src/core/plugin.c

   1 /*
   2  * SysDB - src/core/plugin.c
   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  */
  27
  28 #if HAVE_CONFIG_H
  29 #       include "config.h"
  30 #endif /* HAVE_CONFIG_H */
  31
  32 #include "sysdb.h"
  33 #include "core/plugin.h"
  34 #include "core/time.h"
  35 #include "utils/error.h"
  36 #include "utils/llist.h"
  37 #include "utils/strbuf.h"
  38
  39 #include <assert.h>
  40
  41 #include <errno.h>
  42
  43 #include <stdarg.h>
  44 #include <stdio.h>
  45 #include <string.h>
  46 #include <strings.h>
  47 #include <unistd.h>
  48
  49 #include <ltdl.h>
  50
  51 #include <pthread.h>
  52
  53 /* helper to access info attributes */
  54 #define INFO_GET(i, attr) \
  55         ((i)->attr ? (i)->attr : #attr" not set")
  56
  57 /*
  58  * private data types
  59  */
  60
  61 typedef struct {
  62         sdb_object_t super;
  63         sdb_plugin_ctx_t public;
  64
  65         sdb_plugin_info_t info;
  66         lt_dlhandle handle;
  67
  68         /* The usage count differs from the object's ref count
  69          * in that it provides higher level information about how
  70          * the plugin is in use. */
  71         size_t use_cnt;
  72 } ctx_t;
  73 #define CTX_INIT { SDB_OBJECT_INIT, \
  74         SDB_PLUGIN_CTX_INIT, SDB_PLUGIN_INFO_INIT, NULL, 0 }
  75
  76 #define CTX(obj) ((ctx_t *)(obj))
  77
  78 typedef struct {
  79         sdb_object_t super;
  80         void *cb_callback;
  81         sdb_object_t *cb_user_data;
  82         ctx_t *cb_ctx;
  83 } callback_t;
  84 #define CB_INIT { SDB_OBJECT_INIT, \
  85         /* callback = */ NULL, /* user_data = */ NULL, \
  86         SDB_PLUGIN_CTX_INIT }
  87 #define CB(obj) ((callback_t *)(obj))
  88 #define CONST_CB(obj) ((const callback_t *)(obj))
  89
  90 typedef struct {
  91         callback_t super;
  92 #define ccb_callback super.cb_callback
  93 #define ccb_user_data super.cb_user_data
  94 #define ccb_ctx super.cb_ctx
  95         sdb_time_t ccb_interval;
  96         sdb_time_t ccb_next_update;
  97 } collector_t;
  98 #define CCB(obj) ((collector_t *)(obj))
  99 #define CONST_CCB(obj) ((const collector_t *)(obj))
 100
 101 typedef struct {
 102         callback_t super; /* cb_callback will always be NULL */
 103 #define w_user_data super.cb_user_data
 104 #define w_ctx super.cb_ctx
 105         sdb_store_writer_t impl;
 106 } writer_t;
 107 #define WRITER(obj) ((writer_t *)(obj))
 108
 109 typedef struct {
 110         callback_t super; /* cb_callback will always be NULL */
 111 #define r_user_data super.cb_user_data
 112 #define r_ctx super.cb_ctx
 113         sdb_store_reader_t impl;
 114 } reader_t;
 115 #define READER(obj) ((reader_t *)(obj))
 116
 117 /*
 118  * private variables
 119  */
 120
 121 static sdb_plugin_ctx_t  plugin_default_ctx  = SDB_PLUGIN_CTX_INIT;
 122 static sdb_plugin_info_t plugin_default_info = SDB_PLUGIN_INFO_INIT;
 123
 124 static pthread_key_t     plugin_ctx_key;
 125 static bool              plugin_ctx_key_initialized = 0;
 126
 127 /* a list of the plugin contexts of all registered plugins */
 128 static sdb_llist_t      *all_plugins = NULL;
 129
 130 static sdb_llist_t      *config_list = NULL;
 131 static sdb_llist_t      *init_list = NULL;
 132 static sdb_llist_t      *collector_list = NULL;
 133 static sdb_llist_t      *cname_list = NULL;
 134 static sdb_llist_t      *shutdown_list = NULL;
 135 static sdb_llist_t      *log_list = NULL;
 136 static sdb_llist_t      *ts_fetcher_list = NULL;
 137 static sdb_llist_t      *writer_list = NULL;
 138 static sdb_llist_t      *reader_list = NULL;
 139
 140 static struct {
 141         const char   *type;
 142         sdb_llist_t **list;
 143 } all_lists[] = {
 144         { "config",             &config_list },
 145         { "init",               &init_list },
 146         { "collector",          &collector_list },
 147         { "cname",              &cname_list },
 148         { "shutdown",           &shutdown_list },
 149         { "log",                &log_list },
 150         { "timeseries fetcher", &ts_fetcher_list },
 151         { "store writer",       &writer_list },
 152         { "store reader",       &reader_list },
 153 };
 154
 155 /*
 156  * private helper functions
 157  */
 158
 159 static void
 160 plugin_info_clear(sdb_plugin_info_t *info)
 161 {
 162         sdb_plugin_info_t empty_info = SDB_PLUGIN_INFO_INIT;
 163         if (! info)
 164                 return;
 165
 166         if (info->plugin_name)
 167                 free(info->plugin_name);
 168         if (info->filename)
 169                 free(info->filename);
 170
 171         if (info->description)
 172                 free(info->description);
 173         if (info->copyright)
 174                 free(info->copyright);
 175         if (info->license)
 176                 free(info->license);
 177
 178         *info = empty_info;
 179 } /* plugin_info_clear */
 180
 181 static void
 182 ctx_key_init(void)
 183 {
 184         if (plugin_ctx_key_initialized)
 185                 return;
 186
 187         pthread_key_create(&plugin_ctx_key, /* destructor */ NULL);
 188         plugin_ctx_key_initialized = 1;
 189 } /* ctx_key_init */
 190
 191 static int
 192 plugin_cmp_next_update(const sdb_object_t *a, const sdb_object_t *b)
 193 {
 194         const collector_t *ccb1 = (const collector_t *)a;
 195         const collector_t *ccb2 = (const collector_t *)b;
 196
 197         assert(ccb1 && ccb2);
 198
 199         return (ccb1->ccb_next_update > ccb2->ccb_next_update)
 200                 ? 1 : (ccb1->ccb_next_update < ccb2->ccb_next_update)
 201                 ? -1 : 0;
 202 } /* plugin_cmp_next_update */
 203
 204 static int
 205 plugin_lookup_by_name(const sdb_object_t *obj, const void *id)
 206 {
 207         const callback_t *cb = CONST_CB(obj);
 208         const char *name = id;
 209
 210         assert(cb && id);
 211
 212         /* when a plugin was registered from outside a plugin (e.g. the core),
 213          * we don't have a plugin context */
 214         if (! cb->cb_ctx)
 215                 return 1;
 216
 217         if (!strcasecmp(cb->cb_ctx->info.plugin_name, name))
 218                 return 0;
 219         return 1;
 220 } /* plugin_lookup_by_name */
 221
 222 /* since this function is called from sdb_plugin_reconfigure_finish()
 223  * when iterating through all_plugins, we may not do any additional
 224  * modifications to all_plugins except for the optional removal */
 225 static void
 226 plugin_unregister_by_name(const char *plugin_name)
 227 {
 228         sdb_object_t *obj;
 229         size_t i;
 230
 231         for (i = 0; i < SDB_STATIC_ARRAY_LEN(all_lists); ++i) {
 232                 const char  *type =  all_lists[i].type;
 233                 sdb_llist_t *list = *all_lists[i].list;
 234
 235                 while (1) {
 236                         callback_t *cb;
 237
 238                         cb = CB(sdb_llist_remove(list,
 239                                                 plugin_lookup_by_name, plugin_name));
 240                         if (! cb)
 241                                 break;
 242
 243                         assert(cb->cb_ctx);
 244
 245                         sdb_log(SDB_LOG_INFO, "core: Unregistering "
 246                                         "%s callback '%s' (module %s)", type, cb->super.name,
 247                                         cb->cb_ctx->info.plugin_name);
 248                         sdb_object_deref(SDB_OBJ(cb));
 249                 }
 250         }
 251
 252         obj = sdb_llist_search_by_name(all_plugins, plugin_name);
 253         /* when called from sdb_plugin_reconfigure_finish, the object has already
 254          * been removed from the list */
 255         if (obj && (obj->ref_cnt <= 1)) {
 256                 sdb_llist_remove_by_name(all_plugins, plugin_name);
 257                 sdb_object_deref(obj);
 258         }
 259         /* else: other callbacks still reference it */
 260 } /* plugin_unregister_by_name */
 261
 262 /*
 263  * private types
 264  */
 265
 266 static int
 267 ctx_init(sdb_object_t *obj, va_list __attribute__((unused)) ap)
 268 {
 269         ctx_t *ctx = CTX(obj);
 270
 271         assert(ctx);
 272
 273         ctx->public = plugin_default_ctx;
 274         ctx->info = plugin_default_info;
 275         ctx->handle = NULL;
 276         ctx->use_cnt = 1;
 277         return 0;
 278 } /* ctx_init */
 279
 280 static void
 281 ctx_destroy(sdb_object_t *obj)
 282 {
 283         ctx_t *ctx = CTX(obj);
 284
 285         if (ctx->handle) {
 286                 const char *err;
 287
 288                 sdb_log(SDB_LOG_INFO, "core: Unloading module %s",
 289                                 ctx->info.plugin_name);
 290
 291                 lt_dlerror();
 292                 lt_dlclose(ctx->handle);
 293                 if ((err = lt_dlerror()))
 294                         sdb_log(SDB_LOG_WARNING, "core: Failed to unload module %s: %s",
 295                                         ctx->info.plugin_name, err);
 296         }
 297
 298         plugin_info_clear(&ctx->info);
 299 } /* ctx_destroy */
 300
 301 static sdb_type_t ctx_type = {
 302         sizeof(ctx_t),
 303
 304         ctx_init,
 305         ctx_destroy
 306 };
 307
 308 static ctx_t *
 309 ctx_get(void)
 310 {
 311         if (! plugin_ctx_key_initialized)
 312                 ctx_key_init();
 313         return pthread_getspecific(plugin_ctx_key);
 314 } /* ctx_get */
 315
 316 static ctx_t *
 317 ctx_set(ctx_t *new)
 318 {
 319         ctx_t *old;
 320
 321         if (! plugin_ctx_key_initialized)
 322                 ctx_key_init();
 323
 324         old = pthread_getspecific(plugin_ctx_key);
 325         if (old)
 326                 sdb_object_deref(SDB_OBJ(old));
 327         if (new)
 328                 sdb_object_ref(SDB_OBJ(new));
 329         pthread_setspecific(plugin_ctx_key, new);
 330         return old;
 331 } /* ctx_set */
 332
 333 static ctx_t *
 334 ctx_create(const char *name)
 335 {
 336         ctx_t *ctx;
 337
 338         ctx = CTX(sdb_object_create(name, ctx_type));
 339         if (! ctx)
 340                 return NULL;
 341
 342         if (! plugin_ctx_key_initialized)
 343                 ctx_key_init();
 344         ctx_set(ctx);
 345         return ctx;
 346 } /* ctx_create */
 347
 348 static int
 349 plugin_cb_init(sdb_object_t *obj, va_list ap)
 350 {
 351         sdb_llist_t **list = va_arg(ap, sdb_llist_t **);
 352         const char   *type = va_arg(ap, const char *);
 353         void     *callback = va_arg(ap, void *);
 354         sdb_object_t   *ud = va_arg(ap, sdb_object_t *);
 355
 356         assert(list);
 357         assert(type);
 358         assert(obj);
 359
 360         if (sdb_llist_search_by_name(*list, obj->name)) {
 361                 sdb_log(SDB_LOG_WARNING, "core: %s callback '%s' "
 362                                 "has already been registered. Ignoring newly "
 363                                 "registered version.", type, obj->name);
 364                 return -1;
 365         }
 366
 367         /* cb_ctx may be NULL if the plugin was not registered by a plugin */
 368
 369         CB(obj)->cb_callback = callback;
 370         CB(obj)->cb_ctx      = ctx_get();
 371         sdb_object_ref(SDB_OBJ(CB(obj)->cb_ctx));
 372
 373         sdb_object_ref(ud);
 374         CB(obj)->cb_user_data = ud;
 375         return 0;
 376 } /* plugin_cb_init */
 377
 378 static void
 379 plugin_cb_destroy(sdb_object_t *obj)
 380 {
 381         assert(obj);
 382         sdb_object_deref(CB(obj)->cb_user_data);
 383         sdb_object_deref(SDB_OBJ(CB(obj)->cb_ctx));
 384 } /* plugin_cb_destroy */
 385
 386 static sdb_type_t callback_type = {
 387         sizeof(callback_t),
 388
 389         plugin_cb_init,
 390         plugin_cb_destroy
 391 };
 392
 393 static sdb_type_t collector_type = {
 394         sizeof(collector_t),
 395
 396         plugin_cb_init,
 397         plugin_cb_destroy
 398 };
 399
 400 static int
 401 plugin_writer_init(sdb_object_t *obj, va_list ap)
 402 {
 403         sdb_store_writer_t *impl = va_arg(ap, sdb_store_writer_t *);
 404         sdb_object_t       *ud   = va_arg(ap, sdb_object_t *);
 405
 406         assert(impl);
 407
 408         if ((! impl->store_host) || (! impl->store_service)
 409                         || (! impl->store_metric) || (! impl->store_attribute)) {
 410                 sdb_log(SDB_LOG_ERR, "core: store writer callback '%s' "
 411                                 "does not fully implement the writer interface.",
 412                                 obj->name);
 413                 return -1;
 414         }
 415         if (sdb_llist_search_by_name(writer_list, obj->name)) {
 416                 sdb_log(SDB_LOG_WARNING, "core: store writer callback '%s' "
 417                                 "has already been registered. Ignoring newly "
 418                                 "registered version.", obj->name);
 419                 return -1;
 420         }
 421
 422         /* ctx may be NULL if the callback was not registered by a plugin */
 423
 424         WRITER(obj)->impl = *impl;
 425         WRITER(obj)->w_ctx  = ctx_get();
 426         sdb_object_ref(SDB_OBJ(WRITER(obj)->w_ctx));
 427
 428         sdb_object_ref(ud);
 429         WRITER(obj)->w_user_data = ud;
 430         return 0;
 431 } /* plugin_writer_init */
 432
 433 static void
 434 plugin_writer_destroy(sdb_object_t *obj)
 435 {
 436         assert(obj);
 437         sdb_object_deref(WRITER(obj)->w_user_data);
 438         sdb_object_deref(SDB_OBJ(WRITER(obj)->w_ctx));
 439 } /* plugin_writer_destroy */
 440
 441 static sdb_type_t writer_type = {
 442         sizeof(writer_t),
 443
 444         plugin_writer_init,
 445         plugin_writer_destroy
 446 };
 447
 448 static int
 449 plugin_reader_init(sdb_object_t *obj, va_list ap)
 450 {
 451         sdb_store_reader_t *impl = va_arg(ap, sdb_store_reader_t *);
 452         sdb_object_t       *ud   = va_arg(ap, sdb_object_t *);
 453
 454         assert(impl);
 455
 456         if ((! impl->prepare_query) || (! impl->execute_query)) {
 457                 sdb_log(SDB_LOG_ERR, "core: store reader callback '%s' "
 458                                 "does not fully implement the reader interface.",
 459                                 obj->name);
 460                 return -1;
 461         }
 462         if (sdb_llist_search_by_name(reader_list, obj->name)) {
 463                 sdb_log(SDB_LOG_WARNING, "core: store reader callback '%s' "
 464                                 "has already been registered. Ignoring newly "
 465                                 "registered version.", obj->name);
 466                 return -1;
 467         }
 468
 469         /* ctx may be NULL if the callback was not registered by a plugin */
 470
 471         READER(obj)->impl = *impl;
 472         READER(obj)->r_ctx  = ctx_get();
 473         sdb_object_ref(SDB_OBJ(READER(obj)->r_ctx));
 474
 475         sdb_object_ref(ud);
 476         READER(obj)->r_user_data = ud;
 477         return 0;
 478 } /* plugin_reader_init */
 479
 480 static void
 481 plugin_reader_destroy(sdb_object_t *obj)
 482 {
 483         assert(obj);
 484         sdb_object_deref(READER(obj)->r_user_data);
 485         sdb_object_deref(SDB_OBJ(READER(obj)->r_ctx));
 486 } /* plugin_reader_destroy */
 487
 488 static sdb_type_t reader_type = {
 489         sizeof(reader_t),
 490
 491         plugin_reader_init,
 492         plugin_reader_destroy
 493 };
 494
 495 static int
 496 module_init(const char *name, lt_dlhandle lh, sdb_plugin_info_t *info)
 497 {
 498         int (*mod_init)(sdb_plugin_info_t *);
 499         int status;
 500
 501         mod_init = (int (*)(sdb_plugin_info_t *))lt_dlsym(lh, "sdb_module_init");
 502         if (! mod_init) {
 503                 sdb_log(SDB_LOG_ERR, "core: Failed to load plugin '%s': "
 504                                 "could not find symbol 'sdb_module_init'", name);
 505                 return -1;
 506         }
 507
 508         status = mod_init(info);
 509         if (status) {
 510                 sdb_log(SDB_LOG_ERR, "core: Failed to initialize "
 511                                 "module '%s'", name);
 512                 plugin_unregister_by_name(name);
 513                 return -1;
 514         }
 515         return 0;
 516 } /* module_init */
 517
 518 static int
 519 module_load(const char *basedir, const char *name,
 520                 const sdb_plugin_ctx_t *plugin_ctx)
 521 {
 522         char  base_name[name ? strlen(name) + 1 : 1];
 523         const char *name_ptr;
 524         char *tmp;
 525
 526         char filename[1024];
 527         lt_dlhandle lh;
 528
 529         ctx_t *ctx;
 530
 531         int status;
 532
 533         assert(name);
 534
 535         base_name[0] = '\0';
 536         name_ptr = name;
 537
 538         while ((tmp = strstr(name_ptr, "::"))) {
 539                 strncat(base_name, name_ptr, (size_t)(tmp - name_ptr));
 540                 strcat(base_name, "/");
 541                 name_ptr = tmp + strlen("::");
 542         }
 543         strcat(base_name, name_ptr);
 544
 545         if (! basedir)
 546                 basedir = PKGLIBDIR;
 547
 548         snprintf(filename, sizeof(filename), "%s/%s.so", basedir, base_name);
 549         filename[sizeof(filename) - 1] = '\0';
 550
 551         if (access(filename, R_OK)) {
 552                 char errbuf[1024];
 553                 sdb_log(SDB_LOG_ERR, "core: Failed to load plugin '%s' (%s): %s",
 554                                 name, filename, sdb_strerror(errno, errbuf, sizeof(errbuf)));
 555                 return -1;
 556         }
 557
 558         lt_dlinit();
 559         lt_dlerror();
 560
 561         lh = lt_dlopen(filename);
 562         if (! lh) {
 563                 sdb_log(SDB_LOG_ERR, "core: Failed to load plugin '%s': %s"
 564                                 "The most common cause for this problem are missing "
 565                                 "dependencies.\n", name, lt_dlerror());
 566                 return -1;
 567         }
 568
 569         if (ctx_get())
 570                 sdb_log(SDB_LOG_WARNING, "core: Discarding old plugin context");
 571
 572         ctx = ctx_create(name);
 573         if (! ctx) {
 574                 sdb_log(SDB_LOG_ERR, "core: Failed to initialize plugin context");
 575                 return -1;
 576         }
 577
 578         ctx->info.plugin_name = strdup(name);
 579         ctx->info.filename = strdup(filename);
 580         ctx->handle = lh;
 581
 582         if (plugin_ctx)
 583                 ctx->public = *plugin_ctx;
 584
 585         if ((status = module_init(name, lh, &ctx->info))) {
 586                 sdb_object_deref(SDB_OBJ(ctx));
 587                 return status;
 588         }
 589
 590         /* compare minor version */
 591         if ((ctx->info.version < 0)
 592                         || ((int)(ctx->info.version / 100) != (int)(SDB_VERSION / 100)))
 593                 sdb_log(SDB_LOG_WARNING, "core: WARNING: version of "
 594                                 "plugin '%s' (%i.%i.%i) does not match our version "
 595                                 "(%i.%i.%i); this might cause problems",
 596                                 name, SDB_VERSION_DECODE(ctx->info.version),
 597                                 SDB_VERSION_DECODE(SDB_VERSION));
 598
 599         sdb_llist_append(all_plugins, SDB_OBJ(ctx));
 600
 601         sdb_log(SDB_LOG_INFO, "core: Successfully loaded "
 602                         "plugin %s v%i (%s)", ctx->info.plugin_name,
 603                         ctx->info.plugin_version,
 604                         INFO_GET(&ctx->info, description));
 605         sdb_log(SDB_LOG_INFO, "core: Plugin %s: %s, License: %s",
 606                         ctx->info.plugin_name,
 607                         INFO_GET(&ctx->info, copyright),
 608                         INFO_GET(&ctx->info, license));
 609
 610         /* any registered callbacks took ownership of the context */
 611         sdb_object_deref(SDB_OBJ(ctx));
 612
 613         /* reset */
 614         ctx_set(NULL);
 615         return 0;
 616 } /* module_load */
 617
 618 static char *
 619 plugin_get_name(const char *name, char *buf, size_t bufsize)
 620 {
 621         ctx_t *ctx = ctx_get();
 622
 623         if (ctx)
 624                 snprintf(buf, bufsize, "%s::%s", ctx->info.plugin_name, name);
 625         else
 626                 snprintf(buf, bufsize, "core::%s", name);
 627         return buf;
 628 } /* plugin_get_name */
 629
 630 static int
 631 plugin_add_callback(sdb_llist_t **list, const char *type,
 632                 const char *name, void *callback, sdb_object_t *user_data)
 633 {
 634         sdb_object_t *obj;
 635
 636         if ((! name) || (! callback))
 637                 return -1;
 638
 639         assert(list);
 640
 641         if (! *list)
 642                 *list = sdb_llist_create();
 643         if (! *list)
 644                 return -1;
 645
 646         obj = sdb_object_create(name, callback_type,
 647                         list, type, callback, user_data);
 648         if (! obj)
 649                 return -1;
 650
 651         if (sdb_llist_append(*list, obj)) {
 652                 sdb_object_deref(obj);
 653                 return -1;
 654         }
 655
 656         /* pass control to the list */
 657         sdb_object_deref(obj);
 658
 659         sdb_log(SDB_LOG_INFO, "core: Registered %s callback '%s'.",
 660                         type, name);
 661         return 0;
 662 } /* plugin_add_callback */
 663
 664 /*
 665  * public API
 666  */
 667
 668 int
 669 sdb_plugin_load(const char *basedir, const char *name,
 670                 const sdb_plugin_ctx_t *plugin_ctx)
 671 {
 672         ctx_t *ctx;
 673
 674         int status;
 675
 676         if ((! name) || (! *name))
 677                 return -1;
 678
 679         if (! all_plugins) {
 680                 if (! (all_plugins = sdb_llist_create())) {
 681                         sdb_log(SDB_LOG_ERR, "core: Failed to load plugin '%s': "
 682                                         "internal error while creating linked list", name);
 683                         return -1;
 684                 }
 685         }
 686
 687         ctx = CTX(sdb_llist_search_by_name(all_plugins, name));
 688         if (ctx) {
 689                 /* plugin already loaded */
 690                 if (! ctx->use_cnt) {
 691                         /* reloading plugin */
 692                         ctx_t *old_ctx = ctx_set(ctx);
 693
 694                         status = module_init(ctx->info.plugin_name, ctx->handle, NULL);
 695                         if (status)
 696                                 return status;
 697
 698                         sdb_log(SDB_LOG_INFO, "core: Successfully reloaded plugin "
 699                                         "'%s' (%s)", ctx->info.plugin_name,
 700                                         INFO_GET(&ctx->info, description));
 701                         ctx_set(old_ctx);
 702                 }
 703                 ++ctx->use_cnt;
 704                 return 0;
 705         }
 706
 707         return module_load(basedir, name, plugin_ctx);
 708 } /* sdb_plugin_load */
 709
 710 int
 711 sdb_plugin_set_info(sdb_plugin_info_t *info, int type, ...)
 712 {
 713         va_list ap;
 714
 715         if (! info)
 716                 return -1;
 717
 718         va_start(ap, type);
 719
 720         switch (type) {
 721                 case SDB_PLUGIN_INFO_DESC:
 722                         {
 723                                 char *desc = va_arg(ap, char *);
 724                                 if (desc) {
 725                                         if (info->description)
 726                                                 free(info->description);
 727                                         info->description = strdup(desc);
 728                                 }
 729                         }
 730                         break;
 731                 case SDB_PLUGIN_INFO_COPYRIGHT:
 732                         {
 733                                 char *copyright = va_arg(ap, char *);
 734                                 if (copyright)
 735                                         info->copyright = strdup(copyright);
 736                         }
 737                         break;
 738                 case SDB_PLUGIN_INFO_LICENSE:
 739                         {
 740                                 char *license = va_arg(ap, char *);
 741                                 if (license) {
 742                                         if (info->license)
 743                                                 free(info->license);
 744                                         info->license = strdup(license);
 745                                 }
 746                         }
 747                         break;
 748                 case SDB_PLUGIN_INFO_VERSION:
 749                         {
 750                                 int version = va_arg(ap, int);
 751                                 info->version = version;
 752                         }
 753                         break;
 754                 case SDB_PLUGIN_INFO_PLUGIN_VERSION:
 755                         {
 756                                 int version = va_arg(ap, int);
 757                                 info->plugin_version = version;
 758                         }
 759                         break;
 760                 default:
 761                         va_end(ap);
 762                         return -1;
 763         }
 764
 765         va_end(ap);
 766         return 0;
 767 } /* sdb_plugin_set_info */
 768
 769 int
 770 sdb_plugin_register_config(sdb_plugin_config_cb callback)
 771 {
 772         ctx_t *ctx = ctx_get();
 773
 774         if (! ctx) {
 775                 sdb_log(SDB_LOG_ERR, "core: Invalid attempt to register a "
 776                                 "config callback from outside a plugin");
 777                 return -1;
 778         }
 779         return plugin_add_callback(&config_list, "config", ctx->info.plugin_name,
 780                         (void *)callback, NULL);
 781 } /* sdb_plugin_register_config */
 782
 783 int
 784 sdb_plugin_register_init(const char *name, sdb_plugin_init_cb callback,
 785                 sdb_object_t *user_data)
 786 {
 787         char cb_name[1024];
 788         return plugin_add_callback(&init_list, "init",
 789                         plugin_get_name(name, cb_name, sizeof(cb_name)),
 790                         (void *)callback, user_data);
 791 } /* sdb_plugin_register_init */
 792
 793 int
 794 sdb_plugin_register_shutdown(const char *name, sdb_plugin_shutdown_cb callback,
 795                 sdb_object_t *user_data)
 796 {
 797         char cb_name[1024];
 798         return plugin_add_callback(&shutdown_list, "shutdown",
 799                         plugin_get_name(name, cb_name, sizeof(cb_name)),
 800                         (void *)callback, user_data);
 801 } /* sdb_plugin_register_shutdown */
 802
 803 int
 804 sdb_plugin_register_log(const char *name, sdb_plugin_log_cb callback,
 805                 sdb_object_t *user_data)
 806 {
 807         char cb_name[1024];
 808         return plugin_add_callback(&log_list, "log",
 809                         plugin_get_name(name, cb_name, sizeof(cb_name)),
 810                         callback, user_data);
 811 } /* sdb_plugin_register_log */
 812
 813 int
 814 sdb_plugin_register_cname(const char *name, sdb_plugin_cname_cb callback,
 815                 sdb_object_t *user_data)
 816 {
 817         char cb_name[1024];
 818         return plugin_add_callback(&cname_list, "cname",
 819                         plugin_get_name(name, cb_name, sizeof(cb_name)),
 820                         callback, user_data);
 821 } /* sdb_plugin_register_cname */
 822
 823 int
 824 sdb_plugin_register_collector(const char *name, sdb_plugin_collector_cb callback,
 825                 const sdb_time_t *interval, sdb_object_t *user_data)
 826 {
 827         char cb_name[1024];
 828         sdb_object_t *obj;
 829
 830         if ((! name) || (! callback))
 831                 return -1;
 832
 833         if (! collector_list)
 834                 collector_list = sdb_llist_create();
 835         if (! collector_list)
 836                 return -1;
 837
 838         plugin_get_name(name, cb_name, sizeof(cb_name));
 839
 840         obj = sdb_object_create(cb_name, collector_type,
 841                         &collector_list, "collector", callback, user_data);
 842         if (! obj)
 843                 return -1;
 844
 845         if (interval)
 846                 CCB(obj)->ccb_interval = *interval;
 847         else {
 848                 ctx_t *ctx = ctx_get();
 849
 850                 if (! ctx) {
 851                         sdb_log(SDB_LOG_ERR, "core: Cannot determine interval "
 852                                         "for collector %s; none specified and no plugin "
 853                                         "context found", cb_name);
 854                         return -1;
 855                 }
 856
 857                 CCB(obj)->ccb_interval = ctx->public.interval;
 858         }
 859
 860         if (! (CCB(obj)->ccb_next_update = sdb_gettime())) {
 861                 char errbuf[1024];
 862                 sdb_log(SDB_LOG_ERR, "core: Failed to determine current "
 863                                 "time: %s", sdb_strerror(errno, errbuf, sizeof(errbuf)));
 864                 sdb_object_deref(obj);
 865                 return -1;
 866         }
 867
 868         if (sdb_llist_insert_sorted(collector_list, obj,
 869                                 plugin_cmp_next_update)) {
 870                 sdb_object_deref(obj);
 871                 return -1;
 872         }
 873
 874         /* pass control to the list */
 875         sdb_object_deref(obj);
 876
 877         sdb_log(SDB_LOG_INFO, "core: Registered collector callback '%s' "
 878                         "(interval = %.3fs).", cb_name,
 879                         SDB_TIME_TO_DOUBLE(CCB(obj)->ccb_interval));
 880         return 0;
 881 } /* sdb_plugin_register_collector */
 882
 883 int
 884 sdb_plugin_register_ts_fetcher(const char *name,
 885                 sdb_plugin_fetch_ts_cb callback, sdb_object_t *user_data)
 886 {
 887         return plugin_add_callback(&ts_fetcher_list, "time-series fetcher",
 888                         name, callback, user_data);
 889 } /* sdb_plugin_register_ts_fetcher */
 890
 891 int
 892 sdb_plugin_register_writer(const char *name,
 893                 sdb_store_writer_t *writer, sdb_object_t *user_data)
 894 {
 895         char cb_name[1024];
 896         sdb_object_t *obj;
 897
 898         if ((! name) || (! writer))
 899                 return -1;
 900
 901         if (! writer_list)
 902                 writer_list = sdb_llist_create();
 903         if (! writer_list)
 904                 return -1;
 905
 906         plugin_get_name(name, cb_name, sizeof(cb_name));
 907
 908         obj = sdb_object_create(cb_name, writer_type,
 909                         writer, user_data);
 910         if (! obj)
 911                 return -1;
 912
 913         if (sdb_llist_append(writer_list, obj)) {
 914                 sdb_object_deref(obj);
 915                 return -1;
 916         }
 917
 918         /* pass control to the list */
 919         sdb_object_deref(obj);
 920
 921         sdb_log(SDB_LOG_INFO, "core: Registered store writer callback '%s'.",
 922                         cb_name);
 923         return 0;
 924 } /* sdb_store_register_writer */
 925
 926 int
 927 sdb_plugin_register_reader(const char *name,
 928                 sdb_store_reader_t *reader, sdb_object_t *user_data)
 929 {
 930         char cb_name[1024];
 931         sdb_object_t *obj;
 932
 933         if ((! name) || (! reader))
 934                 return -1;
 935
 936         if (! reader_list)
 937                 reader_list = sdb_llist_create();
 938         if (! reader_list)
 939                 return -1;
 940
 941         plugin_get_name(name, cb_name, sizeof(cb_name));
 942
 943         obj = sdb_object_create(cb_name, reader_type,
 944                         reader, user_data);
 945         if (! obj)
 946                 return -1;
 947
 948         if (sdb_llist_append(reader_list, obj)) {
 949                 sdb_object_deref(obj);
 950                 return -1;
 951         }
 952
 953         /* pass control to the list */
 954         sdb_object_deref(obj);
 955
 956         sdb_log(SDB_LOG_INFO, "core: Registered store reader callback '%s'.",
 957                         cb_name);
 958         return 0;
 959 } /* sdb_plugin_register_reader */
 960
 961 void
 962 sdb_plugin_unregister_all(void)
 963 {
 964         size_t i;
 965
 966         for (i = 0; i < SDB_STATIC_ARRAY_LEN(all_lists); ++i) {
 967                 const char  *type =  all_lists[i].type;
 968                 sdb_llist_t *list = *all_lists[i].list;
 969
 970                 size_t len = sdb_llist_len(list);
 971
 972                 if (! len)
 973                         continue;
 974
 975                 sdb_llist_clear(list);
 976                 sdb_log(SDB_LOG_INFO, "core: Unregistered %zu %s callback%s",
 977                                 len, type, len == 1 ? "" : "s");
 978         }
 979 } /* sdb_plugin_unregister_all */
 980
 981 sdb_plugin_ctx_t
 982 sdb_plugin_get_ctx(void)
 983 {
 984         ctx_t *c;
 985
 986         c = ctx_get();
 987         if (! c) {
 988                 sdb_plugin_log(SDB_LOG_ERR, "core: Invalid read access to plugin "
 989                                 "context outside a plugin");
 990                 return plugin_default_ctx;
 991         }
 992         return c->public;
 993 } /* sdb_plugin_get_ctx */
 994
 995 int
 996 sdb_plugin_set_ctx(sdb_plugin_ctx_t ctx, sdb_plugin_ctx_t *old)
 997 {
 998         ctx_t *c;
 999
1000         c = ctx_get();
1001         if (! c) {
1002                 sdb_plugin_log(SDB_LOG_ERR, "core: Invalid write access to plugin "
1003                                 "context outside a plugin");
1004                 return -1;
1005         }
1006
1007         if (old)
1008                 *old = c->public;
1009         c->public = ctx;
1010         return 0;
1011 } /* sdb_plugin_set_ctx */
1012
1013 const sdb_plugin_info_t *
1014 sdb_plugin_current(void)
1015 {
1016         ctx_t *ctx = ctx_get();
1017
1018         if (! ctx)
1019                 return NULL;
1020         return &ctx->info;
1021 } /* sdb_plugin_current */
1022
1023 int
1024 sdb_plugin_configure(const char *name, oconfig_item_t *ci)
1025 {
1026         callback_t *plugin;
1027         sdb_plugin_config_cb callback;
1028
1029         ctx_t *old_ctx;
1030
1031         int status;
1032
1033         if ((! name) || (! ci))
1034                 return -1;
1035
1036         plugin = CB(sdb_llist_search_by_name(config_list, name));
1037         if (! plugin) {
1038                 ctx_t *ctx = CTX(sdb_llist_search_by_name(all_plugins, name));
1039                 if (! ctx)
1040                         sdb_log(SDB_LOG_ERR, "core: Cannot configure unknown "
1041                                         "plugin '%s'. Missing 'LoadPlugin \"%s\"'?",
1042                                         name, name);
1043                 else
1044                         sdb_log(SDB_LOG_ERR, "core: Plugin '%s' did not register "
1045                                         "a config callback.", name);
1046                 errno = ENOENT;
1047                 return -1;
1048         }
1049
1050         old_ctx = ctx_set(plugin->cb_ctx);
1051         callback = (sdb_plugin_config_cb)plugin->cb_callback;
1052         status = callback(ci);
1053         ctx_set(old_ctx);
1054         return status;
1055 } /* sdb_plugin_configure */
1056
1057 int
1058 sdb_plugin_reconfigure_init(void)
1059 {
1060         sdb_llist_iter_t *iter;
1061
1062         iter = sdb_llist_get_iter(config_list);
1063         if (config_list && (! iter))
1064                 return -1;
1065
1066         /* deconfigure all plugins */
1067         while (sdb_llist_iter_has_next(iter)) {
1068                 callback_t *plugin;
1069                 sdb_plugin_config_cb callback;
1070                 ctx_t *old_ctx;
1071
1072                 plugin = CB(sdb_llist_iter_get_next(iter));
1073                 old_ctx = ctx_set(plugin->cb_ctx);
1074                 callback = (sdb_plugin_config_cb)plugin->cb_callback;
1075                 callback(NULL);
1076                 ctx_set(old_ctx);
1077         }
1078         sdb_llist_iter_destroy(iter);
1079
1080         iter = sdb_llist_get_iter(all_plugins);
1081         if (all_plugins && (! iter))
1082                 return -1;
1083
1084         /* record all plugins as being unused */
1085         while (sdb_llist_iter_has_next(iter))
1086                 CTX(sdb_llist_iter_get_next(iter))->use_cnt = 0;
1087         sdb_llist_iter_destroy(iter);
1088
1089         sdb_plugin_unregister_all();
1090         return 0;
1091 } /* sdb_plugin_reconfigure_init */
1092
1093 int
1094 sdb_plugin_reconfigure_finish(void)
1095 {
1096         sdb_llist_iter_t *iter;
1097
1098         iter = sdb_llist_get_iter(all_plugins);
1099         if (all_plugins && (! iter))
1100                 return -1;
1101
1102         while (sdb_llist_iter_has_next(iter)) {
1103                 ctx_t *ctx = CTX(sdb_llist_iter_get_next(iter));
1104                 if (ctx->use_cnt)
1105                         continue;
1106
1107                 sdb_log(SDB_LOG_INFO, "core: Module %s no longer in use",
1108                                 ctx->info.plugin_name);
1109                 sdb_llist_iter_remove_current(iter);
1110                 plugin_unregister_by_name(ctx->info.plugin_name);
1111                 sdb_object_deref(SDB_OBJ(ctx));
1112         }
1113         sdb_llist_iter_destroy(iter);
1114         return 0;
1115 } /* sdb_plugin_reconfigure_finish */
1116
1117 int
1118 sdb_plugin_init_all(void)
1119 {
1120         sdb_llist_iter_t *iter;
1121         int ret = 0;
1122
1123         iter = sdb_llist_get_iter(init_list);
1124         while (sdb_llist_iter_has_next(iter)) {
1125                 callback_t *cb;
1126                 sdb_plugin_init_cb callback;
1127                 ctx_t *old_ctx;
1128
1129                 sdb_object_t *obj = sdb_llist_iter_get_next(iter);
1130                 assert(obj);
1131                 cb = CB(obj);
1132
1133                 callback = (sdb_plugin_init_cb)cb->cb_callback;
1134
1135                 old_ctx = ctx_set(cb->cb_ctx);
1136                 if (callback(cb->cb_user_data)) {
1137                         sdb_log(SDB_LOG_ERR, "core: Failed to initialize plugin "
1138                                         "'%s'. Unregistering all callbacks.", obj->name);
1139                         ctx_set(old_ctx);
1140                         plugin_unregister_by_name(cb->cb_ctx->info.plugin_name);
1141                         ++ret;
1142                 }
1143                 else
1144                         ctx_set(old_ctx);
1145         }
1146         sdb_llist_iter_destroy(iter);
1147         return ret;
1148 } /* sdb_plugin_init_all */
1149
1150 int
1151 sdb_plugin_shutdown_all(void)
1152 {
1153         sdb_llist_iter_t *iter;
1154         int ret = 0;
1155
1156         iter = sdb_llist_get_iter(shutdown_list);
1157         while (sdb_llist_iter_has_next(iter)) {
1158                 callback_t *cb;
1159                 sdb_plugin_shutdown_cb callback;
1160                 ctx_t *old_ctx;
1161
1162                 sdb_object_t *obj = sdb_llist_iter_get_next(iter);
1163                 assert(obj);
1164                 cb = CB(obj);
1165
1166                 callback = (sdb_plugin_shutdown_cb)cb->cb_callback;
1167
1168                 old_ctx = ctx_set(cb->cb_ctx);
1169                 if (callback(cb->cb_user_data)) {
1170                         sdb_log(SDB_LOG_ERR, "core: Failed to shutdown plugin '%s'.",
1171                                         obj->name);
1172                         ++ret;
1173                 }
1174                 ctx_set(old_ctx);
1175         }
1176         sdb_llist_iter_destroy(iter);
1177         return ret;
1178 } /* sdb_plugin_shutdown_all */
1179
1180 int
1181 sdb_plugin_collector_loop(sdb_plugin_loop_t *loop)
1182 {
1183         if (! collector_list) {
1184                 sdb_log(SDB_LOG_WARNING, "core: No collectors registered. "
1185                                 "Quiting main loop.");
1186                 return -1;
1187         }
1188
1189         if (! loop)
1190                 return -1;
1191
1192         while (loop->do_loop) {
1193                 sdb_plugin_collector_cb callback;
1194                 ctx_t *old_ctx;
1195
1196                 sdb_time_t interval, now;
1197
1198                 sdb_object_t *obj = sdb_llist_shift(collector_list);
1199                 if (! obj)
1200                         return -1;
1201
1202                 callback = (sdb_plugin_collector_cb)CCB(obj)->ccb_callback;
1203
1204                 if (! (now = sdb_gettime())) {
1205                         char errbuf[1024];
1206                         sdb_log(SDB_LOG_ERR, "core: Failed to determine current "
1207                                         "time in collector main loop: %s",
1208                                         sdb_strerror(errno, errbuf, sizeof(errbuf)));
1209                         now = CCB(obj)->ccb_next_update;
1210                 }
1211
1212                 if (now < CCB(obj)->ccb_next_update) {
1213                         interval = CCB(obj)->ccb_next_update - now;
1214
1215                         errno = 0;
1216                         while (loop->do_loop && sdb_sleep(interval, &interval)) {
1217                                 if (errno != EINTR) {
1218                                         char errbuf[1024];
1219                                         sdb_log(SDB_LOG_ERR, "core: Failed to sleep "
1220                                                         "in collector main loop: %s",
1221                                                         sdb_strerror(errno, errbuf, sizeof(errbuf)));
1222                                         sdb_llist_insert_sorted(collector_list, obj,
1223                                                         plugin_cmp_next_update);
1224                                         sdb_object_deref(obj);
1225                                         return -1;
1226                                 }
1227                                 errno = 0;
1228                         }
1229
1230                         if (! loop->do_loop) {
1231                                 /* put back; don't worry about errors */
1232                                 sdb_llist_insert_sorted(collector_list, obj,
1233                                                 plugin_cmp_next_update);
1234                                 sdb_object_deref(obj);
1235                                 return 0;
1236                         }
1237                 }
1238
1239                 old_ctx = ctx_set(CCB(obj)->ccb_ctx);
1240                 if (callback(CCB(obj)->ccb_user_data)) {
1241                         /* XXX */
1242                 }
1243                 ctx_set(old_ctx);
1244
1245                 interval = CCB(obj)->ccb_interval;
1246                 if (! interval)
1247                         interval = loop->default_interval;
1248                 if (! interval) {
1249                         sdb_log(SDB_LOG_WARNING, "core: No interval configured "
1250                                         "for plugin '%s'; skipping any further "
1251                                         "iterations.", obj->name);
1252                         sdb_object_deref(obj);
1253                         continue;
1254                 }
1255
1256                 CCB(obj)->ccb_next_update += interval;
1257
1258                 if (! (now = sdb_gettime())) {
1259                         char errbuf[1024];
1260                         sdb_log(SDB_LOG_ERR, "core: Failed to determine current "
1261                                         "time in collector main loop: %s",
1262                                         sdb_strerror(errno, errbuf, sizeof(errbuf)));
1263                         now = CCB(obj)->ccb_next_update;
1264                 }
1265
1266                 if (now > CCB(obj)->ccb_next_update) {
1267                         sdb_log(SDB_LOG_WARNING, "core: Plugin '%s' took too "
1268                                         "long; skipping iterations to keep up.",
1269                                         obj->name);
1270                         CCB(obj)->ccb_next_update = now;
1271                 }
1272
1273                 if (sdb_llist_insert_sorted(collector_list, obj,
1274                                         plugin_cmp_next_update)) {
1275                         sdb_log(SDB_LOG_ERR, "core: Failed to re-insert "
1276                                         "plugin '%s' into collector list. Unable to further "
1277                                         "use the plugin.",
1278                                         obj->name);
1279                         sdb_object_deref(obj);
1280                         return -1;
1281                 }
1282
1283                 /* pass control back to the list */
1284                 sdb_object_deref(obj);
1285         }
1286         return 0;
1287 } /* sdb_plugin_read_loop */
1288
1289 char *
1290 sdb_plugin_cname(char *hostname)
1291 {
1292         sdb_llist_iter_t *iter;
1293
1294         if (! hostname)
1295                 return NULL;
1296
1297         if (! cname_list)
1298                 return hostname;
1299
1300         iter = sdb_llist_get_iter(cname_list);
1301         while (sdb_llist_iter_has_next(iter)) {
1302                 sdb_plugin_cname_cb callback;
1303                 char *cname;
1304
1305                 sdb_object_t *obj = sdb_llist_iter_get_next(iter);
1306                 assert(obj);
1307
1308                 callback = (sdb_plugin_cname_cb)CB(obj)->cb_callback;
1309                 cname = callback(hostname, CB(obj)->cb_user_data);
1310                 if (cname) {
1311                         free(hostname);
1312                         hostname = cname;
1313                 }
1314                 /* else: don't change hostname */
1315         }
1316         sdb_llist_iter_destroy(iter);
1317         return hostname;
1318 } /* sdb_plugin_cname */
1319
1320 int
1321 sdb_plugin_log(int prio, const char *msg)
1322 {
1323         sdb_llist_iter_t *iter;
1324         int ret = -1;
1325
1326         bool logged = 0;
1327
1328         if (! msg)
1329                 return 0;
1330
1331         iter = sdb_llist_get_iter(log_list);
1332         while (sdb_llist_iter_has_next(iter)) {
1333                 sdb_plugin_log_cb callback;
1334                 int tmp;
1335
1336                 sdb_object_t *obj = sdb_llist_iter_get_next(iter);
1337                 assert(obj);
1338
1339                 callback = (sdb_plugin_log_cb)CB(obj)->cb_callback;
1340                 tmp = callback(prio, msg, CB(obj)->cb_user_data);
1341                 if (tmp > ret)
1342                         ret = tmp;
1343
1344                 if (CB(obj)->cb_ctx)
1345                         logged = 1;
1346                 /* else: this is an internally registered callback */
1347         }
1348         sdb_llist_iter_destroy(iter);
1349
1350         if (! logged)
1351                 return fprintf(stderr, "[%s] %s\n", SDB_LOG_PRIO_TO_STRING(prio), msg);
1352         return ret;
1353 } /* sdb_plugin_log */
1354
1355 int
1356 sdb_plugin_vlogf(int prio, const char *fmt, va_list ap)
1357 {
1358         sdb_strbuf_t *buf;
1359         int ret;
1360
1361         if (! fmt)
1362                 return 0;
1363
1364         buf = sdb_strbuf_create(64);
1365         if (! buf) {
1366                 ret = fprintf(stderr, "[%s] ", SDB_LOG_PRIO_TO_STRING(prio));
1367                 ret += vfprintf(stderr, fmt, ap);
1368                 return ret;
1369         }
1370
1371         if (sdb_strbuf_vsprintf(buf, fmt, ap) < 0) {
1372                 sdb_strbuf_destroy(buf);
1373                 return -1;
1374         }
1375
1376         ret = sdb_plugin_log(prio, sdb_strbuf_string(buf));
1377         sdb_strbuf_destroy(buf);
1378         return ret;
1379 } /* sdb_plugin_vlogf */
1380
1381 int
1382 sdb_plugin_logf(int prio, const char *fmt, ...)
1383 {
1384         va_list ap;
1385         int ret;
1386
1387         if (! fmt)
1388                 return 0;
1389
1390         va_start(ap, fmt);
1391         ret = sdb_plugin_vlogf(prio, fmt, ap);
1392         va_end(ap);
1393         return ret;
1394 } /* sdb_plugin_logf */
1395
1396 sdb_timeseries_t *
1397 sdb_plugin_fetch_timeseries(const char *type, const char *id,
1398                 sdb_timeseries_opts_t *opts)
1399 {
1400         callback_t *plugin;
1401         sdb_plugin_fetch_ts_cb callback;
1402         sdb_timeseries_t *ts;
1403
1404         ctx_t *old_ctx;
1405
1406         if ((! type) || (! id) || (! opts))
1407                 return NULL;
1408
1409         plugin = CB(sdb_llist_search_by_name(ts_fetcher_list, type));
1410         if (! plugin) {
1411                 sdb_log(SDB_LOG_ERR, "core: Cannot fetch time-series of type %s: "
1412                                 "no such plugin loaded", type);
1413                 errno = ENOENT;
1414                 return NULL;
1415         }
1416
1417         old_ctx = ctx_set(plugin->cb_ctx);
1418         callback = (sdb_plugin_fetch_ts_cb)plugin->cb_callback;
1419         ts = callback(id, opts, plugin->cb_user_data);
1420         ctx_set(old_ctx);
1421         return ts;
1422 } /* sdb_plugin_fetch_timeseries */
1423
1424 int
1425 sdb_plugin_query(sdb_ast_node_t *ast, sdb_strbuf_t *buf, sdb_strbuf_t *errbuf)
1426 {
1427         size_t n = sdb_llist_len(reader_list);
1428         reader_t *reader;
1429         sdb_object_t *q;
1430         int status = 0;
1431
1432         if (! ast)
1433                 return 0;
1434
1435         if ((ast->type != SDB_AST_TYPE_FETCH)
1436                         && (ast->type != SDB_AST_TYPE_LIST)
1437                         && (ast->type != SDB_AST_TYPE_LOOKUP)
1438                         && (ast->type != SDB_AST_TYPE_TIMESERIES)) {
1439                 sdb_log(SDB_LOG_ERR, "core: Cannot execute query of type %s",
1440                                 SDB_AST_TYPE_TO_STRING(ast));
1441                 sdb_strbuf_sprintf(errbuf, "Cannot execute query of type %s",
1442                                 SDB_AST_TYPE_TO_STRING(ast));
1443                 return -1;
1444         }
1445
1446         if (n != 1) {
1447                 char *msg = (n > 0)
1448                         ? "Cannot execute query: multiple readers not supported"
1449                         : "Cannot execute query: no readers registered";
1450                 sdb_strbuf_sprintf(errbuf, "%s", msg);
1451                 sdb_log(SDB_LOG_ERR, "core: %s", msg);
1452                 return -1;
1453         }
1454
1455         reader = READER(sdb_llist_get(reader_list, 0));
1456         assert(reader);
1457
1458         q = reader->impl.prepare_query(ast, errbuf, reader->r_user_data);
1459         if (q)
1460                 status = reader->impl.execute_query(q, buf, errbuf, reader->r_user_data);
1461         else
1462                 status = -1;
1463
1464         sdb_object_deref(SDB_OBJ(q));
1465         sdb_object_deref(SDB_OBJ(reader));
1466         return status;
1467 } /* sdb_plugin_query */
1468
1469 int
1470 sdb_plugin_store_host(const char *name, sdb_time_t last_update)
1471 {
1472         sdb_store_host_t host = { 0 };
1473         char *cname;
1474
1475         sdb_llist_iter_t *iter;
1476         int status = 0;
1477
1478         if (! name)
1479                 return -1;
1480
1481         if (! sdb_llist_len(writer_list)) {
1482                 sdb_log(SDB_LOG_ERR, "core: Cannot store host: "
1483                                 "no writers registered");
1484                 return -1;
1485         }
1486
1487         cname = sdb_plugin_cname(strdup(name));
1488         if (! cname) {
1489                 sdb_log(SDB_LOG_ERR, "core: strdup failed");
1490                 return -1;
1491         }
1492
1493         host.name = cname;
1494         host.last_update = last_update;
1495
1496         iter = sdb_llist_get_iter(writer_list);
1497         while (sdb_llist_iter_has_next(iter)) {
1498                 writer_t *writer = WRITER(sdb_llist_iter_get_next(iter));
1499                 int s;
1500                 assert(writer);
1501                 s = writer->impl.store_host(&host, writer->w_user_data);
1502                 if (((s > 0) && (status >= 0)) || (s < 0))
1503                         status = s;
1504         }
1505         sdb_llist_iter_destroy(iter);
1506         free(cname);
1507         return status;
1508 } /* sdb_plugin_store_host */
1509
1510 int
1511 sdb_plugin_store_service(const char *hostname, const char *name,
1512                 sdb_time_t last_update)
1513 {
1514         sdb_store_service_t service = { 0 };
1515         char *cname;
1516
1517         sdb_llist_iter_t *iter;
1518         sdb_data_t d;
1519
1520         int status = 0;
1521
1522         if ((! hostname) || (! name))
1523                 return -1;
1524
1525         if (! sdb_llist_len(writer_list)) {
1526                 sdb_log(SDB_LOG_ERR, "core: Cannot store service: "
1527                                 "no writers registered");
1528                 return -1;
1529         }
1530
1531         cname = sdb_plugin_cname(strdup(hostname));
1532         if (! cname) {
1533                 sdb_log(SDB_LOG_ERR, "core: strdup failed");
1534                 return -1;
1535         }
1536
1537         service.hostname = cname;
1538         service.name = name;
1539         service.last_update = last_update;
1540
1541         iter = sdb_llist_get_iter(writer_list);
1542         while (sdb_llist_iter_has_next(iter)) {
1543                 writer_t *writer = WRITER(sdb_llist_iter_get_next(iter));
1544                 int s;
1545                 assert(writer);
1546                 s = writer->impl.store_service(&service, writer->w_user_data);
1547                 if (((s > 0) && (status >= 0)) || (s < 0))
1548                         status = s;
1549         }
1550         sdb_llist_iter_destroy(iter);
1551
1552         if (! status) {
1553                 /* record the hostname as an attribute */
1554                 d.type = SDB_TYPE_STRING;
1555                 d.data.string = cname;
1556                 if (sdb_plugin_store_service_attribute(cname, name,
1557                                         "hostname", &d, last_update))
1558                         status = -1;
1559         }
1560
1561         free(cname);
1562         return status;
1563 } /* sdb_plugin_store_service */
1564
1565 int
1566 sdb_plugin_store_metric(const char *hostname, const char *name,
1567                 sdb_metric_store_t *store, sdb_time_t last_update)
1568 {
1569         sdb_store_metric_t metric = { 0 };
1570         char *cname;
1571
1572         sdb_llist_iter_t *iter;
1573         sdb_data_t d;
1574
1575         int status = 0;
1576
1577         if ((! hostname) || (! name))
1578                 return -1;
1579
1580         if (! sdb_llist_len(writer_list)) {
1581                 sdb_log(SDB_LOG_ERR, "core: Cannot store metric: "
1582                                 "no writers registered");
1583                 return -1;
1584         }
1585
1586         cname = sdb_plugin_cname(strdup(hostname));
1587         if (! cname) {
1588                 sdb_log(SDB_LOG_ERR, "core: strdup failed");
1589                 return -1;
1590         }
1591
1592         if (store && ((! store->type) || (! store->id)))
1593                 store = NULL;
1594
1595         metric.hostname = cname;
1596         metric.name = name;
1597         if (store) {
1598                 metric.store.type = store->type;
1599                 metric.store.id = store->id;
1600         }
1601         metric.last_update = last_update;
1602
1603         iter = sdb_llist_get_iter(writer_list);
1604         while (sdb_llist_iter_has_next(iter)) {
1605                 writer_t *writer = WRITER(sdb_llist_iter_get_next(iter));
1606                 int s;
1607                 assert(writer);
1608                 s = writer->impl.store_metric(&metric, writer->w_user_data);
1609                 if (((s > 0) && (status >= 0)) || (s < 0))
1610                         status = s;
1611         }
1612         sdb_llist_iter_destroy(iter);
1613
1614         if (! status) {
1615                 /* record the hostname as an attribute */
1616                 d.type = SDB_TYPE_STRING;
1617                 d.data.string = cname;
1618                 if (sdb_plugin_store_metric_attribute(cname, name,
1619                                         "hostname", &d, last_update))
1620                         status = -1;
1621         }
1622
1623         free(cname);
1624         return status;
1625 } /* sdb_plugin_store_metric */
1626
1627 int
1628 sdb_plugin_store_attribute(const char *hostname, const char *key,
1629                 const sdb_data_t *value, sdb_time_t last_update)
1630 {
1631         sdb_store_attribute_t attr = { 0 };
1632         char *cname;
1633
1634         sdb_llist_iter_t *iter;
1635         int status = 0;
1636
1637         if ((! hostname) || (! key) || (! value))
1638                 return -1;
1639
1640         if (! sdb_llist_len(writer_list)) {
1641                 sdb_log(SDB_LOG_ERR, "core: Cannot store attribute: "
1642                                 "no writers registered");
1643                 return -1;
1644         }
1645
1646         cname = sdb_plugin_cname(strdup(hostname));
1647         if (! cname) {
1648                 sdb_log(SDB_LOG_ERR, "core: strdup failed");
1649                 return -1;
1650         }
1651
1652         attr.parent_type = SDB_HOST;
1653         attr.parent = cname;
1654         attr.key = key;
1655         attr.value = *value;
1656         attr.last_update = last_update;
1657
1658         iter = sdb_llist_get_iter(writer_list);
1659         while (sdb_llist_iter_has_next(iter)) {
1660                 writer_t *writer = WRITER(sdb_llist_iter_get_next(iter));
1661                 int s;
1662                 assert(writer);
1663                 s = writer->impl.store_attribute(&attr, writer->w_user_data);
1664                 if (((s > 0) && (status >= 0)) || (s < 0))
1665                         status = s;
1666         }
1667         sdb_llist_iter_destroy(iter);
1668         free(cname);
1669         return status;
1670 } /* sdb_plugin_store_attribute */
1671
1672 int
1673 sdb_plugin_store_service_attribute(const char *hostname, const char *service,
1674                 const char *key, const sdb_data_t *value, sdb_time_t last_update)
1675 {
1676         sdb_store_attribute_t attr = { 0 };
1677         char *cname;
1678
1679         sdb_llist_iter_t *iter;
1680         int status = 0;
1681
1682         if ((! hostname) || (! service) || (! key) || (! value))
1683                 return -1;
1684
1685         if (! sdb_llist_len(writer_list)) {
1686                 sdb_log(SDB_LOG_ERR, "core: Cannot store service attribute: "
1687                                 "no writers registered");
1688                 return -1;
1689         }
1690
1691         cname = sdb_plugin_cname(strdup(hostname));
1692         if (! cname) {
1693                 sdb_log(SDB_LOG_ERR, "core: strdup failed");
1694                 return -1;
1695         }
1696
1697         attr.hostname = cname;
1698         attr.parent_type = SDB_SERVICE;
1699         attr.parent = service;
1700         attr.key = key;
1701         attr.value = *value;
1702         attr.last_update = last_update;
1703
1704         iter = sdb_llist_get_iter(writer_list);
1705         while (sdb_llist_iter_has_next(iter)) {
1706                 writer_t *writer = WRITER(sdb_llist_iter_get_next(iter));
1707                 int s;
1708                 assert(writer);
1709                 s = writer->impl.store_attribute(&attr, writer->w_user_data);
1710                 if (((s > 0) && (status >= 0)) || (s < 0))
1711                         status = s;
1712         }
1713         sdb_llist_iter_destroy(iter);
1714         free(cname);
1715         return status;
1716 } /* sdb_plugin_store_service_attribute */
1717
1718 int
1719 sdb_plugin_store_metric_attribute(const char *hostname, const char *metric,
1720                 const char *key, const sdb_data_t *value, sdb_time_t last_update)
1721 {
1722         sdb_store_attribute_t attr = { 0 };
1723         char *cname;
1724
1725         sdb_llist_iter_t *iter;
1726         int status = 0;
1727
1728         if ((! hostname) || (! metric) || (! key) || (! value))
1729                 return -1;
1730
1731         if (! sdb_llist_len(writer_list)) {
1732                 sdb_log(SDB_LOG_ERR, "core: Cannot store metric attribute: "
1733                                 "no writers registered");
1734                 return -1;
1735         }
1736
1737         cname = sdb_plugin_cname(strdup(hostname));
1738         if (! cname) {
1739                 sdb_log(SDB_LOG_ERR, "core: strdup failed");
1740                 return -1;
1741         }
1742
1743         attr.hostname = cname;
1744         attr.parent_type = SDB_METRIC;
1745         attr.parent = metric;
1746         attr.key = key;
1747         attr.value = *value;
1748         attr.last_update = last_update;
1749
1750         iter = sdb_llist_get_iter(writer_list);
1751         while (sdb_llist_iter_has_next(iter)) {
1752                 writer_t *writer = WRITER(sdb_llist_iter_get_next(iter));
1753                 int s;
1754                 assert(writer);
1755                 s = writer->impl.store_attribute(&attr, writer->w_user_data);
1756                 if (((s > 0) && (status >= 0)) || (s < 0))
1757                         status = s;
1758         }
1759         sdb_llist_iter_destroy(iter);
1760         free(cname);
1761         return status;
1762 } /* sdb_plugin_store_metric_attribute */
1763
1764 /* vim: set tw=78 sw=4 ts=4 noexpandtab : */
1765