a2c117b1f10d07308e7db9afd698c32933342e49
1 /*
2 * SysDB - src/core/store_json.c
3 * Copyright (C) 2013-2015 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 int type;
62 int flags;
63 };
64 #define F(obj) ((sdb_store_json_formatter_t *)(obj))
66 static int
67 formatter_init(sdb_object_t *obj, va_list ap)
68 {
69 sdb_store_json_formatter_t *f = F(obj);
71 f->buf = va_arg(ap, sdb_strbuf_t *);
72 if (! f->buf)
73 return -1;
75 f->type = va_arg(ap, int);
76 if ((f->type != SDB_HOST) && (f->type != SDB_SERVICE) && (f->type != SDB_METRIC))
77 return -1;
79 f->flags = va_arg(ap, int);
81 f->context[0] = 0;
82 f->current = 0;
83 return 0;
84 } /* formatter_init */
86 static sdb_type_t formatter_type = {
87 /* size = */ sizeof(sdb_store_json_formatter_t),
88 /* init = */ formatter_init,
89 /* destroy = */ NULL,
90 };
92 /*
93 * private helper functions
94 */
96 static void
97 escape_string(const char *src, char *dest)
98 {
99 size_t i = 1;
100 dest[0] = '"';
101 for ( ; *src; ++src) {
102 char c = *src;
103 if ((c == '"') || (c == '\\') || iscntrl((int)c)) {
104 dest[i] = '\\';
105 ++i;
106 }
107 switch (c) {
108 case '\a': dest[i] = 'a'; break;
109 case '\b': dest[i] = 'b'; break;
110 case '\t': dest[i] = 't'; break;
111 case '\n': dest[i] = 'n'; break;
112 case '\v': dest[i] = 'v'; break;
113 case '\f': dest[i] = 'f'; break;
114 case '\r': dest[i] = 'r'; break;
115 default: dest[i] = c; break;
116 }
117 ++i;
118 }
119 dest[i] = '"';
120 dest[i + 1] = '\0';
121 } /* escape_string */
123 /* handle_new_object takes care of all maintenance logic related to adding a
124 * new object. That is, it manages context information and emit the prefix and
125 * suffix of an object. */
126 static int
127 handle_new_object(sdb_store_json_formatter_t *f, sdb_store_obj_t *obj)
128 {
129 /* first top-level object */
130 if (! f->context[0]) {
131 if ((obj->type != f->type) && (obj->type != SDB_HOST)) {
132 sdb_log(SDB_LOG_ERR, "store: Unexpected object of type %s "
133 "as the first element during %s JSON serialization",
134 SDB_STORE_TYPE_TO_NAME(obj->type),
135 SDB_STORE_TYPE_TO_NAME(f->type));
136 return -1;
137 }
138 if (f->flags & SDB_WANT_ARRAY)
139 sdb_strbuf_append(f->buf, "[");
140 assert(f->current == 0);
141 f->context[f->current] = obj->type;
142 return 0;
143 }
145 if ((f->context[f->current] != SDB_HOST)
146 && (obj->type != SDB_ATTRIBUTE)) {
147 /* new entry of the same type or a parent object;
148 * rewind to the right state */
149 while ((f->current > 0)
150 && (f->context[f->current] != obj->type)) {
151 sdb_strbuf_append(f->buf, "}]");
152 --f->current;
153 }
154 }
156 if (obj->type == f->context[f->current]) {
157 /* new entry of the same type */
158 sdb_strbuf_append(f->buf, "},");
159 }
160 else if ((f->context[f->current] == SDB_HOST)
161 || (obj->type == SDB_ATTRIBUTE)) {
162 assert(obj->type != SDB_HOST);
163 /* all object types may be children of a host;
164 * attributes may be children of any type */
165 sdb_strbuf_append(f->buf, ", \"%ss\": [",
166 SDB_STORE_TYPE_TO_NAME(obj->type));
167 ++f->current;
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 }
176 assert(f->current < SDB_STATIC_ARRAY_LEN(f->context));
177 f->context[f->current] = obj->type;
178 return 0;
179 } /* handle_new_object */
181 static int
182 json_emit(sdb_store_json_formatter_t *f, sdb_store_obj_t *obj)
183 {
184 char time_str[64];
185 char interval_str[64];
186 char name[2 * strlen(SDB_OBJ(obj)->name) + 3];
187 size_t i;
189 assert(f && obj);
191 handle_new_object(f, obj);
193 escape_string(SDB_OBJ(obj)->name, name);
194 sdb_strbuf_append(f->buf, "{\"name\": %s, ", name);
195 if (obj->type == SDB_ATTRIBUTE) {
196 char tmp[sdb_data_strlen(&ATTR(obj)->value) + 1];
197 char val[2 * sizeof(tmp) + 3];
198 if (! sdb_data_format(&ATTR(obj)->value, tmp, sizeof(tmp),
199 SDB_DOUBLE_QUOTED))
200 snprintf(tmp, sizeof(tmp), "<error>");
202 if (tmp[0] == '"') {
203 /* a string; escape_string handles quoting */
204 tmp[strlen(tmp) - 1] = '\0';
205 escape_string(tmp + 1, val);
206 sdb_strbuf_append(f->buf, "\"value\": %s, ", val);
207 }
208 else
209 sdb_strbuf_append(f->buf, "\"value\": %s, ", tmp);
210 }
211 else if (obj->type == SDB_METRIC) {
212 if (METRIC(obj)->store.type != NULL)
213 sdb_strbuf_append(f->buf, "\"timeseries\": true, ");
214 else
215 sdb_strbuf_append(f->buf, "\"timeseries\": false, ");
216 }
218 /* TODO: make time and interval formats configurable */
219 if (! sdb_strftime(time_str, sizeof(time_str), obj->last_update))
220 snprintf(time_str, sizeof(time_str), "<error>");
221 time_str[sizeof(time_str) - 1] = '\0';
223 if (! sdb_strfinterval(interval_str, sizeof(interval_str),
224 obj->interval))
225 snprintf(interval_str, sizeof(interval_str), "<error>");
226 interval_str[sizeof(interval_str) - 1] = '\0';
228 sdb_strbuf_append(f->buf, "\"last_update\": \"%s\", "
229 "\"update_interval\": \"%s\", \"backends\": [",
230 time_str, interval_str);
232 for (i = 0; i < obj->backends_num; ++i) {
233 sdb_strbuf_append(f->buf, "\"%s\"", obj->backends[i]);
234 if (i < obj->backends_num - 1)
235 sdb_strbuf_append(f->buf, ",");
236 }
237 sdb_strbuf_append(f->buf, "]");
238 return 0;
239 } /* json_emit */
241 /*
242 * public API
243 */
245 sdb_store_json_formatter_t *
246 sdb_store_json_formatter(sdb_strbuf_t *buf, int type, int flags)
247 {
248 return F(sdb_object_create("json-formatter", formatter_type,
249 buf, type, flags));
250 } /* sdb_store_json_formatter */
252 int
253 sdb_store_json_emit(sdb_store_json_formatter_t *f, sdb_store_obj_t *obj)
254 {
255 if ((! f) || (! obj))
256 return -1;
257 return json_emit(f, obj);
258 } /* sdb_store_json_emit */
260 int
261 sdb_store_json_emit_full(sdb_store_json_formatter_t *f, sdb_store_obj_t *obj,
262 sdb_store_matcher_t *filter)
263 {
264 sdb_avltree_t *trees[] = { NULL, NULL, NULL };
265 size_t i;
267 if (sdb_store_json_emit(f, obj))
268 return -1;
270 if (obj->type == SDB_HOST) {
271 trees[0] = HOST(obj)->attributes;
272 trees[1] = HOST(obj)->metrics;
273 trees[2] = HOST(obj)->services;
274 }
275 else if (obj->type == SDB_SERVICE)
276 trees[0] = SVC(obj)->attributes;
277 else if (obj->type == SDB_METRIC)
278 trees[0] = METRIC(obj)->attributes;
279 else if (obj->type == SDB_ATTRIBUTE)
280 return 0;
281 else
282 return -1;
284 for (i = 0; i < SDB_STATIC_ARRAY_LEN(trees); ++i) {
285 sdb_avltree_iter_t *iter;
287 if (! trees[i])
288 continue;
290 iter = sdb_avltree_get_iter(trees[i]);
291 while (sdb_avltree_iter_has_next(iter)) {
292 sdb_store_obj_t *child;
293 child = STORE_OBJ(sdb_avltree_iter_get_next(iter));
295 if (filter && (! sdb_store_matcher_matches(filter, child, NULL)))
296 continue;
298 if (sdb_store_json_emit_full(f, child, filter)) {
299 sdb_avltree_iter_destroy(iter);
300 return -1;
301 }
302 }
303 sdb_avltree_iter_destroy(iter);
304 }
305 return 0;
306 } /* sdb_store_json_emit_full */
308 int
309 sdb_store_json_finish(sdb_store_json_formatter_t *f)
310 {
311 if (! f)
312 return -1;
314 if (! f->context[0]) {
315 /* no content */
316 if (f->flags & SDB_WANT_ARRAY)
317 sdb_strbuf_append(f->buf, "[]");
318 return 0;
319 }
321 while (f->current > 0) {
322 sdb_strbuf_append(f->buf, "}]");
323 --f->current;
324 }
325 sdb_strbuf_append(f->buf, "}");
327 if (f->flags & SDB_WANT_ARRAY)
328 sdb_strbuf_append(f->buf, "]");
329 return 0;
330 } /* sdb_store_json_finish */
332 /* vim: set tw=78 sw=4 ts=4 noexpandtab : */