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 #define SDB_FIELD_TYPE(f) \
110 (((f) == SDB_FIELD_NAME) ? SDB_TYPE_STRING \
111 : ((f) == SDB_FIELD_LAST_UPDATE) ? SDB_TYPE_DATETIME \
112 : ((f) == SDB_FIELD_AGE) ? SDB_TYPE_DATETIME \
113 : ((f) == SDB_FIELD_INTERVAL) ? SDB_TYPE_DATETIME \
114 : ((f) == SDB_FIELD_BACKEND) ? (SDB_TYPE_ARRAY | SDB_TYPE_STRING) \
115 : -1)
117 /*
118 * sdb_store_clear:
119 * Clear the entire store and remove all stored objects.
120 */
121 void
122 sdb_store_clear(void);
124 /*
125 * sdb_store_host:
126 * Add/update a host in the store. If the host, identified by its
127 * canonicalized name, already exists, it will be updated according to the
128 * specified name and timestamp. Else, a new entry will be created in the
129 * store. Any memory required for storing the entry will be allocated an
130 * managed by the store itself.
131 *
132 * Returns:
133 * - 0 on success
134 * - a positive value if the new entry is older than the currently stored
135 * entry (in this case, no update will happen)
136 * - a negative value on error
137 */
138 int
139 sdb_store_host(const char *name, sdb_time_t last_update);
141 /*
142 * sdb_store_has_host:
143 * sdb_store_get_host:
144 * Query the store for a host by its (canonicalized) name.
145 *
146 * sdb_store_get_host increments the ref count of the host object. The caller
147 * needs to deref it when no longer using it.
148 */
149 _Bool
150 sdb_store_has_host(const char *name);
152 sdb_store_obj_t *
153 sdb_store_get_host(const char *name);
155 /*
156 * sdb_store_attribute:
157 * Add/update a host's attribute in the store. If the attribute, identified by
158 * its key, already exists for the specified host, it will be updated to the
159 * specified values. If the referenced host does not exist, an error will be
160 * reported. Else, a new entry will be created in the store. Any memory
161 * required for storing the entry will be allocated and managed by the store
162 * itself.
163 *
164 * Returns:
165 * - 0 on success
166 * - a positive value if the new entry is older than the currently stored
167 * entry (in this case, no update will happen)
168 * - a negative value on error
169 */
170 int
171 sdb_store_attribute(const char *hostname,
172 const char *key, const sdb_data_t *value,
173 sdb_time_t last_update);
175 /*
176 * sdb_store_service:
177 * Add/update a service in the store. If the service, identified by its name,
178 * already exists for the specified host, it will be updated according to the
179 * specified 'service' object. If the referenced host does not exist, an error
180 * will be reported. Else, a new entry will be created in the store. Any
181 * memory required for storing the entry will be allocated an managed by the
182 * store itself.
183 *
184 * Returns:
185 * - 0 on success
186 * - a positive value if the new entry is older than the currently stored
187 * entry (in this case, no update will happen)
188 * - a negative value on error
189 */
190 int
191 sdb_store_service(const char *hostname, const char *name,
192 sdb_time_t last_update);
194 /*
195 * sdb_store_service_attr:
196 * Add/update a service's attribute in the store. If the attribute, identified
197 * by its key, already exists for the specified service, it will be updated to
198 * the specified value. If the references service (for the specified host)
199 * does not exist, an error will be reported. Any memory required for storing
200 * the entry will be allocated and managed by the store itself.
201 *
202 * Returns:
203 * - 0 on success
204 * - a positive value if the new entry is older than the currently stored
205 * entry (in this case, no update will happen)
206 * - a negative value on error
207 */
208 int
209 sdb_store_service_attr(const char *hostname, const char *service,
210 const char *key, const sdb_data_t *value, sdb_time_t last_update);
212 /*
213 * A metric store describes how to access a metric's data.
214 */
215 typedef struct {
216 const char *type;
217 const char *id;
218 } sdb_metric_store_t;
220 /*
221 * sdb_store_metric:
222 * Add/update a metric in the store. If the metric, identified by its name,
223 * already exists for the specified host, it will be updated according to the
224 * specified 'metric' object. If the referenced host does not exist, an error
225 * will be reported. Else, a new entry will be created in the store. Any
226 * memory required for storing the entry will be allocated an managed by the
227 * store itself.
228 *
229 * If specified, the metric store describes where to access the metric's data.
230 *
231 * Returns:
232 * - 0 on success
233 * - a positive value if the new entry is older than the currently stored
234 * entry (in this case, no update will happen)
235 * - a negative value on error
236 */
237 int
238 sdb_store_metric(const char *hostname, const char *name,
239 sdb_metric_store_t *store, sdb_time_t last_update);
241 /*
242 * sdb_store_metric_attr:
243 * Add/update a metric's attribute in the store. If the attribute, identified
244 * by its key, already exists for the specified metric, it will be updated to
245 * the specified value. If the references metric (for the specified host)
246 * does not exist, an error will be reported. Any memory required for storing
247 * the entry will be allocated and managed by the store itself.
248 *
249 * Returns:
250 * - 0 on success
251 * - a positive value if the new entry is older than the currently stored
252 * entry (in this case, no update will happen)
253 * - a negative value on error
254 */
255 int
256 sdb_store_metric_attr(const char *hostname, const char *metric,
257 const char *key, const sdb_data_t *value, sdb_time_t last_update);
259 /*
260 * sdb_store_fetch_timeseries:
261 * Fetch the time-series described by the specified host's metric and
262 * serialize it as JSON into the provided string buffer.
263 *
264 * Returns:
265 * - 0 on success
266 * - a negative value else
267 */
268 int
269 sdb_store_fetch_timeseries(const char *hostname, const char *metric,
270 sdb_timeseries_opts_t *opts, sdb_strbuf_t *buf);
272 /*
273 * sdb_store_get_field:
274 * Get the value of a stored object's queryable field. The caller is
275 * responsible for freeing any dynamically allocated memory possibly stored in
276 * the returned value. If 'res' is NULL, the function will return whether the
277 * field exists.
278 *
279 * Note: Retrieving the backend this way is not currently supported.
280 *
281 * Returns:
282 * - 0 on success
283 * - a negative value else
284 */
285 int
286 sdb_store_get_field(sdb_store_obj_t *obj, int field, sdb_data_t *res);
288 /*
289 * sdb_store_get_attr:
290 * Get the value of a stored object's attribute. The caller is responsible for
291 * freeing any dynamically allocated memory possibly stored in the returned
292 * value. If 'res' is NULL, the function will return whether the attribute
293 * exists. If specified, only attributes matching the filter will be
294 * considered.
295 *
296 * Returns:
297 * - 0 if the attribute exists
298 * - a negative value else
299 */
300 int
301 sdb_store_get_attr(sdb_store_obj_t *obj, const char *name, sdb_data_t *res,
302 sdb_store_matcher_t *filter);
304 /*
305 * sdb_store_expr_create:
306 * Creates an arithmetic expression implementing the specified operator on the
307 * specified left and right operand.
308 *
309 * Returns:
310 * - an expression object on success
311 * - NULL else
312 */
313 sdb_store_expr_t *
314 sdb_store_expr_create(int op, sdb_store_expr_t *left, sdb_store_expr_t *right);
316 /*
317 * sdb_store_expr_fieldvalue:
318 * Creates an expression which evaluates to the value of the specified
319 * queryable field of a stored object.
320 *
321 * Returns:
322 * - an expression object on success
323 * - NULL else
324 */
325 sdb_store_expr_t *
326 sdb_store_expr_fieldvalue(int field);
328 /*
329 * sdb_store_expr_attrvalue:
330 * Creates an expression which evaluates to the value of the specified
331 * attribute of a stored object. Evaluates to a NULL value if the attribute
332 * does not exist.
333 *
334 * Returns:
335 * - an expression object on success
336 * - NULL else
337 */
338 sdb_store_expr_t *
339 sdb_store_expr_attrvalue(const char *name);
341 /*
342 * sdb_store_expr_constvalue:
343 * Creates an expression which evaluates to the specified constant value.
344 *
345 * Returns:
346 * - an expression object on success
347 * - NULL else
348 */
349 sdb_store_expr_t *
350 sdb_store_expr_constvalue(const sdb_data_t *value);
352 /*
353 * sdb_store_expr_eval:
354 * Evaluate an expression for the specified stored object and stores the
355 * result in 'res'. The result's value will be allocated dynamically if
356 * necessary and, thus, should be free'd by the caller (e.g. using
357 * sdb_data_free_datum). The object may be NULL, in which case the expression
358 * needs to evaluate to a constant value. If specified, only objects matching
359 * the filter will be used during the evaluation.
360 *
361 * Returns:
362 * - 0 on success
363 * - a negative value else
364 */
365 int
366 sdb_store_expr_eval(sdb_store_expr_t *expr, sdb_store_obj_t *obj,
367 sdb_data_t *res, sdb_store_matcher_t *filter);
369 /*
370 * sdb_store_isnull_matcher:
371 * Creates a matcher matching NULL values.
372 */
373 sdb_store_matcher_t *
374 sdb_store_isnull_matcher(sdb_store_expr_t *expr);
376 /*
377 * sdb_store_isnnull_matcher:
378 * Creates a matcher matching non-NULL values.
379 */
380 sdb_store_matcher_t *
381 sdb_store_isnnull_matcher(sdb_store_expr_t *expr);
383 /*
384 * sdb_store_child_matcher:
385 * Creates a matcher matching an object's children of the specified type. It
386 * matches if *any* of those children match 'm'.
387 */
388 sdb_store_matcher_t *
389 sdb_store_child_matcher(int type, sdb_store_matcher_t *m);
391 /*
392 * sdb_store_lt_matcher, sdb_store_le_matcher, sdb_store_eq_matcher,
393 * sdb_store_ge_matcher, sdb_store_gt_matcher:
394 * Create conditional matchers comparing the values of two expressions. The
395 * matcher matches if the left expression compres less than, less or equal
396 * than, equal to, not equal to, greater or equal than, or greater than the
397 * right expression.
398 */
399 sdb_store_matcher_t *
400 sdb_store_lt_matcher(sdb_store_expr_t *left, sdb_store_expr_t *right);
401 sdb_store_matcher_t *
402 sdb_store_le_matcher(sdb_store_expr_t *left, sdb_store_expr_t *right);
403 sdb_store_matcher_t *
404 sdb_store_eq_matcher(sdb_store_expr_t *left, sdb_store_expr_t *right);
405 sdb_store_matcher_t *
406 sdb_store_ne_matcher(sdb_store_expr_t *left, sdb_store_expr_t *right);
407 sdb_store_matcher_t *
408 sdb_store_ge_matcher(sdb_store_expr_t *left, sdb_store_expr_t *right);
409 sdb_store_matcher_t *
410 sdb_store_gt_matcher(sdb_store_expr_t *left, sdb_store_expr_t *right);
412 /*
413 * sdb_store_in_matcher:
414 * Creates a matcher which matches if the right value evaluates to an array
415 * value and the left value is included in that array. See sdb_data_inarray
416 * for more details.
417 */
418 sdb_store_matcher_t *
419 sdb_store_in_matcher(sdb_store_expr_t *left, sdb_store_expr_t *right);
421 /*
422 * sdb_store_regex_matcher:
423 * Creates a matcher which matches the string value the left expression
424 * evaluates to against the regular expression the right expression evaluates
425 * to. The right expression may either be a constant value regular expression
426 * or string or a dynamic value evaluating to a string. In the latter case,
427 * the string is compiled to a regex every time the matcher is executed.
428 */
429 sdb_store_matcher_t *
430 sdb_store_regex_matcher(sdb_store_expr_t *left, sdb_store_expr_t *right);
432 /*
433 * sdb_store_nregex_matcher:
434 * Creates a regex matcher just like sdb_store_regex_matcher except that it
435 * matches in case the regular expression does not match.
436 */
437 sdb_store_matcher_t *
438 sdb_store_nregex_matcher(sdb_store_expr_t *left, sdb_store_expr_t *right);
440 /*
441 * sdb_store_matcher_op_cb:
442 * Callback constructing a matcher operator.
443 */
444 typedef sdb_store_matcher_t *(*sdb_store_matcher_op_cb)
445 (sdb_store_expr_t *, sdb_store_expr_t *);
447 /*
448 * sdb_store_parse_matcher_op:
449 * Parse a matcher operator and return a constructor for the respective
450 * matcher.
451 *
452 * Returns:
453 * - matcher operator constructor on success
454 * - NULL else
455 */
456 sdb_store_matcher_op_cb
457 sdb_store_parse_matcher_op(const char *op);
459 /*
460 * sdb_store_parse_object_type:
461 * Parse the type name of a stored object.
462 *
463 * Returns:
464 * - the object type on success
465 * - a negative value else
466 */
467 int
468 sdb_store_parse_object_type(const char *name);
470 /*
471 * sdb_store_parse_object_type_plural:
472 * Parse the type name (plural) of a stored object.
473 *
474 * Returns:
475 * - the object type on success
476 * - a negative value else
477 */
478 int
479 sdb_store_parse_object_type_plural(const char *name);
481 /*
482 * sdb_store_parse_field_name:
483 * Parse the name of a stored object's queryable field.
484 *
485 * Returns:
486 * - the field id on success
487 * - a negative value else
488 */
489 int
490 sdb_store_parse_field_name(const char *name);
492 /*
493 * sdb_store_dis_matcher:
494 * Creates a matcher matching the disjunction (logical OR) of two matchers.
495 */
496 sdb_store_matcher_t *
497 sdb_store_dis_matcher(sdb_store_matcher_t *left, sdb_store_matcher_t *right);
499 /*
500 * sdb_store_con_matcher:
501 * Creates a matcher matching the conjunction (logical AND) of two matchers.
502 */
503 sdb_store_matcher_t *
504 sdb_store_con_matcher(sdb_store_matcher_t *left, sdb_store_matcher_t *right);
506 /*
507 * sdb_store_con_matcher::
508 * Creates a matcher matching the inverse (logical NOT) of a matcher.
509 */
510 sdb_store_matcher_t *
511 sdb_store_inv_matcher(sdb_store_matcher_t *m);
513 /*
514 * sdb_store_matcher_matches:
515 * Check whether the specified matcher matches the specified store object. If
516 * specified, the filter will be used to preselect objects for further
517 * evaluation. It is applied to any object that's used during the evaluation
518 * of the matcher. Only those objects matching the filter will be considered.
519 *
520 * Note that the filter is applied to all object types (hosts, service,
521 * metric, attribute). Thus, any object-specific matchers are mostly unsuited
522 * for this purpose and, if used, may result in unexpected behavior.
523 *
524 * Returns:
525 * - 1 if the object matches
526 * - 0 else
527 */
528 int
529 sdb_store_matcher_matches(sdb_store_matcher_t *m, sdb_store_obj_t *obj,
530 sdb_store_matcher_t *filter);
532 /*
533 * sdb_store_lookup_cb:
534 * Lookup callback. It is called for each matching object when looking up data
535 * in the store. The lookup aborts if the callback returns non-zero.
536 */
537 typedef int (*sdb_store_lookup_cb)(sdb_store_obj_t *obj, void *user_data);
539 /*
540 * sdb_store_scan:
541 * Look up objects in the store. The specified callback function is called for
542 * each object in the store matching 'm'. The function performs a full scan of
543 * all hosts stored in the database. If specified, the filter will be used to
544 * preselect objects for further evaluation. See the description of
545 * 'sdb_store_matcher_matches' for details.
546 *
547 * Returns:
548 * - 0 on success
549 * - a negative value else
550 */
551 int
552 sdb_store_scan(sdb_store_matcher_t *m, sdb_store_matcher_t *filter,
553 sdb_store_lookup_cb cb, void *user_data);
555 /*
556 * Flags for serialization functions.
557 *
558 * By default, the full host object will be included in the serialized output.
559 * When specifying any of the flags, the respective information will be left
560 * out. The SKIP_EMPTY flags may be used to skip host objects entirely.
561 */
562 enum {
563 SDB_SKIP_ATTRIBUTES = 1 << 0,
564 SDB_SKIP_SERVICES = 1 << 1,
565 SDB_SKIP_METRICS = 1 << 2,
566 SDB_SKIP_SERVICE_ATTRIBUTES = 1 << 3,
568 SDB_SKIP_ALL = (1 << 8) - 1,
570 /* skip hosts if they do not reference any services/metrics */
571 SDB_SKIP_EMPTY_SERVICES = 1 << 8,
572 SDB_SKIP_EMPTY_METRICS = 1 << 9,
573 };
575 /*
576 * sdb_store_tojson:
577 * Serialize the entire store to JSON and append the result to the specified
578 * buffer. If specified, only objects matching the filter will be included in
579 * the result (see sdb_store_host_tojson for details).
580 *
581 * Returns:
582 * - 0 on success
583 * - a negative value on error
584 */
585 int
586 sdb_store_tojson(sdb_strbuf_t *buf, sdb_store_matcher_t *filter, int flags);
588 /*
589 * sdb_store_host_tojson:
590 * Serialize a host object to JSON and append the result to the specified
591 * buffer. If specified, only objects matching the filter will be included in
592 * the result. The filter is applied to each object individually and, thus,
593 * should not be of any object-type specific kind. The filter is never applied
594 * to the specified host object; the caller is responsible for this and for
595 * correctly handling skipped hosts.
596 *
597 * Returns:
598 * - 0 on success
599 * - a negative value on error
600 */
601 int
602 sdb_store_host_tojson(sdb_store_obj_t *host, sdb_strbuf_t *buf,
603 sdb_store_matcher_t *filter, int flags);
605 /*
606 * sdb_store_iter_cb:
607 * Store iterator callback. Iteration stops if the callback returns non-zero.
608 */
609 typedef int (*sdb_store_iter_cb)(sdb_store_obj_t *obj, void *user_data);
611 /*
612 * sdb_store_iterate:
613 * Iterate the entire store, calling the specified callback for each object.
614 * The user_data pointer is passed on to each call of the callback.
615 *
616 * Returns:
617 * - 0 on success
618 * - a negative value else
619 */
620 int
621 sdb_store_iterate(sdb_store_iter_cb cb, void *user_data);
623 #ifdef __cplusplus
624 } /* extern "C" */
625 #endif
627 #endif /* ! SDB_CORE_STORE_H */
629 /* vim: set tw=78 sw=4 ts=4 noexpandtab : */