365 new_size);
1366 free(filename);
1367 return ret;
1368 }
1369
1370 static int append_row_index(const struct osl_table *t, char *row_index)
1371 {
1372 char *filename;
1373 int ret;
1374
1375 if (!t->num_mapped_columns)
1376 return 1;
1377 filename = index_filename(t->desc);
1378 ret = append_file(filename, NULL, 0, row_index,
1379 t->row_index_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_DEBUG_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_row_index = 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_row_index = para_malloc(t->row_index_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_cell_index(new_row_index, 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_row_index(t, new_row_index);
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->row_index_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_row_index);
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->num, 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,
1644 uint32_t row_num, unsigned col_num)
1645 {
1646 struct osl_object obj;
1647 char *p;
1648 int ret = get_mapped_object(t, col_num, row_num, &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->num, 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->num);
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 PARA_DEBUG_LOG("updating column %u of %s\n", col_num, t->desc->name);
1924 if (cd->storage_flags & OSL_RBTREE) {
1925 if (search_rbtree(obj, t, col_num, NULL, NULL) > 0)
1926 return -E_RB_KEY_EXISTS;
1927 }
1928 if (cd->storage_flags & OSL_FIXED_SIZE) {
1929 if (obj->size != cd->data_size)
1930 return -E_BAD_DATA_SIZE;
1931 }
1932 remove_rb_node(t, col_num, r);
1933 if (cd->storage_type == OSL_NO_STORAGE) { /* TODO: If fixed size, reuse object? */
1934 free(r->volatile_objects[col->volatile_num].data);
1935 r->volatile_objects[col->volatile_num] = *obj;
1936 } else if (cd->storage_type == OSL_DISK_STORAGE) {
1937 char *ds_name;
1938 ret = disk_storage_name_of_row(t, r, &ds_name);
1939 if (ret < 0)
1940 return ret;
1941 ret = delete_disk_storage_file(t, col_num, ds_name);
1942 if (ret < 0 && ret != -E_NOENT) {
1943 free(ds_name);
1944 return ret;
1945 }
1946 ret = write_disk_storage_file(t, col_num, obj, ds_name);
1947 free(ds_name);
1948 if (ret < 0)
1949 return ret;
1950 } else { /* mapped storage */
1951 struct osl_object old_obj;
1952 ret = get_mapped_object(t, col_num, r->num, &old_obj);
1953 if (ret < 0)
1954 return ret;
1955 /*
1956 * If the updated column is the disk storage name column, the
1957 * disk storage name changes, so we have to rename all disk
1958 * storage objects accordingly.
1959 */
1960 if (col_num == t->disk_storage_name_column) {
1961 ret = rename_disk_storage_objects(t, &old_obj, obj);
1962 if (ret < 0)
1963 return ret;
1964 }
1965 if (cd->storage_flags & OSL_FIXED_SIZE)
1966 memcpy(old_obj.data, obj->data, cd->data_size);
1967 else { /* TODO: if the size doesn't change, use old space */
1968 uint32_t new_data_map_size;
1969 char *row_index;
1970 ret = get_row_index(t, r->num, &row_index);
1971 if (ret < 0)
1972 return ret;
1973 ret = mark_mapped_object_invalid(t, r->num, col_num);
1974 if (ret < 0)
1975 return ret;
1976 unmap_column(t, col_num);
1977 ret = append_map_file(t, col_num, obj,
1978 &new_data_map_size);
1979 if (ret < 0)
1980 return ret;
1981 ret = map_column(t, col_num);
1982 if (ret < 0)
1983 return ret;
1984 update_cell_index(row_index, col, new_data_map_size,
1985 obj->size);
1986 }
1987 }
1988 if (cd->storage_flags & OSL_RBTREE) {
1989 ret = insert_rbtree(t, col_num, r, obj);
1990 if (ret < 0)
1991 return ret;
1992 }
1993 return 1;
1994 }
1995
1996 /**
1997 * Retrieve an object of type \p OSL_DISK_STORAGE by row and column.
1998 *
1999 * \param t Pointer to an open osl table.
2000 * \param r Pointer to the row containing the object.
2001 * \param col_num The column number.
2002 * \param obj Points to the result upon successful return.
2003 *
2004 * For columns of type \p OSL_DISK_STORAGE, this function must be used to
2005 * retrieve one of its containing objects. Afterwards, osl_close_disk_object()
2006 * must be called in order to deallocate the resources.
2007 *
2008 * \return Positive on success, negative on errors. Possible errors include:
2009 * \p E_BAD_TABLE, \p E_BAD_STORAGE_TYPE, errors returned by osl_get_object().
2010 *
2011 * \sa osl_get_object(), osl_storage_type, osl_close_disk_object().
2012 */
2013 int osl_open_disk_object(const struct osl_table *t, const struct osl_row *r,
2014 unsigned col_num, struct osl_object *obj)
2015 {
2016 const struct osl_column_description *cd;
2017 char *ds_name, *filename;
2018 int ret;
2019
2020 if (!t)
2021 return -E_BAD_TABLE;
2022 cd = get_column_description(t->desc, col_num);
2023 if (cd->storage_type != OSL_DISK_STORAGE)
2024 return -E_BAD_STORAGE_TYPE;
2025
2026 ret = disk_storage_name_of_row(t, r, &ds_name);
2027 if (ret < 0)
2028 return ret;
2029 filename = disk_storage_path(t, col_num, ds_name);
2030 free(ds_name);
2031 PARA_DEBUG_LOG("filename: %s\n", filename);
2032 ret = mmap_full_file(filename, O_RDONLY, obj);
2033 free(filename);
2034 return ret;
2035 }
2036
2037 /**
2038 * Free resources that were allocated during osl_open_disk_object().
2039 *
2040 * \param obj Pointer to the object previously returned by open_disk_object().
2041 *
2042 * \return The return value of the underlying call to para_munmap().
2043 *
2044 * \sa para_munmap().
2045 */
2046 int osl_close_disk_object(struct osl_object *obj)
2047 {
2048 return para_munmap(obj->data, obj->size);
2049 }
2050
2051 /**
2052 * Get the number of rows of the given table.
2053 *
2054 * \param t Pointer to an open osl table.
2055 * \param num_rows Result is returned here.
2056 *
2057 * The number of rows returned via \a num_rows excluding any invalid rows.
2058 *
2059 * \return Positive on success, \p -E_BAD_TABLE if \a t is \p NULL.
2060 */
2061 int osl_get_num_rows(const struct osl_table *t, unsigned *num_rows)
2062 {
2063 if (!t)
2064 return -E_BAD_TABLE;
2065 assert(t->num_rows >= t->num_invalid_rows);
2066 *num_rows = t->num_rows - t->num_invalid_rows;
2067 return 1;
2068 }
2069
2070 /**
2071 * Get the rank of a row.
2072 *
2073 * \param t An open osl table.
2074 * \param r The row to get the rank of.
2075 * \param col_num The number of an rbtree column.
2076 * \param rank Result pointer.
2077 *
2078 * The rank is, by definition, the position of the row in the linear order
2079 * determined by an inorder tree walk of the rbtree associated with column
2080 * number \a col_num of \a table.
2081 *
2082 * \return Positive on success, negative on errors.
2083 *
2084 * \sa osl_get_nth_row().
2085 */
2086 int osl_get_rank(const struct osl_table *t, struct osl_row *r,
2087 unsigned col_num, unsigned *rank)
2088 {
2089 struct osl_object obj;
2090 struct osl_column *col;
2091 struct rb_node *node;
2092 int ret = check_rbtree_col(t, col_num, &col);
2093
2094 if (ret < 0)
2095 return ret;
2096 ret = osl_get_object(t, r, col_num, &obj);
2097 if (ret < 0)
2098 return ret;
2099 ret = search_rbtree(&obj, t, col_num, &node, NULL);
2100 if (ret < 0)
2101 return ret;
2102 ret = rb_rank(node, rank);
2103 if (ret < 0)
2104 return -E_BAD_ROW;
2105 return 1;
2106 }
2107
2108 /**
2109 * Get the row with n-th greatest value.
2110 *
2111 * \param t Pointer to an open osl table.
2112 * \param col_num The column number.
2113 * \param n The rank of the desired row.
2114 * \param result Row is returned here.
2115 *
2116 * Retrieve the n-th order statistic with respect to the compare function
2117 * of the rbtree column \a col_num. In other words, get that row with
2118 * \a n th greatest value in column \a col_num. It's an error if
2119 * \a col_num is not a rbtree column, or if \a n is larger than the
2120 * number of rows in the table.
2121 *
2122 * \return Positive on success, negative on errors. Possible errors:
2123 * \p E_BAD_TABLE, \p E_BAD_STORAGE_FLAGS, \p E_RB_KEY_NOT_FOUND.
2124 *
2125 * \sa osl_storage_flags, osl_compare_func, osl_get_row(),
2126 * osl_rbtree_last_row(), osl_rbtree_first_row(), osl_get_rank().
2127 */
2128 int osl_get_nth_row(const struct osl_table *t, unsigned col_num,
2129 unsigned n, struct osl_row **result)
2130 {
2131 struct osl_column *col;
2132 struct rb_node *node;
2133 int ret = check_rbtree_col(t, col_num, &col);
2134
2135 if (ret < 0)
2136 return ret;
2137 node = rb_nth(col->rbtree.rb_node, n);
2138 if (!node)
2139 return -E_RB_KEY_NOT_FOUND;
2140 *result = get_row_pointer(node, col->rbtree_num);
2141 return 1;
2142 }
2143
2144 /**
2145 * Get the row corresponding to the smallest rbtree node of a column.
2146 *
2147 * \param t An open rbtree table.
2148 * \param col_num The number of the rbtree column.
2149 * \param result A pointer to the first row is returned here.
2150 *
2151 * The rbtree node of the smallest object (with respect to the corresponding
2152 * compare function) is selected and the row containing this object is
2153 * returned. It is an error if \a col_num refers to a column without an
2154 * associated rbtree.
2155 *
2156 * \return Positive on success, negative on errors.
2157 *
2158 * \sa osl_get_nth_row(), osl_rbtree_last_row().
2159 */
2160 int osl_rbtree_first_row(const struct osl_table *t, unsigned col_num,
2161 struct osl_row **result)
2162 {
2163 return osl_get_nth_row(t, col_num, 1, result);
2164 }
2165
2166 /**
2167 * Get the row corresponding to the greatest rbtree node of a column.
2168 *
2169 * \param t The same meaning as in \p osl_rbtree_first_row().
2170 * \param col_num The same meaning as in \p osl_rbtree_first_row().
2171 * \param result The same meaning as in \p osl_rbtree_first_row().
2172 *
2173 * This function works just like osl_rbtree_first_row(), the only difference
2174 * is that the row containing the greatest rather than the smallest object is
2175 * returned.
2176 *
2177 * \return Positive on success, negative on errors.
2178 *
2179 * \sa osl_get_nth_row(), osl_rbtree_first_row().
2180 */
2181 int osl_rbtree_last_row(const struct osl_table *t, unsigned col_num,
2182 struct osl_row **result)
2183 {
2184 unsigned num_rows;
2185 int ret = osl_get_num_rows(t, &num_rows);
2186
2187 if (ret < 0)
2188 return ret;
2189 return osl_get_nth_row(t, col_num, num_rows, result);
2190 }