5ecb83cfa015cc6b4cb606c1ad499676d6ebb2f6
1 /**
2 * collectd - src/utils_cache.c
3 * Copyright (C) 2007 Florian octo Forster
4 *
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License as published by the
7 * Free Software Foundation; only version 2 of the License is applicable.
8 *
9 * This program is distributed in the hope that it will be useful, but
10 * WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License along
15 * with this program; if not, write to the Free Software Foundation, Inc.,
16 * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
17 *
18 * Author:
19 * Florian octo Forster <octo at verplant.org>
20 **/
22 #include "collectd.h"
23 #include "common.h"
24 #include "plugin.h"
25 #include "utils_avltree.h"
27 #include <assert.h>
28 #include <pthread.h>
30 typedef struct cache_entry_s
31 {
32 char name[6 * DATA_MAX_NAME_LEN];
33 int values_num;
34 gauge_t *values_gauge;
35 counter_t *values_counter;
36 time_t last_update;
37 } cache_entry_t;
39 static avl_tree_t *cache_tree = NULL;
40 static pthread_mutex_t cache_lock;
42 static int cache_compare (const cache_entry_t *a, const cache_entry_t *b)
43 {
44 assert ((a != NULL) && (b != NULL));
45 return (strcmp (a->name, b->name));
46 } /* int cache_compare */
48 int uc_init (void)
49 {
50 if (cache_tree == NULL)
51 cache_tree = avl_create ((int (*) (const void *, const void *))
52 cache_compare);
54 return (0);
55 } /* int uc_init */
57 int uc_update (const data_set_t *ds, const value_list_t *vl)
58 {
59 char name[6 * DATA_MAX_NAME_LEN];
60 cache_entry_t *ce = NULL;
62 if (FORMAT_VL (name, sizeof (name), vl, ds) != 0)
63 {
64 ERROR ("uc_insert: FORMAT_VL failed.");
65 return (-1);
66 }
68 pthread_mutex_lock (&cache_lock);
70 if (avl_get (cache_tree, name, (void *) &ce) == 0)
71 {
72 int i;
74 assert (ce != NULL);
75 assert (ce->values_num == ds->ds_num);
77 if (ce->last_update >= vl->time)
78 {
79 pthread_mutex_unlock (&cache_lock);
80 NOTICE ("uc_insert: Value too old: name = %s; value time = %u; "
81 "last cache update = %u;",
82 name, (unsigned int) vl->time, (unsigned int) ce->last_update);
83 return (-1);
84 }
86 for (i = 0; i < ds->ds_num; i++)
87 {
88 if (ds->ds[i].type == DS_TYPE_COUNTER)
89 {
90 ce->values_gauge[i] = ((double) (vl->values[i].counter
91 - ce->values_counter[i]))
92 / ((double) (vl->time - ce->last_update));
93 ce->values_counter[i] = vl->values[i].counter;
94 }
95 else /* if (ds->ds[i].type == DS_TYPE_GAUGE) */
96 {
97 ce->values_gauge[i] = vl->values[i].gauge;
98 }
99 DEBUG ("uc_insert: %s: ds[%i] = %lf", name, i, ce->values_gauge[i]);
100 } /* for (i) */
102 ce->last_update = vl->time;
103 }
104 else /* key is not found */
105 {
106 int i;
107 size_t ce_size = sizeof (cache_entry_t)
108 + ds->ds_num * (sizeof (counter_t) + sizeof (gauge_t));
109 char *key;
111 key = strdup (name);
112 if (key == NULL)
113 {
114 pthread_mutex_unlock (&cache_lock);
115 ERROR ("uc_insert: strdup failed.");
116 return (-1);
117 }
119 ce = (cache_entry_t *) malloc (ce_size);
120 if (ce == NULL)
121 {
122 pthread_mutex_unlock (&cache_lock);
123 ERROR ("uc_insert: malloc (%u) failed.", (unsigned int) ce_size);
124 return (-1);
125 }
127 memset (ce, '\0', ce_size);
129 strncpy (ce->name, name, sizeof (ce->name));
130 ce->name[sizeof (ce->name) - 1] = '\0';
132 ce->values_num = ds->ds_num;
133 ce->values_gauge = (gauge_t *) (ce + 1);
134 ce->values_counter = (counter_t *) (ce->values_gauge + ce->values_num);
136 for (i = 0; i < ds->ds_num; i++)
137 {
138 if (ds->ds[i].type == DS_TYPE_COUNTER)
139 {
140 ce->values_gauge[i] = NAN;
141 ce->values_counter[i] = vl->values[i].counter;
142 }
143 else /* if (ds->ds[i].type == DS_TYPE_GAUGE) */
144 {
145 ce->values_gauge[i] = vl->values[i].gauge;
146 }
147 } /* for (i) */
149 ce->last_update = vl->time;
151 if (avl_insert (cache_tree, key, ce) != 0)
152 {
153 pthread_mutex_unlock (&cache_lock);
154 ERROR ("uc_insert: avl_insert failed.");
155 return (-1);
156 }
158 DEBUG ("uc_insert: Added %s to the cache.", name);
159 } /* if (key is not found) */
161 pthread_mutex_unlock (&cache_lock);
163 return (0);
164 } /* int uc_insert */
166 gauge_t *uc_get_rate (const data_set_t *ds, const value_list_t *vl)
167 {
168 char name[6 * DATA_MAX_NAME_LEN];
169 gauge_t *ret = NULL;
170 cache_entry_t *ce = NULL;
172 if (FORMAT_VL (name, sizeof (name), vl, ds) != 0)
173 {
174 ERROR ("uc_insert: FORMAT_VL failed.");
175 return (NULL);
176 }
178 pthread_mutex_lock (&cache_lock);
180 if (avl_get (cache_tree, name, (void *) &ce) == 0)
181 {
182 assert (ce != NULL);
183 assert (ce->values_num == ds->ds_num);
185 ret = (gauge_t *) malloc (ce->values_num * sizeof (gauge_t));
186 if (ret == NULL)
187 {
188 ERROR ("uc_get_rate: malloc failed.");
189 }
190 else
191 {
192 memcpy (ret, ce->values_gauge, ce->values_num * sizeof (gauge_t));
193 }
194 }
196 pthread_mutex_unlock (&cache_lock);
198 return (ret);
199 } /* gauge_t *uc_get_rate */
201 /* vim: set sw=2 ts=8 sts=2 tw=78 : */