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 <stdio.h>
40 #ifdef __cplusplus
41 extern "C" {
42 #endif
44 /*
45 * Store object types.
46 */
47 enum {
48 SDB_HOST = 1,
49 SDB_SERVICE,
50 SDB_METRIC,
51 SDB_ATTRIBUTE,
52 };
53 #define SDB_STORE_TYPE_TO_NAME(t) \
54 (((t) == SDB_HOST) ? "host" \
55 : ((t) == SDB_SERVICE) ? "service" \
56 : ((t) == SDB_METRIC) ? "metric" \
57 : ((t) == SDB_ATTRIBUTE) ? "attribute" : "unknown")
59 /*
60 * sdb_store_obj_t represents the super-class of any object stored in the
61 * database. It inherits from sdb_object_t and may safely be cast to a generic
62 * object to access its name.
63 */
64 struct sdb_store_obj;
65 typedef struct sdb_store_obj sdb_store_obj_t;
67 /*
68 * Expressions represent arithmetic expressions based on stored objects and
69 * their various attributes.
70 *
71 * An expression object inherits from sdb_object_t and, thus, may safely be
72 * cast to a generic object.
73 */
74 struct sdb_store_expr;
75 typedef struct sdb_store_expr sdb_store_expr_t;
76 #define SDB_STORE_EXPR(obj) ((sdb_store_expr_t *)(obj))
78 /*
79 * Store matchers may be used to lookup hosts from the store based on their
80 * various attributes. Service and attribute matchers are applied to a host's
81 * services and attributes and evaluate to true if *any* service or attribute
82 * matches.
83 *
84 * A store matcher object inherits from sdb_object_t and, thus, may safely be
85 * cast to a generic object.
86 */
87 struct sdb_store_matcher;
88 typedef struct sdb_store_matcher sdb_store_matcher_t;
89 #define SDB_STORE_MATCHER(obj) ((sdb_store_matcher_t *)(obj))
91 /*
92 * Queryable fields of a stored object.
93 */
94 enum {
95 SDB_FIELD_NAME = 1, /* string */
96 SDB_FIELD_LAST_UPDATE, /* datetime */
97 SDB_FIELD_AGE, /* datetime */
98 SDB_FIELD_INTERVAL, /* datetime */
99 SDB_FIELD_BACKEND, /* string */
100 };
102 #define SDB_FIELD_TO_NAME(f) \
103 (((f) == SDB_FIELD_NAME) ? "name" \
104 : ((f) == SDB_FIELD_LAST_UPDATE) ? "last-update" \
105 : ((f) == SDB_FIELD_AGE) ? "age" \
106 : ((f) == SDB_FIELD_INTERVAL) ? "interval" \
107 : ((f) == SDB_FIELD_BACKEND) ? "backend" : "unknown")
109 /*
110 * sdb_store_clear:
111 * Clear the entire store and remove all stored objects.
112 */
113 void
114 sdb_store_clear(void);
116 /*
117 * sdb_store_host:
118 * Add/update a host in the store. If the host, identified by its
119 * canonicalized name, already exists, it will be updated according to the
120 * specified name and timestamp. Else, a new entry will be created in the
121 * store. Any memory required for storing the entry will be allocated an
122 * managed by the store itself.
123 *
124 * Returns:
125 * - 0 on success
126 * - a positive value if the new entry is older than the currently stored
127 * entry (in this case, no update will happen)
128 * - a negative value on error
129 */
130 int
131 sdb_store_host(const char *name, sdb_time_t last_update);
133 /*
134 * sdb_store_has_host:
135 * sdb_store_get_host:
136 * Query the store for a host by its (canonicalized) name.
137 *
138 * sdb_store_get_host increments the ref count of the host object. The caller
139 * needs to deref it when no longer using it.
140 */
141 _Bool
142 sdb_store_has_host(const char *name);
144 sdb_store_obj_t *
145 sdb_store_get_host(const char *name);
147 /*
148 * sdb_store_attribute:
149 * Add/update a host's attribute in the store. If the attribute, identified by
150 * its key, already exists for the specified host, it will be updated to the
151 * specified values. If the referenced host does not exist, an error will be
152 * reported. Else, a new entry will be created in the store. Any memory
153 * required for storing the entry will be allocated and managed by the store
154 * itself.
155 *
156 * Returns:
157 * - 0 on success
158 * - a positive value if the new entry is older than the currently stored
159 * entry (in this case, no update will happen)
160 * - a negative value on error
161 */
162 int
163 sdb_store_attribute(const char *hostname,
164 const char *key, const sdb_data_t *value,
165 sdb_time_t last_update);
167 /*
168 * sdb_store_service:
169 * Add/update a service in the store. If the service, identified by its name,
170 * already exists for the specified host, it will be updated according to the
171 * specified 'service' object. If the referenced host does not exist, an error
172 * will be reported. Else, a new entry will be created in the store. Any
173 * memory required for storing the entry will be allocated an managed by the
174 * store itself.
175 *
176 * Returns:
177 * - 0 on success
178 * - a positive value if the new entry is older than the currently stored
179 * entry (in this case, no update will happen)
180 * - a negative value on error
181 */
182 int
183 sdb_store_service(const char *hostname, const char *name,
184 sdb_time_t last_update);
186 /*
187 * sdb_store_service_attr:
188 * Add/update a service's attribute in the store. If the attribute, identified
189 * by its key, already exists for the specified service, it will be updated to
190 * the specified value. If the references service (for the specified host)
191 * does not exist, an error will be reported. Any memory required for storing
192 * the entry will be allocated and managed by the store itself.
193 *
194 * Returns:
195 * - 0 on success
196 * - a positive value if the new entry is older than the currently stored
197 * entry (in this case, no update will happen)
198 * - a negative value on error
199 */
200 int
201 sdb_store_service_attr(const char *hostname, const char *service,
202 const char *key, const sdb_data_t *value, sdb_time_t last_update);
204 /*
205 * A metric store describes how to access a metric's data.
206 */
207 typedef struct {
208 const char *type;
209 const char *id;
210 } sdb_metric_store_t;
212 /*
213 * sdb_store_metric:
214 * Add/update a metric in the store. If the metric, identified by its name,
215 * already exists for the specified host, it will be updated according to the
216 * specified 'metric' object. If the referenced host does not exist, an error
217 * will be reported. Else, a new entry will be created in the store. Any
218 * memory required for storing the entry will be allocated an managed by the
219 * store itself.
220 *
221 * If specified, the metric store describes where to access the metric's data.
222 *
223 * Returns:
224 * - 0 on success
225 * - a positive value if the new entry is older than the currently stored
226 * entry (in this case, no update will happen)
227 * - a negative value on error
228 */
229 int
230 sdb_store_metric(const char *hostname, const char *name,
231 sdb_metric_store_t *store, sdb_time_t last_update);
233 /*
234 * sdb_store_metric_attr:
235 * Add/update a metric's attribute in the store. If the attribute, identified
236 * by its key, already exists for the specified metric, it will be updated to
237 * the specified value. If the references metric (for the specified host)
238 * does not exist, an error will be reported. Any memory required for storing
239 * the entry will be allocated and managed by the store itself.
240 *
241 * Returns:
242 * - 0 on success
243 * - a positive value if the new entry is older than the currently stored
244 * entry (in this case, no update will happen)
245 * - a negative value on error
246 */
247 int
248 sdb_store_metric_attr(const char *hostname, const char *metric,
249 const char *key, const sdb_data_t *value, sdb_time_t last_update);
251 /*
252 * sdb_store_fetch_timeseries:
253 * Fetch the time-series described by the specified host's metric and
254 * serialize it as JSON into the provided string buffer.
255 *
256 * Returns:
257 * - 0 on success
258 * - a negative value else
259 */
260 int
261 sdb_store_fetch_timeseries(const char *hostname, const char *metric,
262 sdb_timeseries_opts_t *opts, sdb_strbuf_t *buf);
264 /*
265 * sdb_store_get_field:
266 * Get the value of a stored object's queryable field. The caller is
267 * responsible for freeing any dynamically allocated memory possibly stored in
268 * the returned value. If 'res' is NULL, the function will return whether the
269 * field exists.
270 *
271 * Note: Retrieving the backend this way is not currently supported.
272 *
273 * Returns:
274 * - 0 on success
275 * - a negative value else
276 */
277 int
278 sdb_store_get_field(sdb_store_obj_t *obj, int field, sdb_data_t *res);
280 /*
281 * sdb_store_get_attr:
282 * Get the value of a stored object's attribute. The caller is responsible for
283 * freeing any dynamically allocated memory possibly stored in the returned
284 * value. If 'res' is NULL, the function will return whether the attribute
285 * exists. If specified, only attributes matching the filter will be
286 * considered.
287 *
288 * Returns:
289 * - 0 if the attribute exists
290 * - a negative value else
291 */
292 int
293 sdb_store_get_attr(sdb_store_obj_t *obj, const char *name, sdb_data_t *res,
294 sdb_store_matcher_t *filter);
296 /*
297 * sdb_store_expr_create:
298 * Creates an arithmetic expression implementing the specified operator on the
299 * specified left and right operand.
300 *
301 * Returns:
302 * - an expression object on success
303 * - NULL else
304 */
305 sdb_store_expr_t *
306 sdb_store_expr_create(int op, sdb_store_expr_t *left, sdb_store_expr_t *right);
308 /*
309 * sdb_store_expr_fieldvalue:
310 * Creates an expression which evaluates to the value of the specified
311 * queryable field of a stored object.
312 *
313 * Returns:
314 * - an expression object on success
315 * - NULL else
316 */
317 sdb_store_expr_t *
318 sdb_store_expr_fieldvalue(int field);
320 /*
321 * sdb_store_expr_attrvalue:
322 * Creates an expression which evaluates to the value of the specified
323 * attribute of a stored object.
324 *
325 * Returns:
326 * - an expression object on success
327 * - NULL else
328 */
329 sdb_store_expr_t *
330 sdb_store_expr_attrvalue(const char *name);
332 /*
333 * sdb_store_expr_constvalue:
334 * Creates an expression which evaluates to the specified constant value.
335 *
336 * Returns:
337 * - an expression object on success
338 * - NULL else
339 */
340 sdb_store_expr_t *
341 sdb_store_expr_constvalue(const sdb_data_t *value);
343 /*
344 * sdb_store_expr_eval:
345 * Evaluate an expression for the specified stored object and stores the
346 * result in 'res'. The result's value will be allocated dynamically if
347 * necessary and, thus, should be free'd by the caller (e.g. using
348 * sdb_data_free_datum). The object may be NULL, in which case the expression
349 * needs to evaluate to a constant value. If specified, only objects matching
350 * the filter will be used during the evaluation.
351 *
352 * Returns:
353 * - 0 on success
354 * - a negative value else
355 */
356 int
357 sdb_store_expr_eval(sdb_store_expr_t *expr, sdb_store_obj_t *obj,
358 sdb_data_t *res, sdb_store_matcher_t *filter);
360 /*
361 * Conditionals may be used to lookup hosts from the store based on a
362 * conditional expression.
363 *
364 * A conditional object inherits from sdb_object_t and, thus, may safely be
365 * cast to a generic object.
366 */
367 struct sdb_store_cond;
368 typedef struct sdb_store_cond sdb_store_cond_t;
369 #define SDB_STORE_COND(obj) ((sdb_store_cond_t *)(obj))
371 /*
372 * sdb_store_attr_cond:
373 * Creates a conditional based on attribute values. The value of stored
374 * attributes is compared against the value the expression evaluates to. See
375 * sdb_data_cmp for details about the comparison.
376 */
377 sdb_store_cond_t *
378 sdb_store_attr_cond(const char *name, sdb_store_expr_t *expr);
380 /*
381 * sdb_store_obj_cond:
382 * Creates a conditional based on queryable object fields. The respective
383 * field of *any* object type is compared against the value the expression
384 * evaluates to.
385 */
386 sdb_store_cond_t *
387 sdb_store_obj_cond(int field, sdb_store_expr_t *expr);
389 /*
390 * sdb_store_name_matcher:
391 * Creates a matcher matching by the specified object type's name. If 're' is
392 * true, the specified name is treated as a POSIX extended regular expression.
393 * Else, the exact name has to match (case-insensitive).
394 */
395 sdb_store_matcher_t *
396 sdb_store_name_matcher(int type, const char *name, _Bool re);
398 /*
399 * sdb_store_attr_matcher:
400 * Creates a matcher matching attributes based on their value. If 're' is
401 * true, the specified name is treated as a POSIX extended regular expression.
402 * Else, the exact name has to match (case-insensitive).
403 */
404 sdb_store_matcher_t *
405 sdb_store_attr_matcher(const char *name, const char *value, _Bool re);
407 /*
408 * sdb_store_isnull_matcher:
409 * Creates a matcher matching "missing" attributes.
410 */
411 sdb_store_matcher_t *
412 sdb_store_isnull_matcher(const char *attr_name);
414 /*
415 * sdb_store_lt_matcher, sdb_store_le_matcher, sdb_store_eq_matcher,
416 * sdb_store_ge_matcher, sdb_store_gt_matcher:
417 * Creates a matcher based on a conditional. The matcher matches objects for
418 * which the conditional evaluates the object to compare less than, less or
419 * equal, equal, greater or equal, or greater than the conditional's value
420 * repsectively.
421 */
422 sdb_store_matcher_t *
423 sdb_store_lt_matcher(sdb_store_cond_t *cond);
424 sdb_store_matcher_t *
425 sdb_store_le_matcher(sdb_store_cond_t *cond);
426 sdb_store_matcher_t *
427 sdb_store_eq_matcher(sdb_store_cond_t *cond);
428 sdb_store_matcher_t *
429 sdb_store_ge_matcher(sdb_store_cond_t *cond);
430 sdb_store_matcher_t *
431 sdb_store_gt_matcher(sdb_store_cond_t *cond);
433 sdb_store_matcher_t *
434 sdb_store_cmp_lt(sdb_store_expr_t *left, sdb_store_expr_t *right);
435 sdb_store_matcher_t *
436 sdb_store_cmp_le(sdb_store_expr_t *left, sdb_store_expr_t *right);
437 sdb_store_matcher_t *
438 sdb_store_cmp_eq(sdb_store_expr_t *left, sdb_store_expr_t *right);
439 sdb_store_matcher_t *
440 sdb_store_cmp_ge(sdb_store_expr_t *left, sdb_store_expr_t *right);
441 sdb_store_matcher_t *
442 sdb_store_cmp_gt(sdb_store_expr_t *left, sdb_store_expr_t *right);
444 /*
445 * sdb_store_parse_object_type_plural:
446 * Parse the type name (plural) of a stored object.
447 *
448 * Returns:
449 * - the object type on success
450 * - a negative value else
451 */
452 int
453 sdb_store_parse_object_type_plural(const char *name);
455 /*
456 * sdb_store_parse_field_name:
457 * Parse the name of a stored object's queryable field.
458 *
459 * Returns:
460 * - the field id on success
461 * - a negative value else
462 */
463 int
464 sdb_store_parse_field_name(const char *name);
466 /*
467 * sdb_store_matcher_parse_cmp:
468 * Parse a simple compare expression (<obj_type>.<attr> <op> <expression>).
469 *
470 * Returns:
471 * - a matcher object on success
472 * - NULL else
473 */
474 sdb_store_matcher_t *
475 sdb_store_matcher_parse_cmp(const char *obj_type, const char *attr,
476 const char *op, sdb_store_expr_t *expr);
478 /*
479 * sdb_store_matcher_parse_field_cmp:
480 * Parse a simple compare expression for queryable object fields (<field> <op>
481 * <expression>).
482 *
483 * Returns:
484 * - a matcher object on success
485 * - NULL else
486 */
487 sdb_store_matcher_t *
488 sdb_store_matcher_parse_field_cmp(const char *name, const char *op,
489 sdb_store_expr_t *expr);
491 /*
492 * sdb_store_dis_matcher:
493 * Creates a matcher matching the disjunction (logical OR) of two matchers.
494 */
495 sdb_store_matcher_t *
496 sdb_store_dis_matcher(sdb_store_matcher_t *left, sdb_store_matcher_t *right);
498 /*
499 * sdb_store_con_matcher:
500 * Creates a matcher matching the conjunction (logical AND) of two matchers.
501 */
502 sdb_store_matcher_t *
503 sdb_store_con_matcher(sdb_store_matcher_t *left, sdb_store_matcher_t *right);
505 /*
506 * sdb_store_con_matcher::
507 * Creates a matcher matching the inverse (logical NOT) of a matcher.
508 */
509 sdb_store_matcher_t *
510 sdb_store_inv_matcher(sdb_store_matcher_t *m);
512 /*
513 * sdb_store_matcher_matches:
514 * Check whether the specified matcher matches the specified store object. If
515 * specified, the filter will be used to preselect objects for further
516 * evaluation. It is applied to any object that's used during the evaluation
517 * of the matcher. Only those objects matching the filter will be considered.
518 *
519 * Note that the filter is applied to all object types (hosts, service,
520 * metric, attribute). Thus, any object-specific matchers are mostly unsuited
521 * for this purpose and, if used, may result in unexpected behavior.
522 *
523 * Returns:
524 * - 1 if the object matches
525 * - 0 else
526 */
527 int
528 sdb_store_matcher_matches(sdb_store_matcher_t *m, sdb_store_obj_t *obj,
529 sdb_store_matcher_t *filter);
531 /*
532 * sdb_store_matcher_tostring:
533 * Format a matcher object as string. This is meant for logging or debugging
534 * purposes.
535 */
536 char *
537 sdb_store_matcher_tostring(sdb_store_matcher_t *m, char *buf, size_t buflen);
539 /*
540 * sdb_store_lookup_cb:
541 * Lookup callback. It is called for each matching object when looking up data
542 * in the store. The lookup aborts if the callback returns non-zero.
543 */
544 typedef int (*sdb_store_lookup_cb)(sdb_store_obj_t *obj, void *user_data);
546 /*
547 * sdb_store_scan:
548 * Look up objects in the store. The specified callback function is called for
549 * each object in the store matching 'm'. The function performs a full scan of
550 * all hosts stored in the database. If specified, the filter will be used to
551 * preselect objects for further evaluation. See the description of
552 * 'sdb_store_matcher_matches' for details.
553 *
554 * Returns:
555 * - 0 on success
556 * - a negative value else
557 */
558 int
559 sdb_store_scan(sdb_store_matcher_t *m, sdb_store_matcher_t *filter,
560 sdb_store_lookup_cb cb, void *user_data);
562 /*
563 * Flags for serialization functions.
564 *
565 * By default, the full host object will be included in the serialized output.
566 * When specifying any of the flags, the respective information will be left
567 * out. The SKIP_EMPTY flags may be used to skip host objects entirely.
568 */
569 enum {
570 SDB_SKIP_ATTRIBUTES = 1 << 0,
571 SDB_SKIP_SERVICES = 1 << 1,
572 SDB_SKIP_METRICS = 1 << 2,
573 SDB_SKIP_SERVICE_ATTRIBUTES = 1 << 3,
575 SDB_SKIP_ALL = (1 << 8) - 1,
577 /* skip hosts if they do not reference any services/metrics */
578 SDB_SKIP_EMPTY_SERVICES = 1 << 8,
579 SDB_SKIP_EMPTY_METRICS = 1 << 9,
580 };
582 /*
583 * sdb_store_tojson:
584 * Serialize the entire store to JSON and append the result to the specified
585 * buffer. If specified, only objects matching the filter will be included in
586 * the result (see sdb_store_host_tojson for details).
587 *
588 * Returns:
589 * - 0 on success
590 * - a negative value on error
591 */
592 int
593 sdb_store_tojson(sdb_strbuf_t *buf, sdb_store_matcher_t *filter, int flags);
595 /*
596 * sdb_store_host_tojson:
597 * Serialize a host object to JSON and append the result to the specified
598 * buffer. If specified, only objects matching the filter will be included in
599 * the result. The filter is applied to each object individually and, thus,
600 * should not be of any object-type specific kind. The filter is never applied
601 * to the specified host object; the caller is responsible for this and for
602 * correctly handling skipped hosts.
603 *
604 * Returns:
605 * - 0 on success
606 * - a negative value on error
607 */
608 int
609 sdb_store_host_tojson(sdb_store_obj_t *host, sdb_strbuf_t *buf,
610 sdb_store_matcher_t *filter, int flags);
612 /*
613 * sdb_store_iter_cb:
614 * Store iterator callback. Iteration stops if the callback returns non-zero.
615 */
616 typedef int (*sdb_store_iter_cb)(sdb_store_obj_t *obj, void *user_data);
618 /*
619 * sdb_store_iterate:
620 * Iterate the entire store, calling the specified callback for each object.
621 * The user_data pointer is passed on to each call of the callback.
622 *
623 * Returns:
624 * - 0 on success
625 * - a negative value else
626 */
627 int
628 sdb_store_iterate(sdb_store_iter_cb cb, void *user_data);
630 #ifdef __cplusplus
631 } /* extern "C" */
632 #endif
634 #endif /* ! SDB_CORE_STORE_H */
636 /* vim: set tw=78 sw=4 ts=4 noexpandtab : */