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
  57 /*
  58  * private helper functions
  59  */
  60
  61 static int
  62 json_emit(sdb_store_json_formatter_t *f, sdb_store_obj_t *obj)
  63 {
  64         char time_str[64];
  65         char interval_str[64];
  66         size_t i;
  67
  68         assert(f && obj);
  69
  70         sdb_strbuf_append(f->buf, "{\"name\": \"%s\", ", SDB_OBJ(obj)->name);
  71         if (obj->type == SDB_ATTRIBUTE) {
  72                 char tmp[sdb_data_strlen(&ATTR(obj)->value) + 1];
  73                 if (sdb_data_format(&ATTR(obj)->value, tmp, sizeof(tmp),
  74                                         SDB_DOUBLE_QUOTED) < 0)
  75                         snprintf(tmp, sizeof(tmp), "<error>");
  76                 sdb_strbuf_append(f->buf, "\"value\": %s, ", tmp);
  77         }
  78
  79         /* TODO: make time and interval formats configurable */
  80         if (! sdb_strftime(time_str, sizeof(time_str),
  81                                 "%F %T %z", obj->last_update))
  82                 snprintf(time_str, sizeof(time_str), "<error>");
  83         time_str[sizeof(time_str) - 1] = '\0';
  84
  85         if (! sdb_strfinterval(interval_str, sizeof(interval_str),
  86                                 obj->interval))
  87                 snprintf(interval_str, sizeof(interval_str), "<error>");
  88         interval_str[sizeof(interval_str) - 1] = '\0';
  89
  90         sdb_strbuf_append(f->buf, "\"last_update\": \"%s\", "
  91                         "\"update_interval\": \"%s\", \"backends\": [",
  92                         time_str, interval_str);
  93
  94         for (i = 0; i < obj->backends_num; ++i) {
  95                 sdb_strbuf_append(f->buf, "\"%s\"", obj->backends[i]);
  96                 if (i < obj->backends_num - 1)
  97                         sdb_strbuf_append(f->buf, ",");
  98         }
  99         sdb_strbuf_append(f->buf, "]");
 100         return 0;
 101 } /* json_emit */
 102
 103 /*
 104  * public API
 105  */
 106
 107 sdb_store_json_formatter_t *
 108 sdb_store_json_formatter(sdb_strbuf_t *buf)
 109 {
 110         sdb_store_json_formatter_t *f;
 111
 112         if (! buf)
 113                 return NULL;
 114
 115         f = calloc(1, sizeof(*f));
 116         if (! f)
 117                 return NULL;
 118
 119         f->buf = buf;
 120         f->context[0] = 0;
 121         f->current = 0;
 122         return f;
 123 } /* sdb_store_json_formatter */
 124
 125 int
 126 sdb_store_json_emit(sdb_store_json_formatter_t *f, sdb_store_obj_t *obj)
 127 {
 128         if ((! f) || (! obj))
 129                 return -1;
 130
 131         /* first host */
 132         if (! f->context[0]) {
 133                 assert(f->current == 0);
 134                 f->context[0] = SDB_HOST;
 135                 return json_emit(f, obj);
 136         }
 137
 138         if (obj->type == f->context[f->current]) {
 139                 /* new entry of the same type */
 140                 sdb_strbuf_append(f->buf, "},");
 141         }
 142         else if ((f->context[f->current] == SDB_HOST)
 143                         || (obj->type == SDB_ATTRIBUTE)) {
 144                 assert(obj->type != SDB_HOST);
 145                 /* all object types may be children of a host;
 146                  * attributes may be children of any type */
 147                 sdb_strbuf_append(f->buf, ", \"%ss\": [",
 148                                 SDB_STORE_TYPE_TO_NAME(obj->type));
 149                 ++f->current;
 150         }
 151         else if (f->current >= 1) {
 152                 /* new entry of a previous type or a new type on the same level
 153                  * -> rewind to the right state and then handle the new object */
 154                 assert(obj->type != SDB_ATTRIBUTE);
 155                 while (f->current > 0) {
 156                         if (f->context[f->current] == obj->type)
 157                                 break;
 158                         assert(f->context[f->current] != SDB_HOST);
 159                         sdb_strbuf_append(f->buf, "}]");
 160                         --f->current;
 161                 }
 162                 return sdb_store_json_emit(f, obj);
 163         }
 164         else {
 165                 sdb_log(SDB_LOG_ERR, "store: Unexpected object of type %s "
 166                                 "on level %zu during JSON serialization",
 167                                 SDB_STORE_TYPE_TO_NAME(obj->type), f->current);
 168                 return -1;
 169         }
 170
 171         json_emit(f, obj);
 172         assert(f->current < SDB_STATIC_ARRAY_LEN(f->context));
 173         f->context[f->current] = obj->type;
 174         return 0;
 175 } /* sdb_store_json_emit */
 176
 177 int
 178 sdb_store_json_emit_full(sdb_store_json_formatter_t *f, sdb_store_obj_t *obj,
 179                 sdb_store_matcher_t *filter)
 180 {
 181         sdb_avltree_t *trees[] = { NULL, NULL, NULL };
 182         size_t i;
 183
 184         if (sdb_store_json_emit(f, obj))
 185                 return -1;
 186
 187         if (obj->type == SDB_HOST) {
 188                 trees[0] = HOST(obj)->attributes;
 189                 trees[1] = HOST(obj)->metrics;
 190                 trees[2] = HOST(obj)->services;
 191         }
 192         else if (obj->type == SDB_SERVICE)
 193                 trees[0] = SVC(obj)->attributes;
 194         else if (obj->type == SDB_METRIC)
 195                 trees[0] = METRIC(obj)->attributes;
 196         else if (obj->type == SDB_ATTRIBUTE)
 197                 return 0;
 198         else
 199                 return -1;
 200
 201         for (i = 0; i < SDB_STATIC_ARRAY_LEN(trees); ++i) {
 202                 sdb_avltree_iter_t *iter;
 203
 204                 if (! trees[i])
 205                         continue;
 206
 207                 iter = sdb_avltree_get_iter(trees[i]);
 208                 while (sdb_avltree_iter_has_next(iter)) {
 209                         sdb_store_obj_t *child;
 210                         child = STORE_OBJ(sdb_avltree_iter_get_next(iter));
 211
 212                         if (filter && (! sdb_store_matcher_matches(filter, child, NULL)))
 213                                 continue;
 214
 215                         if (sdb_store_json_emit_full(f, child, filter)) {
 216                                 sdb_avltree_iter_destroy(iter);
 217                                 return -1;
 218                         }
 219                 }
 220                 sdb_avltree_iter_destroy(iter);
 221         }
 222         return 0;
 223 } /* sdb_store_json_emit_full */
 224
 225 int
 226 sdb_store_json_finish(sdb_store_json_formatter_t *f)
 227 {
 228         if (! f)
 229                 return -1;
 230
 231         while (f->current > 0) {
 232                 sdb_strbuf_append(f->buf, "}]");
 233                 --f->current;
 234         }
 235         if (f->context[0])
 236                 sdb_strbuf_append(f->buf, "}");
 237         return 0;
 238 } /* sdb_store_json_finish */
 239
 240 /* vim: set tw=78 sw=4 ts=4 noexpandtab : */
 241