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 */
28 /*
29 * This module implements JSON support.
30 */
32 #if HAVE_CONFIG_H
33 # include "config.h"
34 #endif /* HAVE_CONFIG_H */
36 #include "sysdb.h"
37 #include "core/store-private.h"
38 #include "utils/error.h"
40 #include <assert.h>
42 #include <stdlib.h>
44 /*
45 * private data types
46 */
48 struct sdb_store_json_formatter {
49 sdb_strbuf_t *buf;
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;
56 /* The current host context when processing non-host objects */
57 sdb_store_obj_t *current_host;
59 int type;
60 int flags;
61 };
63 /*
64 * private helper functions
65 */
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;
74 assert(f && obj);
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 }
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 }
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';
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';
107 sdb_strbuf_append(f->buf, "\"last_update\": \"%s\", "
108 "\"update_interval\": \"%s\", \"backends\": [",
109 time_str, interval_str);
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 */
120 /*
121 * public API
122 */
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;
129 if (! buf)
130 return NULL;
132 if ((type != SDB_HOST) && (type != SDB_SERVICE) && (type != SDB_METRIC))
133 return NULL;
135 f = calloc(1, sizeof(*f));
136 if (! f)
137 return NULL;
139 f->buf = buf;
140 f->context[0] = 0;
141 f->current = 0;
143 f->current_host = NULL;
145 f->type = type;
146 f->flags = flags;
147 return f;
148 } /* sdb_store_json_formatter */
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;
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 }
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 }
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, "}]");
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 }
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 */
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;
226 if (sdb_store_json_emit(f, obj))
227 return -1;
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;
243 for (i = 0; i < SDB_STATIC_ARRAY_LEN(trees); ++i) {
244 sdb_avltree_iter_t *iter;
246 if (! trees[i])
247 continue;
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));
254 if (filter && (! sdb_store_matcher_matches(filter, child, NULL)))
255 continue;
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 */
267 int
268 sdb_store_json_finish(sdb_store_json_formatter_t *f)
269 {
270 if (! f)
271 return -1;
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 }
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, "}");
291 if (f->flags & SDB_WANT_ARRAY)
292 sdb_strbuf_append(f->buf, "]");
293 return 0;
294 } /* sdb_store_json_finish */
296 /* vim: set tw=78 sw=4 ts=4 noexpandtab : */