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 "utils/strbuf.h"
37 #include <stdio.h>
39 #ifdef __cplusplus
40 extern "C" {
41 #endif
43 /*
44 * Store object types.
45 */
46 enum {
47 SDB_HOST = 1,
48 SDB_SERVICE,
49 SDB_ATTRIBUTE,
50 };
51 #define SDB_STORE_TYPE_TO_NAME(t) \
52 (((t) == SDB_HOST) ? "host" \
53 : ((t) == SDB_SERVICE) ? "service" \
54 : ((t) == SDB_ATTRIBUTE) ? "attribute" : "unknown")
56 /*
57 * sdb_store_obj_t represents the super-class of any object stored in the
58 * database. It inherits from sdb_object_t and may safely be cast to a generic
59 * object to access its name.
60 */
61 struct sdb_store_obj;
62 typedef struct sdb_store_obj sdb_store_obj_t;
64 /*
65 * Queryable fields of a stored object.
66 */
67 enum {
68 SDB_FIELD_LAST_UPDATE = 1, /* datetime */
69 SDB_FIELD_AGE, /* datetime */
70 SDB_FIELD_INTERVAL, /* datetime */
71 SDB_FIELD_BACKEND, /* string */
72 };
74 #define SDB_FIELD_TO_NAME(f) \
75 (((f) == SDB_FIELD_LAST_UPDATE) ? "last-update" \
76 : ((f) == SDB_FIELD_AGE) ? "age" \
77 : ((f) == SDB_FIELD_INTERVAL) ? "interval" \
78 : ((f) == SDB_FIELD_BACKEND) ? "backend" : "unknown")
80 /*
81 * sdb_store_clear:
82 * Clear the entire store and remove all stored objects.
83 */
84 void
85 sdb_store_clear(void);
87 /*
88 * sdb_store_host:
89 * Add/update a host in the store. If the host, identified by its
90 * canonicalized name, already exists, it will be updated according to the
91 * specified name and timestamp. Else, a new entry will be created in the
92 * store. Any memory required for storing the entry will be allocated an
93 * managed by the store itself.
94 *
95 * Returns:
96 * - 0 on success
97 * - a positive value if the new entry is older than the currently stored
98 * entry (in this case, no update will happen)
99 * - a negative value on error
100 */
101 int
102 sdb_store_host(const char *name, sdb_time_t last_update);
104 /*
105 * sdb_store_has_host:
106 * sdb_store_get_host:
107 * Query the store for a host by its (canonicalized) name.
108 *
109 * sdb_store_get_host increments the ref count of the host object. The caller
110 * needs to deref it when no longer using it.
111 */
112 _Bool
113 sdb_store_has_host(const char *name);
115 sdb_store_obj_t *
116 sdb_store_get_host(const char *name);
118 /*
119 * sdb_store_attribute:
120 * Add/update a host's attribute in the store. If the attribute, identified by
121 * its key, already exists for the specified host, it will be updated to the
122 * specified values. If the referenced host does not exist, an error will be
123 * reported. Else, a new entry will be created in the store. Any memory
124 * required for storing the entry will be allocated and managed by the store
125 * itself.
126 *
127 * Returns:
128 * - 0 on success
129 * - a positive value if the new entry is older than the currently stored
130 * entry (in this case, no update will happen)
131 * - a negative value on error
132 */
133 int
134 sdb_store_attribute(const char *hostname,
135 const char *key, const sdb_data_t *value,
136 sdb_time_t last_update);
138 /*
139 * sdb_store_service:
140 * Add/update a service in the store. If the service, identified by its name,
141 * already exists for the specified host, it will be updated according to the
142 * specified 'service' object. If the referenced host does not exist, an error
143 * will be reported. Else, a new entry will be created in the store. Any
144 * memory required for storing the entry will be allocated an managed by the
145 * store itself. The specified service-object will not be referenced or
146 * further accessed.
147 *
148 * Returns:
149 * - 0 on success
150 * - a positive value if the new entry is older than the currently stored
151 * entry (in this case, no update will happen)
152 * - a negative value on error
153 */
154 int
155 sdb_store_service(const char *hostname, const char *name,
156 sdb_time_t last_update);
158 /*
159 * sdb_store_service_attr:
160 * Add/update a service's attribute in the store. If the attribute, identified
161 * by its key, already exists for the specified service, it will be updated to
162 * the specified value. If the references service (for the specified host)
163 * does not exist, an error will be reported. Any memory required for storing
164 * the entry will be allocated and managed by the store itself.
165 *
166 * Returns:
167 * - 0 on success
168 * - a positive value if the new entry is older than the currently stored
169 * entry (in this case, no update will happen)
170 * - a negative value on error
171 */
172 int
173 sdb_store_service_attr(const char *hostname, const char *service,
174 const char *key, const sdb_data_t *value, sdb_time_t last_update);
176 /*
177 * Expressions specify arithmetic expressions.
178 *
179 * A expression object inherits from sdb_object_t and, thus, may safely be
180 * cast to a generic object.
181 */
182 struct sdb_store_expr;
183 typedef struct sdb_store_expr sdb_store_expr_t;
184 #define SDB_STORE_EXPR(obj) ((sdb_store_expr_t *)(obj))
186 /*
187 * sdb_store_expr_create:
188 * Creates an arithmetic expression implementing the specified operator on the
189 * specified left and right operand.
190 *
191 * Returns:
192 * - an expression object on success
193 * - NULL else
194 */
195 sdb_store_expr_t *
196 sdb_store_expr_create(int op, sdb_store_expr_t *left, sdb_store_expr_t *right);
198 /*
199 * sdb_store_expr_constvalue:
200 * Creates an expression which evaluates to the specified constant value.
201 *
202 * Returns:
203 * - an expression object on success
204 * - NULL else
205 */
206 sdb_store_expr_t *
207 sdb_store_expr_constvalue(const sdb_data_t *value);
209 /*
210 * sdb_store_expr_eval:
211 * Evaluate an expression and stores the result in 'res'. The result's value
212 * will be allocated dynamically if necessary and, thus, should be free'd by
213 * the caller (e.g. using sdb_data_free_datum);
214 *
215 * Returns:
216 * - 0 on success
217 * - a negative value else
218 */
219 int
220 sdb_store_expr_eval(sdb_store_expr_t *expr, sdb_data_t *res);
222 /*
223 * Conditionals may be used to lookup hosts from the store based on a
224 * conditional expression.
225 *
226 * A conditional object inherits from sdb_object_t and, thus, may safely be
227 * cast to a generic object.
228 */
229 struct sdb_store_cond;
230 typedef struct sdb_store_cond sdb_store_cond_t;
231 #define SDB_STORE_COND(obj) ((sdb_store_cond_t *)(obj))
233 /*
234 * sdb_store_attr_cond:
235 * Creates a conditional based on attribute values. The value of stored
236 * attributes is compared against the value the expression evaluates to. See
237 * sdb_data_cmp for details about the comparison.
238 */
239 sdb_store_cond_t *
240 sdb_store_attr_cond(const char *name, sdb_store_expr_t *expr);
242 /*
243 * sdb_store_obj_cond:
244 * Creates a conditional based on queryable object fields. The respective
245 * field of *any* object type is compared against the value the expression
246 * evaluates to.
247 */
248 sdb_store_cond_t *
249 sdb_store_obj_cond(int field, sdb_store_expr_t *expr);
251 /*
252 * Store matchers may be used to lookup hosts from the store based on their
253 * various attributes. Service and attribute matchers are applied to a host's
254 * services and attributes and evaluate to true if *any* service or attribute
255 * matches.
256 *
257 * A store matcher object inherits from sdb_object_t and, thus, may safely be
258 * cast to a generic object.
259 */
260 struct sdb_store_matcher;
261 typedef struct sdb_store_matcher sdb_store_matcher_t;
262 #define SDB_STORE_MATCHER(obj) ((sdb_store_matcher_t *)(obj))
264 /*
265 * sdb_store_name_matcher:
266 * Creates a matcher matching by the specified object type's name. If 're' is
267 * true, the specified name is treated as a POSIX extended regular expression.
268 * Else, the exact name has to match (case-insensitive).
269 */
270 sdb_store_matcher_t *
271 sdb_store_name_matcher(int type, const char *name, _Bool re);
273 /*
274 * sdb_store_attr_matcher:
275 * Creates a matcher matching attributes based on their value. If 're' is
276 * true, the specified name is treated as a POSIX extended regular expression.
277 * Else, the exact name has to match (case-insensitive).
278 */
279 sdb_store_matcher_t *
280 sdb_store_attr_matcher(const char *name, const char *value, _Bool re);
282 /*
283 * sdb_store_isnull_matcher:
284 * Creates a matcher matching "missing" attributes.
285 */
286 sdb_store_matcher_t *
287 sdb_store_isnull_matcher(const char *attr_name);
289 /*
290 * sdb_store_lt_matcher, sdb_store_le_matcher, sdb_store_eq_matcher,
291 * sdb_store_ge_matcher, sdb_store_gt_matcher:
292 * Creates a matcher based on a conditional. The matcher matches objects for
293 * which the conditional evaluates the object to compare less than, less or
294 * equal, equal, greater or equal, or greater than the conditional's value
295 * repsectively.
296 */
297 sdb_store_matcher_t *
298 sdb_store_lt_matcher(sdb_store_cond_t *cond);
299 sdb_store_matcher_t *
300 sdb_store_le_matcher(sdb_store_cond_t *cond);
301 sdb_store_matcher_t *
302 sdb_store_eq_matcher(sdb_store_cond_t *cond);
303 sdb_store_matcher_t *
304 sdb_store_ge_matcher(sdb_store_cond_t *cond);
305 sdb_store_matcher_t *
306 sdb_store_gt_matcher(sdb_store_cond_t *cond);
308 /*
309 * sdb_store_matcher_parse_cmp:
310 * Parse a simple compare expression (<obj_type>.<attr> <op> <expression>).
311 *
312 * Returns:
313 * - a matcher object on success
314 * - NULL else
315 */
316 sdb_store_matcher_t *
317 sdb_store_matcher_parse_cmp(const char *obj_type, const char *attr,
318 const char *op, sdb_store_expr_t *expr);
320 /*
321 * sdb_store_dis_matcher:
322 * Creates a matcher matching the disjunction (logical OR) of two matchers.
323 */
324 sdb_store_matcher_t *
325 sdb_store_dis_matcher(sdb_store_matcher_t *left, sdb_store_matcher_t *right);
327 /*
328 * sdb_store_con_matcher:
329 * Creates a matcher matching the conjunction (logical AND) of two matchers.
330 */
331 sdb_store_matcher_t *
332 sdb_store_con_matcher(sdb_store_matcher_t *left, sdb_store_matcher_t *right);
334 /*
335 * sdb_store_con_matcher::
336 * Creates a matcher matching the inverse (logical NOT) of a matcher.
337 */
338 sdb_store_matcher_t *
339 sdb_store_inv_matcher(sdb_store_matcher_t *m);
341 /*
342 * sdb_store_matcher_matches:
343 * Check whether the specified matcher matches the specified store object. If
344 * specified, the filter will be used to preselect objects for further
345 * evaluation. It is applied to any object that's used during the evaluation
346 * of the matcher. Only those objects matching the filter will be considered.
347 *
348 * Note that the filter is applied to all object types (hosts, service,
349 * attribute). Thus, any object-specific matchers are mostly unsuited for this
350 * purpose and, if used, may result in unexpected behavior.
351 *
352 * Returns:
353 * - 1 if the object matches
354 * - 0 else
355 */
356 int
357 sdb_store_matcher_matches(sdb_store_matcher_t *m, sdb_store_obj_t *obj,
358 sdb_store_matcher_t *filter);
360 /*
361 * sdb_store_matcher_tostring:
362 * Format a matcher object as string. This is meant for logging or debugging
363 * purposes.
364 */
365 char *
366 sdb_store_matcher_tostring(sdb_store_matcher_t *m, char *buf, size_t buflen);
368 /*
369 * sdb_store_lookup_cb:
370 * Lookup callback. It is called for each matching object when looking up data
371 * in the store. The lookup aborts if the callback returns non-zero.
372 */
373 typedef int (*sdb_store_lookup_cb)(sdb_store_obj_t *obj, void *user_data);
375 /*
376 * sdb_store_scan:
377 * Look up objects in the store. The specified callback function is called for
378 * each object in the store matching 'm'. The function performs a full scan of
379 * all hosts stored in the database. If specified, the filter will be used to
380 * preselect objects for further evaluation. See the description of
381 * 'sdb_store_matcher_matches' for details.
382 *
383 * Returns:
384 * - 0 on success
385 * - a negative value else
386 */
387 int
388 sdb_store_scan(sdb_store_matcher_t *m, sdb_store_matcher_t *filter,
389 sdb_store_lookup_cb cb, void *user_data);
391 /*
392 * Flags for serialization functions.
393 *
394 * By default, the full object will be included in the serialized output. When
395 * specifying any of the flags, the respective information will be left out.
396 */
397 enum {
398 SDB_SKIP_ATTRIBUTES = 1 << 0,
399 SDB_SKIP_SERVICES = 1 << 1,
400 SDB_SKIP_SERVICE_ATTRIBUTES = 1 << 2,
402 SDB_SKIP_ALL = 0xffff,
403 };
405 /*
406 * sdb_store_tojson:
407 * Serialize the entire store to JSON and append the result to the specified
408 * buffer. If specified, only objects matching the filter will be included in
409 * the result (see sdb_store_host_tojson for details).
410 *
411 * Returns:
412 * - 0 on success
413 * - a negative value on error
414 */
415 int
416 sdb_store_tojson(sdb_strbuf_t *buf, sdb_store_matcher_t *filter, int flags);
418 /*
419 * sdb_store_host_tojson:
420 * Serialize a host object to JSON and append the result to the specified
421 * buffer. If specified, only objects matching the filter will be included in
422 * the result. The filter is applied to each object individually and, thus,
423 * should not be of any object-type specific kind. The filter is never applied
424 * to the specified host object; the caller is responsible for this and for
425 * correctly handling skipped hosts.
426 *
427 * Returns:
428 * - 0 on success
429 * - a negative value on error
430 */
431 int
432 sdb_store_host_tojson(sdb_store_obj_t *host, sdb_strbuf_t *buf,
433 sdb_store_matcher_t *filter, int flags);
435 /*
436 * sdb_store_iter_cb:
437 * Store iterator callback. Iteration stops if the callback returns non-zero.
438 */
439 typedef int (*sdb_store_iter_cb)(sdb_store_obj_t *obj, void *user_data);
441 /*
442 * sdb_store_iterate:
443 * Iterate the entire store, calling the specified callback for each object.
444 * The user_data pointer is passed on to each call of the callback.
445 *
446 * Returns:
447 * - 0 on success
448 * - a negative value else
449 */
450 int
451 sdb_store_iterate(sdb_store_iter_cb cb, void *user_data);
453 #ifdef __cplusplus
454 } /* extern "C" */
455 #endif
457 #endif /* ! SDB_CORE_STORE_H */
459 /* vim: set tw=78 sw=4 ts=4 noexpandtab : */