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,
53 /*
54 * Queryable fields of a stored object.
55 */
56 SDB_FIELD_NAME = 1 << 8, /* type: string */
57 SDB_FIELD_LAST_UPDATE, /* type: datetime */
58 SDB_FIELD_AGE, /* type: datetime */
59 SDB_FIELD_INTERVAL, /* type: datetime */
60 SDB_FIELD_BACKEND, /* type: array of strings */
61 };
62 #define SDB_STORE_TYPE_TO_NAME(t) \
63 (((t) == SDB_HOST) ? "host" \
64 : ((t) == SDB_SERVICE) ? "service" \
65 : ((t) == SDB_METRIC) ? "metric" \
66 : ((t) == SDB_ATTRIBUTE) ? "attribute" : "unknown")
68 #define SDB_FIELD_TO_NAME(f) \
69 (((f) == SDB_FIELD_NAME) ? "name" \
70 : ((f) == SDB_FIELD_LAST_UPDATE) ? "last-update" \
71 : ((f) == SDB_FIELD_AGE) ? "age" \
72 : ((f) == SDB_FIELD_INTERVAL) ? "interval" \
73 : ((f) == SDB_FIELD_BACKEND) ? "backend" : "unknown")
75 #define SDB_FIELD_TYPE(f) \
76 (((f) == SDB_FIELD_NAME) ? SDB_TYPE_STRING \
77 : ((f) == SDB_FIELD_LAST_UPDATE) ? SDB_TYPE_DATETIME \
78 : ((f) == SDB_FIELD_AGE) ? SDB_TYPE_DATETIME \
79 : ((f) == SDB_FIELD_INTERVAL) ? SDB_TYPE_DATETIME \
80 : ((f) == SDB_FIELD_BACKEND) ? (SDB_TYPE_ARRAY | SDB_TYPE_STRING) \
81 : -1)
83 /*
84 * sdb_store_obj_t represents the super-class of any object stored in the
85 * database. It inherits from sdb_object_t and may safely be cast to a generic
86 * object to access its name.
87 */
88 struct sdb_store_obj;
89 typedef struct sdb_store_obj sdb_store_obj_t;
91 /*
92 * Expressions represent arithmetic expressions based on stored objects and
93 * their various attributes.
94 *
95 * An expression object inherits from sdb_object_t and, thus, may safely be
96 * cast to a generic object.
97 */
98 struct sdb_store_expr;
99 typedef struct sdb_store_expr sdb_store_expr_t;
100 #define SDB_STORE_EXPR(obj) ((sdb_store_expr_t *)(obj))
102 /*
103 * Store matchers may be used to lookup hosts from the store based on their
104 * various attributes. Service and attribute matchers are applied to a host's
105 * services and attributes and evaluate to true if *any* service or attribute
106 * matches.
107 *
108 * A store matcher object inherits from sdb_object_t and, thus, may safely be
109 * cast to a generic object.
110 */
111 struct sdb_store_matcher;
112 typedef struct sdb_store_matcher sdb_store_matcher_t;
113 #define SDB_STORE_MATCHER(obj) ((sdb_store_matcher_t *)(obj))
115 /*
116 * A JSON formatter converts stored objects into the JSON format.
117 * See http://www.ietf.org/rfc/rfc4627.txt
118 */
119 struct sdb_store_json_formatter;
120 typedef struct sdb_store_json_formatter sdb_store_json_formatter_t;
122 /*
123 * sdb_store_clear:
124 * Clear the entire store and remove all stored objects.
125 */
126 void
127 sdb_store_clear(void);
129 /*
130 * sdb_store_host:
131 * Add/update a host in the store. If the host, identified by its
132 * canonicalized name, already exists, it will be updated according to the
133 * specified name and timestamp. Else, a new entry will be created in the
134 * store. Any memory required for storing the entry will be allocated an
135 * managed by the store itself.
136 *
137 * Returns:
138 * - 0 on success
139 * - a positive value if the new entry is older than the currently stored
140 * entry (in this case, no update will happen)
141 * - a negative value on error
142 */
143 int
144 sdb_store_host(const char *name, sdb_time_t last_update);
146 /*
147 * sdb_store_has_host:
148 * sdb_store_get_host:
149 * Query the store for a host by its (canonicalized) name.
150 *
151 * sdb_store_get_host increments the ref count of the host object. The caller
152 * needs to deref it when no longer using it.
153 */
154 _Bool
155 sdb_store_has_host(const char *name);
157 sdb_store_obj_t *
158 sdb_store_get_host(const char *name);
160 /*
161 * sdb_store_attribute:
162 * Add/update a host's attribute in the store. If the attribute, identified by
163 * its key, already exists for the specified host, it will be updated to the
164 * specified values. If the referenced host does not exist, an error will be
165 * reported. Else, a new entry will be created in the store. Any memory
166 * required for storing the entry will be allocated and managed by the store
167 * itself.
168 *
169 * Returns:
170 * - 0 on success
171 * - a positive value if the new entry is older than the currently stored
172 * entry (in this case, no update will happen)
173 * - a negative value on error
174 */
175 int
176 sdb_store_attribute(const char *hostname,
177 const char *key, const sdb_data_t *value,
178 sdb_time_t last_update);
180 /*
181 * sdb_store_service:
182 * Add/update a service in the store. If the service, identified by its name,
183 * already exists for the specified host, it will be updated according to the
184 * specified 'service' object. If the referenced host does not exist, an error
185 * will be reported. Else, a new entry will be created in the store. Any
186 * memory required for storing the entry will be allocated an managed by the
187 * store itself.
188 *
189 * Returns:
190 * - 0 on success
191 * - a positive value if the new entry is older than the currently stored
192 * entry (in this case, no update will happen)
193 * - a negative value on error
194 */
195 int
196 sdb_store_service(const char *hostname, const char *name,
197 sdb_time_t last_update);
199 /*
200 * sdb_store_service_attr:
201 * Add/update a service's attribute in the store. If the attribute, identified
202 * by its key, already exists for the specified service, it will be updated to
203 * the specified value. If the references service (for the specified host)
204 * does not exist, an error will be reported. Any memory required for storing
205 * the entry will be allocated and managed by the store itself.
206 *
207 * Returns:
208 * - 0 on success
209 * - a positive value if the new entry is older than the currently stored
210 * entry (in this case, no update will happen)
211 * - a negative value on error
212 */
213 int
214 sdb_store_service_attr(const char *hostname, const char *service,
215 const char *key, const sdb_data_t *value, sdb_time_t last_update);
217 /*
218 * A metric store describes how to access a metric's data.
219 */
220 typedef struct {
221 const char *type;
222 const char *id;
223 } sdb_metric_store_t;
225 /*
226 * sdb_store_metric:
227 * Add/update a metric in the store. If the metric, identified by its name,
228 * already exists for the specified host, it will be updated according to the
229 * specified 'metric' object. If the referenced host does not exist, an error
230 * will be reported. Else, a new entry will be created in the store. Any
231 * memory required for storing the entry will be allocated an managed by the
232 * store itself.
233 *
234 * If specified, the metric store describes where to access the metric's data.
235 *
236 * Returns:
237 * - 0 on success
238 * - a positive value if the new entry is older than the currently stored
239 * entry (in this case, no update will happen)
240 * - a negative value on error
241 */
242 int
243 sdb_store_metric(const char *hostname, const char *name,
244 sdb_metric_store_t *store, sdb_time_t last_update);
246 /*
247 * sdb_store_metric_attr:
248 * Add/update a metric's attribute in the store. If the attribute, identified
249 * by its key, already exists for the specified metric, it will be updated to
250 * the specified value. If the references metric (for the specified host)
251 * does not exist, an error will be reported. Any memory required for storing
252 * the entry will be allocated and managed by the store itself.
253 *
254 * Returns:
255 * - 0 on success
256 * - a positive value if the new entry is older than the currently stored
257 * entry (in this case, no update will happen)
258 * - a negative value on error
259 */
260 int
261 sdb_store_metric_attr(const char *hostname, const char *metric,
262 const char *key, const sdb_data_t *value, sdb_time_t last_update);
264 /*
265 * sdb_store_fetch_timeseries:
266 * Fetch the time-series described by the specified host's metric and
267 * serialize it as JSON into the provided string buffer.
268 *
269 * Returns:
270 * - 0 on success
271 * - a negative value else
272 */
273 int
274 sdb_store_fetch_timeseries(const char *hostname, const char *metric,
275 sdb_timeseries_opts_t *opts, sdb_strbuf_t *buf);
277 /*
278 * sdb_store_get_child:
279 * Retrieve a host's child object of the specified type and name. The
280 * reference count of the child object will be incremented before returning
281 * it. The caller is responsible for releasing the object once it's no longer
282 * used.
283 *
284 * Returns:
285 * - the child object on success
286 * - NULL else
287 */
288 sdb_store_obj_t *
289 sdb_store_get_child(sdb_store_obj_t *host, int type, const char *name);
291 /*
292 * sdb_store_get_field:
293 * Get the value of a stored object's queryable field. The caller is
294 * responsible for freeing any dynamically allocated memory possibly stored in
295 * the returned value. If 'res' is NULL, the function will return whether the
296 * field exists.
297 *
298 * Note: Retrieving the backend this way is not currently supported.
299 *
300 * Returns:
301 * - 0 on success
302 * - a negative value else
303 */
304 int
305 sdb_store_get_field(sdb_store_obj_t *obj, int field, sdb_data_t *res);
307 /*
308 * sdb_store_get_attr:
309 * Get the value of a stored object's attribute. The caller is responsible for
310 * freeing any dynamically allocated memory possibly stored in the returned
311 * value. If 'res' is NULL, the function will return whether the attribute
312 * exists. If specified, only attributes matching the filter will be
313 * considered.
314 *
315 * Returns:
316 * - 0 if the attribute exists
317 * - a negative value else
318 */
319 int
320 sdb_store_get_attr(sdb_store_obj_t *obj, const char *name, sdb_data_t *res,
321 sdb_store_matcher_t *filter);
323 /*
324 * sdb_store_expr_create:
325 * Creates an arithmetic expression implementing the specified operator on the
326 * specified left and right operand.
327 *
328 * Returns:
329 * - an expression object on success
330 * - NULL else
331 */
332 sdb_store_expr_t *
333 sdb_store_expr_create(int op, sdb_store_expr_t *left, sdb_store_expr_t *right);
335 /*
336 * sdb_store_expr_fieldvalue:
337 * Creates an expression which evaluates to the value of the specified
338 * queryable field of a stored object.
339 *
340 * Returns:
341 * - an expression object on success
342 * - NULL else
343 */
344 sdb_store_expr_t *
345 sdb_store_expr_fieldvalue(int field);
347 /*
348 * sdb_store_expr_attrvalue:
349 * Creates an expression which evaluates to the value of the specified
350 * attribute of a stored object. Evaluates to a NULL value if the attribute
351 * does not exist.
352 *
353 * Returns:
354 * - an expression object on success
355 * - NULL else
356 */
357 sdb_store_expr_t *
358 sdb_store_expr_attrvalue(const char *name);
360 /*
361 * sdb_store_expr_constvalue:
362 * Creates an expression which evaluates to the specified constant value.
363 *
364 * Returns:
365 * - an expression object on success
366 * - NULL else
367 */
368 sdb_store_expr_t *
369 sdb_store_expr_constvalue(const sdb_data_t *value);
371 /*
372 * sdb_store_expr_eval:
373 * Evaluate an expression for the specified stored object and stores the
374 * result in 'res'. The result's value will be allocated dynamically if
375 * necessary and, thus, should be free'd by the caller (e.g. using
376 * sdb_data_free_datum). The object may be NULL, in which case the expression
377 * needs to evaluate to a constant value. If specified, only objects matching
378 * the filter will be used during the evaluation.
379 *
380 * Returns:
381 * - 0 on success
382 * - a negative value else
383 */
384 int
385 sdb_store_expr_eval(sdb_store_expr_t *expr, sdb_store_obj_t *obj,
386 sdb_data_t *res, sdb_store_matcher_t *filter);
388 /*
389 * sdb_store_dis_matcher:
390 * Creates a matcher matching the disjunction (logical OR) of two matchers.
391 */
392 sdb_store_matcher_t *
393 sdb_store_dis_matcher(sdb_store_matcher_t *left, sdb_store_matcher_t *right);
395 /*
396 * sdb_store_con_matcher:
397 * Creates a matcher matching the conjunction (logical AND) of two matchers.
398 */
399 sdb_store_matcher_t *
400 sdb_store_con_matcher(sdb_store_matcher_t *left, sdb_store_matcher_t *right);
402 /*
403 * sdb_store_inv_matcher::
404 * Creates a matcher matching the inverse (logical NOT) of a matcher.
405 */
406 sdb_store_matcher_t *
407 sdb_store_inv_matcher(sdb_store_matcher_t *m);
409 /*
410 * sdb_store_any_matcher:
411 * Creates a matcher iterating over objects of the specified type. It matches
412 * if *any* of those objects match 'm'.
413 */
414 sdb_store_matcher_t *
415 sdb_store_any_matcher(int type, sdb_store_matcher_t *m);
417 /*
418 * sdb_store_all_matcher:
419 * Creates a matcher iterating over objects of the specified type. It matches
420 * if *all* of those objects match 'm'.
421 */
422 sdb_store_matcher_t *
423 sdb_store_all_matcher(int type, sdb_store_matcher_t *m);
425 /*
426 * sdb_store_in_matcher:
427 * Creates a matcher which matches if the right value evaluates to an array
428 * value and the left value is included in that array. See sdb_data_inarray
429 * for more details.
430 */
431 sdb_store_matcher_t *
432 sdb_store_in_matcher(sdb_store_expr_t *left, sdb_store_expr_t *right);
434 /*
435 * sdb_store_lt_matcher, sdb_store_le_matcher, sdb_store_eq_matcher,
436 * sdb_store_ge_matcher, sdb_store_gt_matcher:
437 * Create conditional matchers comparing the values of two expressions. The
438 * matcher matches if the left expression compres less than, less or equal
439 * than, equal to, not equal to, greater or equal than, or greater than the
440 * right expression.
441 */
442 sdb_store_matcher_t *
443 sdb_store_lt_matcher(sdb_store_expr_t *left, sdb_store_expr_t *right);
444 sdb_store_matcher_t *
445 sdb_store_le_matcher(sdb_store_expr_t *left, sdb_store_expr_t *right);
446 sdb_store_matcher_t *
447 sdb_store_eq_matcher(sdb_store_expr_t *left, sdb_store_expr_t *right);
448 sdb_store_matcher_t *
449 sdb_store_ne_matcher(sdb_store_expr_t *left, sdb_store_expr_t *right);
450 sdb_store_matcher_t *
451 sdb_store_ge_matcher(sdb_store_expr_t *left, sdb_store_expr_t *right);
452 sdb_store_matcher_t *
453 sdb_store_gt_matcher(sdb_store_expr_t *left, sdb_store_expr_t *right);
455 /*
456 * sdb_store_regex_matcher:
457 * Creates a matcher which matches the string value the left expression
458 * evaluates to against the regular expression the right expression evaluates
459 * to. The right expression may either be a constant value regular expression
460 * or string or a dynamic value evaluating to a string. In the latter case,
461 * the string is compiled to a regex every time the matcher is executed.
462 */
463 sdb_store_matcher_t *
464 sdb_store_regex_matcher(sdb_store_expr_t *left, sdb_store_expr_t *right);
466 /*
467 * sdb_store_nregex_matcher:
468 * Creates a regex matcher just like sdb_store_regex_matcher except that it
469 * matches in case the regular expression does not match.
470 */
471 sdb_store_matcher_t *
472 sdb_store_nregex_matcher(sdb_store_expr_t *left, sdb_store_expr_t *right);
474 /*
475 * sdb_store_isnull_matcher:
476 * Creates a matcher matching NULL values.
477 */
478 sdb_store_matcher_t *
479 sdb_store_isnull_matcher(sdb_store_expr_t *expr);
481 /*
482 * sdb_store_isnnull_matcher:
483 * Creates a matcher matching non-NULL values.
484 */
485 sdb_store_matcher_t *
486 sdb_store_isnnull_matcher(sdb_store_expr_t *expr);
488 /*
489 * sdb_store_matcher_matches:
490 * Check whether the specified matcher matches the specified store object. If
491 * specified, the filter will be used to preselect objects for further
492 * evaluation. It is applied to any object that's used during the evaluation
493 * of the matcher. Only those objects matching the filter will be considered.
494 *
495 * Note that the filter is applied to all object types (hosts, service,
496 * metric, attribute). Thus, any object-specific matchers are mostly unsuited
497 * for this purpose and, if used, may result in unexpected behavior.
498 *
499 * Returns:
500 * - 1 if the object matches
501 * - 0 else
502 */
503 int
504 sdb_store_matcher_matches(sdb_store_matcher_t *m, sdb_store_obj_t *obj,
505 sdb_store_matcher_t *filter);
507 /*
508 * sdb_store_matcher_op_cb:
509 * Callback constructing a matcher operator.
510 */
511 typedef sdb_store_matcher_t *(*sdb_store_matcher_op_cb)
512 (sdb_store_expr_t *, sdb_store_expr_t *);
514 /*
515 * sdb_store_parse_matcher_op:
516 * Parse a matcher operator and return a constructor for the respective
517 * matcher.
518 *
519 * Returns:
520 * - matcher operator constructor on success
521 * - NULL else
522 */
523 sdb_store_matcher_op_cb
524 sdb_store_parse_matcher_op(const char *op);
526 /*
527 * sdb_store_parse_object_type:
528 * Parse the type name of a stored object.
529 *
530 * Returns:
531 * - the object type on success
532 * - a negative value else
533 */
534 int
535 sdb_store_parse_object_type(const char *name);
537 /*
538 * sdb_store_parse_object_type_plural:
539 * Parse the type name (plural) of a stored object.
540 *
541 * Returns:
542 * - the object type on success
543 * - a negative value else
544 */
545 int
546 sdb_store_parse_object_type_plural(const char *name);
548 /*
549 * sdb_store_parse_field_name:
550 * Parse the name of a stored object's queryable field.
551 *
552 * Returns:
553 * - the field id on success
554 * - a negative value else
555 */
556 int
557 sdb_store_parse_field_name(const char *name);
559 /*
560 * sdb_store_lookup_cb:
561 * Lookup callback. It is called for each matching object when looking up data
562 * in the store passing on the lookup filter and the specified user-data. The
563 * lookup aborts early if the callback returns non-zero.
564 */
565 typedef int (*sdb_store_lookup_cb)(sdb_store_obj_t *obj,
566 sdb_store_matcher_t *filter, void *user_data);
568 /*
569 * sdb_store_scan:
570 * Look up objects of the specified type in the store. The specified callback
571 * function is called for each object in the store matching 'm'. The function
572 * performs a full scan of all objects stored in the database. If specified,
573 * the filter will be used to preselect objects for further evaluation. See
574 * the description of 'sdb_store_matcher_matches' for details.
575 *
576 * Returns:
577 * - 0 on success
578 * - a negative value else
579 */
580 int
581 sdb_store_scan(int type, sdb_store_matcher_t *m, sdb_store_matcher_t *filter,
582 sdb_store_lookup_cb cb, void *user_data);
584 /*
585 * Flags for JSON formatting.
586 */
587 enum {
588 SDB_WANT_ARRAY = 1 << 0,
589 };
591 /*
592 * sdb_store_json_formatter:
593 * Create a JSON formatter for the specified object types writing to the
594 * specified buffer.
595 */
596 sdb_store_json_formatter_t *
597 sdb_store_json_formatter(sdb_strbuf_t *buf, int type, int flags);
599 /*
600 * sdb_store_json_emit:
601 * Serialize a single object to JSON adding it to the string buffer associated
602 * with the formatter object. The serialized object will not include
603 * attributes or any child objects. Instead, call the function again for each
604 * of those objects. All attributes have to be emitted before any other
605 * children types. Use sdb_store_json_emit_full() to emit a full (filtered)
606 * object.
607 *
608 * Note that the output might not be valid JSON before calling
609 * sdb_store_json_finish().
610 *
611 * Returns:
612 * - 0 on success
613 * - a negative value else
614 */
615 int
616 sdb_store_json_emit(sdb_store_json_formatter_t *f, sdb_store_obj_t *obj);
618 /*
619 * sdb_store_json_emit_full:
620 * Serialize a single object including it's attributes and all children to
621 * JSON, adding it to the string buffer associated with the formatter object.
622 * The filter, if specified, is applied to each attribute and child object.
623 * Only matching objects will be included in the output.
624 *
625 * Note that the output might not be valid JSON before calling
626 * sdb_store_json_finish().
627 *
628 * Returns:
629 * - 0 on success
630 * - a negative value else
631 */
632 int
633 sdb_store_json_emit_full(sdb_store_json_formatter_t *f, sdb_store_obj_t *obj,
634 sdb_store_matcher_t *filter);
636 /*
637 * sdb_store_json_finish:
638 * Finish the JSON output. This function has to be called once after emiting
639 * all objects.
640 */
641 int
642 sdb_store_json_finish(sdb_store_json_formatter_t *f);
644 #ifdef __cplusplus
645 } /* extern "C" */
646 #endif
648 #endif /* ! SDB_CORE_STORE_H */
650 /* vim: set tw=78 sw=4 ts=4 noexpandtab : */