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  */
  27
  28 #if HAVE_CONFIG_H
  29 #       include "config.h"
  30 #endif /* HAVE_CONFIG_H */
  31
  32 #include "sysdb.h"
  33 #include "core/store-private.h"
  34 #include "core/plugin.h"
  35 #include "utils/error.h"
  36 #include "utils/llist.h"
  37
  38 #include <assert.h>
  39
  40 #include <errno.h>
  41
  42 #include <stdio.h>
  43 #include <stdlib.h>
  44 #include <string.h>
  45
  46 #include <pthread.h>
  47
  48 /*
  49  * private variables
  50  */
  51
  52 static sdb_llist_t *host_list = NULL;
  53 static pthread_rwlock_t host_lock = PTHREAD_RWLOCK_INITIALIZER;
  54
  55 /*
  56  * private types
  57  */
  58
  59 static sdb_type_t sdb_host_type;
  60 static sdb_type_t sdb_service_type;
  61 static sdb_type_t sdb_attribute_type;
  62
  63 static int
  64 store_obj_init(sdb_object_t *obj, va_list ap)
  65 {
  66         sdb_store_obj_t *sobj = STORE_OBJ(obj);
  67
  68         sobj->type = va_arg(ap, int);
  69
  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 */
  77
  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;
  83
  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;
  89
  90         if (sobj->parent)
  91                 sdb_object_deref(SDB_OBJ(sobj->parent));
  92 } /* store_obj_destroy */
  93
  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;
  99
 100         /* this will consume the first argument (type) of ap */
 101         ret = store_obj_init(obj, ap);
 102         if (ret)
 103                 return ret;
 104
 105         sobj->services = sdb_llist_create();
 106         if (! sobj->services)
 107                 return -1;
 108         sobj->attributes = sdb_llist_create();
 109         if (! sobj->attributes)
 110                 return -1;
 111         return 0;
 112 } /* sdb_host_init */
 113
 114 static void
 115 sdb_host_destroy(sdb_object_t *obj)
 116 {
 117         sdb_host_t *sobj = HOST(obj);
 118         assert(obj);
 119
 120         store_obj_destroy(obj);
 121
 122         if (sobj->services)
 123                 sdb_llist_destroy(sobj->services);
 124         if (sobj->attributes)
 125                 sdb_llist_destroy(sobj->attributes);
 126 } /* sdb_host_destroy */
 127
 128 static int
 129 sdb_service_init(sdb_object_t *obj, va_list ap)
 130 {
 131         sdb_service_t *sobj = SVC(obj);
 132         int ret;
 133
 134         /* this will consume the first argument (type) of ap */
 135         ret = store_obj_init(obj, ap);
 136         if (ret)
 137                 return ret;
 138
 139         sobj->attributes = sdb_llist_create();
 140         if (! sobj->attributes)
 141                 return -1;
 142         return 0;
 143 } /* sdb_service_init */
 144
 145 static void
 146 sdb_service_destroy(sdb_object_t *obj)
 147 {
 148         sdb_service_t *sobj = SVC(obj);
 149         assert(obj);
 150
 151         store_obj_destroy(obj);
 152
 153         if (sobj->attributes)
 154                 sdb_llist_destroy(sobj->attributes);
 155 } /* sdb_service_destroy */
 156
 157 static int
 158 sdb_attr_init(sdb_object_t *obj, va_list ap)
 159 {
 160         const sdb_data_t *value;
 161         int ret;
 162
 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 *);
 169
 170         if (value)
 171                 if (sdb_data_copy(&ATTR(obj)->value, value))
 172                         return -1;
 173         return 0;
 174 } /* sdb_attr_init */
 175
 176 static void
 177 sdb_attr_destroy(sdb_object_t *obj)
 178 {
 179         assert(obj);
 180
 181         store_obj_destroy(obj);
 182         sdb_data_free_datum(&ATTR(obj)->value);
 183 } /* sdb_attr_destroy */
 184
 185 static sdb_type_t sdb_host_type = {
 186         sizeof(sdb_host_t),
 187         sdb_host_init,
 188         sdb_host_destroy
 189 };
 190
 191 static sdb_type_t sdb_service_type = {
 192         sizeof(sdb_service_t),
 193         sdb_service_init,
 194         sdb_service_destroy
 195 };
 196
 197 static sdb_type_t sdb_attribute_type = {
 198         sizeof(sdb_attribute_t),
 199         sdb_attr_init,
 200         sdb_attr_destroy
 201 };
 202
 203 /*
 204  * private helper functions
 205  */
 206
 207 static sdb_host_t *
 208 lookup_host(const char *name)
 209 {
 210         return HOST(sdb_llist_search_by_name(host_list, name));
 211 } /* lookup_host */
 212
 213 static int
 214 record_backend(sdb_store_obj_t *obj)
 215 {
 216         const sdb_plugin_info_t *info;
 217         char **tmp;
 218         size_t i;
 219
 220         info = sdb_plugin_current();
 221         if (! info)
 222                 return 0;
 223
 224         for (i = 0; i < obj->backends_num; ++i)
 225                 if (!strcasecmp(obj->backends[i], info->plugin_name))
 226                         return 0;
 227
 228         tmp = realloc(obj->backends,
 229                         (obj->backends_num + 1) * sizeof(*obj->backends));
 230         if (! tmp)
 231                 return -1;
 232
 233         obj->backends = tmp;
 234         obj->backends[obj->backends_num] = strdup(info->plugin_name);
 235         if (! obj->backends[obj->backends_num])
 236                 return -1;
 237
 238         ++obj->backends_num;
 239         return 0;
 240 } /* record_backend */
 241
 242 static int
 243 store_obj(sdb_llist_t *parent_list, int type, const char *name,
 244                 sdb_time_t last_update, sdb_store_obj_t **updated_obj)
 245 {
 246         sdb_store_obj_t *old, *new;
 247         int status = 0;
 248
 249         assert(parent_list);
 250
 251         old = STORE_OBJ(sdb_llist_search_by_name(parent_list, name));
 252         if (old) {
 253                 if (old->last_update > last_update) {
 254                         sdb_log(SDB_LOG_DEBUG, "store: Cannot update %s '%s' - "
 255                                         "value too old (%"PRIscTIME" < %"PRIscTIME")",
 256                                         SDB_STORE_TYPE_TO_NAME(type), name,
 257                                         last_update, old->last_update);
 258                         /* don't report an error; the object may be updated by multiple
 259                          * backends */
 260                         status = 1;
 261                 }
 262                 else {
 263                         sdb_time_t interval = last_update - old->last_update;
 264                         old->last_update = last_update;
 265                         if (interval) {
 266                                 if (old->interval)
 267                                         old->interval = (sdb_time_t)((0.9 * (double)old->interval)
 268                                                         + (0.1 * (double)interval));
 269                                 else
 270                                         old->interval = interval;
 271                         }
 272                 }
 273
 274                 new = old;
 275         }
 276         else {
 277                 if (type == SDB_ATTRIBUTE) {
 278                         /* the value will be updated by the caller */
 279                         new = STORE_OBJ(sdb_object_create(name, sdb_attribute_type,
 280                                                 type, last_update, NULL));
 281                 }
 282                 else {
 283                         sdb_type_t t;
 284                         t = type == SDB_HOST ? sdb_host_type : sdb_service_type;
 285                         new = STORE_OBJ(sdb_object_create(name, t, type, last_update));
 286                 }
 287
 288                 if (new) {
 289                         status = sdb_llist_insert_sorted(parent_list, SDB_OBJ(new),
 290                                         sdb_object_cmp_by_name);
 291
 292                         /* pass control to the list or destroy in case of an error */
 293                         sdb_object_deref(SDB_OBJ(new));
 294                 }
 295                 else {
 296                         char errbuf[1024];
 297                         sdb_log(SDB_LOG_ERR, "store: Failed to create %s '%s': %s",
 298                                         SDB_STORE_TYPE_TO_NAME(type), name,
 299                                         sdb_strerror(errno, errbuf, sizeof(errbuf)));
 300                         status = -1;
 301                 }
 302         }
 303
 304         if (status < 0)
 305                 return status;
 306         assert(new);
 307
 308         if (updated_obj)
 309                 *updated_obj = new;
 310
 311         if (record_backend(new))
 312                 return -1;
 313         return status;
 314 } /* store_obj */
 315
 316 /* The host_lock has to be acquired before calling this function. */
 317 static int
 318 store_host_obj(const char *hostname, int type, const char *name,
 319                 sdb_time_t last_update, sdb_store_obj_t **updated_obj)
 320 {
 321         char *cname = NULL;
 322         sdb_host_t *host;
 323         sdb_llist_t *parent_list;
 324
 325         int status = 0;
 326
 327         if (last_update <= 0)
 328                 last_update = sdb_gettime();
 329
 330         assert(hostname);
 331         assert((type == SDB_SERVICE) || (type == SDB_ATTRIBUTE));
 332
 333         if (! host_list)
 334                 return -1;
 335
 336         cname = sdb_plugin_cname(strdup(hostname));
 337         if (! cname) {
 338                 sdb_log(SDB_LOG_ERR, "store: strdup failed");
 339                 return -1;
 340         }
 341
 342         host = lookup_host(cname);
 343         if (! host) {
 344                 sdb_log(SDB_LOG_ERR, "store: Failed to store %s '%s' - "
 345                                 "host '%s' not found", SDB_STORE_TYPE_TO_NAME(type),
 346                                 name, hostname);
 347                 free(cname);
 348                 return -1;
 349         }
 350
 351         if (type == SDB_ATTRIBUTE)
 352                 parent_list = host->attributes;
 353         else
 354                 parent_list = host->services;
 355
 356         status = store_obj(parent_list, type, name,
 357                         last_update, updated_obj);
 358
 359         free(cname);
 360         return status;
 361 } /* store_host_obj */
 362
 363 /*
 364  * store_common_tojson serializes common object attributes to JSON.
 365  *
 366  * The function never returns an error. Rather, an error message will be part
 367  * of the serialized data.
 368  */
 369 static void
 370 store_common_tojson(sdb_store_obj_t *obj, sdb_strbuf_t *buf)
 371 {
 372         char time_str[64];
 373         char interval_str[64];
 374         size_t i;
 375
 376         if (! sdb_strftime(time_str, sizeof(time_str),
 377                                 "%F %T %z", obj->last_update))
 378                 snprintf(time_str, sizeof(time_str), "<error>");
 379         time_str[sizeof(time_str) - 1] = '\0';
 380
 381         if (! sdb_strfinterval(interval_str, sizeof(interval_str),
 382                                 obj->interval))
 383                 snprintf(interval_str, sizeof(interval_str), "<error>");
 384         interval_str[sizeof(interval_str) - 1] = '\0';
 385
 386         sdb_strbuf_append(buf, "\"last_update\": \"%s\", "
 387                         "\"update_interval\": \"%s\", \"backends\": [",
 388                         time_str, interval_str);
 389
 390         for (i = 0; i < obj->backends_num; ++i) {
 391                 sdb_strbuf_append(buf, "\"%s\"", obj->backends[i]);
 392                 if (i < obj->backends_num - 1)
 393                         sdb_strbuf_append(buf, ",");
 394         }
 395         sdb_strbuf_append(buf, "]");
 396 } /* store_common_tojson */
 397
 398 /*
 399  * store_obj_tojson serializes attribute / service objects to JSON.
 400  *
 401  * The function never returns an error. Rather, an error message will be part
 402  * of the serialized data.
 403  */
 404 static void
 405 store_obj_tojson(sdb_llist_t *list, int type, sdb_strbuf_t *buf)
 406 {
 407         sdb_llist_iter_t *iter;
 408
 409         assert((type == SDB_ATTRIBUTE) || (type == SDB_SERVICE));
 410
 411         sdb_strbuf_append(buf, "[");
 412         iter = sdb_llist_get_iter(list);
 413         if (! iter) {
 414                 char errbuf[1024];
 415                 sdb_log(SDB_LOG_ERR, "store: Failed to retrieve %ss: %s\n",
 416                                 SDB_STORE_TYPE_TO_NAME(type),
 417                                 sdb_strerror(errno, errbuf, sizeof(errbuf)));
 418                 sdb_strbuf_append(buf, "{\"error\": \"failed to retrieve %ss: %s\"}",
 419                                 SDB_STORE_TYPE_TO_NAME(type), errbuf);
 420         }
 421
 422         /* has_next returns false if the iterator is NULL */
 423         while (sdb_llist_iter_has_next(iter)) {
 424                 sdb_store_obj_t *sobj = STORE_OBJ(sdb_llist_iter_get_next(iter));
 425                 assert(sobj);
 426                 assert(sobj->type == type);
 427
 428                 sdb_strbuf_append(buf, "{\"name\": \"%s\", ", SDB_OBJ(sobj)->name);
 429                 if (sobj->type == SDB_ATTRIBUTE) {
 430                         char tmp[sdb_data_strlen(&ATTR(sobj)->value) + 1];
 431                         sdb_data_format(&ATTR(sobj)->value, tmp, sizeof(tmp),
 432                                         SDB_DOUBLE_QUOTED);
 433                         sdb_strbuf_append(buf, "\"value\": %s, ", tmp);
 434                 }
 435
 436                 store_common_tojson(sobj, buf);
 437                 sdb_strbuf_append(buf, "}");
 438
 439                 if (sdb_llist_iter_has_next(iter))
 440                         sdb_strbuf_append(buf, ",");
 441         }
 442
 443         sdb_llist_iter_destroy(iter);
 444         sdb_strbuf_append(buf, "]");
 445 } /* store_obj_tojson */
 446
 447 /*
 448  * public API
 449  */
 450
 451 void
 452 sdb_store_clear(void)
 453 {
 454         sdb_llist_destroy(host_list);
 455         host_list = NULL;
 456 } /* sdb_store_clear */
 457
 458 int
 459 sdb_store_host(const char *name, sdb_time_t last_update)
 460 {
 461         char *cname = NULL;
 462         int status = 0;
 463
 464         if (! name)
 465                 return -1;
 466
 467         if (last_update <= 0)
 468                 last_update = sdb_gettime();
 469
 470         cname = sdb_plugin_cname(strdup(name));
 471         if (! cname) {
 472                 sdb_log(SDB_LOG_ERR, "store: strdup failed");
 473                 return -1;
 474         }
 475
 476         pthread_rwlock_wrlock(&host_lock);
 477         if (! host_list)
 478                 if (! (host_list = sdb_llist_create()))
 479                         status = -1;
 480
 481         if (! status)
 482                 status = store_obj(host_list, SDB_HOST, cname, last_update, NULL);
 483         pthread_rwlock_unlock(&host_lock);
 484
 485         free(cname);
 486         return status;
 487 } /* sdb_store_host */
 488
 489 _Bool
 490 sdb_store_has_host(const char *name)
 491 {
 492         sdb_host_t *host;
 493
 494         if (! name)
 495                 return NULL;
 496
 497         host = lookup_host(name);
 498         return host != NULL;
 499 } /* sdb_store_has_host */
 500
 501 sdb_store_obj_t *
 502 sdb_store_get_host(const char *name)
 503 {
 504         sdb_host_t *host;
 505
 506         if (! name)
 507                 return NULL;
 508
 509         host = lookup_host(name);
 510         if (! host)
 511                 return NULL;
 512
 513         sdb_object_ref(SDB_OBJ(host));
 514         return STORE_OBJ(host);
 515 } /* sdb_store_get_host */
 516
 517 int
 518 sdb_store_attribute(const char *hostname,
 519                 const char *key, const sdb_data_t *value,
 520                 sdb_time_t last_update)
 521 {
 522         int status;
 523
 524         sdb_store_obj_t *updated_attr = NULL;
 525
 526         if ((! hostname) || (! key))
 527                 return -1;
 528
 529         pthread_rwlock_wrlock(&host_lock);
 530         status = store_host_obj(hostname, SDB_ATTRIBUTE, key, last_update,
 531                         &updated_attr);
 532
 533         if (status >= 0) {
 534                 assert(updated_attr);
 535                 sdb_data_free_datum(&ATTR(updated_attr)->value);
 536                 if (sdb_data_copy(&ATTR(updated_attr)->value, value)) {
 537                         status = -1;
 538                 }
 539         }
 540
 541         pthread_rwlock_unlock(&host_lock);
 542         return status;
 543 } /* sdb_store_attribute */
 544
 545 int
 546 sdb_store_service(const char *hostname, const char *name,
 547                 sdb_time_t last_update)
 548 {
 549         int status;
 550
 551         if ((! hostname) || (! name))
 552                 return -1;
 553
 554         pthread_rwlock_wrlock(&host_lock);
 555         status = store_host_obj(hostname, SDB_SERVICE, name, last_update, NULL);
 556         pthread_rwlock_unlock(&host_lock);
 557         return status;
 558 } /* sdb_store_service */
 559
 560 int
 561 sdb_store_host_tojson(sdb_store_obj_t *h, sdb_strbuf_t *buf, int flags)
 562 {
 563         sdb_host_t *host;
 564
 565         if ((! h) || (h->type != SDB_HOST) || (! buf))
 566                 return -1;
 567
 568         host = HOST(h);
 569
 570         sdb_strbuf_append(buf, "{\"name\": \"%s\", ", SDB_OBJ(host)->name);
 571         store_common_tojson(h, buf);
 572
 573         if (! (flags & SDB_SKIP_ATTRIBUTES)) {
 574                 sdb_strbuf_append(buf, ", \"attributes\": ");
 575                 store_obj_tojson(host->attributes, SDB_ATTRIBUTE, buf);
 576         }
 577
 578         if (! (flags & SDB_SKIP_SERVICES)) {
 579                 sdb_strbuf_append(buf, ", \"services\": ");
 580                 store_obj_tojson(host->services, SDB_SERVICE, buf);
 581         }
 582
 583         sdb_strbuf_append(buf, "}");
 584         return 0;
 585 } /* sdb_store_host_tojson */
 586
 587 int
 588 sdb_store_tojson(sdb_strbuf_t *buf, int flags)
 589 {
 590         sdb_llist_iter_t *host_iter;
 591
 592         if (! buf)
 593                 return -1;
 594
 595         pthread_rwlock_rdlock(&host_lock);
 596
 597         host_iter = sdb_llist_get_iter(host_list);
 598         if (! host_iter) {
 599                 pthread_rwlock_unlock(&host_lock);
 600                 return -1;
 601         }
 602
 603         sdb_strbuf_append(buf, "{\"hosts\":[");
 604
 605         while (sdb_llist_iter_has_next(host_iter)) {
 606                 sdb_store_obj_t *host = STORE_OBJ(sdb_llist_iter_get_next(host_iter));
 607                 assert(host);
 608
 609                 if (sdb_store_host_tojson(host, buf, flags))
 610                         return -1;
 611
 612                 if (sdb_llist_iter_has_next(host_iter))
 613                         sdb_strbuf_append(buf, ",");
 614         }
 615
 616         sdb_strbuf_append(buf, "]}");
 617
 618         sdb_llist_iter_destroy(host_iter);
 619         pthread_rwlock_unlock(&host_lock);
 620         return 0;
 621 } /* sdb_store_tojson */
 622
 623 /* TODO: actually support hierarchical data */
 624 int
 625 sdb_store_iterate(sdb_store_iter_cb cb, void *user_data)
 626 {
 627         sdb_llist_iter_t *host_iter;
 628         int status = 0;
 629
 630         pthread_rwlock_rdlock(&host_lock);
 631
 632         host_iter = sdb_llist_get_iter(host_list);
 633         if (! host_iter)
 634                 status = -1;
 635
 636         /* has_next returns false if the iterator is NULL */
 637         while (sdb_llist_iter_has_next(host_iter)) {
 638                 sdb_store_obj_t *host = STORE_OBJ(sdb_llist_iter_get_next(host_iter));
 639                 assert(host);
 640
 641                 if (cb(host, user_data)) {
 642                         status = -1;
 643                         break;
 644                 }
 645         }
 646
 647         sdb_llist_iter_destroy(host_iter);
 648         pthread_rwlock_unlock(&host_lock);
 649         return status;
 650 } /* sdb_store_iterate */
 651
 652 /* vim: set tw=78 sw=4 ts=4 noexpandtab : */
 653