1 /**
2 * collection4 - action_instance_data_json.c
3 * Copyright (C) 2010 Florian octo Forster
4 *
5 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU Lesser General Public
7 * License as published by the Free Software Foundation; either
8 * version 2.1 of the License, or (at your option) any later version.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * Lesser General Public License for more details.
14 *
15 * You should have received a copy of the GNU Lesser General Public
16 * License along with this program; if not, write to the Free Software
17 * Foundation, Inc., 51 Franklin Street, Fifth Floor,
18 * Boston, MA 02110-1301 USA
19 *
20 * Authors:
21 * Florian octo Forster <ff at octo.it>
22 **/
24 #include <stdlib.h>
25 #include <stdio.h>
26 #include <string.h>
27 #include <errno.h>
28 #include <stdint.h>
29 #include <inttypes.h>
30 #include <assert.h>
32 #include "action_instance_data_json.h"
33 #include "common.h"
34 #include "graph.h"
35 #include "graph_instance.h"
36 #include "graph_list.h"
37 #include "utils_cgi.h"
39 #include <fcgiapp.h>
40 #include <fcgi_stdio.h>
42 /* Expire data after one day. */
43 #define EXPIRES_SECS 86400
45 static void write_callback (__attribute__((unused)) void *ctx, /* {{{ */
46 const char *str, unsigned int len)
47 {
48 fwrite ((void *) str, /* size = */ len, /* nmemb = */ 1, stdout);
49 } /* }}} void write_callback */
51 static int param_get_resolution (dp_time_t *resolution) /* {{{ */
52 {
53 const char *tmp;
54 char *endptr;
55 double value;
57 tmp = param ("resolution");
58 if (tmp == NULL)
59 return (ENOENT);
61 errno = 0;
62 endptr = NULL;
63 value = strtod (tmp, &endptr);
64 if (errno != 0)
65 return (errno);
66 else if ((value <= 0.0) || (endptr == tmp))
67 return (EINVAL);
69 resolution->tv_sec = (time_t) value;
70 resolution->tv_nsec = (long) ((value - ((double) resolution->tv_sec)) * 1000000000.0);
71 return (0);
72 } /* }}} int param_get_resolution */
74 int action_instance_data_json (void) /* {{{ */
75 {
76 graph_config_t *cfg;
77 graph_instance_t *inst;
79 time_t tt_begin = 0;
80 time_t tt_end = 0;
81 time_t tt_now = 0;
83 dp_time_t dp_begin = { 0, 0 };
84 dp_time_t dp_end = { 0, 0 };
85 dp_time_t dp_resolution = { 0, 0 };
87 yajl_gen_config handler_config;
88 yajl_gen handler;
90 time_t expires;
91 char time_buffer[128];
92 int status;
94 cfg = gl_graph_get_selected ();
95 if (cfg == NULL)
96 return (ENOMEM);
98 inst = inst_get_selected (cfg);
99 if (inst == NULL)
100 return (EINVAL);
102 /* Get selected time(s) */
103 tt_begin = tt_end = tt_now = 0;
104 status = get_time_args (&tt_begin, &tt_end, &tt_now);
105 if (status != 0)
106 return (status);
108 dp_begin.tv_sec = tt_begin;
109 dp_begin.tv_nsec = 0;
110 dp_end.tv_sec = tt_end;
111 dp_end.tv_nsec = 0;
113 dp_resolution.tv_sec = (tt_end - tt_begin) / 324;
114 param_get_resolution (&dp_resolution);
116 memset (&handler_config, 0, sizeof (handler_config));
117 handler_config.beautify = 0;
118 handler_config.indentString = " ";
120 handler = yajl_gen_alloc2 (write_callback,
121 &handler_config,
122 /* alloc functions = */ NULL,
123 /* context = */ NULL);
124 if (handler == NULL)
125 return (-1);
127 printf ("Content-Type: application/json\n");
129 /* By default, permit caching until 1/1000th after the last data. If that
130 * data is in the past, assume the entire data is in the past and allow
131 * caching for one day. */
132 expires = tt_end + ((tt_end - tt_begin) / 1000);
133 if (expires < tt_now)
134 expires = tt_now + 86400;
136 status = time_to_rfc1123 (expires, time_buffer, sizeof (time_buffer));
137 if (status == 0)
138 printf ("Expires: %s\n"
139 "Cache-Control: public\n",
140 time_buffer);
141 printf ("\n");
143 status = inst_data_to_json (inst,
144 dp_begin, dp_end, dp_resolution, handler);
146 yajl_gen_free (handler);
148 return (status);
149 } /* }}} int action_instance_data_json */
151 /* vim: set sw=2 sts=2 et fdm=marker : */