0cee91362998d55c4f329c031572d5096e68400c
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. The query result will be passed back via the specified
292 * store writer.
293 */
294 int (*execute_query)(sdb_object_t *q,
295 sdb_store_writer_t *w, sdb_object_t *wd,
296 sdb_strbuf_t *errbuf, sdb_object_t *user_data);
297 } sdb_store_reader_t;
299 /*
300 * sdb_store_reader:
301 * A store reader implementation that uses an in-memory object store. It
302 * expects a store object as its user-data argument.
303 */
304 extern sdb_store_reader_t sdb_store_reader;
306 /*
307 * sdb_store_create:
308 * Allocate a new in-memory store.
309 */
310 sdb_store_t *
311 sdb_store_create(void);
313 /*
314 * sdb_store_host, sdb_store_service, sdb_store_metric, sdb_store_attribute,
315 * sdb_store_metric_attr:
316 * Store an object in the specified store. The hostname is expected to be
317 * canonical.
318 */
319 int
320 sdb_store_host(sdb_store_t *store, const char *name, sdb_time_t last_update);
321 int
322 sdb_store_service(sdb_store_t *store, const char *hostname, const char *name,
323 sdb_time_t last_update);
324 int
325 sdb_store_metric(sdb_store_t *store, const char *hostname, const char *name,
326 sdb_metric_store_t *metric_store, sdb_time_t last_update);
327 int
328 sdb_store_attribute(sdb_store_t *store, const char *hostname,
329 const char *key, const sdb_data_t *value, sdb_time_t last_update);
330 int
331 sdb_store_service_attr(sdb_store_t *store, const char *hostname,
332 const char *service, const char *key, const sdb_data_t *value,
333 sdb_time_t last_update);
334 int
335 sdb_store_metric_attr(sdb_store_t *store, const char *hostname,
336 const char *metric, const char *key, const sdb_data_t *value,
337 sdb_time_t last_update);
339 /*
340 * sdb_store_get_host:
341 * Query the specified store for a host by its (canonicalized) name.
342 *
343 * The function increments the ref count of the host object. The caller needs
344 * to deref it when no longer using it.
345 */
346 sdb_store_obj_t *
347 sdb_store_get_host(sdb_store_t *store, const char *name);
349 /*
350 * sdb_store_fetch_timeseries:
351 * Fetch the time-series described by the specified host's metric and
352 * serialize it as JSON into the provided string buffer. The host data is
353 * retrieved from the specified store.
354 *
355 * Returns:
356 * - 0 on success
357 * - a negative value else
358 */
359 int
360 sdb_store_fetch_timeseries(sdb_store_t *store,
361 const char *hostname, const char *metric,
362 sdb_timeseries_opts_t *opts, sdb_strbuf_t *buf);
364 /*
365 * sdb_store_get_child:
366 * Retrieve a host's child object of the specified type and name. The
367 * reference count of the child object will be incremented before returning
368 * it. The caller is responsible for releasing the object once it's no longer
369 * used.
370 *
371 * Returns:
372 * - the child object on success
373 * - NULL else
374 */
375 sdb_store_obj_t *
376 sdb_store_get_child(sdb_store_obj_t *host, int type, const char *name);
378 /*
379 * sdb_store_get_field:
380 * Get the value of a stored object's queryable field. The caller is
381 * responsible for freeing any dynamically allocated memory possibly stored in
382 * the returned value. If 'res' is NULL, the function will return whether the
383 * field exists.
384 *
385 * Returns:
386 * - 0 on success
387 * - a negative value else
388 */
389 int
390 sdb_store_get_field(sdb_store_obj_t *obj, int field, sdb_data_t *res);
392 /*
393 * sdb_store_get_attr:
394 * Get the value of a stored object's attribute. The caller is responsible for
395 * freeing any dynamically allocated memory possibly stored in the returned
396 * value. If 'res' is NULL, the function will return whether the attribute
397 * exists. If specified, only attributes matching the filter will be
398 * considered.
399 *
400 * Returns:
401 * - 0 if the attribute exists
402 * - a negative value else
403 */
404 int
405 sdb_store_get_attr(sdb_store_obj_t *obj, const char *name, sdb_data_t *res,
406 sdb_store_matcher_t *filter);
408 /*
409 * Querying a store:
410 *
411 * - Query interface: A query is a formal description of an interaction with
412 * the store. It can be used, both, for read and write access. The query is
413 * described by its abstract syntax tree (AST). The parser package provides
414 * means to parse a string (SysQL) representation of the query into an AST.
415 *
416 * - Matcher / expression interface: This low-level interface provides direct
417 * control over how to access the store. It is used by the query
418 * implementation internally and can only be used for read access.
419 */
421 /*
422 * sdb_store_query_t:
423 * A parsed query readily prepared for execution.
424 */
425 struct sdb_store_query;
426 typedef struct sdb_store_query sdb_store_query_t;
428 /*
429 * sdb_store_query_prepare:
430 * Prepare the query described by 'ast' for execution in a store.
431 *
432 * Returns:
433 * - a store query on success
434 * - NULL else
435 */
436 sdb_store_query_t *
437 sdb_store_query_prepare(sdb_ast_node_t *ast);
439 /*
440 * sdb_store_query_prepare_matcher:
441 * Prepare the logical expression described by 'ast' for execution as a store
442 * matcher.
443 *
444 * Returns:
445 * - a matcher on success
446 * - NULL else
447 */
448 sdb_store_matcher_t *
449 sdb_store_query_prepare_matcher(sdb_ast_node_t *ast);
451 /*
452 * sdb_store_query_execute:
453 * Execute a previously prepared query in the specified store. The query
454 * result will be written to 'buf' and any errors to 'errbuf'.
455 *
456 * Returns:
457 * - the result type (to be used by the server reply)
458 * - a negative value on error
459 */
460 int
461 sdb_store_query_execute(sdb_store_t *store, sdb_store_query_t *m,
462 sdb_store_writer_t *w, sdb_object_t *wd, sdb_strbuf_t *errbuf);
464 /*
465 * sdb_store_expr_create:
466 * Creates an arithmetic expression implementing the specified operator on the
467 * specified left and right operand.
468 *
469 * Returns:
470 * - an expression object on success
471 * - NULL else
472 */
473 sdb_store_expr_t *
474 sdb_store_expr_create(int op, sdb_store_expr_t *left, sdb_store_expr_t *right);
476 /*
477 * sdb_store_expr_typed:
478 * Creates an expression which evaluates in the context of an object's sibling
479 * as specified by the given type.
480 *
481 * Returns:
482 * - an expression object on success
483 * - NULL else
484 */
485 sdb_store_expr_t *
486 sdb_store_expr_typed(int typ, sdb_store_expr_t *expr);
488 /*
489 * sdb_store_expr_fieldvalue:
490 * Creates an expression which evaluates to the value of the specified
491 * queryable field of a stored object.
492 *
493 * Returns:
494 * - an expression object on success
495 * - NULL else
496 */
497 sdb_store_expr_t *
498 sdb_store_expr_fieldvalue(int field);
500 /*
501 * sdb_store_expr_attrvalue:
502 * Creates an expression which evaluates to the value of the specified
503 * attribute of a stored object. Evaluates to a NULL value if the attribute
504 * does not exist.
505 *
506 * Returns:
507 * - an expression object on success
508 * - NULL else
509 */
510 sdb_store_expr_t *
511 sdb_store_expr_attrvalue(const char *name);
513 /*
514 * sdb_store_expr_constvalue:
515 * Creates an expression which evaluates to the specified constant value.
516 *
517 * Returns:
518 * - an expression object on success
519 * - NULL else
520 */
521 sdb_store_expr_t *
522 sdb_store_expr_constvalue(const sdb_data_t *value);
524 /*
525 * sdb_store_expr_eval:
526 * Evaluate an expression for the specified stored object and stores the
527 * result in 'res'. The result's value will be allocated dynamically if
528 * necessary and, thus, should be free'd by the caller (e.g. using
529 * sdb_data_free_datum). The object may be NULL, in which case the expression
530 * needs to evaluate to a constant value. If specified, only objects matching
531 * the filter will be used during the evaluation.
532 *
533 * Returns:
534 * - 0 on success
535 * - a negative value else
536 */
537 int
538 sdb_store_expr_eval(sdb_store_expr_t *expr, sdb_store_obj_t *obj,
539 sdb_data_t *res, sdb_store_matcher_t *filter);
541 /*
542 * sdb_store_expr_iter:
543 * Iterate over the elements of an iterable expression. sdb_store_expr_iter
544 * returns NULL if the expression is not iterable (for the specified object).
545 *
546 * sdb_store_expr_iter_get_next returns NULL if there is no next element.
547 */
548 sdb_store_expr_iter_t *
549 sdb_store_expr_iter(sdb_store_expr_t *expr, sdb_store_obj_t *obj,
550 sdb_store_matcher_t *filter);
551 void
552 sdb_store_expr_iter_destroy(sdb_store_expr_iter_t *iter);
554 bool
555 sdb_store_expr_iter_has_next(sdb_store_expr_iter_t *iter);
556 sdb_data_t
557 sdb_store_expr_iter_get_next(sdb_store_expr_iter_t *iter);
559 /*
560 * sdb_store_dis_matcher:
561 * Creates a matcher matching the disjunction (logical OR) of two matchers.
562 */
563 sdb_store_matcher_t *
564 sdb_store_dis_matcher(sdb_store_matcher_t *left, sdb_store_matcher_t *right);
566 /*
567 * sdb_store_con_matcher:
568 * Creates a matcher matching the conjunction (logical AND) of two matchers.
569 */
570 sdb_store_matcher_t *
571 sdb_store_con_matcher(sdb_store_matcher_t *left, sdb_store_matcher_t *right);
573 /*
574 * sdb_store_inv_matcher::
575 * Creates a matcher matching the inverse (logical NOT) of a matcher.
576 */
577 sdb_store_matcher_t *
578 sdb_store_inv_matcher(sdb_store_matcher_t *m);
580 /*
581 * sdb_store_any_matcher:
582 * Creates a matcher iterating over values of the first expression (which has
583 * to be iterable). It matches if *any* of those elements match 'm'. 'm' has
584 * to be an ary operation with the left operand unset.
585 */
586 sdb_store_matcher_t *
587 sdb_store_any_matcher(sdb_store_expr_t *iter, sdb_store_matcher_t *m);
589 /*
590 * sdb_store_all_matcher:
591 * Creates a matcher iterating over values of the first expression (which has
592 * to be iterable). It matches if *all* of those elements match 'm'. 'm' has
593 * to be an ary operation with the left operand unset.
594 */
595 sdb_store_matcher_t *
596 sdb_store_all_matcher(sdb_store_expr_t *iter, sdb_store_matcher_t *m);
598 /*
599 * sdb_store_in_matcher:
600 * Creates a matcher which matches if the right value evaluates to an array
601 * value and the left value is included in that array. See sdb_data_inarray
602 * for more details.
603 */
604 sdb_store_matcher_t *
605 sdb_store_in_matcher(sdb_store_expr_t *left, sdb_store_expr_t *right);
607 /*
608 * sdb_store_lt_matcher, sdb_store_le_matcher, sdb_store_eq_matcher,
609 * sdb_store_ge_matcher, sdb_store_gt_matcher:
610 * Create conditional matchers comparing the values of two expressions. The
611 * matcher matches if the left expression compres less than, less or equal
612 * than, equal to, not equal to, greater or equal than, or greater than the
613 * right expression.
614 */
615 sdb_store_matcher_t *
616 sdb_store_lt_matcher(sdb_store_expr_t *left, sdb_store_expr_t *right);
617 sdb_store_matcher_t *
618 sdb_store_le_matcher(sdb_store_expr_t *left, sdb_store_expr_t *right);
619 sdb_store_matcher_t *
620 sdb_store_eq_matcher(sdb_store_expr_t *left, sdb_store_expr_t *right);
621 sdb_store_matcher_t *
622 sdb_store_ne_matcher(sdb_store_expr_t *left, sdb_store_expr_t *right);
623 sdb_store_matcher_t *
624 sdb_store_ge_matcher(sdb_store_expr_t *left, sdb_store_expr_t *right);
625 sdb_store_matcher_t *
626 sdb_store_gt_matcher(sdb_store_expr_t *left, sdb_store_expr_t *right);
628 /*
629 * sdb_store_regex_matcher:
630 * Creates a matcher which matches the string value the left expression
631 * evaluates to against the regular expression the right expression evaluates
632 * to. The right expression may either be a constant value regular expression
633 * or string or a dynamic value evaluating to a string. In the latter case,
634 * the string is compiled to a regex every time the matcher is executed.
635 */
636 sdb_store_matcher_t *
637 sdb_store_regex_matcher(sdb_store_expr_t *left, sdb_store_expr_t *right);
639 /*
640 * sdb_store_nregex_matcher:
641 * Creates a regex matcher just like sdb_store_regex_matcher except that it
642 * matches in case the regular expression does not match.
643 */
644 sdb_store_matcher_t *
645 sdb_store_nregex_matcher(sdb_store_expr_t *left, sdb_store_expr_t *right);
647 /*
648 * sdb_store_isnull_matcher:
649 * Creates a matcher matching NULL values.
650 */
651 sdb_store_matcher_t *
652 sdb_store_isnull_matcher(sdb_store_expr_t *expr);
654 /*
655 * sdb_store_istrue_matcher, sdb_store_isfalse_matcher:
656 * Creates a matcher matching boolean values.
657 */
658 sdb_store_matcher_t *
659 sdb_store_istrue_matcher(sdb_store_expr_t *expr);
660 sdb_store_matcher_t *
661 sdb_store_isfalse_matcher(sdb_store_expr_t *expr);
663 /*
664 * sdb_store_matcher_matches:
665 * Check whether the specified matcher matches the specified store object. If
666 * specified, the filter will be used to preselect objects for further
667 * evaluation. It is applied to any object that's used during the evaluation
668 * of the matcher. Only those objects matching the filter will be considered.
669 *
670 * Note that the filter is applied to all object types (hosts, service,
671 * metric, attribute). Thus, any object-specific matchers are mostly unsuited
672 * for this purpose and, if used, may result in unexpected behavior.
673 *
674 * Returns:
675 * - 1 if the object matches
676 * - 0 else
677 */
678 int
679 sdb_store_matcher_matches(sdb_store_matcher_t *m, sdb_store_obj_t *obj,
680 sdb_store_matcher_t *filter);
682 /*
683 * sdb_store_matcher_op_cb:
684 * Callback constructing a matcher operator.
685 */
686 typedef sdb_store_matcher_t *(*sdb_store_matcher_op_cb)
687 (sdb_store_expr_t *, sdb_store_expr_t *);
689 /*
690 * sdb_store_lookup_cb:
691 * Lookup callback. It is called for each matching object when looking up data
692 * in the store passing on the lookup filter and the specified user-data. The
693 * lookup aborts early if the callback returns non-zero.
694 */
695 typedef int (*sdb_store_lookup_cb)(sdb_store_obj_t *obj,
696 sdb_store_matcher_t *filter, void *user_data);
698 /*
699 * sdb_store_scan:
700 * Look up objects of the specified type in the specified store. The specified
701 * callback function is called for each object in the store matching 'm'. The
702 * function performs a full scan of all stored objects. If specified, the
703 * filter will be used to preselect objects for further evaluation. See the
704 * description of 'sdb_store_matcher_matches' for details.
705 *
706 * Returns:
707 * - 0 on success
708 * - a negative value else
709 */
710 int
711 sdb_store_scan(sdb_store_t *store, int type,
712 sdb_store_matcher_t *m, sdb_store_matcher_t *filter,
713 sdb_store_lookup_cb cb, void *user_data);
715 /*
716 * Flags for JSON formatting.
717 */
718 enum {
719 SDB_WANT_ARRAY = 1 << 0,
720 };
722 /*
723 * sdb_store_json_formatter:
724 * Create a JSON formatter for the specified object types writing to the
725 * specified buffer.
726 */
727 sdb_store_json_formatter_t *
728 sdb_store_json_formatter(sdb_strbuf_t *buf, int type, int flags);
730 /*
731 * sdb_store_emit:
732 * Serialize a single object to JSON adding it to the string buffer associated
733 * with the formatter object. The serialized object will not include
734 * attributes or any child objects. Instead, call the function again for each
735 * of those objects. All attributes have to be emitted before any other
736 * children types. Use sdb_store_emit_full() to emit a full (filtered) object.
737 *
738 * Note that the output might not be valid JSON before calling
739 * sdb_store_json_finish().
740 *
741 * Returns:
742 * - 0 on success
743 * - a negative value else
744 */
745 int
746 sdb_store_emit(sdb_store_obj_t *obj, sdb_store_writer_t *w, sdb_object_t *wd);
748 /*
749 * sdb_store_emit_full:
750 * Serialize a single object including it's attributes and all children to
751 * JSON, adding it to the string buffer associated with the formatter object.
752 * The filter, if specified, is applied to each attribute and child object.
753 * Only matching objects will be included in the output.
754 *
755 * Note that the output might not be valid JSON before calling
756 * sdb_store_json_finish().
757 *
758 * Returns:
759 * - 0 on success
760 * - a negative value else
761 */
762 int
763 sdb_store_emit_full(sdb_store_obj_t *obj, sdb_store_matcher_t *filter,
764 sdb_store_writer_t *w, sdb_object_t *wd);
766 /*
767 * sdb_store_json_finish:
768 * Finish the JSON output. This function has to be called once after emiting
769 * all objects.
770 */
771 int
772 sdb_store_json_finish(sdb_store_json_formatter_t *f);
774 /*
775 * sdb_store_json_writer:
776 * A store writer implementation that generates JSON output. It expects a
777 * store JSON formatter as its user-data argument.
778 */
779 extern sdb_store_writer_t sdb_store_json_writer;
781 #ifdef __cplusplus
782 } /* extern "C" */
783 #endif
785 #endif /* ! SDB_CORE_STORE_H */
787 /* vim: set tw=78 sw=4 ts=4 noexpandtab : */