3722a7262d6aa773d4f3210e12217e7505d449f1
1 /*
2 * SysDB - src/include/core/store.h
3 * Copyright (C) 2012 Sebastian 'tokkee' Harl <sh@tokkee.org>
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
16 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
17 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
18 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR
19 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
20 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
21 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
22 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
23 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
24 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
25 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 */
28 #ifndef SDB_CORE_STORE_H
29 #define SDB_CORE_STORE_H 1
31 #include "sysdb.h"
32 #include "core/object.h"
33 #include "core/data.h"
34 #include "core/time.h"
35 #include "core/timeseries.h"
36 #include "utils/strbuf.h"
38 #include <stdbool.h>
39 #include <stdio.h>
41 #ifdef __cplusplus
42 extern "C" {
43 #endif
45 /*
46 * Store object types.
47 */
48 enum {
49 SDB_HOST = 1,
50 SDB_SERVICE,
51 SDB_METRIC,
53 SDB_ATTRIBUTE = 1 << 4,
55 /*
56 * Queryable fields of a stored object.
57 */
58 SDB_FIELD_NAME = 1 << 8, /* type: string */
59 SDB_FIELD_LAST_UPDATE, /* type: datetime */
60 SDB_FIELD_AGE, /* type: datetime */
61 SDB_FIELD_INTERVAL, /* type: datetime */
62 SDB_FIELD_BACKEND, /* type: array of strings */
63 };
64 #define SDB_STORE_TYPE_TO_NAME(t) \
65 (((t) == SDB_HOST) ? "host" \
66 : ((t) == SDB_SERVICE) ? "service" \
67 : ((t) == SDB_METRIC) ? "metric" \
68 : ((t) == SDB_ATTRIBUTE) ? "attribute" \
69 : ((t) == (SDB_ATTRIBUTE | SDB_HOST)) ? "host attribute" \
70 : ((t) == (SDB_ATTRIBUTE | SDB_SERVICE)) ? "service attribute" \
71 : ((t) == (SDB_ATTRIBUTE | SDB_METRIC)) ? "metric attribute" \
72 : "unknown")
74 #define SDB_FIELD_TO_NAME(f) \
75 (((f) == SDB_FIELD_NAME) ? "name" \
76 : ((f) == SDB_FIELD_LAST_UPDATE) ? "last-update" \
77 : ((f) == SDB_FIELD_AGE) ? "age" \
78 : ((f) == SDB_FIELD_INTERVAL) ? "interval" \
79 : ((f) == SDB_FIELD_BACKEND) ? "backend" : "unknown")
81 #define SDB_FIELD_TYPE(f) \
82 (((f) == SDB_FIELD_NAME) ? SDB_TYPE_STRING \
83 : ((f) == SDB_FIELD_LAST_UPDATE) ? SDB_TYPE_DATETIME \
84 : ((f) == SDB_FIELD_AGE) ? SDB_TYPE_DATETIME \
85 : ((f) == SDB_FIELD_INTERVAL) ? SDB_TYPE_DATETIME \
86 : ((f) == SDB_FIELD_BACKEND) ? (SDB_TYPE_ARRAY | SDB_TYPE_STRING) \
87 : -1)
89 /*
90 * sdb_store_obj_t represents the super-class of any object stored in the
91 * database. It inherits from sdb_object_t and may safely be cast to a generic
92 * object to access its name.
93 */
94 struct sdb_store_obj;
95 typedef struct sdb_store_obj sdb_store_obj_t;
97 /*
98 * A metric store describes how to access a metric's data.
99 */
100 typedef struct {
101 const char *type;
102 const char *id;
103 } sdb_metric_store_t;
105 /*
106 * Expressions represent arithmetic expressions based on stored objects and
107 * their various attributes.
108 *
109 * An expression object inherits from sdb_object_t and, thus, may safely be
110 * cast to a generic object.
111 */
112 struct sdb_store_expr;
113 typedef struct sdb_store_expr sdb_store_expr_t;
114 #define SDB_STORE_EXPR(obj) ((sdb_store_expr_t *)(obj))
116 /*
117 * An expression iterator iterates over the values of an iterable expression
118 * (see sdb_store_expr_iterable).
119 */
120 struct sdb_store_expr_iter;
121 typedef struct sdb_store_expr_iter sdb_store_expr_iter_t;
123 /*
124 * Store matchers may be used to lookup hosts from the store based on their
125 * various attributes. Service and attribute matchers are applied to a host's
126 * services and attributes and evaluate to true if *any* service or attribute
127 * matches.
128 *
129 * A store matcher object inherits from sdb_object_t and, thus, may safely be
130 * cast to a generic object.
131 */
132 struct sdb_store_matcher;
133 typedef struct sdb_store_matcher sdb_store_matcher_t;
134 #define SDB_STORE_MATCHER(obj) ((sdb_store_matcher_t *)(obj))
136 /*
137 * A JSON formatter converts stored objects into the JSON format.
138 * See http://www.ietf.org/rfc/rfc4627.txt
139 */
140 struct sdb_store_json_formatter;
141 typedef struct sdb_store_json_formatter sdb_store_json_formatter_t;
143 /*
144 * A store writer describes the interface for plugins implementing a store.
145 */
146 typedef struct {
147 int (*store_host)(const char *name, sdb_time_t last_update,
148 sdb_object_t *user_data);
149 int (*store_service)(const char *hostname, const char *name,
150 sdb_time_t last_update, sdb_object_t *user_data);
151 int (*store_metric)(const char *hostname, const char *name,
152 sdb_metric_store_t *store, sdb_time_t last_update,
153 sdb_object_t *user_data);
154 int (*store_attribute)(const char *hostname,
155 const char *key, const sdb_data_t *value, sdb_time_t last_update,
156 sdb_object_t *user_data);
157 int (*store_service_attr)(const char *hostname, const char *service,
158 const char *key, const sdb_data_t *value, sdb_time_t last_update,
159 sdb_object_t *user_data);
160 int (*store_metric_attr)(const char *hostname, const char *metric,
161 const char *key, const sdb_data_t *value, sdb_time_t last_update,
162 sdb_object_t *user_data);
163 } sdb_store_writer_t;
165 /*
166 * sdb_store_clear:
167 * Clear the entire store and remove all stored objects.
168 */
169 void
170 sdb_store_clear(void);
172 /*
173 * sdb_store_host:
174 * Add/update a host in the store. If the host, identified by its
175 * canonicalized name, already exists, it will be updated according to the
176 * specified name and timestamp. Else, a new entry will be created in the
177 * store. Any memory required for storing the entry will be allocated an
178 * managed by the store itself.
179 *
180 * Returns:
181 * - 0 on success
182 * - a positive value if the new entry is older than the currently stored
183 * entry (in this case, no update will happen)
184 * - a negative value on error
185 */
186 int
187 sdb_store_host(const char *name, sdb_time_t last_update);
189 /*
190 * sdb_store_has_host:
191 * sdb_store_get_host:
192 * Query the store for a host by its (canonicalized) name.
193 *
194 * sdb_store_get_host increments the ref count of the host object. The caller
195 * needs to deref it when no longer using it.
196 */
197 bool
198 sdb_store_has_host(const char *name);
200 sdb_store_obj_t *
201 sdb_store_get_host(const char *name);
203 /*
204 * sdb_store_attribute:
205 * Add/update a host's attribute in the store. If the attribute, identified by
206 * its key, already exists for the specified host, it will be updated to the
207 * specified values. If the referenced host does not exist, an error will be
208 * reported. Else, a new entry will be created in the store. Any memory
209 * required for storing the entry will be allocated and managed by the store
210 * itself.
211 *
212 * Returns:
213 * - 0 on success
214 * - a positive value if the new entry is older than the currently stored
215 * entry (in this case, no update will happen)
216 * - a negative value on error
217 */
218 int
219 sdb_store_attribute(const char *hostname,
220 const char *key, const sdb_data_t *value,
221 sdb_time_t last_update);
223 /*
224 * sdb_store_service:
225 * Add/update a service in the store. If the service, identified by its name,
226 * already exists for the specified host, it will be updated according to the
227 * specified 'service' object. If the referenced host does not exist, an error
228 * will be reported. Else, a new entry will be created in the store. Any
229 * memory required for storing the entry will be allocated an managed by the
230 * store itself.
231 *
232 * Returns:
233 * - 0 on success
234 * - a positive value if the new entry is older than the currently stored
235 * entry (in this case, no update will happen)
236 * - a negative value on error
237 */
238 int
239 sdb_store_service(const char *hostname, const char *name,
240 sdb_time_t last_update);
242 /*
243 * sdb_store_service_attr:
244 * Add/update a service's attribute in the store. If the attribute, identified
245 * by its key, already exists for the specified service, it will be updated to
246 * the specified value. If the references service (for the specified host)
247 * does not exist, an error will be reported. Any memory required for storing
248 * the entry will be allocated and managed by the store itself.
249 *
250 * Returns:
251 * - 0 on success
252 * - a positive value if the new entry is older than the currently stored
253 * entry (in this case, no update will happen)
254 * - a negative value on error
255 */
256 int
257 sdb_store_service_attr(const char *hostname, const char *service,
258 const char *key, const sdb_data_t *value, sdb_time_t last_update);
260 /*
261 * sdb_store_metric:
262 * Add/update a metric in the store. If the metric, identified by its name,
263 * already exists for the specified host, it will be updated according to the
264 * specified 'metric' object. If the referenced host does not exist, an error
265 * will be reported. Else, a new entry will be created in the store. Any
266 * memory required for storing the entry will be allocated an managed by the
267 * store itself.
268 *
269 * If specified, the metric store describes where to access the metric's data.
270 *
271 * Returns:
272 * - 0 on success
273 * - a positive value if the new entry is older than the currently stored
274 * entry (in this case, no update will happen)
275 * - a negative value on error
276 */
277 int
278 sdb_store_metric(const char *hostname, const char *name,
279 sdb_metric_store_t *store, sdb_time_t last_update);
281 /*
282 * sdb_store_metric_attr:
283 * Add/update a metric's attribute in the store. If the attribute, identified
284 * by its key, already exists for the specified metric, it will be updated to
285 * the specified value. If the references metric (for the specified host)
286 * does not exist, an error will be reported. Any memory required for storing
287 * the entry will be allocated and managed by the store itself.
288 *
289 * Returns:
290 * - 0 on success
291 * - a positive value if the new entry is older than the currently stored
292 * entry (in this case, no update will happen)
293 * - a negative value on error
294 */
295 int
296 sdb_store_metric_attr(const char *hostname, const char *metric,
297 const char *key, const sdb_data_t *value, sdb_time_t last_update);
299 /*
300 * sdb_store_fetch_timeseries:
301 * Fetch the time-series described by the specified host's metric and
302 * serialize it as JSON into the provided string buffer.
303 *
304 * Returns:
305 * - 0 on success
306 * - a negative value else
307 */
308 int
309 sdb_store_fetch_timeseries(const char *hostname, const char *metric,
310 sdb_timeseries_opts_t *opts, sdb_strbuf_t *buf);
312 /*
313 * sdb_store_get_child:
314 * Retrieve a host's child object of the specified type and name. The
315 * reference count of the child object will be incremented before returning
316 * it. The caller is responsible for releasing the object once it's no longer
317 * used.
318 *
319 * Returns:
320 * - the child object on success
321 * - NULL else
322 */
323 sdb_store_obj_t *
324 sdb_store_get_child(sdb_store_obj_t *host, int type, const char *name);
326 /*
327 * sdb_store_get_field:
328 * Get the value of a stored object's queryable field. The caller is
329 * responsible for freeing any dynamically allocated memory possibly stored in
330 * the returned value. If 'res' is NULL, the function will return whether the
331 * field exists.
332 *
333 * Note: Retrieving the backend this way is not currently supported.
334 *
335 * Returns:
336 * - 0 on success
337 * - a negative value else
338 */
339 int
340 sdb_store_get_field(sdb_store_obj_t *obj, int field, sdb_data_t *res);
342 /*
343 * sdb_store_get_attr:
344 * Get the value of a stored object's attribute. The caller is responsible for
345 * freeing any dynamically allocated memory possibly stored in the returned
346 * value. If 'res' is NULL, the function will return whether the attribute
347 * exists. If specified, only attributes matching the filter will be
348 * considered.
349 *
350 * Returns:
351 * - 0 if the attribute exists
352 * - a negative value else
353 */
354 int
355 sdb_store_get_attr(sdb_store_obj_t *obj, const char *name, sdb_data_t *res,
356 sdb_store_matcher_t *filter);
358 /*
359 * sdb_store_expr_create:
360 * Creates an arithmetic expression implementing the specified operator on the
361 * specified left and right operand.
362 *
363 * Returns:
364 * - an expression object on success
365 * - NULL else
366 */
367 sdb_store_expr_t *
368 sdb_store_expr_create(int op, sdb_store_expr_t *left, sdb_store_expr_t *right);
370 /*
371 * sdb_store_expr_typed:
372 * Creates an expression which evaluates in the context of an object's sibling
373 * as specified by the given type.
374 *
375 * Returns:
376 * - an expression object on success
377 * - NULL else
378 */
379 sdb_store_expr_t *
380 sdb_store_expr_typed(int typ, sdb_store_expr_t *expr);
382 /*
383 * sdb_store_expr_fieldvalue:
384 * Creates an expression which evaluates to the value of the specified
385 * queryable field of a stored object.
386 *
387 * Returns:
388 * - an expression object on success
389 * - NULL else
390 */
391 sdb_store_expr_t *
392 sdb_store_expr_fieldvalue(int field);
394 /*
395 * sdb_store_expr_attrvalue:
396 * Creates an expression which evaluates to the value of the specified
397 * attribute of a stored object. Evaluates to a NULL value if the attribute
398 * does not exist.
399 *
400 * Returns:
401 * - an expression object on success
402 * - NULL else
403 */
404 sdb_store_expr_t *
405 sdb_store_expr_attrvalue(const char *name);
407 /*
408 * sdb_store_expr_constvalue:
409 * Creates an expression which evaluates to the specified constant value.
410 *
411 * Returns:
412 * - an expression object on success
413 * - NULL else
414 */
415 sdb_store_expr_t *
416 sdb_store_expr_constvalue(const sdb_data_t *value);
418 /*
419 * sdb_store_expr_eval:
420 * Evaluate an expression for the specified stored object and stores the
421 * result in 'res'. The result's value will be allocated dynamically if
422 * necessary and, thus, should be free'd by the caller (e.g. using
423 * sdb_data_free_datum). The object may be NULL, in which case the expression
424 * needs to evaluate to a constant value. If specified, only objects matching
425 * the filter will be used during the evaluation.
426 *
427 * Returns:
428 * - 0 on success
429 * - a negative value else
430 */
431 int
432 sdb_store_expr_eval(sdb_store_expr_t *expr, sdb_store_obj_t *obj,
433 sdb_data_t *res, sdb_store_matcher_t *filter);
435 /*
436 * sdb_store_expr_iterable:
437 * Check whether an expression, evaluated in the specified context (HOST,
438 * SERVICE, METRIC) is iterable, that is, if it may evaluate to multiple
439 * values.
440 */
441 bool
442 sdb_store_expr_iterable(sdb_store_expr_t *expr, int context);
444 /*
445 * sdb_store_expr_iter:
446 * Iterate over the elements of an iterable expression. sdb_store_expr_iter
447 * returns NULL if the expression is not iterable (for the specified object).
448 * See also sdb_store_expr_iterable.
449 *
450 * sdb_store_expr_iter_get_next returns NULL if there is no next element.
451 */
452 sdb_store_expr_iter_t *
453 sdb_store_expr_iter(sdb_store_expr_t *expr, sdb_store_obj_t *obj,
454 sdb_store_matcher_t *filter);
455 void
456 sdb_store_expr_iter_destroy(sdb_store_expr_iter_t *iter);
458 bool
459 sdb_store_expr_iter_has_next(sdb_store_expr_iter_t *iter);
460 sdb_data_t
461 sdb_store_expr_iter_get_next(sdb_store_expr_iter_t *iter);
463 /*
464 * sdb_store_dis_matcher:
465 * Creates a matcher matching the disjunction (logical OR) of two matchers.
466 */
467 sdb_store_matcher_t *
468 sdb_store_dis_matcher(sdb_store_matcher_t *left, sdb_store_matcher_t *right);
470 /*
471 * sdb_store_con_matcher:
472 * Creates a matcher matching the conjunction (logical AND) of two matchers.
473 */
474 sdb_store_matcher_t *
475 sdb_store_con_matcher(sdb_store_matcher_t *left, sdb_store_matcher_t *right);
477 /*
478 * sdb_store_inv_matcher::
479 * Creates a matcher matching the inverse (logical NOT) of a matcher.
480 */
481 sdb_store_matcher_t *
482 sdb_store_inv_matcher(sdb_store_matcher_t *m);
484 /*
485 * sdb_store_any_matcher:
486 * Creates a matcher iterating over values of the first expression (which has
487 * to be iterable). It matches if *any* of those elements match 'm'. 'm' has
488 * to be an ary operation with the left operand unset.
489 */
490 sdb_store_matcher_t *
491 sdb_store_any_matcher(sdb_store_expr_t *iter, sdb_store_matcher_t *m);
493 /*
494 * sdb_store_all_matcher:
495 * Creates a matcher iterating over values of the first expression (which has
496 * to be iterable). It matches if *all* of those elements match 'm'. 'm' has
497 * to be an ary operation with the left operand unset.
498 */
499 sdb_store_matcher_t *
500 sdb_store_all_matcher(sdb_store_expr_t *iter, sdb_store_matcher_t *m);
502 /*
503 * sdb_store_in_matcher:
504 * Creates a matcher which matches if the right value evaluates to an array
505 * value and the left value is included in that array. See sdb_data_inarray
506 * for more details.
507 */
508 sdb_store_matcher_t *
509 sdb_store_in_matcher(sdb_store_expr_t *left, sdb_store_expr_t *right);
511 /*
512 * sdb_store_nin_matcher:
513 * Like sdb_store_in_matcher but matches if the left value is not included in
514 * the right value.
515 */
516 sdb_store_matcher_t *
517 sdb_store_nin_matcher(sdb_store_expr_t *left, sdb_store_expr_t *right);
519 /*
520 * sdb_store_lt_matcher, sdb_store_le_matcher, sdb_store_eq_matcher,
521 * sdb_store_ge_matcher, sdb_store_gt_matcher:
522 * Create conditional matchers comparing the values of two expressions. The
523 * matcher matches if the left expression compres less than, less or equal
524 * than, equal to, not equal to, greater or equal than, or greater than the
525 * right expression.
526 */
527 sdb_store_matcher_t *
528 sdb_store_lt_matcher(sdb_store_expr_t *left, sdb_store_expr_t *right);
529 sdb_store_matcher_t *
530 sdb_store_le_matcher(sdb_store_expr_t *left, sdb_store_expr_t *right);
531 sdb_store_matcher_t *
532 sdb_store_eq_matcher(sdb_store_expr_t *left, sdb_store_expr_t *right);
533 sdb_store_matcher_t *
534 sdb_store_ne_matcher(sdb_store_expr_t *left, sdb_store_expr_t *right);
535 sdb_store_matcher_t *
536 sdb_store_ge_matcher(sdb_store_expr_t *left, sdb_store_expr_t *right);
537 sdb_store_matcher_t *
538 sdb_store_gt_matcher(sdb_store_expr_t *left, sdb_store_expr_t *right);
540 /*
541 * sdb_store_regex_matcher:
542 * Creates a matcher which matches the string value the left expression
543 * evaluates to against the regular expression the right expression evaluates
544 * to. The right expression may either be a constant value regular expression
545 * or string or a dynamic value evaluating to a string. In the latter case,
546 * the string is compiled to a regex every time the matcher is executed.
547 */
548 sdb_store_matcher_t *
549 sdb_store_regex_matcher(sdb_store_expr_t *left, sdb_store_expr_t *right);
551 /*
552 * sdb_store_nregex_matcher:
553 * Creates a regex matcher just like sdb_store_regex_matcher except that it
554 * matches in case the regular expression does not match.
555 */
556 sdb_store_matcher_t *
557 sdb_store_nregex_matcher(sdb_store_expr_t *left, sdb_store_expr_t *right);
559 /*
560 * sdb_store_isnull_matcher:
561 * Creates a matcher matching NULL values.
562 */
563 sdb_store_matcher_t *
564 sdb_store_isnull_matcher(sdb_store_expr_t *expr);
566 /*
567 * sdb_store_isnnull_matcher:
568 * Creates a matcher matching non-NULL values.
569 */
570 sdb_store_matcher_t *
571 sdb_store_isnnull_matcher(sdb_store_expr_t *expr);
573 /*
574 * sdb_store_matcher_matches:
575 * Check whether the specified matcher matches the specified store object. If
576 * specified, the filter will be used to preselect objects for further
577 * evaluation. It is applied to any object that's used during the evaluation
578 * of the matcher. Only those objects matching the filter will be considered.
579 *
580 * Note that the filter is applied to all object types (hosts, service,
581 * metric, attribute). Thus, any object-specific matchers are mostly unsuited
582 * for this purpose and, if used, may result in unexpected behavior.
583 *
584 * Returns:
585 * - 1 if the object matches
586 * - 0 else
587 */
588 int
589 sdb_store_matcher_matches(sdb_store_matcher_t *m, sdb_store_obj_t *obj,
590 sdb_store_matcher_t *filter);
592 /*
593 * sdb_store_matcher_op_cb:
594 * Callback constructing a matcher operator.
595 */
596 typedef sdb_store_matcher_t *(*sdb_store_matcher_op_cb)
597 (sdb_store_expr_t *, sdb_store_expr_t *);
599 /*
600 * sdb_store_parse_matcher_op:
601 * Parse a matcher operator and return a constructor for the respective
602 * matcher.
603 *
604 * Returns:
605 * - matcher operator constructor on success
606 * - NULL else
607 */
608 sdb_store_matcher_op_cb
609 sdb_store_parse_matcher_op(const char *op);
611 /*
612 * sdb_store_parse_object_type:
613 * Parse the type name of a stored object.
614 *
615 * Returns:
616 * - the object type on success
617 * - a negative value else
618 */
619 int
620 sdb_store_parse_object_type(const char *name);
622 /*
623 * sdb_store_parse_object_type_plural:
624 * Parse the type name (plural) of a stored object.
625 *
626 * Returns:
627 * - the object type on success
628 * - a negative value else
629 */
630 int
631 sdb_store_parse_object_type_plural(const char *name);
633 /*
634 * sdb_store_parse_field_name:
635 * Parse the name of a stored object's queryable field.
636 *
637 * Returns:
638 * - the field id on success
639 * - a negative value else
640 */
641 int
642 sdb_store_parse_field_name(const char *name);
644 /*
645 * sdb_store_lookup_cb:
646 * Lookup callback. It is called for each matching object when looking up data
647 * in the store passing on the lookup filter and the specified user-data. The
648 * lookup aborts early if the callback returns non-zero.
649 */
650 typedef int (*sdb_store_lookup_cb)(sdb_store_obj_t *obj,
651 sdb_store_matcher_t *filter, void *user_data);
653 /*
654 * sdb_store_scan:
655 * Look up objects of the specified type in the store. The specified callback
656 * function is called for each object in the store matching 'm'. The function
657 * performs a full scan of all objects stored in the database. If specified,
658 * the filter will be used to preselect objects for further evaluation. See
659 * the description of 'sdb_store_matcher_matches' for details.
660 *
661 * Returns:
662 * - 0 on success
663 * - a negative value else
664 */
665 int
666 sdb_store_scan(int type, sdb_store_matcher_t *m, sdb_store_matcher_t *filter,
667 sdb_store_lookup_cb cb, void *user_data);
669 /*
670 * Flags for JSON formatting.
671 */
672 enum {
673 SDB_WANT_ARRAY = 1 << 0,
674 };
676 /*
677 * sdb_store_json_formatter:
678 * Create a JSON formatter for the specified object types writing to the
679 * specified buffer.
680 */
681 sdb_store_json_formatter_t *
682 sdb_store_json_formatter(sdb_strbuf_t *buf, int type, int flags);
684 /*
685 * sdb_store_json_emit:
686 * Serialize a single object to JSON adding it to the string buffer associated
687 * with the formatter object. The serialized object will not include
688 * attributes or any child objects. Instead, call the function again for each
689 * of those objects. All attributes have to be emitted before any other
690 * children types. Use sdb_store_json_emit_full() to emit a full (filtered)
691 * object.
692 *
693 * Note that the output might not be valid JSON before calling
694 * sdb_store_json_finish().
695 *
696 * Returns:
697 * - 0 on success
698 * - a negative value else
699 */
700 int
701 sdb_store_json_emit(sdb_store_json_formatter_t *f, sdb_store_obj_t *obj);
703 /*
704 * sdb_store_json_emit_full:
705 * Serialize a single object including it's attributes and all children to
706 * JSON, adding it to the string buffer associated with the formatter object.
707 * The filter, if specified, is applied to each attribute and child object.
708 * Only matching objects will be included in the output.
709 *
710 * Note that the output might not be valid JSON before calling
711 * sdb_store_json_finish().
712 *
713 * Returns:
714 * - 0 on success
715 * - a negative value else
716 */
717 int
718 sdb_store_json_emit_full(sdb_store_json_formatter_t *f, sdb_store_obj_t *obj,
719 sdb_store_matcher_t *filter);
721 /*
722 * sdb_store_json_finish:
723 * Finish the JSON output. This function has to be called once after emiting
724 * all objects.
725 */
726 int
727 sdb_store_json_finish(sdb_store_json_formatter_t *f);
729 #ifdef __cplusplus
730 } /* extern "C" */
731 #endif
733 #endif /* ! SDB_CORE_STORE_H */
735 /* vim: set tw=78 sw=4 ts=4 noexpandtab : */