src/core/store_json.c

   1 /*
   2  * SysDB - src/core/store_json.c
   3  * Copyright (C) 2013-2014 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 /*
  29  * This module implements JSON support.
  30  */
  31
  32 #if HAVE_CONFIG_H
  33 #       include "config.h"
  34 #endif /* HAVE_CONFIG_H */
  35
  36 #include "sysdb.h"
  37 #include "core/store-private.h"
  38 #include "utils/error.h"
  39
  40 #include <assert.h>
  41
  42 #include <stdlib.h>
  43
  44 /*
  45  * private data types
  46  */
  47
  48 struct sdb_store_json_formatter {
  49         sdb_strbuf_t *buf;
  50
  51         /* The context describes the state of the formatter through
  52          * the path pointing to the current object */
  53         int context[8];
  54         size_t current;
  55
  56         /* The current host context when processing non-host objects */
  57         sdb_store_obj_t *current_host;
  58
  59         int type;
  60         int flags;
  61 };
  62
  63 /*
  64  * private helper functions
  65  */
  66
  67 static int
  68 json_emit(sdb_store_json_formatter_t *f, sdb_store_obj_t *obj)
  69 {
  70         char time_str[64];
  71         char interval_str[64];
  72         size_t i;
  73
  74         assert(f && obj);
  75
  76         if ((f->type != SDB_HOST) && (f->type == obj->type)) {
  77                 /* create the host for the current entry first */
  78                 assert(obj->parent && (obj->parent->type == SDB_HOST));
  79                 if (f->current_host != obj->parent) {
  80                         json_emit(f, obj->parent);
  81                         sdb_strbuf_append(f->buf, ", \"%ss\": [",
  82                                         SDB_STORE_TYPE_TO_NAME(obj->type));
  83                         f->current_host = obj->parent;
  84                 }
  85         }
  86
  87         sdb_strbuf_append(f->buf, "{\"name\": \"%s\", ", SDB_OBJ(obj)->name);
  88         if (obj->type == SDB_ATTRIBUTE) {
  89                 char tmp[sdb_data_strlen(&ATTR(obj)->value) + 1];
  90                 if (sdb_data_format(&ATTR(obj)->value, tmp, sizeof(tmp),
  91                                         SDB_DOUBLE_QUOTED) < 0)
  92                         snprintf(tmp, sizeof(tmp), "<error>");
  93                 sdb_strbuf_append(f->buf, "\"value\": %s, ", tmp);
  94         }
  95
  96         /* TODO: make time and interval formats configurable */
  97         if (! sdb_strftime(time_str, sizeof(time_str),
  98                                 "%F %T %z", obj->last_update))
  99                 snprintf(time_str, sizeof(time_str), "<error>");
 100         time_str[sizeof(time_str) - 1] = '\0';
 101
 102         if (! sdb_strfinterval(interval_str, sizeof(interval_str),
 103                                 obj->interval))
 104                 snprintf(interval_str, sizeof(interval_str), "<error>");
 105         interval_str[sizeof(interval_str) - 1] = '\0';
 106
 107         sdb_strbuf_append(f->buf, "\"last_update\": \"%s\", "
 108                         "\"update_interval\": \"%s\", \"backends\": [",
 109                         time_str, interval_str);
 110
 111         for (i = 0; i < obj->backends_num; ++i) {
 112                 sdb_strbuf_append(f->buf, "\"%s\"", obj->backends[i]);
 113                 if (i < obj->backends_num - 1)
 114                         sdb_strbuf_append(f->buf, ",");
 115         }
 116         sdb_strbuf_append(f->buf, "]");
 117         return 0;
 118 } /* json_emit */
 119
 120 /*
 121  * public API
 122  */
 123
 124 sdb_store_json_formatter_t *
 125 sdb_store_json_formatter(sdb_strbuf_t *buf, int type, int flags)
 126 {
 127         sdb_store_json_formatter_t *f;
 128
 129         if (! buf)
 130                 return NULL;
 131
 132         if ((type != SDB_HOST) && (type != SDB_SERVICE) && (type != SDB_METRIC))
 133                 return NULL;
 134
 135         f = calloc(1, sizeof(*f));
 136         if (! f)
 137                 return NULL;
 138
 139         f->buf = buf;
 140         f->context[0] = 0;
 141         f->current = 0;
 142
 143         f->current_host = NULL;
 144
 145         f->type = type;
 146         f->flags = flags;
 147         return f;
 148 } /* sdb_store_json_formatter */
 149
 150 int
 151 sdb_store_json_emit(sdb_store_json_formatter_t *f, sdb_store_obj_t *obj)
 152 {
 153         if ((! f) || (! obj))
 154                 return -1;
 155
 156         if ((f->type != SDB_HOST) && (obj->type == SDB_HOST)) {
 157                 sdb_log(SDB_LOG_ERR, "store: Unexpected object of type host "
 158                                 "during %s JSON serialization",
 159                                 SDB_STORE_TYPE_TO_NAME(f->type));
 160                 return -1;
 161         }
 162
 163         /* first top-level object */
 164         if (! f->context[0]) {
 165                 if (obj->type != f->type) {
 166                         sdb_log(SDB_LOG_ERR, "store: Unexpected object of type %s "
 167                                         "as the first element during %s JSON serialization",
 168                                         SDB_STORE_TYPE_TO_NAME(obj->type),
 169                                         SDB_STORE_TYPE_TO_NAME(f->type));
 170                         return -1;
 171                 }
 172                 if (f->flags & SDB_WANT_ARRAY)
 173                         sdb_strbuf_append(f->buf, "[");
 174                 assert(f->current == 0);
 175                 f->context[0] = obj->type;
 176                 return json_emit(f, obj);
 177         }
 178
 179         if ((f->current >= 1) && (obj->type != SDB_ATTRIBUTE)) {
 180                 /* new entry of a previous type or a new type on the same level;
 181                  * rewind to the right state */
 182                 while (f->current > 0) {
 183                         if (f->context[f->current] == obj->type)
 184                                 break;
 185                         sdb_strbuf_append(f->buf, "}]");
 186                         --f->current;
 187                 }
 188         }
 189         if ((obj->type == f->type) && (f->type != SDB_HOST))
 190                 if (obj->parent != f->current_host)
 191                         sdb_strbuf_append(f->buf, "}]");
 192
 193         if (obj->type == f->context[f->current]) {
 194                 /* new entry of the same type */
 195                 sdb_strbuf_append(f->buf, "},");
 196         }
 197         else if ((f->context[f->current] == SDB_HOST)
 198                         || (obj->type == SDB_ATTRIBUTE)) {
 199                 assert(obj->type != SDB_HOST);
 200                 /* all object types may be children of a host;
 201                  * attributes may be children of any type */
 202                 sdb_strbuf_append(f->buf, ", \"%ss\": [",
 203                                 SDB_STORE_TYPE_TO_NAME(obj->type));
 204                 ++f->current;
 205         }
 206         else {
 207                 sdb_log(SDB_LOG_ERR, "store: Unexpected object of type %s "
 208                                 "on level %zu during JSON serialization",
 209                                 SDB_STORE_TYPE_TO_NAME(obj->type), f->current);
 210                 return -1;
 211         }
 212
 213         json_emit(f, obj);
 214         assert(f->current < SDB_STATIC_ARRAY_LEN(f->context));
 215         f->context[f->current] = obj->type;
 216         return 0;
 217 } /* sdb_store_json_emit */
 218
 219 int
 220 sdb_store_json_emit_full(sdb_store_json_formatter_t *f, sdb_store_obj_t *obj,
 221                 sdb_store_matcher_t *filter)
 222 {
 223         sdb_avltree_t *trees[] = { NULL, NULL, NULL };
 224         size_t i;
 225
 226         if (sdb_store_json_emit(f, obj))
 227                 return -1;
 228
 229         if (obj->type == SDB_HOST) {
 230                 trees[0] = HOST(obj)->attributes;
 231                 trees[1] = HOST(obj)->metrics;
 232                 trees[2] = HOST(obj)->services;
 233         }
 234         else if (obj->type == SDB_SERVICE)
 235                 trees[0] = SVC(obj)->attributes;
 236         else if (obj->type == SDB_METRIC)
 237                 trees[0] = METRIC(obj)->attributes;
 238         else if (obj->type == SDB_ATTRIBUTE)
 239                 return 0;
 240         else
 241                 return -1;
 242
 243         for (i = 0; i < SDB_STATIC_ARRAY_LEN(trees); ++i) {
 244                 sdb_avltree_iter_t *iter;
 245
 246                 if (! trees[i])
 247                         continue;
 248
 249                 iter = sdb_avltree_get_iter(trees[i]);
 250                 while (sdb_avltree_iter_has_next(iter)) {
 251                         sdb_store_obj_t *child;
 252                         child = STORE_OBJ(sdb_avltree_iter_get_next(iter));
 253
 254                         if (filter && (! sdb_store_matcher_matches(filter, child, NULL)))
 255                                 continue;
 256
 257                         if (sdb_store_json_emit_full(f, child, filter)) {
 258                                 sdb_avltree_iter_destroy(iter);
 259                                 return -1;
 260                         }
 261                 }
 262                 sdb_avltree_iter_destroy(iter);
 263         }
 264         return 0;
 265 } /* sdb_store_json_emit_full */
 266
 267 int
 268 sdb_store_json_finish(sdb_store_json_formatter_t *f)
 269 {
 270         if (! f)
 271                 return -1;
 272
 273         if (! f->context[0]) {
 274                 /* no content */
 275                 if (f->flags & SDB_WANT_ARRAY)
 276                         sdb_strbuf_append(f->buf, "[]");
 277                 return 0;
 278         }
 279
 280         while (f->current > 0) {
 281                 sdb_strbuf_append(f->buf, "}]");
 282                 --f->current;
 283         }
 284         if (f->context[0] != SDB_HOST) {
 285                 assert(f->type != SDB_HOST);
 286                 sdb_strbuf_append(f->buf, "}]}");
 287         }
 288         else
 289                 sdb_strbuf_append(f->buf, "}");
 290
 291         if (f->flags & SDB_WANT_ARRAY)
 292                 sdb_strbuf_append(f->buf, "]");
 293         return 0;
 294 } /* sdb_store_json_finish */
 295
 296 /* vim: set tw=78 sw=4 ts=4 noexpandtab : */
 297