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 <ctype.h>
43 #include <stdlib.h>
44 #include <string.h>
46 /*
47 * private data types
48 */
50 struct sdb_store_json_formatter {
51 sdb_object_t super;
53 /* The string buffer to write to */
54 sdb_strbuf_t *buf;
56 /* The context describes the state of the formatter through
57 * the path pointing to the current object */
58 int context[8];
59 size_t current;
61 /* The current host context when processing non-host objects */
62 sdb_store_obj_t *current_host;
64 int type;
65 int flags;
66 };
67 #define F(obj) ((sdb_store_json_formatter_t *)(obj))
69 static int
70 formatter_init(sdb_object_t *obj, va_list ap)
71 {
72 sdb_store_json_formatter_t *f = F(obj);
74 f->buf = va_arg(ap, sdb_strbuf_t *);
75 if (! f->buf)
76 return -1;
78 f->type = va_arg(ap, int);
79 if ((f->type != SDB_HOST) && (f->type != SDB_SERVICE) && (f->type != SDB_METRIC))
80 return -1;
82 f->flags = va_arg(ap, int);
84 f->context[0] = 0;
85 f->current = 0;
87 f->current_host = NULL;
88 return 0;
89 } /* formatter_init */
91 static sdb_type_t formatter_type = {
92 /* size = */ sizeof(sdb_store_json_formatter_t),
93 /* init = */ formatter_init,
94 /* destroy = */ NULL,
95 };
97 /*
98 * private helper functions
99 */
101 static void
102 escape_string(const char *src, char *dest)
103 {
104 size_t i = 1;
105 dest[0] = '"';
106 for ( ; *src; ++src) {
107 char c = *src;
108 if ((c == '"') || (c == '\\') || iscntrl((int)c)) {
109 dest[i] = '\\';
110 ++i;
111 }
112 switch (c) {
113 case '\a': dest[i] = 'a'; break;
114 case '\b': dest[i] = 'b'; break;
115 case '\t': dest[i] = 't'; break;
116 case '\n': dest[i] = 'n'; break;
117 case '\v': dest[i] = 'v'; break;
118 case '\f': dest[i] = 'f'; break;
119 case '\r': dest[i] = 'r'; break;
120 default: dest[i] = c; break;
121 }
122 ++i;
123 }
124 dest[i] = '"';
125 dest[i + 1] = '\0';
126 } /* escape_string */
128 static int
129 json_emit(sdb_store_json_formatter_t *f, sdb_store_obj_t *obj)
130 {
131 char time_str[64];
132 char interval_str[64];
133 char name[2 * strlen(SDB_OBJ(obj)->name) + 3];
134 size_t i;
136 assert(f && obj);
138 if ((f->type != SDB_HOST) && (f->type == obj->type)) {
139 /* create the host for the current entry first */
140 assert(obj->parent && (obj->parent->type == SDB_HOST));
141 if (f->current_host != obj->parent) {
142 json_emit(f, obj->parent);
143 sdb_strbuf_append(f->buf, ", \"%ss\": [",
144 SDB_STORE_TYPE_TO_NAME(obj->type));
145 f->current_host = obj->parent;
146 }
147 }
149 escape_string(SDB_OBJ(obj)->name, name);
150 sdb_strbuf_append(f->buf, "{\"name\": %s, ", name);
151 if (obj->type == SDB_ATTRIBUTE) {
152 char tmp[sdb_data_strlen(&ATTR(obj)->value) + 1];
153 char val[2 * sizeof(tmp) + 3];
154 if (! sdb_data_format(&ATTR(obj)->value, tmp, sizeof(tmp),
155 SDB_DOUBLE_QUOTED))
156 snprintf(tmp, sizeof(tmp), "<error>");
158 if (tmp[0] == '"') {
159 /* a string; escape_string handles quoting */
160 tmp[strlen(tmp) - 1] = '\0';
161 escape_string(tmp + 1, val);
162 sdb_strbuf_append(f->buf, "\"value\": %s, ", val);
163 }
164 else
165 sdb_strbuf_append(f->buf, "\"value\": %s, ", tmp);
166 }
167 else if (obj->type == SDB_METRIC) {
168 if (METRIC(obj)->store.type != NULL)
169 sdb_strbuf_append(f->buf, "\"timeseries\": true, ");
170 else
171 sdb_strbuf_append(f->buf, "\"timeseries\": false, ");
172 }
174 /* TODO: make time and interval formats configurable */
175 if (! sdb_strftime(time_str, sizeof(time_str), obj->last_update))
176 snprintf(time_str, sizeof(time_str), "<error>");
177 time_str[sizeof(time_str) - 1] = '\0';
179 if (! sdb_strfinterval(interval_str, sizeof(interval_str),
180 obj->interval))
181 snprintf(interval_str, sizeof(interval_str), "<error>");
182 interval_str[sizeof(interval_str) - 1] = '\0';
184 sdb_strbuf_append(f->buf, "\"last_update\": \"%s\", "
185 "\"update_interval\": \"%s\", \"backends\": [",
186 time_str, interval_str);
188 for (i = 0; i < obj->backends_num; ++i) {
189 sdb_strbuf_append(f->buf, "\"%s\"", obj->backends[i]);
190 if (i < obj->backends_num - 1)
191 sdb_strbuf_append(f->buf, ",");
192 }
193 sdb_strbuf_append(f->buf, "]");
194 return 0;
195 } /* json_emit */
197 /*
198 * public API
199 */
201 sdb_store_json_formatter_t *
202 sdb_store_json_formatter(sdb_strbuf_t *buf, int type, int flags)
203 {
204 return F(sdb_object_create("json-formatter", formatter_type,
205 buf, type, flags));
206 } /* sdb_store_json_formatter */
208 int
209 sdb_store_json_emit(sdb_store_json_formatter_t *f, sdb_store_obj_t *obj)
210 {
211 if ((! f) || (! obj))
212 return -1;
214 if ((f->type != SDB_HOST) && (obj->type == SDB_HOST)) {
215 sdb_log(SDB_LOG_ERR, "store: Unexpected object of type host "
216 "during %s JSON serialization",
217 SDB_STORE_TYPE_TO_NAME(f->type));
218 return -1;
219 }
221 /* first top-level object */
222 if (! f->context[0]) {
223 if (obj->type != f->type) {
224 sdb_log(SDB_LOG_ERR, "store: Unexpected object of type %s "
225 "as the first element during %s JSON serialization",
226 SDB_STORE_TYPE_TO_NAME(obj->type),
227 SDB_STORE_TYPE_TO_NAME(f->type));
228 return -1;
229 }
230 if (f->flags & SDB_WANT_ARRAY)
231 sdb_strbuf_append(f->buf, "[");
232 assert(f->current == 0);
233 f->context[0] = obj->type;
234 return json_emit(f, obj);
235 }
237 if ((f->current >= 1) && (obj->type != SDB_ATTRIBUTE)) {
238 /* new entry of a previous type or a new type on the same level;
239 * rewind to the right state */
240 while (f->current > 0) {
241 if (f->context[f->current] == obj->type)
242 break;
243 sdb_strbuf_append(f->buf, "}]");
244 --f->current;
245 }
246 }
247 if ((obj->type == f->type) && (f->type != SDB_HOST))
248 if (obj->parent != f->current_host)
249 sdb_strbuf_append(f->buf, "}]");
251 if (obj->type == f->context[f->current]) {
252 /* new entry of the same type */
253 sdb_strbuf_append(f->buf, "},");
254 }
255 else if ((f->context[f->current] == SDB_HOST)
256 || (obj->type == SDB_ATTRIBUTE)) {
257 assert(obj->type != SDB_HOST);
258 /* all object types may be children of a host;
259 * attributes may be children of any type */
260 sdb_strbuf_append(f->buf, ", \"%ss\": [",
261 SDB_STORE_TYPE_TO_NAME(obj->type));
262 ++f->current;
263 }
264 else {
265 sdb_log(SDB_LOG_ERR, "store: Unexpected object of type %s "
266 "on level %zu during JSON serialization",
267 SDB_STORE_TYPE_TO_NAME(obj->type), f->current);
268 return -1;
269 }
271 json_emit(f, obj);
272 assert(f->current < SDB_STATIC_ARRAY_LEN(f->context));
273 f->context[f->current] = obj->type;
274 return 0;
275 } /* sdb_store_json_emit */
277 int
278 sdb_store_json_emit_full(sdb_store_json_formatter_t *f, sdb_store_obj_t *obj,
279 sdb_store_matcher_t *filter)
280 {
281 sdb_avltree_t *trees[] = { NULL, NULL, NULL };
282 size_t i;
284 if (sdb_store_json_emit(f, obj))
285 return -1;
287 if (obj->type == SDB_HOST) {
288 trees[0] = HOST(obj)->attributes;
289 trees[1] = HOST(obj)->metrics;
290 trees[2] = HOST(obj)->services;
291 }
292 else if (obj->type == SDB_SERVICE)
293 trees[0] = SVC(obj)->attributes;
294 else if (obj->type == SDB_METRIC)
295 trees[0] = METRIC(obj)->attributes;
296 else if (obj->type == SDB_ATTRIBUTE)
297 return 0;
298 else
299 return -1;
301 for (i = 0; i < SDB_STATIC_ARRAY_LEN(trees); ++i) {
302 sdb_avltree_iter_t *iter;
304 if (! trees[i])
305 continue;
307 iter = sdb_avltree_get_iter(trees[i]);
308 while (sdb_avltree_iter_has_next(iter)) {
309 sdb_store_obj_t *child;
310 child = STORE_OBJ(sdb_avltree_iter_get_next(iter));
312 if (filter && (! sdb_store_matcher_matches(filter, child, NULL)))
313 continue;
315 if (sdb_store_json_emit_full(f, child, filter)) {
316 sdb_avltree_iter_destroy(iter);
317 return -1;
318 }
319 }
320 sdb_avltree_iter_destroy(iter);
321 }
322 return 0;
323 } /* sdb_store_json_emit_full */
325 int
326 sdb_store_json_finish(sdb_store_json_formatter_t *f)
327 {
328 if (! f)
329 return -1;
331 if (! f->context[0]) {
332 /* no content */
333 if (f->flags & SDB_WANT_ARRAY)
334 sdb_strbuf_append(f->buf, "[]");
335 return 0;
336 }
338 while (f->current > 0) {
339 sdb_strbuf_append(f->buf, "}]");
340 --f->current;
341 }
342 if (f->context[0] != SDB_HOST) {
343 assert(f->type != SDB_HOST);
344 sdb_strbuf_append(f->buf, "}]}");
345 }
346 else
347 sdb_strbuf_append(f->buf, "}");
349 if (f->flags & SDB_WANT_ARRAY)
350 sdb_strbuf_append(f->buf, "]");
351 return 0;
352 } /* sdb_store_json_finish */
354 /* vim: set tw=78 sw=4 ts=4 noexpandtab : */