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 /* The host_lock has to be acquired before calling this function. */
 214 static int
 215 store_obj(const char *hostname, int type, const char *name,
 216                 sdb_time_t last_update, sdb_store_obj_t **updated_obj)
 217 {
 218         char *host_cname = NULL, *cname = NULL;
 219         char **tmp;
 220
 221         sdb_llist_t *parent_list;
 222         sdb_store_obj_t *old, *new;
 223         const sdb_plugin_info_t *info;
 224
 225         int status = 0;
 226         size_t i;
 227
 228         if (last_update <= 0)
 229                 last_update = sdb_gettime();
 230
 231         assert((type == 0)
 232                         || (type == SDB_HOST)
 233                         || (type == SDB_SERVICE)
 234                         || (type == SDB_ATTRIBUTE));
 235
 236         assert(hostname || (type == SDB_HOST));
 237         assert((! hostname)
 238                         || (type == SDB_SERVICE)
 239                         || (type == SDB_ATTRIBUTE));
 240
 241         if (! host_list)
 242                 if (! (host_list = sdb_llist_create()))
 243                         return -1;
 244         parent_list = host_list;
 245
 246         if (type == SDB_HOST) {
 247                 cname = sdb_plugin_cname(strdup(name));
 248                 if (! cname) {
 249                         sdb_log(SDB_LOG_ERR, "store: strdup failed");
 250                         return -1;
 251                 }
 252                 name = cname;
 253         }
 254
 255         if (hostname) {
 256                 sdb_host_t *host;
 257
 258                 host_cname = sdb_plugin_cname(strdup(hostname));
 259                 if (! host_cname) {
 260                         sdb_log(SDB_LOG_ERR, "store: strdup failed");
 261                         free(cname);
 262                         return -1;
 263                 }
 264                 hostname = host_cname;
 265
 266                 host = lookup_host(hostname);
 267                 if (! host) {
 268                         sdb_log(SDB_LOG_ERR, "store: Failed to store %s '%s' - "
 269                                         "host '%s' not found", SDB_STORE_TYPE_TO_NAME(type),
 270                                         name, hostname);
 271                         free(host_cname);
 272                         free(cname);
 273                         return -1;
 274                 }
 275
 276                 if (type == SDB_ATTRIBUTE)
 277                         parent_list = host->attributes;
 278                 else
 279                         parent_list = host->services;
 280         }
 281
 282         if (type == SDB_HOST)
 283                 old = STORE_OBJ(sdb_llist_search_by_name(host_list, name));
 284         else
 285                 old = STORE_OBJ(sdb_llist_search_by_name(parent_list, name));
 286
 287         if (old) {
 288                 if (old->last_update > last_update) {
 289                         sdb_log(SDB_LOG_DEBUG, "store: Cannot update %s '%s' - "
 290                                         "value too old (%"PRIscTIME" < %"PRIscTIME")",
 291                                         SDB_STORE_TYPE_TO_NAME(type), name,
 292                                         last_update, old->last_update);
 293                         /* don't report an error; the object may be updated by multiple
 294                          * backends */
 295                         status = 1;
 296                 }
 297                 else {
 298                         sdb_time_t interval = last_update - old->last_update;
 299                         old->last_update = last_update;
 300                         if (interval) {
 301                                 if (old->interval)
 302                                         old->interval = (sdb_time_t)((0.9 * (double)old->interval)
 303                                                         + (0.1 * (double)interval));
 304                                 else
 305                                         old->interval = interval;
 306                         }
 307                 }
 308
 309                 new = old;
 310         }
 311         else {
 312                 if (type == SDB_ATTRIBUTE) {
 313                         /* the value will be updated by the caller */
 314                         new = STORE_OBJ(sdb_object_create(name, sdb_attribute_type,
 315                                                 type, last_update, NULL));
 316                 }
 317                 else {
 318                         sdb_type_t t;
 319                         t = type == SDB_HOST ? sdb_host_type : sdb_service_type;
 320                         new = STORE_OBJ(sdb_object_create(name, t, type, last_update));
 321                 }
 322
 323                 if (new) {
 324                         status = sdb_llist_insert_sorted(parent_list, SDB_OBJ(new),
 325                                         sdb_object_cmp_by_name);
 326
 327                         /* pass control to the list or destroy in case of an error */
 328                         sdb_object_deref(SDB_OBJ(new));
 329                 }
 330                 else {
 331                         char errbuf[1024];
 332                         sdb_log(SDB_LOG_ERR, "store: Failed to create %s '%s': %s",
 333                                         SDB_STORE_TYPE_TO_NAME(type), name,
 334                                         sdb_strerror(errno, errbuf, sizeof(errbuf)));
 335                         status = -1;
 336                 }
 337         }
 338
 339         free(host_cname);
 340         free(cname);
 341
 342         if (status < 0)
 343                 return status;
 344         assert(new);
 345
 346         if (updated_obj)
 347                 *updated_obj = new;
 348
 349         info = sdb_plugin_current();
 350         if (! info)
 351                 return status;
 352
 353         for (i = 0; i < new->backends_num; ++i)
 354                 if (!strcasecmp(new->backends[i], info->plugin_name))
 355                         return status;
 356
 357         tmp = realloc(new->backends,
 358                         (new->backends_num + 1) * sizeof(*new->backends));
 359         if (! tmp)
 360                 return -1;
 361
 362         new->backends = tmp;
 363         new->backends[new->backends_num] = strdup(info->plugin_name);
 364         if (! new->backends[new->backends_num])
 365                 return -1;
 366
 367         ++new->backends_num;
 368         return status;
 369 } /* store_obj */
 370
 371 /*
 372  * store_common_tojson serializes common object attributes to JSON.
 373  *
 374  * The function never returns an error. Rather, an error message will be part
 375  * of the serialized data.
 376  */
 377 static void
 378 store_common_tojson(sdb_store_obj_t *obj, sdb_strbuf_t *buf)
 379 {
 380         char time_str[64];
 381         char interval_str[64];
 382
 383         if (! sdb_strftime(time_str, sizeof(time_str),
 384                                 "%F %T %z", obj->last_update))
 385                 snprintf(time_str, sizeof(time_str), "<error>");
 386         time_str[sizeof(time_str) - 1] = '\0';
 387
 388         if (! sdb_strfinterval(interval_str, sizeof(interval_str),
 389                                 obj->interval))
 390                 snprintf(interval_str, sizeof(interval_str), "<error>");
 391         interval_str[sizeof(interval_str) - 1] = '\0';
 392
 393         sdb_strbuf_append(buf, "\"last_update\": \"%s\", "
 394                         "\"update_interval\": \"%s\"", time_str, interval_str);
 395 } /* store_common_tojson */
 396
 397 /*
 398  * store_obj_tojson serializes attribute / service objects to JSON.
 399  *
 400  * The function never returns an error. Rather, an error message will be part
 401  * of the serialized data.
 402  */
 403 static void
 404 store_obj_tojson(sdb_llist_t *list, int type, sdb_strbuf_t *buf)
 405 {
 406         sdb_llist_iter_t *iter;
 407
 408         assert((type == SDB_ATTRIBUTE) || (type == SDB_SERVICE));
 409
 410         sdb_strbuf_append(buf, "[");
 411         iter = sdb_llist_get_iter(list);
 412         if (! iter) {
 413                 char errbuf[1024];
 414                 sdb_log(SDB_LOG_ERR, "store: Failed to retrieve %ss: %s\n",
 415                                 SDB_STORE_TYPE_TO_NAME(type),
 416                                 sdb_strerror(errno, errbuf, sizeof(errbuf)));
 417                 sdb_strbuf_append(buf, "{\"error\": \"failed to retrieve %ss: %s\"}",
 418                                 SDB_STORE_TYPE_TO_NAME(type), errbuf);
 419         }
 420
 421         /* has_next returns false if the iterator is NULL */
 422         while (sdb_llist_iter_has_next(iter)) {
 423                 sdb_store_obj_t *sobj = STORE_OBJ(sdb_llist_iter_get_next(iter));
 424                 assert(sobj);
 425                 assert(sobj->type == type);
 426
 427                 sdb_strbuf_append(buf, "{\"name\": \"%s\", ", SDB_OBJ(sobj)->name);
 428                 if (sobj->type == SDB_ATTRIBUTE) {
 429                         char tmp[sdb_data_strlen(&ATTR(sobj)->value) + 1];
 430                         sdb_data_format(&ATTR(sobj)->value, tmp, sizeof(tmp),
 431                                         SDB_DOUBLE_QUOTED);
 432                         sdb_strbuf_append(buf, "\"value\": %s, ", tmp);
 433                 }
 434
 435                 store_common_tojson(sobj, buf);
 436                 sdb_strbuf_append(buf, "}");
 437
 438                 if (sdb_llist_iter_has_next(iter))
 439                         sdb_strbuf_append(buf, ",");
 440         }
 441
 442         sdb_llist_iter_destroy(iter);
 443         sdb_strbuf_append(buf, "]");
 444 } /* store_obj_tojson */
 445
 446 /*
 447  * public API
 448  */
 449
 450 void
 451 sdb_store_clear(void)
 452 {
 453         sdb_llist_destroy(host_list);
 454         host_list = NULL;
 455 } /* sdb_store_clear */
 456
 457 int
 458 sdb_store_host(const char *name, sdb_time_t last_update)
 459 {
 460         int status;
 461
 462         if (! name)
 463                 return -1;
 464
 465         pthread_rwlock_wrlock(&host_lock);
 466         status = store_obj(/* hostname = */ NULL,
 467                         /* stored object = */ SDB_HOST, name, last_update,
 468                         /* updated_obj = */ NULL);
 469         pthread_rwlock_unlock(&host_lock);
 470         return status;
 471 } /* sdb_store_host */
 472
 473 _Bool
 474 sdb_store_has_host(const char *name)
 475 {
 476         sdb_host_t *host;
 477
 478         if (! name)
 479                 return NULL;
 480
 481         host = lookup_host(name);
 482         return host != NULL;
 483 } /* sdb_store_has_host */
 484
 485 sdb_store_obj_t *
 486 sdb_store_get_host(const char *name)
 487 {
 488         sdb_host_t *host;
 489
 490         if (! name)
 491                 return NULL;
 492
 493         host = lookup_host(name);
 494         if (! host)
 495                 return NULL;
 496
 497         sdb_object_ref(SDB_OBJ(host));
 498         return STORE_OBJ(host);
 499 } /* sdb_store_get_host */
 500
 501 int
 502 sdb_store_attribute(const char *hostname,
 503                 const char *key, const sdb_data_t *value,
 504                 sdb_time_t last_update)
 505 {
 506         int status;
 507
 508         sdb_store_obj_t *updated_attr = NULL;
 509
 510         if ((! hostname) || (! key))
 511                 return -1;
 512
 513         pthread_rwlock_wrlock(&host_lock);
 514         status = store_obj(hostname,
 515                         /* stored object = */ SDB_ATTRIBUTE, key, last_update,
 516                         &updated_attr);
 517
 518         if (status >= 0) {
 519                 assert(updated_attr);
 520                 sdb_data_free_datum(&ATTR(updated_attr)->value);
 521                 if (sdb_data_copy(&ATTR(updated_attr)->value, value)) {
 522                         sdb_object_deref(SDB_OBJ(updated_attr));
 523                         status = -1;
 524                 }
 525         }
 526
 527         pthread_rwlock_unlock(&host_lock);
 528         return status;
 529 } /* sdb_store_attribute */
 530
 531 int
 532 sdb_store_service(const char *hostname, const char *name,
 533                 sdb_time_t last_update)
 534 {
 535         int status;
 536
 537         if ((! hostname) || (! name))
 538                 return -1;
 539
 540         pthread_rwlock_wrlock(&host_lock);
 541         status = store_obj(hostname,
 542                         /* stored object = */ SDB_SERVICE, name, last_update,
 543                         /* updated obj = */ NULL);
 544         pthread_rwlock_unlock(&host_lock);
 545         return status;
 546 } /* sdb_store_service */
 547
 548 int
 549 sdb_store_host_tojson(sdb_store_obj_t *h, sdb_strbuf_t *buf, int flags)
 550 {
 551         sdb_host_t *host;
 552
 553         if ((! h) || (h->type != SDB_HOST) || (! buf))
 554                 return -1;
 555
 556         host = HOST(h);
 557
 558         sdb_strbuf_append(buf, "{\"name\": \"%s\", ", SDB_OBJ(host)->name);
 559         store_common_tojson(h, buf);
 560
 561         if (! (flags & SDB_SKIP_ATTRIBUTES)) {
 562                 sdb_strbuf_append(buf, ", \"attributes\": ");
 563                 store_obj_tojson(host->attributes, SDB_ATTRIBUTE, buf);
 564         }
 565
 566         if (! (flags & SDB_SKIP_SERVICES)) {
 567                 sdb_strbuf_append(buf, ", \"services\": ");
 568                 store_obj_tojson(host->services, SDB_SERVICE, buf);
 569         }
 570
 571         sdb_strbuf_append(buf, "}");
 572         return 0;
 573 } /* sdb_store_host_tojson */
 574
 575 int
 576 sdb_store_tojson(sdb_strbuf_t *buf, int flags)
 577 {
 578         sdb_llist_iter_t *host_iter;
 579
 580         if (! buf)
 581                 return -1;
 582
 583         pthread_rwlock_rdlock(&host_lock);
 584
 585         host_iter = sdb_llist_get_iter(host_list);
 586         if (! host_iter) {
 587                 pthread_rwlock_unlock(&host_lock);
 588                 return -1;
 589         }
 590
 591         sdb_strbuf_append(buf, "{\"hosts\":[");
 592
 593         while (sdb_llist_iter_has_next(host_iter)) {
 594                 sdb_store_obj_t *host = STORE_OBJ(sdb_llist_iter_get_next(host_iter));
 595                 assert(host);
 596
 597                 if (sdb_store_host_tojson(host, buf, flags))
 598                         return -1;
 599
 600                 if (sdb_llist_iter_has_next(host_iter))
 601                         sdb_strbuf_append(buf, ",");
 602         }
 603
 604         sdb_strbuf_append(buf, "]}");
 605
 606         sdb_llist_iter_destroy(host_iter);
 607         pthread_rwlock_unlock(&host_lock);
 608         return 0;
 609 } /* sdb_store_tojson */
 610
 611 /* TODO: actually support hierarchical data */
 612 int
 613 sdb_store_iterate(sdb_store_iter_cb cb, void *user_data)
 614 {
 615         sdb_llist_iter_t *host_iter;
 616         int status = 0;
 617
 618         pthread_rwlock_rdlock(&host_lock);
 619
 620         host_iter = sdb_llist_get_iter(host_list);
 621         if (! host_iter)
 622                 status = -1;
 623
 624         /* has_next returns false if the iterator is NULL */
 625         while (sdb_llist_iter_has_next(host_iter)) {
 626                 sdb_store_obj_t *host = STORE_OBJ(sdb_llist_iter_get_next(host_iter));
 627                 assert(host);
 628
 629                 if (cb(host, user_data)) {
 630                         status = -1;
 631                         break;
 632                 }
 633         }
 634
 635         sdb_llist_iter_destroy(host_iter);
 636         pthread_rwlock_unlock(&host_lock);
 637         return status;
 638 } /* sdb_store_iterate */
 639
 640 /* vim: set tw=78 sw=4 ts=4 noexpandtab : */
 641