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         int flags;
  57 };
  58
  59 /*
  60  * private helper functions
  61  */
  62
  63 static int
  64 json_emit(sdb_store_json_formatter_t *f, sdb_store_obj_t *obj)
  65 {
  66         char time_str[64];
  67         char interval_str[64];
  68         size_t i;
  69
  70         assert(f && obj);
  71
  72         sdb_strbuf_append(f->buf, "{\"name\": \"%s\", ", SDB_OBJ(obj)->name);
  73         if (obj->type == SDB_ATTRIBUTE) {
  74                 char tmp[sdb_data_strlen(&ATTR(obj)->value) + 1];
  75                 if (sdb_data_format(&ATTR(obj)->value, tmp, sizeof(tmp),
  76                                         SDB_DOUBLE_QUOTED) < 0)
  77                         snprintf(tmp, sizeof(tmp), "<error>");
  78                 sdb_strbuf_append(f->buf, "\"value\": %s, ", tmp);
  79         }
  80
  81         /* TODO: make time and interval formats configurable */
  82         if (! sdb_strftime(time_str, sizeof(time_str),
  83                                 "%F %T %z", obj->last_update))
  84                 snprintf(time_str, sizeof(time_str), "<error>");
  85         time_str[sizeof(time_str) - 1] = '\0';
  86
  87         if (! sdb_strfinterval(interval_str, sizeof(interval_str),
  88                                 obj->interval))
  89                 snprintf(interval_str, sizeof(interval_str), "<error>");
  90         interval_str[sizeof(interval_str) - 1] = '\0';
  91
  92         sdb_strbuf_append(f->buf, "\"last_update\": \"%s\", "
  93                         "\"update_interval\": \"%s\", \"backends\": [",
  94                         time_str, interval_str);
  95
  96         for (i = 0; i < obj->backends_num; ++i) {
  97                 sdb_strbuf_append(f->buf, "\"%s\"", obj->backends[i]);
  98                 if (i < obj->backends_num - 1)
  99                         sdb_strbuf_append(f->buf, ",");
 100         }
 101         sdb_strbuf_append(f->buf, "]");
 102         return 0;
 103 } /* json_emit */
 104
 105 /*
 106  * public API
 107  */
 108
 109 sdb_store_json_formatter_t *
 110 sdb_store_json_formatter(sdb_strbuf_t *buf, int flags)
 111 {
 112         sdb_store_json_formatter_t *f;
 113
 114         if (! buf)
 115                 return NULL;
 116
 117         f = calloc(1, sizeof(*f));
 118         if (! f)
 119                 return NULL;
 120
 121         f->buf = buf;
 122         f->context[0] = 0;
 123         f->current = 0;
 124         f->flags = flags;
 125         return f;
 126 } /* sdb_store_json_formatter */
 127
 128 int
 129 sdb_store_json_emit(sdb_store_json_formatter_t *f, sdb_store_obj_t *obj)
 130 {
 131         if ((! f) || (! obj))
 132                 return -1;
 133
 134         /* first host */
 135         if (! f->context[0]) {
 136                 if (f->flags & SDB_WANT_ARRAY)
 137                         sdb_strbuf_append(f->buf, "[");
 138                 assert(f->current == 0);
 139                 f->context[0] = SDB_HOST;
 140                 return json_emit(f, obj);
 141         }
 142
 143         if (obj->type == f->context[f->current]) {
 144                 /* new entry of the same type */
 145                 sdb_strbuf_append(f->buf, "},");
 146         }
 147         else if ((f->context[f->current] == SDB_HOST)
 148                         || (obj->type == SDB_ATTRIBUTE)) {
 149                 assert(obj->type != SDB_HOST);
 150                 /* all object types may be children of a host;
 151                  * attributes may be children of any type */
 152                 sdb_strbuf_append(f->buf, ", \"%ss\": [",
 153                                 SDB_STORE_TYPE_TO_NAME(obj->type));
 154                 ++f->current;
 155         }
 156         else if (f->current >= 1) {
 157                 /* new entry of a previous type or a new type on the same level
 158                  * -> rewind to the right state and then handle the new object */
 159                 assert(obj->type != SDB_ATTRIBUTE);
 160                 while (f->current > 0) {
 161                         if (f->context[f->current] == obj->type)
 162                                 break;
 163                         assert(f->context[f->current] != SDB_HOST);
 164                         sdb_strbuf_append(f->buf, "}]");
 165                         --f->current;
 166                 }
 167                 return sdb_store_json_emit(f, obj);
 168         }
 169         else {
 170                 sdb_log(SDB_LOG_ERR, "store: Unexpected object of type %s "
 171                                 "on level %zu during JSON serialization",
 172                                 SDB_STORE_TYPE_TO_NAME(obj->type), f->current);
 173                 return -1;
 174         }
 175
 176         json_emit(f, obj);
 177         assert(f->current < SDB_STATIC_ARRAY_LEN(f->context));
 178         f->context[f->current] = obj->type;
 179         return 0;
 180 } /* sdb_store_json_emit */
 181
 182 int
 183 sdb_store_json_emit_full(sdb_store_json_formatter_t *f, sdb_store_obj_t *obj,
 184                 sdb_store_matcher_t *filter)
 185 {
 186         sdb_avltree_t *trees[] = { NULL, NULL, NULL };
 187         size_t i;
 188
 189         if (sdb_store_json_emit(f, obj))
 190                 return -1;
 191
 192         if (obj->type == SDB_HOST) {
 193                 trees[0] = HOST(obj)->attributes;
 194                 trees[1] = HOST(obj)->metrics;
 195                 trees[2] = HOST(obj)->services;
 196         }
 197         else if (obj->type == SDB_SERVICE)
 198                 trees[0] = SVC(obj)->attributes;
 199         else if (obj->type == SDB_METRIC)
 200                 trees[0] = METRIC(obj)->attributes;
 201         else if (obj->type == SDB_ATTRIBUTE)
 202                 return 0;
 203         else
 204                 return -1;
 205
 206         for (i = 0; i < SDB_STATIC_ARRAY_LEN(trees); ++i) {
 207                 sdb_avltree_iter_t *iter;
 208
 209                 if (! trees[i])
 210                         continue;
 211
 212                 iter = sdb_avltree_get_iter(trees[i]);
 213                 while (sdb_avltree_iter_has_next(iter)) {
 214                         sdb_store_obj_t *child;
 215                         child = STORE_OBJ(sdb_avltree_iter_get_next(iter));
 216
 217                         if (filter && (! sdb_store_matcher_matches(filter, child, NULL)))
 218                                 continue;
 219
 220                         if (sdb_store_json_emit_full(f, child, filter)) {
 221                                 sdb_avltree_iter_destroy(iter);
 222                                 return -1;
 223                         }
 224                 }
 225                 sdb_avltree_iter_destroy(iter);
 226         }
 227         return 0;
 228 } /* sdb_store_json_emit_full */
 229
 230 int
 231 sdb_store_json_finish(sdb_store_json_formatter_t *f)
 232 {
 233         if (! f)
 234                 return -1;
 235
 236         if (! f->context[0]) {
 237                 /* no content */
 238                 if (f->flags & SDB_WANT_ARRAY)
 239                         sdb_strbuf_append(f->buf, "[]");
 240                 return 0;
 241         }
 242
 243         while (f->current > 0) {
 244                 sdb_strbuf_append(f->buf, "}]");
 245                 --f->current;
 246         }
 247
 248         sdb_strbuf_append(f->buf, "}");
 249         if (f->flags & SDB_WANT_ARRAY)
 250                 sdb_strbuf_append(f->buf, "]");
 251         return 0;
 252 } /* sdb_store_json_finish */
 253
 254 /* vim: set tw=78 sw=4 ts=4 noexpandtab : */
 255