2 * Copyright (C) 2007 Andre Noll <maan@systemlinux.org>
4 * Licensed under the GPL v2. For licencing details see COPYING.
7 /** \file osl.c Object storage layer functions. */
8 #include <dirent.h> /* readdir() */
18 * A wrapper for lseek(2).
20 * \param fd The filedescriptor whose offset is to be to repositioned.
21 * \param offset A value-result parameter.
22 * \param whence Usual repositioning directive.
24 * Reposition the offset of the file descriptor \a fd to the argument \a offset
25 * according to the directive \a whence. Upon successful return, \a offset
26 * contains the resulting offset location as measured in bytes from the
27 * beginning of the file.
29 * \return Positive on success. Otherwise, the function returns \p -E_LSEEK.
33 int para_lseek(int fd, off_t *offset, int whence)
35 *offset = lseek(fd, *offset, whence);
43 * Wrapper for the write system call.
45 * \param fd The file descriptor to write to.
46 * \param buf The buffer to write.
47 * \param size The length of \a buf in bytes.
49 * This function writes out the given bufffer and retries if an interrupt
50 * occured during the write.
52 * \return On success, the number of bytes written is returned, otherwise, the
53 * function returns \p -E_WRITE.
57 ssize_t para_write(int fd, const void *buf, size_t size)
62 ret = write(fd, buf, size);
63 if ((ret < 0) && (errno == EAGAIN || errno == EINTR))
65 return ret >= 0? ret : -E_WRITE;
70 * Write the whole buffer to a file descriptor.
72 * \param fd The file descriptor to write to.
73 * \param buf The buffer to write.
74 * \param size The length of \a buf in bytes.
76 * This function writes the given buffer and continues on short writes and
77 * when interrupted by a signal.
79 * \return Positive on success, negative on errors. Possible errors: any
80 * errors returned by para_write().
84 ssize_t para_write_all(int fd, const void *buf, size_t size)
86 // PARA_DEBUG_LOG("writing %zu bytes\n", size);
89 ssize_t ret = para_write(fd, b, size);
90 // PARA_DEBUG_LOG("ret: %zd\n", ret);
99 * Open a file, write the given buffer and close the file.
101 * \param filename Full path to the file to open.
102 * \param buf The buffer to write to the file.
103 * \param size The size of \a buf.
105 * \return Positive on success, negative on errors. Possible errors include:
106 * any errors from para_open() or para_write().
108 * \sa para_open(), para_write().
110 int para_write_file(const char *filename, const void *buf, size_t size)
114 ret = para_open(filename, O_WRONLY | O_CREAT | O_EXCL, 0644);
118 ret = para_write_all(fd, buf, size);
127 static int append_file(const char *filename, char *header, size_t header_size,
128 char *data, size_t data_size, uint32_t *new_pos)
132 // PARA_DEBUG_LOG("appending %zu + %zu bytes\n", header_size, data_size);
133 ret = para_open(filename, O_WRONLY | O_CREAT | O_APPEND, 0644);
137 if (header && header_size) {
138 ret = para_write_all(fd, header, header_size);
142 ret = para_write_all(fd, data, data_size);
147 ret = para_lseek(fd, &offset, SEEK_END);
150 // PARA_DEBUG_LOG("new file size: " FMT_OFF_T "\n", offset);
160 * Map a file into memory.
162 * \param path Name of the regular file to map.
163 * \param open_mode Either \p O_RDONLY or \p O_RDWR.
164 * \param obj On success, the mapping is returned here.
166 * \return Positive on success, negative on errors. Possible errors include: \p
167 * E_FSTAT, any errors returned by para_open(), \p E_EMPTY, \p E_MMAP.
169 * \sa para_open(), mmap(2).
171 int mmap_full_file(const char *path, int open_mode, struct osl_object *obj)
173 int fd, ret, mmap_prot, mmap_flags;
174 struct stat file_status;
176 if (open_mode == O_RDONLY) {
177 mmap_prot = PROT_READ;
178 mmap_flags = MAP_PRIVATE;
180 mmap_prot = PROT_READ | PROT_WRITE;
181 mmap_flags = MAP_SHARED;
183 ret = para_open(path, open_mode, 0);
188 if (fstat(fd, &file_status) < 0)
190 obj->size = file_status.st_size;
192 PARA_DEBUG_LOG("%s: size %zu\n", path, obj->size);
195 obj->data = mmap(NULL, obj->size, mmap_prot, mmap_flags, fd, 0);
196 if (obj->data == MAP_FAILED) {
208 * Traverse the given directory recursively.
210 * \param dirname The directory to traverse.
211 * \param func The function to call for each entry.
212 * \param private_data Pointer to an arbitrary data structure.
214 * For each regular file in \a dirname, the supplied function \a func is
215 * called. The full path of the regular file and the \a private_data pointer
216 * are passed to \a func.
218 * \return On success, 1 is returned. Otherwise, this function returns a
219 * negative value which indicates the kind of the error.
221 int for_each_file_in_dir(const char *dirname,
222 int (*func)(const char *, const void *), const void *private_data)
225 struct dirent *entry;
226 int cwd_fd, ret2, ret = para_opendir(dirname, &dir, &cwd_fd);
230 /* scan cwd recursively */
231 while ((entry = readdir(dir))) {
236 if (!strcmp(entry->d_name, "."))
238 if (!strcmp(entry->d_name, ".."))
240 if (lstat(entry->d_name, &s) == -1)
243 if (!S_ISREG(m) && !S_ISDIR(m))
245 tmp = make_message("%s/%s", dirname, entry->d_name);
247 ret = func(tmp, private_data);
254 ret = for_each_file_in_dir(tmp, func, private_data);
262 ret2 = para_fchdir(cwd_fd);
263 if (ret2 < 0 && ret >= 0)
269 static int verify_name(const char *name)
275 if (strchr(name, '/'))
277 if (!strcmp(name, ".."))
279 if (!strcmp(name, "."))
285 * Compare two osl objects pointing to unsigned integers of 32 bit size.
287 * \param obj1 Pointer to the first integer.
288 * \param obj2 Pointer to the second integer.
290 * \return The values required for an osl compare function.
292 * \sa osl_compare_func, osl_hash_compare().
294 int uint32_compare(const struct osl_object *obj1, const struct osl_object *obj2)
296 uint32_t d1 = read_u32((const char *)obj1->data);
297 uint32_t d2 = read_u32((const char *)obj2->data);
307 * Compare two osl objects pointing to hash values.
309 * \param obj1 Pointer to the first hash object.
310 * \param obj2 Pointer to the second hash object.
312 * \return The values required for an osl compare function.
314 * \sa osl_compare_func, uint32_compare().
316 int osl_hash_compare(const struct osl_object *obj1, const struct osl_object *obj2)
318 return hash_compare((HASH_TYPE *)obj1->data, (HASH_TYPE *)obj2->data);
321 static char *disk_storage_dirname(const struct osl_table *t, unsigned col_num,
324 char *dirname, *column_name = column_filename(t, col_num);
326 if (!(t->desc->flags & OSL_LARGE_TABLE))
328 dirname = make_message("%s/%.2s", column_name, ds_name);
333 static char *disk_storage_name_of_object(const struct osl_table *t,
334 const struct osl_object *obj)
336 HASH_TYPE hash[HASH_SIZE];
337 hash_object(obj, hash);
338 return disk_storage_name_of_hash(t, hash);
341 static int disk_storage_name_of_row(const struct osl_table *t,
342 const struct osl_row *row, char **name)
344 struct osl_object obj;
345 int ret = osl_get_object(t, row, t->disk_storage_name_column, &obj);
349 *name = disk_storage_name_of_object(t, &obj);
353 static void column_name_hash(const char *col_name, HASH_TYPE *hash)
355 return hash_function(col_name, strlen(col_name), hash);
358 static int init_column_descriptions(struct osl_table *t)
361 const struct osl_column_description *cd;
363 ret = -E_BAD_TABLE_DESC;
364 ret = verify_name(t->desc->name);
370 /* the size of the index header without column descriptions */
371 t->index_header_size = IDX_COLUMN_DESCRIPTIONS;
372 FOR_EACH_COLUMN(i, t->desc, cd) {
373 struct osl_column *col = t->columns + i;
374 if (cd->storage_flags & OSL_RBTREE) {
375 if (!cd->compare_function)
376 return -E_NO_COMPARE_FUNC;
378 if (cd->storage_type == OSL_NO_STORAGE)
380 ret = -E_NO_COLUMN_NAME;
381 if (!cd->name || !cd->name[0])
383 ret = verify_name(cd->name);
386 t->index_header_size += index_column_description_size(cd->name);
387 column_name_hash(cd->name, col->name_hash);
388 ret = -E_DUPLICATE_COL_NAME;
389 for (j = i + 1; j < t->desc->num_columns; j++) {
390 const char *name2 = get_column_description(t->desc,
392 if (cd->name && name2 && !strcmp(cd->name, name2))
402 * Initialize a struct table from given table description.
404 * \param desc The description of the osl table.
405 * \param table_ptr Result is returned here.
407 * This function performs several sanity checks on \p desc and returns if any
408 * of these tests fail. On success, a struct \p osl_table is allocated and
409 * initialized with data derived from \p desc.
411 * \return Positive on success, negative on errors. Possible errors include: \p
412 * E_BAD_TABLE_DESC, \p E_NO_COLUMN_DESC, \p E_NO_COLUMNS, \p
413 * E_BAD_STORAGE_TYPE, \p E_BAD_STORAGE_FLAGS, \p E_BAD_STORAGE_SIZE, \p
414 * E_NO_UNIQUE_RBTREE_COLUMN, \p E_NO_RBTREE_COL.
416 * \sa struct osl_table.
418 int init_table_structure(const struct osl_table_description *desc,
419 struct osl_table **table_ptr)
421 const struct osl_column_description *cd;
422 struct osl_table *t = para_calloc(sizeof(*t));
423 int i, ret = -E_BAD_TABLE_DESC, have_disk_storage_name_column = 0;
427 PARA_DEBUG_LOG("creating table structure for '%s' from table "
428 "description\n", desc->name);
429 ret = -E_NO_COLUMN_DESC;
430 if (!desc->column_descriptions)
433 if (!desc->num_columns)
435 t->columns = para_calloc(desc->num_columns * sizeof(struct osl_column));
437 FOR_EACH_COLUMN(i, t->desc, cd) {
438 enum osl_storage_type st = cd->storage_type;
439 enum osl_storage_flags sf = cd->storage_flags;
440 struct osl_column *col = &t->columns[i];
442 ret = -E_BAD_STORAGE_TYPE;
443 if (st != OSL_MAPPED_STORAGE && st != OSL_DISK_STORAGE
444 && st != OSL_NO_STORAGE)
446 ret = -E_BAD_STORAGE_FLAGS;
447 if (st == OSL_DISK_STORAGE && sf & OSL_RBTREE)
449 ret = -E_BAD_STORAGE_SIZE;
450 if (sf & OSL_FIXED_SIZE && !cd->data_size)
453 case OSL_DISK_STORAGE:
454 t->num_disk_storage_columns++;
456 case OSL_MAPPED_STORAGE:
457 t->num_mapped_columns++;
458 col->index_offset = t->row_index_size;
459 t->row_index_size += 8;
462 col->volatile_num = t->num_volatile_columns;
463 t->num_volatile_columns++;
466 if (sf & OSL_RBTREE) {
467 col->rbtree_num = t->num_rbtrees;
469 if ((sf & OSL_UNIQUE) && (st == OSL_MAPPED_STORAGE)) {
470 if (!have_disk_storage_name_column)
471 t->disk_storage_name_column = i;
472 have_disk_storage_name_column = 1;
476 ret = -E_NO_UNIQUE_RBTREE_COLUMN;
477 if (t->num_disk_storage_columns && !have_disk_storage_name_column)
479 ret = -E_NO_RBTREE_COL;
483 PARA_DEBUG_LOG("OK. Index entry size: %u\n", t->row_index_size);
484 ret = init_column_descriptions(t);
496 * Read the table description from index header.
498 * \param map The memory mapping of the index file.
499 * \param desc The values found in the index header are returned here.
501 * Read the index header, check for the paraslash magic string and the table version number.
502 * Read all information stored in the index header into \a desc.
504 * \return Positive on success, negative on errors.
506 * \sa struct osl_table_description, osl_create_table.
508 int read_table_desc(struct osl_object *map, struct osl_table_description *desc)
510 char *buf = map->data;
512 uint16_t header_size;
515 struct osl_column_description *cd;
517 if (map->size < MIN_INDEX_HEADER_SIZE(1))
518 return -E_SHORT_TABLE;
519 if (strncmp(buf + IDX_PARA_MAGIC, PARA_MAGIC, strlen(PARA_MAGIC)))
521 version = read_u8(buf + IDX_VERSION);
522 if (version < MIN_TABLE_VERSION || version > MAX_TABLE_VERSION)
523 return -E_VERSION_MISMATCH;
524 desc->num_columns = read_u8(buf + IDX_TABLE_FLAGS);
525 desc->flags = read_u8(buf + IDX_TABLE_FLAGS);
526 desc->num_columns = read_u16(buf + IDX_NUM_COLUMNS);
527 PARA_DEBUG_LOG("%u columns\n", desc->num_columns);
528 if (!desc->num_columns)
529 return -E_NO_COLUMNS;
530 header_size = read_u16(buf + IDX_HEADER_SIZE);
531 if (map->size < header_size)
533 desc->column_descriptions = para_calloc(desc->num_columns
534 * sizeof(struct osl_column_description));
535 offset = IDX_COLUMN_DESCRIPTIONS;
536 FOR_EACH_COLUMN(i, desc, cd) {
539 ret = -E_SHORT_TABLE;
540 if (map->size < offset + MIN_IDX_COLUMN_DESCRIPTION_SIZE) {
541 PARA_ERROR_LOG("map size = %zu < %u = offset + min desc size\n",
542 map->size, offset + MIN_IDX_COLUMN_DESCRIPTION_SIZE);
545 cd->storage_type = read_u16(buf + offset + IDX_CD_STORAGE_TYPE);
546 cd->storage_flags = read_u16(buf + offset +
547 IDX_CD_STORAGE_FLAGS);
548 cd->data_size = read_u32(buf + offset + IDX_CD_DATA_SIZE);
549 null_byte = memchr(buf + offset + IDX_CD_NAME, '\0',
550 map->size - offset - IDX_CD_NAME);
551 ret = -E_INDEX_CORRUPTION;
554 cd->name = para_strdup(buf + offset + IDX_CD_NAME);
555 offset += index_column_description_size(cd->name);
557 if (offset != header_size) {
558 ret = -E_INDEX_CORRUPTION;
559 PARA_ERROR_LOG("real header size = %u != %u = stored header size\n",
560 offset, header_size);
565 FOR_EACH_COLUMN(i, desc, cd)
571 * check whether the table description given by \p t->desc matches the on-disk
572 * table structure stored in the index of \a t.
574 static int compare_table_descriptions(struct osl_table *t)
577 struct osl_table_description desc;
578 const struct osl_column_description *cd1, *cd2;
580 /* read the on-disk structure into desc */
581 ret = read_table_desc(&t->index_map, &desc);
584 ret = -E_BAD_TABLE_FLAGS;
585 if (desc.flags != t->desc->flags)
587 ret = -E_BAD_COLUMN_NUM;
588 if (desc.num_columns != t->desc->num_columns)
590 FOR_EACH_COLUMN(i, t->desc, cd1) {
591 cd2 = get_column_description(&desc, i);
592 ret = -E_BAD_STORAGE_TYPE;
593 if (cd1->storage_type != cd2->storage_type)
595 ret = -E_BAD_STORAGE_FLAGS;
596 if (cd1->storage_flags != cd2->storage_flags) {
597 PARA_ERROR_LOG("sf1 = %u != %u = sf2\n",
598 cd1->storage_flags, cd2->storage_flags);
601 ret = -E_BAD_DATA_SIZE;
602 if (cd1->storage_flags & OSL_FIXED_SIZE)
603 if (cd1->data_size != cd2->data_size)
605 ret = -E_BAD_COLUMN_NAME;
606 if (strcmp(cd1->name, cd2->name))
609 PARA_DEBUG_LOG("table description of '%s' matches on-disk data, good\n",
613 FOR_EACH_COLUMN(i, &desc, cd1)
615 free(desc.column_descriptions);
619 static int create_table_index(struct osl_table *t)
621 char *buf, *filename;
623 size_t size = t->index_header_size;
624 const struct osl_column_description *cd;
627 PARA_INFO_LOG("creating %zu byte index for table %s\n", size,
629 buf = para_calloc(size);
630 sprintf(buf + IDX_PARA_MAGIC, "%s", PARA_MAGIC);
631 write_u8(buf + IDX_TABLE_FLAGS, t->desc->flags);
632 write_u8(buf + IDX_DIRTY_FLAG, 0);
633 write_u8(buf + IDX_VERSION, CURRENT_TABLE_VERSION);
634 write_u16(buf + IDX_NUM_COLUMNS, t->desc->num_columns);
635 write_u16(buf + IDX_HEADER_SIZE, t->index_header_size);
636 offset = IDX_COLUMN_DESCRIPTIONS;
637 FOR_EACH_COLUMN(i, t->desc, cd) {
638 write_u16(buf + offset + IDX_CD_STORAGE_TYPE,
640 write_u16(buf + offset + IDX_CD_STORAGE_FLAGS,
642 if (cd->storage_flags & OSL_FIXED_SIZE)
643 write_u32(buf + offset + IDX_CD_DATA_SIZE,
645 strcpy(buf + offset + IDX_CD_NAME, cd->name);
646 offset += index_column_description_size(cd->name);
648 assert(offset = size);
649 filename = index_filename(t->desc);
650 ret = para_write_file(filename, buf, size);
657 * Create a new osl table.
659 * \param desc Pointer to the table description.
661 * \return Positive on success, negative on errors. Possible errors include: \p
662 * E_BAD_TABLE_DESC, \p E_BAD_DB_DIR, \p E_BAD_NAME, \p E_NO_COMPARE_FUNC, \p
663 * E_NO_COLUMN_NAME, \p E_DUPLICATE_COL_NAME, \p E_MKDIR, any errors returned
666 int osl_create_table(const struct osl_table_description *desc)
668 const struct osl_column_description *cd;
669 char *table_dir = NULL, *filename;
671 int i, ret = init_table_structure(desc, &t);
675 PARA_INFO_LOG("creating %s\n", desc->name);
676 FOR_EACH_COLUMN(i, t->desc, cd) {
677 if (cd->storage_type == OSL_NO_STORAGE)
680 ret = para_mkdir(desc->dir, 0777);
681 if (ret < 0 && ret != -E_EXIST)
683 table_dir = make_message("%s/%s", desc->dir,
685 ret = para_mkdir(table_dir, 0777);
689 filename = column_filename(t, i);
690 PARA_INFO_LOG("filename: %s\n", filename);
691 if (cd->storage_type == OSL_MAPPED_STORAGE) {
692 ret = para_open(filename, O_RDWR | O_CREAT | O_EXCL,
701 ret = para_mkdir(filename, 0777);
706 if (t->num_mapped_columns) {
707 ret = create_table_index(t);
719 static int table_is_dirty(struct osl_table *t)
721 char *buf = (char *)t->index_map.data + IDX_DIRTY_FLAG;
722 uint8_t dirty = read_u8(buf) & 0x1;
726 static void mark_table_dirty(struct osl_table *t)
728 char *buf = (char *)t->index_map.data + IDX_DIRTY_FLAG;
729 write_u8(buf, read_u8(buf) | 1);
732 static void mark_table_clean(struct osl_table *t)
734 char *buf = (char *)t->index_map.data + IDX_DIRTY_FLAG;
735 write_u8(buf, read_u8(buf) & 0xfe);
738 static void unmap_column(struct osl_table *t, unsigned col_num)
740 struct osl_object map = t->columns[col_num].data_map;
744 ret = para_munmap(map.data, map.size);
750 * Unmap all mapped files of an osl table.
752 * \param t Pointer to a mapped table.
753 * \param flags Options for unmapping.
755 * \return Positive on success, negative on errors.
757 * \sa map_table(), enum osl_close_flags, para_munmap().
759 int unmap_table(struct osl_table *t, enum osl_close_flags flags)
762 const struct osl_column_description *cd;
765 if (!t->num_mapped_columns) /* can this ever happen? */
767 PARA_DEBUG_LOG("unmapping table '%s'\n", t->desc->name);
768 if (!t->index_map.data)
769 return -E_NOT_MAPPED;
770 if (flags & OSL_MARK_CLEAN)
772 ret = para_munmap(t->index_map.data, t->index_map.size);
775 t->index_map.data = NULL;
778 FOR_EACH_MAPPED_COLUMN(i, t, cd)
783 static int map_column(struct osl_table *t, unsigned col_num)
786 char *filename = column_filename(t, col_num);
788 if (stat(filename, &statbuf) < 0) {
792 if (!(S_IFREG & statbuf.st_mode)) {
796 ret = mmap_full_file(filename, O_RDWR,
797 &t->columns[col_num].data_map);
803 * Map the index file and all columns of type \p OSL_MAPPED_STORAGE into memory.
805 * \param t Pointer to an initialized table structure.
806 * \param flags Mapping options.
808 * \return Negative return value on errors; on success the number of rows
809 * (including invalid rows) is returned.
811 * \sa unmap_table(), enum map_table_flags, osl_open_table(), mmap(2).
813 int map_table(struct osl_table *t, enum map_table_flags flags)
816 const struct osl_column_description *cd;
817 int i = 0, ret, num_rows = 0;
819 if (!t->num_mapped_columns)
821 if (t->index_map.data)
822 return -E_ALREADY_MAPPED;
823 filename = index_filename(t->desc);
824 PARA_DEBUG_LOG("mapping table '%s' (index: %s)\n", t->desc->name, filename);
825 ret = mmap_full_file(filename, flags & MAP_TBL_FL_MAP_RDONLY?
826 O_RDONLY : O_RDWR, &t->index_map);
830 if (flags & MAP_TBL_FL_VERIFY_INDEX) {
831 ret = compare_table_descriptions(t);
836 if (!(flags & MAP_TBL_FL_IGNORE_DIRTY)) {
837 if (table_is_dirty(t)) {
838 PARA_ERROR_LOG("%s is dirty\n", t->desc->name);
843 num_rows = table_num_rows(t);
847 FOR_EACH_MAPPED_COLUMN(i, t, cd) {
848 ret = map_column(t, i);
853 err: /* unmap what is already mapped */
854 for (i--; i >= 0; i--) {
855 struct osl_object map = t->columns[i].data_map;
856 para_munmap(map.data, map.size);
859 para_munmap(t->index_map.data, t->index_map.size);
860 t->index_map.data = NULL;
865 * Retrieve a mapped object by row and column number.
867 * \param t Pointer to an open osl table.
868 * \param col_num Number of the mapped column containing the object to retrieve.
869 * \param row_num Number of the row containing the object to retrieve.
870 * \param obj The result is returned here.
872 * It is considered an error if \a col_num does not refer to a column
873 * of storage type \p OSL_MAPPED_STORAGE.
875 * \return Positive on success, negative on errors. Possible errors include:
876 * \p E_BAD_ROW_NUM, \p E_INVALID_OBJECT.
878 * \sa osl_storage_type.
880 int get_mapped_object(const struct osl_table *t, unsigned col_num,
881 uint32_t row_num, struct osl_object *obj)
883 struct osl_column *col = &t->columns[col_num];
889 if (t->num_rows <= row_num)
890 return -E_BAD_ROW_NUM;
891 ret = get_cell_index(t, row_num, col_num, &cell_index);
894 offset = read_u32(cell_index);
895 obj->size = read_u32(cell_index + 4) - 1;
896 header = col->data_map.data + offset;
897 obj->data = header + 1;
898 if (read_u8(header) == 0xff) {
899 PARA_ERROR_LOG("col %u, size %zu, offset %u\n", col_num,
901 return -E_INVALID_OBJECT;
906 static int search_rbtree(const struct osl_object *obj,
907 const struct osl_table *t, unsigned col_num,
908 struct rb_node **result, struct rb_node ***rb_link)
910 struct osl_column *col = &t->columns[col_num];
911 struct rb_node **new = &col->rbtree.rb_node, *parent = NULL;
912 const struct osl_column_description *cd =
913 get_column_description(t->desc, col_num);
914 enum osl_storage_type st = cd->storage_type;
916 struct osl_row *this_row = get_row_pointer(*new,
919 struct osl_object this_obj;
921 if (st == OSL_MAPPED_STORAGE) {
922 ret = get_mapped_object(t, col_num, this_row->num,
927 this_obj = this_row->volatile_objects[col->volatile_num];
928 ret = cd->compare_function(obj, &this_obj);
931 *result = get_rb_node_pointer(this_row,
936 new = &((*new)->rb_left);
938 new = &((*new)->rb_right);
944 return -E_RB_KEY_NOT_FOUND;
947 static int insert_rbtree(struct osl_table *t, unsigned col_num,
948 const struct osl_row *row, const struct osl_object *obj)
950 struct rb_node *parent, **rb_link;
953 int ret = search_rbtree(obj, t, col_num, &parent, &rb_link);
956 return -E_RB_KEY_EXISTS;
957 rbtree_num = t->columns[col_num].rbtree_num;
958 n = get_rb_node_pointer(row, rbtree_num);
959 rb_link_node(n, parent, rb_link);
960 rb_insert_color(n, &t->columns[col_num].rbtree);
964 static void remove_rb_node(struct osl_table *t, unsigned col_num,
965 const struct osl_row *row)
967 struct osl_column *col = &t->columns[col_num];
968 const struct osl_column_description *cd =
969 get_column_description(t->desc, col_num);
970 enum osl_storage_flags sf = cd->storage_flags;
971 struct rb_node *victim, *splice_out_node, *tmp;
972 if (!(sf & OSL_RBTREE))
975 * Which node is removed/spliced out actually depends on how many
976 * children the victim node has: If it has no children, it gets
977 * deleted. If it has one child, it gets spliced out. If it has two
978 * children, its successor (which has at most a right child) gets
981 victim = get_rb_node_pointer(row, col->rbtree_num);
982 if (victim->rb_left && victim->rb_right)
983 splice_out_node = rb_next(victim);
985 splice_out_node = victim;
986 /* Go up to the root and decrement the size of each node in the path. */
987 for (tmp = splice_out_node; tmp; tmp = rb_parent(tmp))
989 rb_erase(victim, &col->rbtree);
992 static int add_row_to_rbtrees(struct osl_table *t, uint32_t row_num,
993 struct osl_object *volatile_objs, struct osl_row **row_ptr)
997 struct osl_row *row = allocate_row(t->num_rbtrees);
998 const struct osl_column_description *cd;
1001 row->volatile_objects = volatile_objs;
1002 FOR_EACH_RBTREE_COLUMN(i, t, cd) {
1003 if (cd->storage_type == OSL_MAPPED_STORAGE) {
1004 struct osl_object obj;
1005 ret = get_mapped_object(t, i, row_num, &obj);
1008 ret = insert_rbtree(t, i, row, &obj);
1009 } else { /* volatile */
1010 const struct osl_object *obj
1011 = volatile_objs + t->columns[i].volatile_num;
1012 ret = insert_rbtree(t, i, row, obj);
1020 err: /* rollback changes, i.e. remove added entries from rbtrees */
1022 remove_rb_node(t, i--, row);
1027 static void free_volatile_objects(const struct osl_table *t,
1028 enum osl_close_flags flags)
1032 struct osl_column *rb_col;
1033 const struct osl_column_description *cd;
1035 if (!t->num_volatile_columns)
1037 /* find the first rbtree column (any will do) */
1038 FOR_EACH_RBTREE_COLUMN(i, t, cd)
1040 rb_col = t->columns + i;
1041 /* walk that rbtree and free all volatile objects */
1042 for (n = rb_first(&rb_col->rbtree); n; n = rb_next(n)) {
1043 struct osl_row *r = get_row_pointer(n, rb_col->rbtree_num);
1044 if (flags & OSL_FREE_VOLATILE)
1045 for (j = 0; j < t->num_volatile_columns; j++)
1046 free(r->volatile_objects[j].data);
1047 free(r->volatile_objects);
1052 * Erase all rbtree nodes and free resources.
1054 * \param t Pointer to an open osl table.
1056 * This function is called by osl_close_table().
1058 void clear_rbtrees(struct osl_table *t)
1060 const struct osl_column_description *cd;
1061 unsigned i, rbtrees_cleared = 0;
1063 FOR_EACH_RBTREE_COLUMN(i, t, cd) {
1064 struct osl_column *col = &t->columns[i];
1067 for (n = rb_first(&col->rbtree); n;) {
1069 rb_erase(n, &col->rbtree);
1070 if (rbtrees_cleared == t->num_rbtrees) {
1071 r = get_row_pointer(n, col->rbtree_num);
1082 * Close an osl table.
1084 * \param t Pointer to the table to be closed.
1085 * \param flags Options for what should be cleaned up.
1087 * If osl_open_table() succeeds, the resulting table pointer must later be
1088 * passed to this function in order to flush all changes to the filesystem and
1089 * to free the resources that were allocated by osl_open_table().
1091 * \return Positive on success, negative on errors. Possible errors: \p E_BAD_TABLE,
1092 * errors returned by unmap_table().
1094 * \sa osl_open_table(), unmap_table().
1096 int osl_close_table(struct osl_table *t, enum osl_close_flags flags)
1101 return -E_BAD_TABLE;
1102 free_volatile_objects(t, flags);
1104 ret = unmap_table(t, flags);
1106 PARA_ERROR_LOG("unmap_table failed: %d\n", ret);
1113 * Find out whether the given row number corresponds to an invalid row.
1115 * \param t Pointer to the osl table.
1116 * \param row_num The number of the row in question.
1118 * By definition, a row is considered invalid if all its index entries
1121 * \return Positive if \a row_num corresponds to an invalid row,
1122 * zero if it corresponds to a valid row, negative on errors.
1124 int row_is_invalid(struct osl_table *t, uint32_t row_num)
1127 int i, ret = get_row_index(t, row_num, &row_index);
1131 for (i = 0; i < t->row_index_size; i++) {
1132 if ((unsigned char)row_index[i] != 0xff)
1135 PARA_INFO_LOG("row %d is invalid\n", row_num);
1140 * Invalidate a row of an osl table.
1142 * \param t Pointer to an open osl table.
1143 * \param row_num Number of the row to mark as invalid.
1145 * This function marks each mapped object in the index entry of \a row as
1148 * \return Positive on success, negative on errors.
1150 int mark_row_invalid(struct osl_table *t, uint32_t row_num)
1153 int ret = get_row_index(t, row_num, &row_index);
1157 PARA_INFO_LOG("marking row %d as invalid\n", row_num);
1158 memset(row_index, 0xff, t->row_index_size);
1163 * Initialize all rbtrees and compute number of invalid rows.
1165 * \param t The table containing the rbtrees to be initialized.
1167 * \return Positive on success, negative on errors.
1169 int init_rbtrees(struct osl_table *t)
1172 const struct osl_column_description *cd;
1174 /* create rbtrees */
1175 FOR_EACH_RBTREE_COLUMN(i, t, cd)
1176 t->columns[i].rbtree = RB_ROOT;
1177 /* add valid rows to rbtrees */
1178 t->num_invalid_rows = 0;
1179 for (i = 0; i < t->num_rows; i++) {
1180 ret = row_is_invalid(t, i);
1184 t->num_invalid_rows++;
1187 ret = add_row_to_rbtrees(t, i, NULL, NULL);
1195 * Open an osl table.
1197 * Each osl table must be opened before its data can be accessed.
1199 * \param table_desc Describes the table to be opened.
1200 * \param result Contains a pointer to the open table on success.
1202 * The table description given by \a desc should coincide with the
1203 * description used at creation time.
1205 * \return Positive on success, negative on errors. Possible errors include:
1206 * errors returned by init_table_structure(), \p E_NOENT, \p E_STAT, \p \p
1207 * E_NOTDIR, \p E_BAD_TABLE_DESC, \p E_BAD_DB_DIR, \p E_NO_COMPARE_FUNC, \p
1208 * E_NO_COLUMN_NAME, errors returned by init_rbtrees().
1210 int osl_open_table(const struct osl_table_description *table_desc,
1211 struct osl_table **result)
1214 struct osl_table *t;
1215 const struct osl_column_description *cd;
1217 PARA_INFO_LOG("opening table %s\n", table_desc->name);
1218 ret = init_table_structure(table_desc, &t);
1221 FOR_EACH_DISK_STORAGE_COLUMN(i, t, cd) {
1222 /* check if directory exists */
1223 char *dirname = column_filename(t, i);
1224 struct stat statbuf;
1225 ret = stat(dirname, &statbuf);
1228 if (errno == ENOENT)
1235 if (!S_ISDIR(statbuf.st_mode))
1238 ret = map_table(t, MAP_TBL_FL_VERIFY_INDEX);
1242 PARA_DEBUG_LOG("num rows: %d\n", t->num_rows);
1243 ret = init_rbtrees(t);
1245 osl_close_table(t, OSL_MARK_CLEAN); /* ignore further errors */
1256 static int create_disk_storage_object_dir(const struct osl_table *t,
1257 unsigned col_num, const char *ds_name)
1262 if (!(t->desc->flags & OSL_LARGE_TABLE))
1264 dirname = disk_storage_dirname(t, col_num, ds_name);
1265 ret = para_mkdir(dirname, 0777);
1267 if (ret < 0 && ret != -E_EXIST)
1272 static int write_disk_storage_file(const struct osl_table *t, unsigned col_num,
1273 const struct osl_object *obj, const char *ds_name)
1278 ret = create_disk_storage_object_dir(t, col_num, ds_name);
1281 filename = disk_storage_path(t, col_num, ds_name);
1282 ret = para_write_file(filename, obj->data, obj->size);
1287 static int append_map_file(const struct osl_table *t, unsigned col_num,
1288 const struct osl_object *obj, uint32_t *new_size)
1290 char *filename = column_filename(t, col_num);
1292 char header = 0; /* zero means valid object */
1294 // PARA_DEBUG_LOG("appending %zu + 1 byte\n", obj->size);
1295 ret = append_file(filename, &header, 1, obj->data, obj->size,
1301 static int append_row_index(const struct osl_table *t, char *row_index)
1306 if (!t->num_mapped_columns)
1308 filename = index_filename(t->desc);
1309 ret = append_file(filename, NULL, 0, row_index,
1310 t->row_index_size, NULL);
1316 * A wrapper for truncate(2)
1318 * \param path Name of the regular file to truncate
1319 * \param size Number of bytes to \b shave \b off
1321 * Truncate the regular file named by \a path by \a size bytes.
1323 * \return Positive on success, negative on errors. Possible errors include: \p
1324 * E_STAT, \p E_BAD_SIZE, \p E_TRUNC.
1328 int para_truncate(const char *path, off_t size)
1331 struct stat statbuf;
1334 if (stat(path, &statbuf) < 0)
1337 if (statbuf.st_size < size)
1340 if (truncate(path, statbuf.st_size - size) < 0)
1347 static int truncate_mapped_file(const struct osl_table *t, unsigned col_num,
1350 char *filename = column_filename(t, col_num);
1351 int ret = para_truncate(filename, size);
1356 static int delete_disk_storage_file(const struct osl_table *t, unsigned col_num,
1357 const char *ds_name)
1359 char *dirname, *filename = disk_storage_path(t, col_num, ds_name);
1360 int ret = unlink(filename);
1362 PARA_DEBUG_LOG("deleted %s\n", filename);
1365 if (errno == ENOENT)
1369 if (!(t->desc->flags & OSL_LARGE_TABLE))
1371 dirname = disk_storage_dirname(t, col_num, ds_name);
1378 * Add a new row to an osl table and retrieve this row.
1380 * \param t Pointer to an open osl table.
1381 * \param objects Array of objects to be added.
1382 * \param row Result pointer.
1384 * The \a objects parameter must point to an array containing one object per
1385 * column. The order of the objects in the array is given by the table
1386 * description of \a table. Several sanity checks are performed during object
1387 * insertion and the function returns without modifying the table if any of
1388 * these tests fail. In fact, it is atomic in the sense that it either
1389 * succeeds or leaves the table unchanged (i.e. either all or none of the
1390 * objects are added to the table).
1392 * It is considered an error if an object is added to a column with associated
1393 * rbtree if this object is equal to an object already contained in that column
1394 * (i.e. the compare function for the column's rbtree returns zero).
1396 * Possible errors include: \p E_RB_KEY_EXISTS, \p E_BAD_DATA_SIZE.
1398 * \return Positive on success, negative on errors.
1400 * \sa struct osl_table_description, osl_compare_func, osl_add_row().
1402 int osl_add_and_get_row(struct osl_table *t, struct osl_object *objects,
1403 struct osl_row **row)
1406 char *ds_name = NULL;
1407 struct rb_node **rb_parents = NULL, ***rb_links = NULL;
1408 char *new_row_index = NULL;
1409 struct osl_object *volatile_objs = NULL;
1410 const struct osl_column_description *cd;
1413 return -E_BAD_TABLE;
1414 rb_parents = para_malloc(t->num_rbtrees * sizeof(struct rn_node*));
1415 rb_links = para_malloc(t->num_rbtrees * sizeof(struct rn_node**));
1416 if (t->num_mapped_columns)
1417 new_row_index = para_malloc(t->row_index_size);
1418 /* pass 1: sanity checks */
1419 // PARA_DEBUG_LOG("sanity tests: %p:%p\n", objects[0].data,
1420 // objects[1].data);
1421 FOR_EACH_COLUMN(i, t->desc, cd) {
1422 enum osl_storage_type st = cd->storage_type;
1423 enum osl_storage_flags sf = cd->storage_flags;
1425 // ret = -E_NULL_OBJECT;
1428 if (st == OSL_DISK_STORAGE)
1430 if (sf & OSL_RBTREE) {
1431 unsigned rbtree_num = t->columns[i].rbtree_num;
1432 ret = -E_RB_KEY_EXISTS;
1433 // PARA_DEBUG_LOG("checking whether %p exists\n",
1434 // objects[i].data);
1435 if (search_rbtree(objects + i, t, i,
1436 &rb_parents[rbtree_num],
1437 &rb_links[rbtree_num]) > 0)
1440 if (sf & OSL_FIXED_SIZE) {
1441 // PARA_DEBUG_LOG("fixed size. need: %zu, have: %d\n",
1442 // objects[i].size, cd->data_size);
1443 ret = -E_BAD_DATA_SIZE;
1444 if (objects[i].size != cd->data_size)
1448 if (t->num_disk_storage_columns)
1449 ds_name = disk_storage_name_of_object(t,
1450 &objects[t->disk_storage_name_column]);
1451 ret = unmap_table(t, OSL_MARK_CLEAN);
1454 // PARA_DEBUG_LOG("sanity tests passed%s\n", "");
1455 /* pass 2: create data files, append map data */
1456 FOR_EACH_COLUMN(i, t->desc, cd) {
1457 enum osl_storage_type st = cd->storage_type;
1458 if (st == OSL_NO_STORAGE)
1460 if (st == OSL_MAPPED_STORAGE) {
1462 struct osl_column *col = &t->columns[i];
1463 // PARA_DEBUG_LOG("appending object of size %zu\n",
1464 // objects[i].size);
1465 ret = append_map_file(t, i, objects + i, &new_size);
1468 update_cell_index(new_row_index, col, new_size,
1473 ret = write_disk_storage_file(t, i, objects + i, ds_name);
1477 ret = append_row_index(t, new_row_index);
1480 ret = map_table(t, MAP_TBL_FL_VERIFY_INDEX);
1481 if (ret < 0) { /* truncate index and rollback changes */
1482 char *filename = index_filename(t->desc);
1483 para_truncate(filename, t->row_index_size);
1487 /* pass 3: add entry to rbtrees */
1488 if (t->num_volatile_columns) {
1489 volatile_objs = para_calloc(t->num_volatile_columns
1490 * sizeof(struct osl_object));
1491 FOR_EACH_VOLATILE_COLUMN(i, t, cd)
1492 volatile_objs[t->columns[i].volatile_num] = objects[i];
1495 // PARA_DEBUG_LOG("adding new entry as row #%d\n", t->num_rows - 1);
1496 ret = add_row_to_rbtrees(t, t->num_rows - 1, volatile_objs, row);
1499 // PARA_DEBUG_LOG("added new entry as row #%d\n", t->num_rows - 1);
1502 rollback: /* rollback all changes made, ignore further errors */
1503 for (i--; i >= 0; i--) {
1504 cd = get_column_description(t->desc, i);
1505 enum osl_storage_type st = cd->storage_type;
1506 if (st == OSL_NO_STORAGE)
1509 if (st == OSL_MAPPED_STORAGE)
1510 truncate_mapped_file(t, i, objects[i].size);
1511 else /* disk storage */
1512 delete_disk_storage_file(t, i, ds_name);
1514 /* ignore error and return previous error value */
1515 map_table(t, MAP_TBL_FL_VERIFY_INDEX);
1517 free(new_row_index);
1525 * Add a new row to an osl table.
1527 * \param t Same meaning as osl_add_and_get_row().
1528 * \param objects Same meaning as osl_add_and_get_row().
1530 * \return The return value of the underlying call to osl_add_and_get_row().
1532 * This is equivalent to osl_add_and_get_row(t, objects, NULL).
1534 int osl_add_row(struct osl_table *t, struct osl_object *objects)
1536 return osl_add_and_get_row(t, objects, NULL);
1540 * Retrieve an object identified by row and column
1542 * \param t Pointer to an open osl table.
1543 * \param r Pointer to the row.
1544 * \param col_num The column number.
1545 * \param object The result pointer.
1547 * The column determined by \a col_num must be of type \p OSL_MAPPED_STORAGE
1548 * or \p OSL_NO_STORAGE, i.e. no disk storage objects may be retrieved by this
1551 * \return Positive if object was found, negative on errors. Possible errors
1552 * include: \p E_BAD_TABLE, \p E_BAD_STORAGE_TYPE.
1554 * \sa osl_storage_type, osl_open_disk_object().
1556 int osl_get_object(const struct osl_table *t, const struct osl_row *r,
1557 unsigned col_num, struct osl_object *object)
1559 const struct osl_column_description *cd;
1562 return -E_BAD_TABLE;
1563 cd = get_column_description(t->desc, col_num);
1564 /* col must not be disk storage */
1565 if (cd->storage_type == OSL_DISK_STORAGE)
1566 return -E_BAD_STORAGE_TYPE;
1567 if (cd->storage_type == OSL_MAPPED_STORAGE)
1568 return get_mapped_object(t, col_num, r->num, object);
1570 *object = r->volatile_objects[t->columns[col_num].volatile_num];
1574 static int mark_mapped_object_invalid(const struct osl_table *t,
1575 uint32_t row_num, unsigned col_num)
1577 struct osl_object obj;
1579 int ret = get_mapped_object(t, col_num, row_num, &obj);
1590 * Delete a row from an osl table.
1592 * \param t Pointer to an open osl table.
1593 * \param row Pointer to the row to delete.
1595 * This removes all disk storage objects, removes all rbtree nodes, and frees
1596 * all volatile objects belonging to the given row. For mapped columns, the
1597 * data is merely marked invalid and may be pruned from time to time by
1600 * \return Positive on success, negative on errors. Possible errors include:
1601 * \p E_BAD_TABLE, errors returned by osl_get_object().
1603 int osl_del_row(struct osl_table *t, struct osl_row *row)
1605 struct osl_row *r = row;
1607 const struct osl_column_description *cd;
1610 return -E_BAD_TABLE;
1611 PARA_INFO_LOG("deleting row %p\n", row);
1613 if (t->num_disk_storage_columns) {
1615 ret = disk_storage_name_of_row(t, r, &ds_name);
1618 FOR_EACH_DISK_STORAGE_COLUMN(i, t, cd)
1619 delete_disk_storage_file(t, i, ds_name);
1622 FOR_EACH_COLUMN(i, t->desc, cd) {
1623 struct osl_column *col = t->columns + i;
1624 enum osl_storage_type st = cd->storage_type;
1625 remove_rb_node(t, i, r);
1626 if (st == OSL_MAPPED_STORAGE) {
1627 mark_mapped_object_invalid(t, r->num, i);
1630 if (st == OSL_NO_STORAGE)
1631 free(r->volatile_objects[col->volatile_num].data);
1633 if (t->num_mapped_columns) {
1634 ret = mark_row_invalid(t, r->num);
1637 t->num_invalid_rows++;
1642 free(r->volatile_objects);
1647 /* test if column has an rbtree */
1648 static int check_rbtree_col(const struct osl_table *t, unsigned col_num,
1649 struct osl_column **col)
1652 return -E_BAD_TABLE;
1653 if (!(get_column_description(t->desc, col_num)->storage_flags & OSL_RBTREE))
1654 return -E_BAD_STORAGE_FLAGS;
1655 *col = t->columns + col_num;
1660 * Get the row that contains the given object.
1662 * \param t Pointer to an open osl table.
1663 * \param col_num The number of the column to be searched.
1664 * \param obj The object to be looked up.
1665 * \param result Points to the row containing \a obj.
1667 * Lookup \a obj in \a t and return the row containing \a obj. The column
1668 * specified by \a col_num must have an associated rbtree.
1670 * \return Positive on success, negative on errors. If an error occured, \a
1671 * result is set to \p NULL. Possible errors include: \p E_BAD_TABLE, \p
1672 * E_BAD_STORAGE_FLAGS, errors returned by get_mapped_object(), \p
1673 * E_RB_KEY_NOT_FOUND.
1675 * \sa osl_storage_flags
1677 int osl_get_row(const struct osl_table *t, unsigned col_num,
1678 const struct osl_object *obj, struct osl_row **result)
1681 struct rb_node *node;
1682 struct osl_row *row;
1683 struct osl_column *col;
1686 ret = check_rbtree_col(t, col_num, &col);
1689 ret = search_rbtree(obj, t, col_num, &node, NULL);
1692 row = get_row_pointer(node, t->columns[col_num].rbtree_num);
1697 static int rbtree_loop(struct osl_column *col, void *private_data,
1698 osl_rbtree_loop_func *func)
1700 struct rb_node *n, *tmp;
1702 /* this for-loop is safe against removal of an entry */
1703 for (n = rb_first(&col->rbtree), tmp = n? rb_next(n) : NULL;
1705 n = tmp, tmp = tmp? rb_next(tmp) : NULL) {
1706 struct osl_row *r = get_row_pointer(n, col->rbtree_num);
1707 int ret = func(r, private_data);
1714 static int rbtree_loop_reverse(struct osl_column *col, void *private_data,
1715 osl_rbtree_loop_func *func)
1717 struct rb_node *n, *tmp;
1719 /* safe against removal of an entry */
1720 for (n = rb_last(&col->rbtree), tmp = n? rb_prev(n) : NULL;
1722 n = tmp, tmp = tmp? rb_prev(tmp) : NULL) {
1723 struct osl_row *r = get_row_pointer(n, col->rbtree_num);
1724 int ret = func(r, private_data);
1732 * Loop over all nodes in an rbtree.
1734 * \param t Pointer to an open osl table.
1735 * \param col_num The column to use for iterating over the elements.
1736 * \param private_data Pointer that gets passed to \a func.
1737 * \param func The function to be called for each node in the rbtree.
1739 * This function does an in-order walk of the rbtree associated with \a
1740 * col_num. It is an error if the \p OSL_RBTREE flag is not set for this
1741 * column. For each node in the rbtree, the given function \a func is called
1742 * with two pointers as arguments: The first osl_row* argument points to the
1743 * row that contains the object corresponding to the rbtree node currently
1744 * traversed, and the \a private_data pointer is passed verbatim to \a func as the
1745 * second argument. The loop terminates either if \a func returns a negative
1746 * value, or if all nodes of the tree have been visited.
1749 * \return Positive on success, negative on errors. If the termination of the
1750 * loop was caused by \a func returning a negative value, this value is
1753 * \sa osl_storage_flags, osl_rbtree_loop_reverse(), osl_compare_func.
1755 int osl_rbtree_loop(const struct osl_table *t, unsigned col_num,
1756 void *private_data, osl_rbtree_loop_func *func)
1758 struct osl_column *col;
1760 int ret = check_rbtree_col(t, col_num, &col);
1763 return rbtree_loop(col, private_data, func);
1767 * Loop over all nodes in an rbtree in reverse order.
1769 * \param t Identical meaning as in \p osl_rbtree_loop().
1770 * \param col_num Identical meaning as in \p osl_rbtree_loop().
1771 * \param private_data Identical meaning as in \p osl_rbtree_loop().
1772 * \param func Identical meaning as in \p osl_rbtree_loop().
1774 * This function is identical to \p osl_rbtree_loop(), the only difference
1775 * is that the tree is walked in reverse order.
1777 * \return The same return value as \p osl_rbtree_loop().
1779 * \sa osl_rbtree_loop().
1781 int osl_rbtree_loop_reverse(const struct osl_table *t, unsigned col_num,
1782 void *private_data, osl_rbtree_loop_func *func)
1784 struct osl_column *col;
1786 int ret = check_rbtree_col(t, col_num, &col);
1789 return rbtree_loop_reverse(col, private_data, func);
1792 /* TODO: Rollback changes on errors */
1793 static int rename_disk_storage_objects(struct osl_table *t,
1794 struct osl_object *old_obj, struct osl_object *new_obj)
1797 const struct osl_column_description *cd;
1798 char *old_ds_name, *new_ds_name;
1800 if (!t->num_disk_storage_columns)
1801 return 1; /* nothing to do */
1802 if (old_obj->size == new_obj->size && !memcmp(new_obj->data,
1803 old_obj->data, new_obj->size))
1804 return 1; /* object did not change */
1805 old_ds_name = disk_storage_name_of_object(t, old_obj);
1806 new_ds_name = disk_storage_name_of_object(t, new_obj);
1807 FOR_EACH_DISK_STORAGE_COLUMN(i, t, cd) {
1808 char *old_filename, *new_filename;
1809 ret = create_disk_storage_object_dir(t, i, new_ds_name);
1812 old_filename = disk_storage_path(t, i, old_ds_name);
1813 new_filename = disk_storage_path(t, i, new_ds_name);
1814 ret = para_rename(old_filename, new_filename);
1829 * Change an object in an osl table.
1831 * \param t Pointer to an open osl table.
1832 * \param r Pointer to the row containing the object to be updated.
1833 * \param col_num Number of the column containing the object to be updated.
1834 * \param obj Pointer to the replacement object.
1836 * This function gets rid of all references to the old object. This includes
1837 * removal of the rbtree node in case there is an rbtree associated with \a
1838 * col_num. It then inserts \a obj into the table and the rbtree if neccessary.
1840 * If the \p OSL_RBTREE flag is set for \a col_num, you \b MUST call this
1841 * function in order to change the contents of an object, even for volatile or
1842 * mapped columns of constant size (which may be updated directly if \p
1843 * OSL_RBTREE is not set). Otherwise the rbtree might become corrupted.
1845 * \return Positive on success, negative on errors. Possible errors include: \p
1846 * E_BAD_TABLE, \p E_RB_KEY_EXISTS, \p E_BAD_SIZE, \p E_NOENT, \p E_UNLINK,
1847 * errors returned by para_write_file(), \p E_MKDIR.
1849 int osl_update_object(struct osl_table *t, const struct osl_row *r,
1850 unsigned col_num, struct osl_object *obj)
1852 struct osl_column *col;
1853 const struct osl_column_description *cd;
1857 return -E_BAD_TABLE;
1858 col = &t->columns[col_num];
1859 cd = get_column_description(t->desc, col_num);
1860 PARA_DEBUG_LOG("updating column %u of %s\n", col_num, t->desc->name);
1861 if (cd->storage_flags & OSL_RBTREE) {
1862 if (search_rbtree(obj, t, col_num, NULL, NULL) > 0)
1863 return -E_RB_KEY_EXISTS;
1865 if (cd->storage_flags & OSL_FIXED_SIZE) {
1866 if (obj->size != cd->data_size)
1867 return -E_BAD_DATA_SIZE;
1869 remove_rb_node(t, col_num, r);
1870 if (cd->storage_type == OSL_NO_STORAGE) { /* TODO: If fixed size, reuse object? */
1871 free(r->volatile_objects[col->volatile_num].data);
1872 r->volatile_objects[col->volatile_num] = *obj;
1873 } else if (cd->storage_type == OSL_DISK_STORAGE) {
1875 ret = disk_storage_name_of_row(t, r, &ds_name);
1878 ret = delete_disk_storage_file(t, col_num, ds_name);
1879 if (ret < 0 && ret != -E_NOENT) {
1883 ret = write_disk_storage_file(t, col_num, obj, ds_name);
1887 } else { /* mapped storage */
1888 struct osl_object old_obj;
1889 ret = get_mapped_object(t, col_num, r->num, &old_obj);
1893 * If the updated column is the disk storage name column, the
1894 * disk storage name changes, so we have to rename all disk
1895 * storage objects accordingly.
1897 if (col_num == t->disk_storage_name_column) {
1898 ret = rename_disk_storage_objects(t, &old_obj, obj);
1902 if (cd->storage_flags & OSL_FIXED_SIZE)
1903 memcpy(old_obj.data, obj->data, cd->data_size);
1904 else { /* TODO: if the size doesn't change, use old space */
1905 uint32_t new_data_map_size;
1907 ret = get_row_index(t, r->num, &row_index);
1910 ret = mark_mapped_object_invalid(t, r->num, col_num);
1913 unmap_column(t, col_num);
1914 ret = append_map_file(t, col_num, obj,
1915 &new_data_map_size);
1918 ret = map_column(t, col_num);
1921 update_cell_index(row_index, col, new_data_map_size,
1925 if (cd->storage_flags & OSL_RBTREE) {
1926 ret = insert_rbtree(t, col_num, r, obj);
1934 * Retrieve an object of type \p OSL_DISK_STORAGE by row and column.
1936 * \param t Pointer to an open osl table.
1937 * \param r Pointer to the row containing the object.
1938 * \param col_num The column number.
1939 * \param obj Points to the result upon successful return.
1941 * For columns of type \p OSL_DISK_STORAGE, this function must be used to
1942 * retrieve one of its containing objects. Afterwards, osl_close_disk_object()
1943 * must be called in order to deallocate the resources.
1945 * \return Positive on success, negative on errors. Possible errors include:
1946 * \p E_BAD_TABLE, \p E_BAD_STORAGE_TYPE, errors returned by osl_get_object().
1948 * \sa osl_get_object(), osl_storage_type, osl_close_disk_object().
1950 int osl_open_disk_object(const struct osl_table *t, const struct osl_row *r,
1951 unsigned col_num, struct osl_object *obj)
1953 const struct osl_column_description *cd;
1954 char *ds_name, *filename;
1958 return -E_BAD_TABLE;
1959 cd = get_column_description(t->desc, col_num);
1960 if (cd->storage_type != OSL_DISK_STORAGE)
1961 return -E_BAD_STORAGE_TYPE;
1963 ret = disk_storage_name_of_row(t, r, &ds_name);
1966 filename = disk_storage_path(t, col_num, ds_name);
1968 PARA_DEBUG_LOG("filename: %s\n", filename);
1969 ret = mmap_full_file(filename, O_RDONLY, obj);
1975 * Free resources that were allocated during osl_open_disk_object().
1977 * \param obj Pointer to the object previously returned by open_disk_object().
1979 * \return The return value of the underlying call to para_munmap().
1981 * \sa para_munmap().
1983 int osl_close_disk_object(struct osl_object *obj)
1985 return para_munmap(obj->data, obj->size);
1989 * Get the number of rows of the given table.
1991 * \param t Pointer to an open osl table.
1992 * \param num_rows Result is returned here.
1994 * The number of rows returned via \a num_rows excluding any invalid rows.
1996 * \return Positive on success, \p -E_BAD_TABLE if \a t is \p NULL.
1998 int osl_get_num_rows(const struct osl_table *t, unsigned *num_rows)
2001 return -E_BAD_TABLE;
2002 assert(t->num_rows >= t->num_invalid_rows);
2003 *num_rows = t->num_rows - t->num_invalid_rows;
2008 * Get the rank of a row.
2010 * \param t An open osl table.
2011 * \param r The row to get the rank of.
2012 * \param col_num The number of an rbtree column.
2013 * \param rank Result pointer.
2015 * The rank is, by definition, the position of the row in the linear order
2016 * determined by an inorder tree walk of the rbtree associated with column
2017 * number \a col_num of \a table.
2019 * \return Positive on success, negative on errors.
2021 * \sa osl_get_nth_row().
2023 int osl_get_rank(const struct osl_table *t, struct osl_row *r,
2024 unsigned col_num, unsigned *rank)
2026 struct osl_object obj;
2027 struct osl_column *col;
2028 struct rb_node *node;
2029 int ret = check_rbtree_col(t, col_num, &col);
2033 ret = osl_get_object(t, r, col_num, &obj);
2036 ret = search_rbtree(&obj, t, col_num, &node, NULL);
2039 ret = rb_rank(node, rank);
2046 * Get the row with n-th greatest value.
2048 * \param t Pointer to an open osl table.
2049 * \param col_num The column number.
2050 * \param n The rank of the desired row.
2051 * \param result Row is returned here.
2053 * Retrieve the n-th order statistic with respect to the compare function
2054 * of the rbtree column \a col_num. In other words, get that row with
2055 * \a n th greatest value in column \a col_num. It's an error if
2056 * \a col_num is not a rbtree column, or if \a n is larger than the
2057 * number of rows in the table.
2059 * \return Positive on success, negative on errors. Possible errors:
2060 * \p E_BAD_TABLE, \p E_BAD_STORAGE_FLAGS, \p E_RB_KEY_NOT_FOUND.
2062 * \sa osl_storage_flags, osl_compare_func, osl_get_row(),
2063 * osl_rbtree_last_row(), osl_rbtree_first_row(), osl_get_rank().
2065 int osl_get_nth_row(const struct osl_table *t, unsigned col_num,
2066 unsigned n, struct osl_row **result)
2068 struct osl_column *col;
2069 struct rb_node *node;
2070 int ret = check_rbtree_col(t, col_num, &col);
2074 node = rb_nth(col->rbtree.rb_node, n);
2076 return -E_RB_KEY_NOT_FOUND;
2077 *result = get_row_pointer(node, col->rbtree_num);
2082 * Get the row corresponding to the smallest rbtree node of a column.
2084 * \param t An open rbtree table.
2085 * \param col_num The number of the rbtree column.
2086 * \param result A pointer to the first row is returned here.
2088 * The rbtree node of the smallest object (with respect to the corresponding
2089 * compare function) is selected and the row containing this object is
2090 * returned. It is an error if \a col_num refers to a column without an
2091 * associated rbtree.
2093 * \return Positive on success, negative on errors.
2095 * \sa osl_get_nth_row(), osl_rbtree_last_row().
2097 int osl_rbtree_first_row(const struct osl_table *t, unsigned col_num,
2098 struct osl_row **result)
2100 return osl_get_nth_row(t, col_num, 1, result);
2104 * Get the row corresponding to the greatest rbtree node of a column.
2106 * \param t The same meaning as in \p osl_rbtree_first_row().
2107 * \param col_num The same meaning as in \p osl_rbtree_first_row().
2108 * \param result The same meaning as in \p osl_rbtree_first_row().
2110 * This function works just like osl_rbtree_first_row(), the only difference
2111 * is that the row containing the greatest rather than the smallest object is
2114 * \return Positive on success, negative on errors.
2116 * \sa osl_get_nth_row(), osl_rbtree_first_row().
2118 int osl_rbtree_last_row(const struct osl_table *t, unsigned col_num,
2119 struct osl_row **result)
2122 int ret = osl_get_num_rows(t, &num_rows);
2126 return osl_get_nth_row(t, col_num, num_rows, result);