src/core/timeseries.c

   1 /*
   2  * SysDB - src/core/timeseries.c
   3  * Copyright (C) 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 #if HAVE_CONFIG_H
  29 #       include "config.h"
  30 #endif /* HAVE_CONFIG_H */
  31
  32 #include "sysdb.h"
  33 #include "core/timeseries.h"
  34
  35 #include <stdlib.h>
  36 #include <string.h>
  37 #include <math.h>
  38
  39 /*
  40  * public API
  41  */
  42
  43 sdb_timeseries_t *
  44 sdb_timeseries_create(size_t data_names_len, const char * const *data_names,
  45                 size_t data_len)
  46 {
  47         sdb_timeseries_t *ts;
  48         size_t i;
  49
  50         ts = calloc(1, sizeof(*ts));
  51         if (! ts)
  52                 return NULL;
  53
  54         ts->data = calloc(data_names_len, sizeof(*ts->data));
  55         if (! ts->data) {
  56                 sdb_timeseries_destroy(ts);
  57                 return NULL;
  58         }
  59         ts->data_names_len = data_names_len;
  60         for (i = 0; i < data_names_len; ++i) {
  61                 ts->data[i] = calloc(data_len, sizeof(**ts->data));
  62                 if (! ts->data[i]) {
  63                         sdb_timeseries_destroy(ts);
  64                         return NULL;
  65                 }
  66         }
  67         ts->data_len = data_len;
  68
  69         ts->data_names = calloc(data_names_len, sizeof(*ts->data_names));
  70         if (! ts->data_names) {
  71                 sdb_timeseries_destroy(ts);
  72                 return NULL;
  73         }
  74         for (i = 0; i < data_names_len; ++i) {
  75                 ts->data_names[i] = strdup(data_names[i]);
  76                 if (! ts->data_names[i]) {
  77                         sdb_timeseries_destroy(ts);
  78                         return NULL;
  79                 }
  80         }
  81         return ts;
  82 } /* sdb_timeseries_create */
  83
  84 void
  85 sdb_timeseries_destroy(sdb_timeseries_t *ts)
  86 {
  87         size_t i;
  88
  89         if (! ts)
  90                 return;
  91
  92         if (ts->data) {
  93                 for (i = 0; i < ts->data_names_len; ++i) {
  94                         if (ts->data[i])
  95                                 free(ts->data[i]);
  96                         ts->data[i] = NULL;
  97                 }
  98                 free(ts->data);
  99         }
 100         ts->data = NULL;
 101         ts->data_len = 0;
 102
 103         if (ts->data_names) {
 104                 for (i = 0; i < ts->data_names_len; ++i) {
 105                         if (ts->data_names[i])
 106                                 free(ts->data_names[i]);
 107                         ts->data_names[i] = NULL;
 108                 }
 109                 free(ts->data_names);
 110         }
 111         ts->data_names = NULL;
 112         ts->data_names_len = 0;
 113         free(ts);
 114 } /* sdb_timeseries_destroy */
 115
 116 int
 117 sdb_timeseries_tojson(sdb_timeseries_t *ts, sdb_strbuf_t *buf)
 118 {
 119         char start_str[64];
 120         char end_str[64];
 121
 122         size_t i;
 123
 124         if ((! ts) || (! buf))
 125                 return -1;
 126
 127         /* TODO: make time format configurable */
 128         if (! sdb_strftime(start_str, sizeof(start_str), ts->start))
 129                 snprintf(start_str, sizeof(start_str), "<error>");
 130         start_str[sizeof(start_str) - 1] = '\0';
 131         if (! sdb_strftime(end_str, sizeof(end_str), ts->end))
 132                 snprintf(end_str, sizeof(end_str), "<error>");
 133         end_str[sizeof(end_str) - 1] = '\0';
 134
 135         sdb_strbuf_append(buf, "{\"start\": \"%s\", \"end\": \"%s\", \"data\": {",
 136                         start_str, end_str);
 137
 138         for (i = 0; i < ts->data_names_len; ++i) {
 139                 size_t j;
 140                 sdb_strbuf_append(buf, "\"%s\": [", ts->data_names[i]);
 141
 142                 for (j = 0; j < ts->data_len; ++j) {
 143                         char time_str[64];
 144
 145                         if (! sdb_strftime(time_str, sizeof(time_str), ts->data[i][j].timestamp))
 146                                 snprintf(time_str, sizeof(time_str), "<error>");
 147                         time_str[sizeof(time_str) - 1] = '\0';
 148
 149                         /* Some GNU libc versions may print '-nan' which we dont' want */
 150                         if (isnan(ts->data[i][j].value))
 151                                 sdb_strbuf_append(buf, "{\"timestamp\": \"%s\", "
 152                                                 "\"value\": \"nan\"}", time_str);
 153                         else
 154                                 sdb_strbuf_append(buf, "{\"timestamp\": \"%s\", "
 155                                                 "\"value\": \"%f\"}", time_str, ts->data[i][j].value);
 156
 157                         if (j < ts->data_len - 1)
 158                                 sdb_strbuf_append(buf, ",");
 159                 }
 160
 161                 if (i < ts->data_names_len - 1)
 162                         sdb_strbuf_append(buf, "],");
 163                 else
 164                         sdb_strbuf_append(buf, "]");
 165         }
 166         sdb_strbuf_append(buf, "}}");
 167         return 0;
 168 } /* sdb_timeseries_tojson */
 169 /* vim: set tw=78 sw=4 ts=4 noexpandtab : */
 170