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 * Queryable fields of a stored object.
69 */
70 enum {
71 SDB_FIELD_LAST_UPDATE = 1, /* datetime */
72 SDB_FIELD_AGE, /* datetime */
73 SDB_FIELD_INTERVAL, /* datetime */
74 SDB_FIELD_BACKEND, /* string */
75 };
77 #define SDB_FIELD_TO_NAME(f) \
78 (((f) == SDB_FIELD_LAST_UPDATE) ? "last-update" \
79 : ((f) == SDB_FIELD_AGE) ? "age" \
80 : ((f) == SDB_FIELD_INTERVAL) ? "interval" \
81 : ((f) == SDB_FIELD_BACKEND) ? "backend" : "unknown")
83 /*
84 * sdb_store_clear:
85 * Clear the entire store and remove all stored objects.
86 */
87 void
88 sdb_store_clear(void);
90 /*
91 * sdb_store_host:
92 * Add/update a host in the store. If the host, identified by its
93 * canonicalized name, already exists, it will be updated according to the
94 * specified name and timestamp. Else, a new entry will be created in the
95 * store. Any memory required for storing the entry will be allocated an
96 * managed by the store itself.
97 *
98 * Returns:
99 * - 0 on success
100 * - a positive value if the new entry is older than the currently stored
101 * entry (in this case, no update will happen)
102 * - a negative value on error
103 */
104 int
105 sdb_store_host(const char *name, sdb_time_t last_update);
107 /*
108 * sdb_store_has_host:
109 * sdb_store_get_host:
110 * Query the store for a host by its (canonicalized) name.
111 *
112 * sdb_store_get_host increments the ref count of the host object. The caller
113 * needs to deref it when no longer using it.
114 */
115 _Bool
116 sdb_store_has_host(const char *name);
118 sdb_store_obj_t *
119 sdb_store_get_host(const char *name);
121 /*
122 * sdb_store_attribute:
123 * Add/update a host's attribute in the store. If the attribute, identified by
124 * its key, already exists for the specified host, it will be updated to the
125 * specified values. If the referenced host does not exist, an error will be
126 * reported. Else, a new entry will be created in the store. Any memory
127 * required for storing the entry will be allocated and managed by the store
128 * itself.
129 *
130 * Returns:
131 * - 0 on success
132 * - a positive value if the new entry is older than the currently stored
133 * entry (in this case, no update will happen)
134 * - a negative value on error
135 */
136 int
137 sdb_store_attribute(const char *hostname,
138 const char *key, const sdb_data_t *value,
139 sdb_time_t last_update);
141 /*
142 * sdb_store_service:
143 * Add/update a service in the store. If the service, identified by its name,
144 * already exists for the specified host, it will be updated according to the
145 * specified 'service' object. If the referenced host does not exist, an error
146 * will be reported. Else, a new entry will be created in the store. Any
147 * memory required for storing the entry will be allocated an managed by the
148 * store itself.
149 *
150 * Returns:
151 * - 0 on success
152 * - a positive value if the new entry is older than the currently stored
153 * entry (in this case, no update will happen)
154 * - a negative value on error
155 */
156 int
157 sdb_store_service(const char *hostname, const char *name,
158 sdb_time_t last_update);
160 /*
161 * sdb_store_service_attr:
162 * Add/update a service's attribute in the store. If the attribute, identified
163 * by its key, already exists for the specified service, it will be updated to
164 * the specified value. If the references service (for the specified host)
165 * does not exist, an error will be reported. Any memory required for storing
166 * the entry will be allocated and managed by the store itself.
167 *
168 * Returns:
169 * - 0 on success
170 * - a positive value if the new entry is older than the currently stored
171 * entry (in this case, no update will happen)
172 * - a negative value on error
173 */
174 int
175 sdb_store_service_attr(const char *hostname, const char *service,
176 const char *key, const sdb_data_t *value, sdb_time_t last_update);
178 /*
179 * A metric store describes how to access a metric's data.
180 */
181 typedef struct {
182 const char *type;
183 const char *id;
184 } sdb_metric_store_t;
186 /*
187 * sdb_store_metric:
188 * Add/update a metric in the store. If the metric, identified by its name,
189 * already exists for the specified host, it will be updated according to the
190 * specified 'metric' object. If the referenced host does not exist, an error
191 * will be reported. Else, a new entry will be created in the store. Any
192 * memory required for storing the entry will be allocated an managed by the
193 * store itself.
194 *
195 * If specified, the metric store describes where to access the metric's data.
196 *
197 * Returns:
198 * - 0 on success
199 * - a positive value if the new entry is older than the currently stored
200 * entry (in this case, no update will happen)
201 * - a negative value on error
202 */
203 int
204 sdb_store_metric(const char *hostname, const char *name,
205 sdb_metric_store_t *store, sdb_time_t last_update);
207 /*
208 * sdb_store_metric_attr:
209 * Add/update a metric's attribute in the store. If the attribute, identified
210 * by its key, already exists for the specified metric, it will be updated to
211 * the specified value. If the references metric (for the specified host)
212 * does not exist, an error will be reported. Any memory required for storing
213 * the entry will be allocated and managed by the store itself.
214 *
215 * Returns:
216 * - 0 on success
217 * - a positive value if the new entry is older than the currently stored
218 * entry (in this case, no update will happen)
219 * - a negative value on error
220 */
221 int
222 sdb_store_metric_attr(const char *hostname, const char *metric,
223 const char *key, const sdb_data_t *value, sdb_time_t last_update);
225 /*
226 * sdb_store_fetch_timeseries:
227 * Fetch the time-series described by the specified host's metric and
228 * serialize it as JSON into the provided string buffer.
229 *
230 * Returns:
231 * - 0 on success
232 * - a negative value else
233 */
234 int
235 sdb_store_fetch_timeseries(const char *hostname, const char *metric,
236 sdb_timeseries_opts_t *opts, sdb_strbuf_t *buf);
238 /*
239 * sdb_store_get_field:
240 * Get the value of a stored object's queryable field. The caller is
241 * responsible for freeing any dynamically allocated memory possibly stored in
242 * the returned value.
243 *
244 * Note: Retrieving the backend this way is not currently supported.
245 *
246 * Returns:
247 * - 0 on success
248 * - a negative value else
249 */
250 int
251 sdb_store_get_field(sdb_store_obj_t *obj, int field, sdb_data_t *res);
253 /*
254 * Expressions specify arithmetic expressions.
255 *
256 * A expression object inherits from sdb_object_t and, thus, may safely be
257 * cast to a generic object.
258 */
259 struct sdb_store_expr;
260 typedef struct sdb_store_expr sdb_store_expr_t;
261 #define SDB_STORE_EXPR(obj) ((sdb_store_expr_t *)(obj))
263 /*
264 * sdb_store_expr_create:
265 * Creates an arithmetic expression implementing the specified operator on the
266 * specified left and right operand.
267 *
268 * Returns:
269 * - an expression object on success
270 * - NULL else
271 */
272 sdb_store_expr_t *
273 sdb_store_expr_create(int op, sdb_store_expr_t *left, sdb_store_expr_t *right);
275 /*
276 * sdb_store_expr_fieldvalue:
277 * Creates an expression which evaluates to the value of the specified
278 * queryable field of a stored object.
279 *
280 * Returns:
281 * - an expression object on success
282 * - NULL else
283 */
284 sdb_store_expr_t *
285 sdb_store_expr_fieldvalue(int field);
287 /*
288 * sdb_store_expr_constvalue:
289 * Creates an expression which evaluates to the specified constant value.
290 *
291 * Returns:
292 * - an expression object on success
293 * - NULL else
294 */
295 sdb_store_expr_t *
296 sdb_store_expr_constvalue(const sdb_data_t *value);
298 /*
299 * sdb_store_expr_eval:
300 * Evaluate an expression for the specified stored object and stores the
301 * result in 'res'. The result's value will be allocated dynamically if
302 * necessary and, thus, should be free'd by the caller (e.g. using
303 * sdb_data_free_datum). The object may be NULL, in which case the expression
304 * needs to evaluate to a constant value.
305 *
306 * Returns:
307 * - 0 on success
308 * - a negative value else
309 */
310 int
311 sdb_store_expr_eval(sdb_store_expr_t *expr, sdb_store_obj_t *obj,
312 sdb_data_t *res);
314 /*
315 * Conditionals may be used to lookup hosts from the store based on a
316 * conditional expression.
317 *
318 * A conditional object inherits from sdb_object_t and, thus, may safely be
319 * cast to a generic object.
320 */
321 struct sdb_store_cond;
322 typedef struct sdb_store_cond sdb_store_cond_t;
323 #define SDB_STORE_COND(obj) ((sdb_store_cond_t *)(obj))
325 /*
326 * sdb_store_attr_cond:
327 * Creates a conditional based on attribute values. The value of stored
328 * attributes is compared against the value the expression evaluates to. See
329 * sdb_data_cmp for details about the comparison.
330 */
331 sdb_store_cond_t *
332 sdb_store_attr_cond(const char *name, sdb_store_expr_t *expr);
334 /*
335 * sdb_store_obj_cond:
336 * Creates a conditional based on queryable object fields. The respective
337 * field of *any* object type is compared against the value the expression
338 * evaluates to.
339 */
340 sdb_store_cond_t *
341 sdb_store_obj_cond(int field, sdb_store_expr_t *expr);
343 /*
344 * Store matchers may be used to lookup hosts from the store based on their
345 * various attributes. Service and attribute matchers are applied to a host's
346 * services and attributes and evaluate to true if *any* service or attribute
347 * matches.
348 *
349 * A store matcher object inherits from sdb_object_t and, thus, may safely be
350 * cast to a generic object.
351 */
352 struct sdb_store_matcher;
353 typedef struct sdb_store_matcher sdb_store_matcher_t;
354 #define SDB_STORE_MATCHER(obj) ((sdb_store_matcher_t *)(obj))
356 /*
357 * sdb_store_name_matcher:
358 * Creates a matcher matching by the specified object type's name. If 're' is
359 * true, the specified name is treated as a POSIX extended regular expression.
360 * Else, the exact name has to match (case-insensitive).
361 */
362 sdb_store_matcher_t *
363 sdb_store_name_matcher(int type, const char *name, _Bool re);
365 /*
366 * sdb_store_attr_matcher:
367 * Creates a matcher matching attributes based on their value. If 're' is
368 * true, the specified name is treated as a POSIX extended regular expression.
369 * Else, the exact name has to match (case-insensitive).
370 */
371 sdb_store_matcher_t *
372 sdb_store_attr_matcher(const char *name, const char *value, _Bool re);
374 /*
375 * sdb_store_isnull_matcher:
376 * Creates a matcher matching "missing" attributes.
377 */
378 sdb_store_matcher_t *
379 sdb_store_isnull_matcher(const char *attr_name);
381 /*
382 * sdb_store_lt_matcher, sdb_store_le_matcher, sdb_store_eq_matcher,
383 * sdb_store_ge_matcher, sdb_store_gt_matcher:
384 * Creates a matcher based on a conditional. The matcher matches objects for
385 * which the conditional evaluates the object to compare less than, less or
386 * equal, equal, greater or equal, or greater than the conditional's value
387 * repsectively.
388 */
389 sdb_store_matcher_t *
390 sdb_store_lt_matcher(sdb_store_cond_t *cond);
391 sdb_store_matcher_t *
392 sdb_store_le_matcher(sdb_store_cond_t *cond);
393 sdb_store_matcher_t *
394 sdb_store_eq_matcher(sdb_store_cond_t *cond);
395 sdb_store_matcher_t *
396 sdb_store_ge_matcher(sdb_store_cond_t *cond);
397 sdb_store_matcher_t *
398 sdb_store_gt_matcher(sdb_store_cond_t *cond);
400 /*
401 * sdb_store_parse_object_type_plural:
402 * Parse the type name (plural) of a stored object.
403 *
404 * Returns:
405 * - the object type on success
406 * - a negative value else
407 */
408 int
409 sdb_store_parse_object_type_plural(const char *name);
411 /*
412 * sdb_store_parse_field_name:
413 * Parse the name of a stored object's queryable field.
414 *
415 * Returns:
416 * - the field id on success
417 * - a negative value else
418 */
419 int
420 sdb_store_parse_field_name(const char *name);
422 /*
423 * sdb_store_matcher_parse_cmp:
424 * Parse a simple compare expression (<obj_type>.<attr> <op> <expression>).
425 *
426 * Returns:
427 * - a matcher object on success
428 * - NULL else
429 */
430 sdb_store_matcher_t *
431 sdb_store_matcher_parse_cmp(const char *obj_type, const char *attr,
432 const char *op, sdb_store_expr_t *expr);
434 /*
435 * sdb_store_matcher_parse_field_cmp:
436 * Parse a simple compare expression for queryable object fields (<field> <op>
437 * <expression>).
438 *
439 * Returns:
440 * - a matcher object on success
441 * - NULL else
442 */
443 sdb_store_matcher_t *
444 sdb_store_matcher_parse_field_cmp(const char *name, const char *op,
445 sdb_store_expr_t *expr);
447 /*
448 * sdb_store_dis_matcher:
449 * Creates a matcher matching the disjunction (logical OR) of two matchers.
450 */
451 sdb_store_matcher_t *
452 sdb_store_dis_matcher(sdb_store_matcher_t *left, sdb_store_matcher_t *right);
454 /*
455 * sdb_store_con_matcher:
456 * Creates a matcher matching the conjunction (logical AND) of two matchers.
457 */
458 sdb_store_matcher_t *
459 sdb_store_con_matcher(sdb_store_matcher_t *left, sdb_store_matcher_t *right);
461 /*
462 * sdb_store_con_matcher::
463 * Creates a matcher matching the inverse (logical NOT) of a matcher.
464 */
465 sdb_store_matcher_t *
466 sdb_store_inv_matcher(sdb_store_matcher_t *m);
468 /*
469 * sdb_store_matcher_matches:
470 * Check whether the specified matcher matches the specified store object. If
471 * specified, the filter will be used to preselect objects for further
472 * evaluation. It is applied to any object that's used during the evaluation
473 * of the matcher. Only those objects matching the filter will be considered.
474 *
475 * Note that the filter is applied to all object types (hosts, service,
476 * metric, attribute). Thus, any object-specific matchers are mostly unsuited
477 * for this purpose and, if used, may result in unexpected behavior.
478 *
479 * Returns:
480 * - 1 if the object matches
481 * - 0 else
482 */
483 int
484 sdb_store_matcher_matches(sdb_store_matcher_t *m, sdb_store_obj_t *obj,
485 sdb_store_matcher_t *filter);
487 /*
488 * sdb_store_matcher_tostring:
489 * Format a matcher object as string. This is meant for logging or debugging
490 * purposes.
491 */
492 char *
493 sdb_store_matcher_tostring(sdb_store_matcher_t *m, char *buf, size_t buflen);
495 /*
496 * sdb_store_lookup_cb:
497 * Lookup callback. It is called for each matching object when looking up data
498 * in the store. The lookup aborts if the callback returns non-zero.
499 */
500 typedef int (*sdb_store_lookup_cb)(sdb_store_obj_t *obj, void *user_data);
502 /*
503 * sdb_store_scan:
504 * Look up objects in the store. The specified callback function is called for
505 * each object in the store matching 'm'. The function performs a full scan of
506 * all hosts stored in the database. If specified, the filter will be used to
507 * preselect objects for further evaluation. See the description of
508 * 'sdb_store_matcher_matches' for details.
509 *
510 * Returns:
511 * - 0 on success
512 * - a negative value else
513 */
514 int
515 sdb_store_scan(sdb_store_matcher_t *m, sdb_store_matcher_t *filter,
516 sdb_store_lookup_cb cb, void *user_data);
518 /*
519 * Flags for serialization functions.
520 *
521 * By default, the full object will be included in the serialized output. When
522 * specifying any of the flags, the respective information will be left out.
523 */
524 enum {
525 SDB_SKIP_ATTRIBUTES = 1 << 0,
526 SDB_SKIP_SERVICES = 1 << 1,
527 SDB_SKIP_METRICS = 1 << 2,
528 SDB_SKIP_SERVICE_ATTRIBUTES = 1 << 3,
530 SDB_SKIP_ALL = 0xffff,
531 };
533 /*
534 * sdb_store_tojson:
535 * Serialize the entire store to JSON and append the result to the specified
536 * buffer. If specified, only objects matching the filter will be included in
537 * the result (see sdb_store_host_tojson for details).
538 *
539 * Returns:
540 * - 0 on success
541 * - a negative value on error
542 */
543 int
544 sdb_store_tojson(sdb_strbuf_t *buf, sdb_store_matcher_t *filter, int flags);
546 /*
547 * sdb_store_host_tojson:
548 * Serialize a host object to JSON and append the result to the specified
549 * buffer. If specified, only objects matching the filter will be included in
550 * the result. The filter is applied to each object individually and, thus,
551 * should not be of any object-type specific kind. The filter is never applied
552 * to the specified host object; the caller is responsible for this and for
553 * correctly handling skipped hosts.
554 *
555 * Returns:
556 * - 0 on success
557 * - a negative value on error
558 */
559 int
560 sdb_store_host_tojson(sdb_store_obj_t *host, sdb_strbuf_t *buf,
561 sdb_store_matcher_t *filter, int flags);
563 /*
564 * sdb_store_iter_cb:
565 * Store iterator callback. Iteration stops if the callback returns non-zero.
566 */
567 typedef int (*sdb_store_iter_cb)(sdb_store_obj_t *obj, void *user_data);
569 /*
570 * sdb_store_iterate:
571 * Iterate the entire store, calling the specified callback for each object.
572 * The user_data pointer is passed on to each call of the callback.
573 *
574 * Returns:
575 * - 0 on success
576 * - a negative value else
577 */
578 int
579 sdb_store_iterate(sdb_store_iter_cb cb, void *user_data);
581 #ifdef __cplusplus
582 } /* extern "C" */
583 #endif
585 #endif /* ! SDB_CORE_STORE_H */
587 /* vim: set tw=78 sw=4 ts=4 noexpandtab : */