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 "parser/ast.h"
37 #include "utils/strbuf.h"
39 #include <stdbool.h>
40 #include <stdio.h>
42 #ifdef __cplusplus
43 extern "C" {
44 #endif
46 /*
47 * Store object types.
48 */
49 enum {
50 SDB_HOST = 1,
51 SDB_SERVICE,
52 SDB_METRIC,
54 SDB_ATTRIBUTE = 1 << 4,
56 /*
57 * Queryable fields of a stored object.
58 */
59 SDB_FIELD_NAME = 1 << 8, /* type: string */
60 SDB_FIELD_LAST_UPDATE, /* type: datetime */
61 SDB_FIELD_AGE, /* type: datetime */
62 SDB_FIELD_INTERVAL, /* type: datetime */
63 SDB_FIELD_BACKEND, /* type: array of strings */
64 SDB_FIELD_VALUE, /* attributes only; type: type of the value */
65 SDB_FIELD_TIMESERIES, /* metrics only; type: boolean */
66 };
67 #define SDB_STORE_TYPE_TO_NAME(t) \
68 (((t) == SDB_HOST) ? "host" \
69 : ((t) == SDB_SERVICE) ? "service" \
70 : ((t) == SDB_METRIC) ? "metric" \
71 : ((t) == SDB_ATTRIBUTE) ? "attribute" \
72 : ((t) == (SDB_ATTRIBUTE | SDB_HOST)) ? "host attribute" \
73 : ((t) == (SDB_ATTRIBUTE | SDB_SERVICE)) ? "service attribute" \
74 : ((t) == (SDB_ATTRIBUTE | SDB_METRIC)) ? "metric attribute" \
75 : "unknown")
77 #define SDB_FIELD_TO_NAME(f) \
78 (((f) == SDB_FIELD_NAME) ? "name" \
79 : ((f) == SDB_FIELD_LAST_UPDATE) ? "last-update" \
80 : ((f) == SDB_FIELD_AGE) ? "age" \
81 : ((f) == SDB_FIELD_INTERVAL) ? "interval" \
82 : ((f) == SDB_FIELD_BACKEND) ? "backend" \
83 : ((f) == SDB_FIELD_VALUE) ? "value" \
84 : ((f) == SDB_FIELD_TIMESERIES) ? "timeseries" \
85 : "unknown")
87 #define SDB_FIELD_TYPE(f) \
88 (((f) == SDB_FIELD_NAME) ? SDB_TYPE_STRING \
89 : ((f) == SDB_FIELD_LAST_UPDATE) ? SDB_TYPE_DATETIME \
90 : ((f) == SDB_FIELD_AGE) ? SDB_TYPE_DATETIME \
91 : ((f) == SDB_FIELD_INTERVAL) ? SDB_TYPE_DATETIME \
92 : ((f) == SDB_FIELD_BACKEND) ? (SDB_TYPE_ARRAY | SDB_TYPE_STRING) \
93 : ((f) == SDB_FIELD_VALUE) ? -1 /* unknown */ \
94 : ((f) == SDB_FIELD_TIMESERIES) ? SDB_TYPE_BOOLEAN \
95 : -1)
97 /*
98 * sdb_store_t represents an in-memory store. It inherits from sdb_object_t
99 * and may safely be case to a generic object.
100 */
101 struct sdb_store;
102 typedef struct sdb_store sdb_store_t;
103 #define SDB_STORE(obj) ((sdb_store_t *)(obj))
105 /*
106 * sdb_store_obj_t represents the super-class of any stored object. It
107 * inherits from sdb_object_t and may safely be cast to a generic object to
108 * access its name.
109 */
110 struct sdb_store_obj;
111 typedef struct sdb_store_obj sdb_store_obj_t;
113 /*
114 * sdb_store_host_t represents the meta-data of a stored host object.
115 */
116 typedef struct {
117 const char *name;
119 sdb_time_t last_update;
120 sdb_time_t interval;
121 const char * const *backends;
122 size_t backends_num;
123 } sdb_store_host_t;
125 /*
126 * sdb_store_service_t represents the meta-data of a stored service object.
127 */
128 typedef struct {
129 const char *hostname;
130 const char *name;
132 sdb_time_t last_update;
133 sdb_time_t interval;
134 const char * const *backends;
135 size_t backends_num;
136 } sdb_store_service_t;
138 /*
139 * sdb_metric_store_t specifies how to access a metric's data.
140 */
141 typedef struct {
142 const char *type;
143 const char *id;
144 } sdb_metric_store_t;
146 /*
147 * sdb_store_metric_t represents the meta-data of a stored metric object.
148 */
149 typedef struct {
150 const char *hostname;
151 const char *name;
152 struct {
153 const char *type;
154 const char *id;
155 } store;
157 sdb_time_t last_update;
158 sdb_time_t interval;
159 const char * const *backends;
160 size_t backends_num;
161 } sdb_store_metric_t;
163 /*
164 * sdb_store_attribute_t represents a stored attribute.
165 */
166 typedef struct {
167 const char *hostname; /* optional */
168 int parent_type;
169 const char *parent;
170 const char *key;
171 sdb_data_t value;
173 sdb_time_t last_update;
174 sdb_time_t interval;
175 const char * const *backends;
176 size_t backends_num;
177 } sdb_store_attribute_t;
179 /*
180 * Expressions represent arithmetic expressions based on stored objects and
181 * their various attributes.
182 *
183 * An expression object inherits from sdb_object_t and, thus, may safely be
184 * cast to a generic object.
185 */
186 struct sdb_store_expr;
187 typedef struct sdb_store_expr sdb_store_expr_t;
188 #define SDB_STORE_EXPR(obj) ((sdb_store_expr_t *)(obj))
190 /*
191 * An expression iterator iterates over the values of an iterable expression.
192 */
193 struct sdb_store_expr_iter;
194 typedef struct sdb_store_expr_iter sdb_store_expr_iter_t;
196 /*
197 * Store matchers may be used to lookup hosts from the store based on their
198 * various attributes. Service and attribute matchers are applied to a host's
199 * services and attributes and evaluate to true if *any* service or attribute
200 * matches.
201 *
202 * A store matcher object inherits from sdb_object_t and, thus, may safely be
203 * cast to a generic object.
204 */
205 struct sdb_store_matcher;
206 typedef struct sdb_store_matcher sdb_store_matcher_t;
207 #define SDB_STORE_MATCHER(obj) ((sdb_store_matcher_t *)(obj))
209 /*
210 * A JSON formatter converts stored objects into the JSON format.
211 * See http://www.ietf.org/rfc/rfc4627.txt
212 *
213 * A JSON formatter object inherits from sdb_object_t and, thus, may safely be
214 * cast to a generic object.
215 */
216 struct sdb_store_json_formatter;
217 typedef struct sdb_store_json_formatter sdb_store_json_formatter_t;
219 /*
220 * A store writer describes the interface for plugins implementing a store.
221 *
222 * Any of the call-back functions shall return:
223 * - 0 on success
224 * - a positive value if the new entry is older than the currently stored
225 * entry (in this case, no update will happen)
226 * - a negative value on error
227 */
228 typedef struct {
229 /*
230 * store_host:
231 * Add/update a host in the store. If the host, identified by its
232 * canonicalized name, already exists, it will be updated according to the
233 * specified name and timestamp. Else, a new entry will be created in the
234 * store.
235 */
236 int (*store_host)(sdb_store_host_t *host, sdb_object_t *user_data);
238 /*
239 * store_service:
240 * Add/update a service in the store. If the service, identified by its
241 * name, already exists for the specified host, it will be updated
242 * according to the specified name and timestamp. If the referenced host
243 * does not exist, an error will be reported. Else, a new entry will be
244 * created in the store.
245 */
246 int (*store_service)(sdb_store_service_t *service, sdb_object_t *user_data);
248 /*
249 * store_metric:
250 * Add/update a metric in the store. If the metric, identified by its
251 * name, already exists for the specified host, it will be updated
252 * according to the specified attributes. If the referenced host does not
253 * exist, an error will be reported. Else, a new entry will be created in
254 * the store.
255 */
256 int (*store_metric)(sdb_store_metric_t *metric, sdb_object_t *user_data);
258 /*
259 * store_attribute:
260 * Add/update a host's attribute in the store. If the attribute,
261 * identified by its key, already exists for the specified host, it will
262 * be updated to the specified values. If the referenced host does not
263 * exist, an error will be reported. Else, a new entry will be created in
264 * the store.
265 */
266 int (*store_attribute)(sdb_store_attribute_t *attr, sdb_object_t *user_data);
267 } sdb_store_writer_t;
269 /*
270 * sdb_store_writer:
271 * A store writer implementation that provides an in-memory object store. It
272 * expects a store object as its user-data argument.
273 */
274 extern sdb_store_writer_t sdb_store_writer;
276 /*
277 * A store reader describes the interface to query a store implementation.
278 */
279 typedef struct {
280 /*
281 * prepare_query:
282 * Prepare the query described by 'ast' for execution.
283 */
284 sdb_object_t *(*prepare_query)(sdb_ast_node_t *ast,
285 sdb_strbuf_t *errbuf, sdb_object_t *user_data);
287 /*
288 * execute_query:
289 * Execute a previously prepared query. The callback may expect that only
290 * queries prepared by its respective prepare callback will be passed to
291 * this function.
292 *
293 * TODO: Instead of letting the executor write directly to a string buffer
294 * (which cannot easily be merged with other results), let it hand
295 * all objects to a store-writer.
296 */
297 int (*execute_query)(sdb_object_t *q,
298 sdb_strbuf_t *buf, sdb_strbuf_t *errbuf,
299 sdb_object_t *user_data);
300 } sdb_store_reader_t;
302 /*
303 * sdb_store_reader:
304 * A store reader implementation that uses an in-memory object store. It
305 * expects a store object as its user-data argument.
306 */
307 extern sdb_store_reader_t sdb_store_reader;
309 /*
310 * sdb_store_create:
311 * Allocate a new in-memory store.
312 */
313 sdb_store_t *
314 sdb_store_create(void);
316 /*
317 * sdb_store_host, sdb_store_service, sdb_store_metric, sdb_store_attribute,
318 * sdb_store_metric_attr:
319 * Store an object in the specified store. The hostname is expected to be
320 * canonical.
321 */
322 int
323 sdb_store_host(sdb_store_t *store, const char *name, sdb_time_t last_update);
324 int
325 sdb_store_service(sdb_store_t *store, const char *hostname, const char *name,
326 sdb_time_t last_update);
327 int
328 sdb_store_metric(sdb_store_t *store, const char *hostname, const char *name,
329 sdb_metric_store_t *metric_store, sdb_time_t last_update);
330 int
331 sdb_store_attribute(sdb_store_t *store, const char *hostname,
332 const char *key, const sdb_data_t *value, sdb_time_t last_update);
333 int
334 sdb_store_service_attr(sdb_store_t *store, const char *hostname,
335 const char *service, const char *key, const sdb_data_t *value,
336 sdb_time_t last_update);
337 int
338 sdb_store_metric_attr(sdb_store_t *store, const char *hostname,
339 const char *metric, const char *key, const sdb_data_t *value,
340 sdb_time_t last_update);
342 /*
343 * sdb_store_get_host:
344 * Query the specified store for a host by its (canonicalized) name.
345 *
346 * The function increments the ref count of the host object. The caller needs
347 * to deref it when no longer using it.
348 */
349 sdb_store_obj_t *
350 sdb_store_get_host(sdb_store_t *store, const char *name);
352 /*
353 * sdb_store_fetch_timeseries:
354 * Fetch the time-series described by the specified host's metric and
355 * serialize it as JSON into the provided string buffer. The host data is
356 * retrieved from the specified store.
357 *
358 * Returns:
359 * - 0 on success
360 * - a negative value else
361 */
362 int
363 sdb_store_fetch_timeseries(sdb_store_t *store,
364 const char *hostname, const char *metric,
365 sdb_timeseries_opts_t *opts, sdb_strbuf_t *buf);
367 /*
368 * sdb_store_get_child:
369 * Retrieve a host's child object of the specified type and name. The
370 * reference count of the child object will be incremented before returning
371 * it. The caller is responsible for releasing the object once it's no longer
372 * used.
373 *
374 * Returns:
375 * - the child object on success
376 * - NULL else
377 */
378 sdb_store_obj_t *
379 sdb_store_get_child(sdb_store_obj_t *host, int type, const char *name);
381 /*
382 * sdb_store_get_field:
383 * Get the value of a stored object's queryable field. The caller is
384 * responsible for freeing any dynamically allocated memory possibly stored in
385 * the returned value. If 'res' is NULL, the function will return whether the
386 * field exists.
387 *
388 * Returns:
389 * - 0 on success
390 * - a negative value else
391 */
392 int
393 sdb_store_get_field(sdb_store_obj_t *obj, int field, sdb_data_t *res);
395 /*
396 * sdb_store_get_attr:
397 * Get the value of a stored object's attribute. The caller is responsible for
398 * freeing any dynamically allocated memory possibly stored in the returned
399 * value. If 'res' is NULL, the function will return whether the attribute
400 * exists. If specified, only attributes matching the filter will be
401 * considered.
402 *
403 * Returns:
404 * - 0 if the attribute exists
405 * - a negative value else
406 */
407 int
408 sdb_store_get_attr(sdb_store_obj_t *obj, const char *name, sdb_data_t *res,
409 sdb_store_matcher_t *filter);
411 /*
412 * Querying a store:
413 *
414 * - Query interface: A query is a formal description of an interaction with
415 * the store. It can be used, both, for read and write access. The query is
416 * described by its abstract syntax tree (AST). The parser package provides
417 * means to parse a string (SysQL) representation of the query into an AST.
418 *
419 * - Matcher / expression interface: This low-level interface provides direct
420 * control over how to access the store. It is used by the query
421 * implementation internally and can only be used for read access.
422 */
424 /*
425 * sdb_store_query_t:
426 * A parsed query readily prepared for execution.
427 */
428 struct sdb_store_query;
429 typedef struct sdb_store_query sdb_store_query_t;
431 /*
432 * sdb_store_query_prepare:
433 * Prepare the query described by 'ast' for execution in a store.
434 *
435 * Returns:
436 * - a store query on success
437 * - NULL else
438 */
439 sdb_store_query_t *
440 sdb_store_query_prepare(sdb_ast_node_t *ast);
442 /*
443 * sdb_store_query_prepare_matcher:
444 * Prepare the logical expression described by 'ast' for execution as a store
445 * matcher.
446 *
447 * Returns:
448 * - a matcher on success
449 * - NULL else
450 */
451 sdb_store_matcher_t *
452 sdb_store_query_prepare_matcher(sdb_ast_node_t *ast);
454 /*
455 * sdb_store_query_execute:
456 * Execute a previously prepared query in the specified store. The query
457 * result will be written to 'buf' and any errors to 'errbuf'.
458 *
459 * Returns:
460 * - the result type (to be used by the server reply)
461 * - a negative value on error
462 */
463 int
464 sdb_store_query_execute(sdb_store_t *store, sdb_store_query_t *m,
465 sdb_strbuf_t *buf, sdb_strbuf_t *errbuf);
467 /*
468 * sdb_store_expr_create:
469 * Creates an arithmetic expression implementing the specified operator on the
470 * specified left and right operand.
471 *
472 * Returns:
473 * - an expression object on success
474 * - NULL else
475 */
476 sdb_store_expr_t *
477 sdb_store_expr_create(int op, sdb_store_expr_t *left, sdb_store_expr_t *right);
479 /*
480 * sdb_store_expr_typed:
481 * Creates an expression which evaluates in the context of an object's sibling
482 * as specified by the given type.
483 *
484 * Returns:
485 * - an expression object on success
486 * - NULL else
487 */
488 sdb_store_expr_t *
489 sdb_store_expr_typed(int typ, sdb_store_expr_t *expr);
491 /*
492 * sdb_store_expr_fieldvalue:
493 * Creates an expression which evaluates to the value of the specified
494 * queryable field of a stored object.
495 *
496 * Returns:
497 * - an expression object on success
498 * - NULL else
499 */
500 sdb_store_expr_t *
501 sdb_store_expr_fieldvalue(int field);
503 /*
504 * sdb_store_expr_attrvalue:
505 * Creates an expression which evaluates to the value of the specified
506 * attribute of a stored object. Evaluates to a NULL value if the attribute
507 * does not exist.
508 *
509 * Returns:
510 * - an expression object on success
511 * - NULL else
512 */
513 sdb_store_expr_t *
514 sdb_store_expr_attrvalue(const char *name);
516 /*
517 * sdb_store_expr_constvalue:
518 * Creates an expression which evaluates to the specified constant value.
519 *
520 * Returns:
521 * - an expression object on success
522 * - NULL else
523 */
524 sdb_store_expr_t *
525 sdb_store_expr_constvalue(const sdb_data_t *value);
527 /*
528 * sdb_store_expr_eval:
529 * Evaluate an expression for the specified stored object and stores the
530 * result in 'res'. The result's value will be allocated dynamically if
531 * necessary and, thus, should be free'd by the caller (e.g. using
532 * sdb_data_free_datum). The object may be NULL, in which case the expression
533 * needs to evaluate to a constant value. If specified, only objects matching
534 * the filter will be used during the evaluation.
535 *
536 * Returns:
537 * - 0 on success
538 * - a negative value else
539 */
540 int
541 sdb_store_expr_eval(sdb_store_expr_t *expr, sdb_store_obj_t *obj,
542 sdb_data_t *res, sdb_store_matcher_t *filter);
544 /*
545 * sdb_store_expr_iter:
546 * Iterate over the elements of an iterable expression. sdb_store_expr_iter
547 * returns NULL if the expression is not iterable (for the specified object).
548 *
549 * sdb_store_expr_iter_get_next returns NULL if there is no next element.
550 */
551 sdb_store_expr_iter_t *
552 sdb_store_expr_iter(sdb_store_expr_t *expr, sdb_store_obj_t *obj,
553 sdb_store_matcher_t *filter);
554 void
555 sdb_store_expr_iter_destroy(sdb_store_expr_iter_t *iter);
557 bool
558 sdb_store_expr_iter_has_next(sdb_store_expr_iter_t *iter);
559 sdb_data_t
560 sdb_store_expr_iter_get_next(sdb_store_expr_iter_t *iter);
562 /*
563 * sdb_store_dis_matcher:
564 * Creates a matcher matching the disjunction (logical OR) of two matchers.
565 */
566 sdb_store_matcher_t *
567 sdb_store_dis_matcher(sdb_store_matcher_t *left, sdb_store_matcher_t *right);
569 /*
570 * sdb_store_con_matcher:
571 * Creates a matcher matching the conjunction (logical AND) of two matchers.
572 */
573 sdb_store_matcher_t *
574 sdb_store_con_matcher(sdb_store_matcher_t *left, sdb_store_matcher_t *right);
576 /*
577 * sdb_store_inv_matcher::
578 * Creates a matcher matching the inverse (logical NOT) of a matcher.
579 */
580 sdb_store_matcher_t *
581 sdb_store_inv_matcher(sdb_store_matcher_t *m);
583 /*
584 * sdb_store_any_matcher:
585 * Creates a matcher iterating over values of the first expression (which has
586 * to be iterable). It matches if *any* of those elements match 'm'. 'm' has
587 * to be an ary operation with the left operand unset.
588 */
589 sdb_store_matcher_t *
590 sdb_store_any_matcher(sdb_store_expr_t *iter, sdb_store_matcher_t *m);
592 /*
593 * sdb_store_all_matcher:
594 * Creates a matcher iterating over values of the first expression (which has
595 * to be iterable). It matches if *all* of those elements match 'm'. 'm' has
596 * to be an ary operation with the left operand unset.
597 */
598 sdb_store_matcher_t *
599 sdb_store_all_matcher(sdb_store_expr_t *iter, sdb_store_matcher_t *m);
601 /*
602 * sdb_store_in_matcher:
603 * Creates a matcher which matches if the right value evaluates to an array
604 * value and the left value is included in that array. See sdb_data_inarray
605 * for more details.
606 */
607 sdb_store_matcher_t *
608 sdb_store_in_matcher(sdb_store_expr_t *left, sdb_store_expr_t *right);
610 /*
611 * sdb_store_lt_matcher, sdb_store_le_matcher, sdb_store_eq_matcher,
612 * sdb_store_ge_matcher, sdb_store_gt_matcher:
613 * Create conditional matchers comparing the values of two expressions. The
614 * matcher matches if the left expression compres less than, less or equal
615 * than, equal to, not equal to, greater or equal than, or greater than the
616 * right expression.
617 */
618 sdb_store_matcher_t *
619 sdb_store_lt_matcher(sdb_store_expr_t *left, sdb_store_expr_t *right);
620 sdb_store_matcher_t *
621 sdb_store_le_matcher(sdb_store_expr_t *left, sdb_store_expr_t *right);
622 sdb_store_matcher_t *
623 sdb_store_eq_matcher(sdb_store_expr_t *left, sdb_store_expr_t *right);
624 sdb_store_matcher_t *
625 sdb_store_ne_matcher(sdb_store_expr_t *left, sdb_store_expr_t *right);
626 sdb_store_matcher_t *
627 sdb_store_ge_matcher(sdb_store_expr_t *left, sdb_store_expr_t *right);
628 sdb_store_matcher_t *
629 sdb_store_gt_matcher(sdb_store_expr_t *left, sdb_store_expr_t *right);
631 /*
632 * sdb_store_regex_matcher:
633 * Creates a matcher which matches the string value the left expression
634 * evaluates to against the regular expression the right expression evaluates
635 * to. The right expression may either be a constant value regular expression
636 * or string or a dynamic value evaluating to a string. In the latter case,
637 * the string is compiled to a regex every time the matcher is executed.
638 */
639 sdb_store_matcher_t *
640 sdb_store_regex_matcher(sdb_store_expr_t *left, sdb_store_expr_t *right);
642 /*
643 * sdb_store_nregex_matcher:
644 * Creates a regex matcher just like sdb_store_regex_matcher except that it
645 * matches in case the regular expression does not match.
646 */
647 sdb_store_matcher_t *
648 sdb_store_nregex_matcher(sdb_store_expr_t *left, sdb_store_expr_t *right);
650 /*
651 * sdb_store_isnull_matcher:
652 * Creates a matcher matching NULL values.
653 */
654 sdb_store_matcher_t *
655 sdb_store_isnull_matcher(sdb_store_expr_t *expr);
657 /*
658 * sdb_store_istrue_matcher, sdb_store_isfalse_matcher:
659 * Creates a matcher matching boolean values.
660 */
661 sdb_store_matcher_t *
662 sdb_store_istrue_matcher(sdb_store_expr_t *expr);
663 sdb_store_matcher_t *
664 sdb_store_isfalse_matcher(sdb_store_expr_t *expr);
666 /*
667 * sdb_store_matcher_matches:
668 * Check whether the specified matcher matches the specified store object. If
669 * specified, the filter will be used to preselect objects for further
670 * evaluation. It is applied to any object that's used during the evaluation
671 * of the matcher. Only those objects matching the filter will be considered.
672 *
673 * Note that the filter is applied to all object types (hosts, service,
674 * metric, attribute). Thus, any object-specific matchers are mostly unsuited
675 * for this purpose and, if used, may result in unexpected behavior.
676 *
677 * Returns:
678 * - 1 if the object matches
679 * - 0 else
680 */
681 int
682 sdb_store_matcher_matches(sdb_store_matcher_t *m, sdb_store_obj_t *obj,
683 sdb_store_matcher_t *filter);
685 /*
686 * sdb_store_matcher_op_cb:
687 * Callback constructing a matcher operator.
688 */
689 typedef sdb_store_matcher_t *(*sdb_store_matcher_op_cb)
690 (sdb_store_expr_t *, sdb_store_expr_t *);
692 /*
693 * sdb_store_lookup_cb:
694 * Lookup callback. It is called for each matching object when looking up data
695 * in the store passing on the lookup filter and the specified user-data. The
696 * lookup aborts early if the callback returns non-zero.
697 */
698 typedef int (*sdb_store_lookup_cb)(sdb_store_obj_t *obj,
699 sdb_store_matcher_t *filter, void *user_data);
701 /*
702 * sdb_store_scan:
703 * Look up objects of the specified type in the specified store. The specified
704 * callback function is called for each object in the store matching 'm'. The
705 * function performs a full scan of all stored objects. If specified, the
706 * filter will be used to preselect objects for further evaluation. See the
707 * description of 'sdb_store_matcher_matches' for details.
708 *
709 * Returns:
710 * - 0 on success
711 * - a negative value else
712 */
713 int
714 sdb_store_scan(sdb_store_t *store, int type,
715 sdb_store_matcher_t *m, sdb_store_matcher_t *filter,
716 sdb_store_lookup_cb cb, void *user_data);
718 /*
719 * Flags for JSON formatting.
720 */
721 enum {
722 SDB_WANT_ARRAY = 1 << 0,
723 };
725 /*
726 * sdb_store_json_formatter:
727 * Create a JSON formatter for the specified object types writing to the
728 * specified buffer.
729 */
730 sdb_store_json_formatter_t *
731 sdb_store_json_formatter(sdb_strbuf_t *buf, int type, int flags);
733 /*
734 * sdb_store_json_emit:
735 * Serialize a single object to JSON adding it to the string buffer associated
736 * with the formatter object. The serialized object will not include
737 * attributes or any child objects. Instead, call the function again for each
738 * of those objects. All attributes have to be emitted before any other
739 * children types. Use sdb_store_json_emit_full() to emit a full (filtered)
740 * object.
741 *
742 * Note that the output might not be valid JSON before calling
743 * sdb_store_json_finish().
744 *
745 * Returns:
746 * - 0 on success
747 * - a negative value else
748 */
749 int
750 sdb_store_json_emit(sdb_store_json_formatter_t *f, sdb_store_obj_t *obj);
752 /*
753 * sdb_store_json_emit_full:
754 * Serialize a single object including it's attributes and all children to
755 * JSON, adding it to the string buffer associated with the formatter object.
756 * The filter, if specified, is applied to each attribute and child object.
757 * Only matching objects will be included in the output.
758 *
759 * Note that the output might not be valid JSON before calling
760 * sdb_store_json_finish().
761 *
762 * Returns:
763 * - 0 on success
764 * - a negative value else
765 */
766 int
767 sdb_store_json_emit_full(sdb_store_json_formatter_t *f, sdb_store_obj_t *obj,
768 sdb_store_matcher_t *filter);
770 /*
771 * sdb_store_json_finish:
772 * Finish the JSON output. This function has to be called once after emiting
773 * all objects.
774 */
775 int
776 sdb_store_json_finish(sdb_store_json_formatter_t *f);
778 /*
779 * sdb_store_json_writer:
780 * A store writer implementation that generates JSON output. It expects a
781 * store JSON formatter as its user-data argument.
782 */
783 extern sdb_store_writer_t sdb_store_json_writer;
785 #ifdef __cplusplus
786 } /* extern "C" */
787 #endif
789 #endif /* ! SDB_CORE_STORE_H */
791 /* vim: set tw=78 sw=4 ts=4 noexpandtab : */