Code

store: Use AVL trees to store all objects.
[sysdb.git] / src / core / store.c
1 /*
2  * SysDB - src/core/store.c
3  * Copyright (C) 2012-2013 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 #if HAVE_CONFIG_H
29 #       include "config.h"
30 #endif /* HAVE_CONFIG_H */
32 #include "sysdb.h"
33 #include "core/store-private.h"
34 #include "core/plugin.h"
35 #include "utils/avltree.h"
36 #include "utils/error.h"
38 #include <assert.h>
40 #include <errno.h>
42 #include <stdio.h>
43 #include <stdlib.h>
44 #include <string.h>
46 #include <pthread.h>
48 /*
49  * private variables
50  */
52 static sdb_avltree_t *hosts = NULL;
53 static pthread_rwlock_t host_lock = PTHREAD_RWLOCK_INITIALIZER;
55 /*
56  * private types
57  */
59 static sdb_type_t sdb_host_type;
60 static sdb_type_t sdb_service_type;
61 static sdb_type_t sdb_attribute_type;
63 static int
64 store_obj_init(sdb_object_t *obj, va_list ap)
65 {
66         sdb_store_obj_t *sobj = STORE_OBJ(obj);
68         sobj->type = va_arg(ap, int);
70         sobj->last_update = va_arg(ap, sdb_time_t);
71         sobj->interval = 0;
72         sobj->backends = NULL;
73         sobj->backends_num = 0;
74         sobj->parent = NULL;
75         return 0;
76 } /* store_obj_init */
78 static void
79 store_obj_destroy(sdb_object_t *obj)
80 {
81         sdb_store_obj_t *sobj = STORE_OBJ(obj);
82         size_t i;
84         for (i = 0; i < sobj->backends_num; ++i)
85                 free(sobj->backends[i]);
86         free(sobj->backends);
87         sobj->backends = NULL;
88         sobj->backends_num = 0;
90         if (sobj->parent)
91                 sdb_object_deref(SDB_OBJ(sobj->parent));
92 } /* store_obj_destroy */
94 static int
95 sdb_host_init(sdb_object_t *obj, va_list ap)
96 {
97         sdb_host_t *sobj = HOST(obj);
98         int ret;
100         /* this will consume the first argument (type) of ap */
101         ret = store_obj_init(obj, ap);
102         if (ret)
103                 return ret;
105         sobj->services = sdb_avltree_create();
106         if (! sobj->services)
107                 return -1;
108         sobj->attributes = sdb_avltree_create();
109         if (! sobj->attributes)
110                 return -1;
111         return 0;
112 } /* sdb_host_init */
114 static void
115 sdb_host_destroy(sdb_object_t *obj)
117         sdb_host_t *sobj = HOST(obj);
118         assert(obj);
120         store_obj_destroy(obj);
122         if (sobj->services)
123                 sdb_avltree_destroy(sobj->services);
124         if (sobj->attributes)
125                 sdb_avltree_destroy(sobj->attributes);
126 } /* sdb_host_destroy */
128 static int
129 sdb_service_init(sdb_object_t *obj, va_list ap)
131         sdb_service_t *sobj = SVC(obj);
132         int ret;
134         /* this will consume the first argument (type) of ap */
135         ret = store_obj_init(obj, ap);
136         if (ret)
137                 return ret;
139         sobj->attributes = sdb_avltree_create();
140         if (! sobj->attributes)
141                 return -1;
142         return 0;
143 } /* sdb_service_init */
145 static void
146 sdb_service_destroy(sdb_object_t *obj)
148         sdb_service_t *sobj = SVC(obj);
149         assert(obj);
151         store_obj_destroy(obj);
153         if (sobj->attributes)
154                 sdb_avltree_destroy(sobj->attributes);
155 } /* sdb_service_destroy */
157 static int
158 sdb_attr_init(sdb_object_t *obj, va_list ap)
160         const sdb_data_t *value;
161         int ret;
163         /* this will consume the first two arguments
164          * (type and last_update) of ap */
165         ret = store_obj_init(obj, ap);
166         if (ret)
167                 return ret;
168         value = va_arg(ap, const sdb_data_t *);
170         if (value)
171                 if (sdb_data_copy(&ATTR(obj)->value, value))
172                         return -1;
173         return 0;
174 } /* sdb_attr_init */
176 static void
177 sdb_attr_destroy(sdb_object_t *obj)
179         assert(obj);
181         store_obj_destroy(obj);
182         sdb_data_free_datum(&ATTR(obj)->value);
183 } /* sdb_attr_destroy */
185 static sdb_type_t sdb_host_type = {
186         sizeof(sdb_host_t),
187         sdb_host_init,
188         sdb_host_destroy
189 };
191 static sdb_type_t sdb_service_type = {
192         sizeof(sdb_service_t),
193         sdb_service_init,
194         sdb_service_destroy
195 };
197 static sdb_type_t sdb_attribute_type = {
198         sizeof(sdb_attribute_t),
199         sdb_attr_init,
200         sdb_attr_destroy
201 };
203 /*
204  * private helper functions
205  */
207 static sdb_host_t *
208 lookup_host(const char *name)
210         return HOST(sdb_avltree_lookup(hosts, name));
211 } /* lookup_host */
213 static int
214 record_backend(sdb_store_obj_t *obj)
216         const sdb_plugin_info_t *info;
217         char **tmp;
218         size_t i;
220         info = sdb_plugin_current();
221         if (! info)
222                 return 0;
224         for (i = 0; i < obj->backends_num; ++i)
225                 if (!strcasecmp(obj->backends[i], info->plugin_name))
226                         return 0;
228         tmp = realloc(obj->backends,
229                         (obj->backends_num + 1) * sizeof(*obj->backends));
230         if (! tmp)
231                 return -1;
233         obj->backends = tmp;
234         obj->backends[obj->backends_num] = strdup(info->plugin_name);
235         if (! obj->backends[obj->backends_num])
236                 return -1;
238         ++obj->backends_num;
239         return 0;
240 } /* record_backend */
242 static int
243 store_obj(sdb_avltree_t *parent_tree, int type, const char *name,
244                 sdb_time_t last_update, sdb_store_obj_t **updated_obj)
246         sdb_store_obj_t *old, *new;
247         int status = 0;
249         assert(parent_tree);
251         if (last_update <= 0)
252                 last_update = sdb_gettime();
254         old = STORE_OBJ(sdb_avltree_lookup(parent_tree, name));
255         if (old) {
256                 if (old->last_update > last_update) {
257                         sdb_log(SDB_LOG_DEBUG, "store: Cannot update %s '%s' - "
258                                         "value too old (%"PRIscTIME" < %"PRIscTIME")",
259                                         SDB_STORE_TYPE_TO_NAME(type), name,
260                                         last_update, old->last_update);
261                         /* don't report an error; the object may be updated by multiple
262                          * backends */
263                         status = 1;
264                 }
265                 else if (old->last_update == last_update) {
266                         /* don't report an error and also don't even log this to avoid
267                          * excessive noise on high sampling frequencies */
268                         status = 1;
269                 }
270                 else {
271                         sdb_time_t interval = last_update - old->last_update;
272                         old->last_update = last_update;
273                         if (interval) {
274                                 if (old->interval)
275                                         old->interval = (sdb_time_t)((0.9 * (double)old->interval)
276                                                         + (0.1 * (double)interval));
277                                 else
278                                         old->interval = interval;
279                         }
280                 }
282                 new = old;
283                 sdb_object_deref(SDB_OBJ(old));
284         }
285         else {
286                 if (type == SDB_ATTRIBUTE) {
287                         /* the value will be updated by the caller */
288                         new = STORE_OBJ(sdb_object_create(name, sdb_attribute_type,
289                                                 type, last_update, NULL));
290                 }
291                 else {
292                         sdb_type_t t;
293                         t = type == SDB_HOST ? sdb_host_type : sdb_service_type;
294                         new = STORE_OBJ(sdb_object_create(name, t, type, last_update));
295                 }
297                 if (new) {
298                         status = sdb_avltree_insert(parent_tree, SDB_OBJ(new));
300                         /* pass control to the tree or destroy in case of an error */
301                         sdb_object_deref(SDB_OBJ(new));
302                 }
303                 else {
304                         char errbuf[1024];
305                         sdb_log(SDB_LOG_ERR, "store: Failed to create %s '%s': %s",
306                                         SDB_STORE_TYPE_TO_NAME(type), name,
307                                         sdb_strerror(errno, errbuf, sizeof(errbuf)));
308                         status = -1;
309                 }
310         }
312         if (status < 0)
313                 return status;
314         assert(new);
316         if (updated_obj)
317                 *updated_obj = new;
319         if (record_backend(new))
320                 return -1;
321         return status;
322 } /* store_obj */
324 static int
325 store_attr(sdb_avltree_t *attributes, const char *key, const sdb_data_t *value,
326                 sdb_time_t last_update)
328         sdb_store_obj_t *attr = NULL;
329         int status;
331         status = store_obj(attributes, SDB_ATTRIBUTE, key, last_update, &attr);
332         if (status)
333                 return status;
335         /* don't update unchanged values */
336         if (! sdb_data_cmp(&ATTR(attr)->value, value))
337                 return status;
339         assert(attr);
340         if (sdb_data_copy(&ATTR(attr)->value, value))
341                 return -1;
342         return status;
343 } /* store_attr */
345 /* The host_lock has to be acquired before calling this function. */
346 static sdb_avltree_t *
347 get_host_children(const char *hostname, int type)
349         char *cname = NULL;
350         sdb_host_t *host;
352         assert(hostname);
353         assert((type == SDB_SERVICE) || (type == SDB_ATTRIBUTE));
355         if (! hosts)
356                 return NULL;
358         cname = sdb_plugin_cname(strdup(hostname));
359         if (! cname) {
360                 sdb_log(SDB_LOG_ERR, "store: strdup failed");
361                 return NULL;
362         }
364         host = lookup_host(cname);
365         free(cname);
366         if (! host)
367                 return NULL;
369         sdb_object_deref(SDB_OBJ(host));
370         if (type == SDB_ATTRIBUTE)
371                 return host->attributes;
372         else
373                 return host->services;
374 } /* get_host_children */
376 /*
377  * store_common_tojson serializes common object attributes to JSON.
378  *
379  * The function never returns an error. Rather, an error message will be part
380  * of the serialized data.
381  */
382 static void
383 store_common_tojson(sdb_store_obj_t *obj, sdb_strbuf_t *buf)
385         char time_str[64];
386         char interval_str[64];
387         size_t i;
389         if (! sdb_strftime(time_str, sizeof(time_str),
390                                 "%F %T %z", obj->last_update))
391                 snprintf(time_str, sizeof(time_str), "<error>");
392         time_str[sizeof(time_str) - 1] = '\0';
394         if (! sdb_strfinterval(interval_str, sizeof(interval_str),
395                                 obj->interval))
396                 snprintf(interval_str, sizeof(interval_str), "<error>");
397         interval_str[sizeof(interval_str) - 1] = '\0';
399         sdb_strbuf_append(buf, "\"last_update\": \"%s\", "
400                         "\"update_interval\": \"%s\", \"backends\": [",
401                         time_str, interval_str);
403         for (i = 0; i < obj->backends_num; ++i) {
404                 sdb_strbuf_append(buf, "\"%s\"", obj->backends[i]);
405                 if (i < obj->backends_num - 1)
406                         sdb_strbuf_append(buf, ",");
407         }
408         sdb_strbuf_append(buf, "]");
409 } /* store_common_tojson */
411 /*
412  * store_obj_tojson serializes attribute / service objects to JSON.
413  *
414  * The function never returns an error. Rather, an error message will be part
415  * of the serialized data.
416  */
417 static void
418 store_obj_tojson(sdb_avltree_t *tree, int type, sdb_strbuf_t *buf, int flags)
420         sdb_avltree_iter_t *iter;
422         assert((type == SDB_ATTRIBUTE) || (type == SDB_SERVICE));
424         sdb_strbuf_append(buf, "[");
425         iter = sdb_avltree_get_iter(tree);
426         if (! iter) {
427                 char errbuf[1024];
428                 sdb_log(SDB_LOG_ERR, "store: Failed to retrieve %ss: %s\n",
429                                 SDB_STORE_TYPE_TO_NAME(type),
430                                 sdb_strerror(errno, errbuf, sizeof(errbuf)));
431                 sdb_strbuf_append(buf, "{\"error\": \"failed to retrieve %ss: %s\"}",
432                                 SDB_STORE_TYPE_TO_NAME(type), errbuf);
433         }
435         /* has_next returns false if the iterator is NULL */
436         while (sdb_avltree_iter_has_next(iter)) {
437                 sdb_store_obj_t *sobj = STORE_OBJ(sdb_avltree_iter_get_next(iter));
438                 assert(sobj);
439                 assert(sobj->type == type);
441                 sdb_strbuf_append(buf, "{\"name\": \"%s\", ", SDB_OBJ(sobj)->name);
442                 if (sobj->type == SDB_ATTRIBUTE) {
443                         char tmp[sdb_data_strlen(&ATTR(sobj)->value) + 1];
444                         sdb_data_format(&ATTR(sobj)->value, tmp, sizeof(tmp),
445                                         SDB_DOUBLE_QUOTED);
446                         sdb_strbuf_append(buf, "\"value\": %s, ", tmp);
447                 }
448                 store_common_tojson(sobj, buf);
450                 if ((sobj->type == SDB_SERVICE)
451                                 && (! (flags & SDB_SKIP_ATTRIBUTES))) {
452                         sdb_strbuf_append(buf, ", \"attributes\": ");
453                         store_obj_tojson(SVC(sobj)->attributes, SDB_ATTRIBUTE,
454                                         buf, flags);
455                 }
456                 sdb_strbuf_append(buf, "}");
458                 if (sdb_avltree_iter_has_next(iter))
459                         sdb_strbuf_append(buf, ",");
460         }
462         sdb_avltree_iter_destroy(iter);
463         sdb_strbuf_append(buf, "]");
464 } /* store_obj_tojson */
466 /*
467  * public API
468  */
470 void
471 sdb_store_clear(void)
473         sdb_avltree_destroy(hosts);
474         hosts = NULL;
475 } /* sdb_store_clear */
477 int
478 sdb_store_host(const char *name, sdb_time_t last_update)
480         char *cname = NULL;
481         int status = 0;
483         if (! name)
484                 return -1;
486         cname = sdb_plugin_cname(strdup(name));
487         if (! cname) {
488                 sdb_log(SDB_LOG_ERR, "store: strdup failed");
489                 return -1;
490         }
492         pthread_rwlock_wrlock(&host_lock);
493         if (! hosts)
494                 if (! (hosts = sdb_avltree_create()))
495                         status = -1;
497         if (! status)
498                 status = store_obj(hosts, SDB_HOST, cname, last_update, NULL);
499         pthread_rwlock_unlock(&host_lock);
501         free(cname);
502         return status;
503 } /* sdb_store_host */
505 _Bool
506 sdb_store_has_host(const char *name)
508         sdb_host_t *host;
510         if (! name)
511                 return NULL;
513         host = lookup_host(name);
514         return host != NULL;
515 } /* sdb_store_has_host */
517 sdb_store_obj_t *
518 sdb_store_get_host(const char *name)
520         sdb_host_t *host;
522         if (! name)
523                 return NULL;
525         host = lookup_host(name);
526         if (! host)
527                 return NULL;
529         return STORE_OBJ(host);
530 } /* sdb_store_get_host */
532 int
533 sdb_store_attribute(const char *hostname,
534                 const char *key, const sdb_data_t *value,
535                 sdb_time_t last_update)
537         sdb_avltree_t *attrs;
538         int status = 0;
540         if ((! hostname) || (! key))
541                 return -1;
543         pthread_rwlock_wrlock(&host_lock);
544         attrs = get_host_children(hostname, SDB_ATTRIBUTE);
545         if (! attrs) {
546                 sdb_log(SDB_LOG_ERR, "store: Failed to store attribute '%s' - "
547                                 "host '%s' not found", key, hostname);
548                 status = -1;
549         }
551         if (! status)
552                 status = store_attr(attrs, key, value, last_update);
554         pthread_rwlock_unlock(&host_lock);
555         return status;
556 } /* sdb_store_attribute */
558 int
559 sdb_store_service(const char *hostname, const char *name,
560                 sdb_time_t last_update)
562         sdb_avltree_t *services;
564         int status = 0;
566         if ((! hostname) || (! name))
567                 return -1;
569         pthread_rwlock_wrlock(&host_lock);
570         services = get_host_children(hostname, SDB_SERVICE);
571         if (! services) {
572                 sdb_log(SDB_LOG_ERR, "store: Failed to store service '%s' - "
573                                 "host '%s' not found", name, hostname);
574                 status = -1;
575         }
577         if (! status)
578                 status = store_obj(services, SDB_SERVICE, name, last_update, NULL);
579         pthread_rwlock_unlock(&host_lock);
580         return status;
581 } /* sdb_store_service */
583 int
584 sdb_store_service_attr(const char *hostname, const char *service,
585                 const char *key, const sdb_data_t *value, sdb_time_t last_update)
587         sdb_avltree_t *services;
588         sdb_service_t *svc;
589         int status = 0;
591         if ((! hostname) || (! service) || (! key))
592                 return -1;
594         pthread_rwlock_wrlock(&host_lock);
595         services = get_host_children(hostname, SDB_SERVICE);
596         if (! services) {
597                 sdb_log(SDB_LOG_ERR, "store: Failed to store attribute '%s' "
598                                 "for service '%s' - host '%ss' not found",
599                                 key, service, hostname);
600                 pthread_rwlock_unlock(&host_lock);
601                 return -1;
602         }
604         svc = SVC(sdb_avltree_lookup(services, service));
605         if (! svc) {
606                 sdb_log(SDB_LOG_ERR, "store: Failed to store attribute '%s' - "
607                                 "service '%s/%s' not found", key, hostname, service);
608                 status = -1;
609         }
611         if (! status)
612                 status = store_attr(svc->attributes, key, value, last_update);
614         sdb_object_deref(SDB_OBJ(svc));
615         pthread_rwlock_unlock(&host_lock);
616         return status;
617 } /* sdb_store_service_attr */
619 int
620 sdb_store_host_tojson(sdb_store_obj_t *h, sdb_strbuf_t *buf, int flags)
622         sdb_host_t *host;
624         if ((! h) || (h->type != SDB_HOST) || (! buf))
625                 return -1;
627         host = HOST(h);
629         sdb_strbuf_append(buf, "{\"name\": \"%s\", ", SDB_OBJ(host)->name);
630         store_common_tojson(h, buf);
632         if (! (flags & SDB_SKIP_ATTRIBUTES)) {
633                 sdb_strbuf_append(buf, ", \"attributes\": ");
634                 store_obj_tojson(host->attributes, SDB_ATTRIBUTE, buf, flags);
635         }
637         if (! (flags & SDB_SKIP_SERVICES)) {
638                 sdb_strbuf_append(buf, ", \"services\": ");
639                 store_obj_tojson(host->services, SDB_SERVICE, buf, flags);
640         }
642         sdb_strbuf_append(buf, "}");
643         return 0;
644 } /* sdb_store_host_tojson */
646 int
647 sdb_store_tojson(sdb_strbuf_t *buf, int flags)
649         sdb_avltree_iter_t *host_iter;
651         if (! buf)
652                 return -1;
654         pthread_rwlock_rdlock(&host_lock);
656         host_iter = sdb_avltree_get_iter(hosts);
657         if (! host_iter) {
658                 pthread_rwlock_unlock(&host_lock);
659                 return -1;
660         }
662         sdb_strbuf_append(buf, "{\"hosts\":[");
664         while (sdb_avltree_iter_has_next(host_iter)) {
665                 sdb_store_obj_t *host;
667                 host = STORE_OBJ(sdb_avltree_iter_get_next(host_iter));
668                 assert(host);
670                 if (sdb_store_host_tojson(host, buf, flags))
671                         return -1;
673                 if (sdb_avltree_iter_has_next(host_iter))
674                         sdb_strbuf_append(buf, ",");
675         }
677         sdb_strbuf_append(buf, "]}");
679         sdb_avltree_iter_destroy(host_iter);
680         pthread_rwlock_unlock(&host_lock);
681         return 0;
682 } /* sdb_store_tojson */
684 /* TODO: actually support hierarchical data */
685 int
686 sdb_store_iterate(sdb_store_iter_cb cb, void *user_data)
688         sdb_avltree_iter_t *host_iter;
689         int status = 0;
691         pthread_rwlock_rdlock(&host_lock);
693         host_iter = sdb_avltree_get_iter(hosts);
694         if (! host_iter)
695                 status = -1;
697         /* has_next returns false if the iterator is NULL */
698         while (sdb_avltree_iter_has_next(host_iter)) {
699                 sdb_store_obj_t *host;
701                 host = STORE_OBJ(sdb_avltree_iter_get_next(host_iter));
702                 assert(host);
704                 if (cb(host, user_data)) {
705                         status = -1;
706                         break;
707                 }
708         }
710         sdb_avltree_iter_destroy(host_iter);
711         pthread_rwlock_unlock(&host_lock);
712         return status;
713 } /* sdb_store_iterate */
715 /* vim: set tw=78 sw=4 ts=4 noexpandtab : */