2 * collectd - src/utils_cache.c
3 * Copyright (C) 2007-2010 Florian octo Forster
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.
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.
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
19 * Florian octo Forster <octo at collectd.org>
25 #include "utils_avltree.h"
26 #include "utils_cache.h"
27 #include "meta_data.h"
32 typedef struct cache_entry_s
34 char name[6 * DATA_MAX_NAME_LEN];
36 gauge_t *values_gauge;
38 /* Time contained in the package
39 * (for calculating rates) */
41 /* Time according to the local clock
42 * (for purging old entries) */
44 /* Interval in which the data is collected
45 * (for purding old entries) */
51 * +-----+-----+-----+-----+-----+-----+-----+-----+-----+----
52 * ! 0 ! 1 ! 2 ! 3 ! 4 ! 5 ! 6 ! 7 ! 8 ! ...
53 * +-----+-----+-----+-----+-----+-----+-----+-----+-----+----
54 * ! ds0 ! ds1 ! ds2 ! ds0 ! ds1 ! ds2 ! ds0 ! ds1 ! ds2 ! ...
55 * +-----+-----+-----+-----+-----+-----+-----+-----+-----+----
56 * ! t = 0 ! t = 1 ! t = 2 ! ...
57 * +-----------------+-----------------+-----------------+----
60 size_t history_index; /* points to the next position to write to. */
61 size_t history_length;
66 static c_avl_tree_t *cache_tree = NULL;
67 static pthread_mutex_t cache_lock = PTHREAD_MUTEX_INITIALIZER;
69 static int cache_compare (const cache_entry_t *a, const cache_entry_t *b)
71 assert ((a != NULL) && (b != NULL));
72 return (strcmp (a->name, b->name));
73 } /* int cache_compare */
75 static cache_entry_t *cache_alloc (int values_num)
79 ce = (cache_entry_t *) malloc (sizeof (cache_entry_t));
82 ERROR ("utils_cache: cache_alloc: malloc failed.");
85 memset (ce, '\0', sizeof (cache_entry_t));
86 ce->values_num = values_num;
88 ce->values_gauge = calloc (values_num, sizeof (*ce->values_gauge));
89 ce->values_raw = calloc (values_num, sizeof (*ce->values_raw));
90 if ((ce->values_gauge == NULL) || (ce->values_raw == NULL))
92 sfree (ce->values_gauge);
93 sfree (ce->values_raw);
95 ERROR ("utils_cache: cache_alloc: calloc failed.");
100 ce->history_length = 0;
104 } /* cache_entry_t *cache_alloc */
106 static void cache_free (cache_entry_t *ce)
111 sfree (ce->values_gauge);
112 sfree (ce->values_raw);
114 if (ce->meta != NULL)
116 meta_data_destroy (ce->meta);
120 } /* void cache_free */
122 static void uc_check_range (const data_set_t *ds, cache_entry_t *ce)
126 for (i = 0; i < ds->ds_num; i++)
128 if (isnan (ce->values_gauge[i]))
130 else if (ce->values_gauge[i] < ds->ds[i].min)
131 ce->values_gauge[i] = NAN;
132 else if (ce->values_gauge[i] > ds->ds[i].max)
133 ce->values_gauge[i] = NAN;
135 } /* void uc_check_range */
137 static int uc_insert (const data_set_t *ds, const value_list_t *vl,
144 /* `cache_lock' has been locked by `uc_update' */
146 key_copy = strdup (key);
147 if (key_copy == NULL)
149 ERROR ("uc_insert: strdup failed.");
153 ce = cache_alloc (ds->ds_num);
157 ERROR ("uc_insert: cache_alloc (%i) failed.", ds->ds_num);
161 sstrncpy (ce->name, key, sizeof (ce->name));
163 for (i = 0; i < ds->ds_num; i++)
165 switch (ds->ds[i].type)
167 case DS_TYPE_COUNTER:
168 ce->values_gauge[i] = NAN;
169 ce->values_raw[i].counter = vl->values[i].counter;
173 ce->values_gauge[i] = vl->values[i].gauge;
174 ce->values_raw[i].gauge = vl->values[i].gauge;
178 ce->values_gauge[i] = NAN;
179 ce->values_raw[i].derive = vl->values[i].derive;
182 case DS_TYPE_ABSOLUTE:
183 ce->values_gauge[i] = NAN;
184 if (vl->interval > 0)
185 ce->values_gauge[i] = ((double) vl->values[i].absolute)
186 / CDTIME_T_TO_DOUBLE (vl->interval);
187 ce->values_raw[i].absolute = vl->values[i].absolute;
191 /* This shouldn't happen. */
192 ERROR ("uc_insert: Don't know how to handle data source type %i.",
195 } /* switch (ds->ds[i].type) */
198 /* Prune invalid gauge data */
199 uc_check_range (ds, ce);
201 ce->last_time = vl->time;
202 ce->last_update = cdtime ();
203 ce->interval = vl->interval;
204 ce->state = STATE_OKAY;
206 if (c_avl_insert (cache_tree, key_copy, ce) != 0)
209 ERROR ("uc_insert: c_avl_insert failed.");
213 DEBUG ("uc_insert: Added %s to the cache.", key);
215 } /* int uc_insert */
219 if (cache_tree == NULL)
220 cache_tree = c_avl_create ((int (*) (const void *, const void *))
226 int uc_check_timeout (void)
232 cdtime_t *keys_time = NULL;
233 cdtime_t *keys_interval = NULL;
237 c_avl_iterator_t *iter;
242 pthread_mutex_lock (&cache_lock);
246 /* Build a list of entries to be flushed */
247 iter = c_avl_get_iterator (cache_tree);
248 while (c_avl_iterator_next (iter, (void *) &key, (void *) &ce) == 0)
253 /* If the entry is fresh enough, continue. */
254 if ((now - ce->last_update) < (ce->interval * timeout_g))
257 /* If entry has not been updated, add to `keys' array */
258 tmp = (char **) realloc ((void *) keys,
259 (keys_len + 1) * sizeof (char *));
262 ERROR ("uc_check_timeout: realloc failed.");
267 tmp_time = realloc (keys_time, (keys_len + 1) * sizeof (*keys_time));
268 if (tmp_time == NULL)
270 ERROR ("uc_check_timeout: realloc failed.");
273 keys_time = tmp_time;
275 tmp_time = realloc (keys_interval, (keys_len + 1) * sizeof (*keys_interval));
276 if (tmp_time == NULL)
278 ERROR ("uc_check_timeout: realloc failed.");
281 keys_interval = tmp_time;
283 keys[keys_len] = strdup (key);
284 if (keys[keys_len] == NULL)
286 ERROR ("uc_check_timeout: strdup failed.");
289 keys_time[keys_len] = ce->last_time;
290 keys_interval[keys_len] = ce->interval;
293 } /* while (c_avl_iterator_next) */
295 c_avl_iterator_destroy (iter);
296 pthread_mutex_unlock (&cache_lock);
301 /* Call the "missing" callback for each value. Do this before removing the
302 * value from the cache, so that callbacks can still access the data stored,
303 * including plugin specific meta data, rates, history, …. This must be done
304 * without holding the lock, otherwise we will run into a deadlock if a
305 * plugin calls the cache interface. */
306 for (i = 0; i < keys_len; i++)
308 value_list_t vl = VALUE_LIST_INIT;
314 status = parse_identifier_vl (keys[i], &vl);
317 ERROR ("uc_check_timeout: parse_identifier_vl (\"%s\") failed.", keys[i]);
321 vl.time = keys_time[i];
322 vl.interval = keys_interval[i];
324 plugin_dispatch_missing (&vl);
325 } /* for (i = 0; i < keys_len; i++) */
327 /* Now actually remove all the values from the cache. We don't re-evaluate
328 * the timestamp again, so in theory it is possible we remove a value after
329 * it is updated here. */
330 pthread_mutex_lock (&cache_lock);
331 for (i = 0; i < keys_len; i++)
336 status = c_avl_remove (cache_tree, keys[i],
337 (void *) &key, (void *) &ce);
340 ERROR ("uc_check_timeout: c_avl_remove (\"%s\") failed.", keys[i]);
348 } /* for (i = 0; i < keys_len; i++) */
349 pthread_mutex_unlock (&cache_lock);
353 sfree (keys_interval);
356 } /* int uc_check_timeout */
358 int uc_update (const data_set_t *ds, const value_list_t *vl)
360 char name[6 * DATA_MAX_NAME_LEN];
361 cache_entry_t *ce = NULL;
365 if (FORMAT_VL (name, sizeof (name), vl) != 0)
367 ERROR ("uc_update: FORMAT_VL failed.");
371 pthread_mutex_lock (&cache_lock);
373 status = c_avl_get (cache_tree, name, (void *) &ce);
374 if (status != 0) /* entry does not yet exist */
376 status = uc_insert (ds, vl, name);
377 pthread_mutex_unlock (&cache_lock);
382 assert (ce->values_num == ds->ds_num);
384 if (ce->last_time >= vl->time)
386 pthread_mutex_unlock (&cache_lock);
387 NOTICE ("uc_update: Value too old: name = %s; value time = %.3f; "
388 "last cache update = %.3f;",
390 CDTIME_T_TO_DOUBLE (vl->time),
391 CDTIME_T_TO_DOUBLE (ce->last_time));
395 for (i = 0; i < ds->ds_num; i++)
397 switch (ds->ds[i].type)
399 case DS_TYPE_COUNTER:
403 /* check if the counter has wrapped around */
404 if (vl->values[i].counter < ce->values_raw[i].counter)
406 if (ce->values_raw[i].counter <= 4294967295U)
407 diff = (4294967295U - ce->values_raw[i].counter)
408 + vl->values[i].counter;
410 diff = (18446744073709551615ULL - ce->values_raw[i].counter)
411 + vl->values[i].counter;
413 else /* counter has NOT wrapped around */
415 diff = vl->values[i].counter - ce->values_raw[i].counter;
418 ce->values_gauge[i] = ((double) diff)
419 / (CDTIME_T_TO_DOUBLE (vl->time - ce->last_time));
420 ce->values_raw[i].counter = vl->values[i].counter;
425 ce->values_raw[i].gauge = vl->values[i].gauge;
426 ce->values_gauge[i] = vl->values[i].gauge;
433 diff = vl->values[i].derive - ce->values_raw[i].derive;
435 ce->values_gauge[i] = ((double) diff)
436 / (CDTIME_T_TO_DOUBLE (vl->time - ce->last_time));
437 ce->values_raw[i].derive = vl->values[i].derive;
441 case DS_TYPE_ABSOLUTE:
442 ce->values_gauge[i] = ((double) vl->values[i].absolute)
443 / (CDTIME_T_TO_DOUBLE (vl->time - ce->last_time));
444 ce->values_raw[i].absolute = vl->values[i].absolute;
448 /* This shouldn't happen. */
449 pthread_mutex_unlock (&cache_lock);
450 ERROR ("uc_update: Don't know how to handle data source type %i.",
453 } /* switch (ds->ds[i].type) */
455 DEBUG ("uc_update: %s: ds[%i] = %lf", name, i, ce->values_gauge[i]);
458 /* Update the history if it exists. */
459 if (ce->history != NULL)
461 assert (ce->history_index < ce->history_length);
462 for (i = 0; i < ce->values_num; i++)
464 size_t hist_idx = (ce->values_num * ce->history_index) + i;
465 ce->history[hist_idx] = ce->values_gauge[i];
468 assert (ce->history_length > 0);
469 ce->history_index = (ce->history_index + 1) % ce->history_length;
472 /* Prune invalid gauge data */
473 uc_check_range (ds, ce);
475 ce->last_time = vl->time;
476 ce->last_update = cdtime ();
477 ce->interval = vl->interval;
479 pthread_mutex_unlock (&cache_lock);
482 } /* int uc_update */
484 int uc_get_rate_by_name (const char *name, gauge_t **ret_values, size_t *ret_values_num)
488 cache_entry_t *ce = NULL;
491 pthread_mutex_lock (&cache_lock);
493 if (c_avl_get (cache_tree, name, (void *) &ce) == 0)
497 /* remove missing values from getval */
498 if (ce->state == STATE_MISSING)
504 ret_num = ce->values_num;
505 ret = (gauge_t *) malloc (ret_num * sizeof (gauge_t));
508 ERROR ("utils_cache: uc_get_rate_by_name: malloc failed.");
513 memcpy (ret, ce->values_gauge, ret_num * sizeof (gauge_t));
519 DEBUG ("utils_cache: uc_get_rate_by_name: No such value: %s", name);
523 pthread_mutex_unlock (&cache_lock);
528 *ret_values_num = ret_num;
532 } /* gauge_t *uc_get_rate_by_name */
534 gauge_t *uc_get_rate (const data_set_t *ds, const value_list_t *vl)
536 char name[6 * DATA_MAX_NAME_LEN];
541 if (FORMAT_VL (name, sizeof (name), vl) != 0)
543 ERROR ("utils_cache: uc_get_rate: FORMAT_VL failed.");
547 status = uc_get_rate_by_name (name, &ret, &ret_num);
551 /* This is important - the caller has no other way of knowing how many
552 * values are returned. */
553 if (ret_num != (size_t) ds->ds_num)
555 ERROR ("utils_cache: uc_get_rate: ds[%s] has %i values, "
556 "but uc_get_rate_by_name returned %zu.",
557 ds->type, ds->ds_num, ret_num);
563 } /* gauge_t *uc_get_rate */
565 int uc_get_names (char ***ret_names, cdtime_t **ret_times, size_t *ret_number)
567 c_avl_iterator_t *iter;
569 cache_entry_t *value;
572 cdtime_t *times = NULL;
574 size_t size_arrays = 0;
578 if ((ret_names == NULL) || (ret_number == NULL))
581 pthread_mutex_lock (&cache_lock);
583 size_arrays = (size_t) c_avl_size (cache_tree);
586 /* Handle the "no values" case here, to avoid the error message when
587 * calloc() returns NULL. */
588 pthread_mutex_unlock (&cache_lock);
592 names = calloc (size_arrays, sizeof (*names));
593 times = calloc (size_arrays, sizeof (*times));
594 if ((names == NULL) || (times == NULL))
596 ERROR ("uc_get_names: calloc failed.");
599 pthread_mutex_unlock (&cache_lock);
603 iter = c_avl_get_iterator (cache_tree);
604 while (c_avl_iterator_next (iter, (void *) &key, (void *) &value) == 0)
606 /* remove missing values when list values */
607 if (value->state == STATE_MISSING)
610 /* c_avl_size does not return a number smaller than the number of elements
611 * returned by c_avl_iterator_next. */
612 assert (number < size_arrays);
614 if (ret_times != NULL)
615 times[number] = value->last_time;
617 names[number] = strdup (key);
618 if (names[number] == NULL)
625 } /* while (c_avl_iterator_next) */
627 c_avl_iterator_destroy (iter);
628 pthread_mutex_unlock (&cache_lock);
634 for (i = 0; i < number; i++)
644 if (ret_times != NULL)
646 *ret_number = number;
649 } /* int uc_get_names */
651 int uc_get_state (const data_set_t *ds, const value_list_t *vl)
653 char name[6 * DATA_MAX_NAME_LEN];
654 cache_entry_t *ce = NULL;
655 int ret = STATE_ERROR;
657 if (FORMAT_VL (name, sizeof (name), vl) != 0)
659 ERROR ("uc_get_state: FORMAT_VL failed.");
660 return (STATE_ERROR);
663 pthread_mutex_lock (&cache_lock);
665 if (c_avl_get (cache_tree, name, (void *) &ce) == 0)
671 pthread_mutex_unlock (&cache_lock);
674 } /* int uc_get_state */
676 int uc_set_state (const data_set_t *ds, const value_list_t *vl, int state)
678 char name[6 * DATA_MAX_NAME_LEN];
679 cache_entry_t *ce = NULL;
682 if (FORMAT_VL (name, sizeof (name), vl) != 0)
684 ERROR ("uc_get_state: FORMAT_VL failed.");
685 return (STATE_ERROR);
688 pthread_mutex_lock (&cache_lock);
690 if (c_avl_get (cache_tree, name, (void *) &ce) == 0)
697 pthread_mutex_unlock (&cache_lock);
700 } /* int uc_set_state */
702 int uc_get_history_by_name (const char *name,
703 gauge_t *ret_history, size_t num_steps, size_t num_ds)
705 cache_entry_t *ce = NULL;
709 pthread_mutex_lock (&cache_lock);
711 status = c_avl_get (cache_tree, name, (void *) &ce);
714 pthread_mutex_unlock (&cache_lock);
718 if (((size_t) ce->values_num) != num_ds)
720 pthread_mutex_unlock (&cache_lock);
724 /* Check if there are enough values available. If not, increase the buffer
726 if (ce->history_length < num_steps)
731 tmp = realloc (ce->history, sizeof (*ce->history)
732 * num_steps * ce->values_num);
735 pthread_mutex_unlock (&cache_lock);
739 for (i = ce->history_length * ce->values_num;
740 i < (num_steps * ce->values_num);
745 ce->history_length = num_steps;
746 } /* if (ce->history_length < num_steps) */
748 /* Copy the values to the output buffer. */
749 for (i = 0; i < num_steps; i++)
754 if (i < ce->history_index)
755 src_index = ce->history_index - (i + 1);
757 src_index = ce->history_length + ce->history_index - (i + 1);
758 src_index = src_index * num_ds;
760 dst_index = i * num_ds;
762 memcpy (ret_history + dst_index, ce->history + src_index,
763 sizeof (*ret_history) * num_ds);
766 pthread_mutex_unlock (&cache_lock);
769 } /* int uc_get_history_by_name */
771 int uc_get_history (const data_set_t *ds, const value_list_t *vl,
772 gauge_t *ret_history, size_t num_steps, size_t num_ds)
774 char name[6 * DATA_MAX_NAME_LEN];
776 if (FORMAT_VL (name, sizeof (name), vl) != 0)
778 ERROR ("utils_cache: uc_get_history: FORMAT_VL failed.");
782 return (uc_get_history_by_name (name, ret_history, num_steps, num_ds));
783 } /* int uc_get_history */
785 int uc_get_hits (const data_set_t *ds, const value_list_t *vl)
787 char name[6 * DATA_MAX_NAME_LEN];
788 cache_entry_t *ce = NULL;
789 int ret = STATE_ERROR;
791 if (FORMAT_VL (name, sizeof (name), vl) != 0)
793 ERROR ("uc_get_state: FORMAT_VL failed.");
794 return (STATE_ERROR);
797 pthread_mutex_lock (&cache_lock);
799 if (c_avl_get (cache_tree, name, (void *) &ce) == 0)
805 pthread_mutex_unlock (&cache_lock);
808 } /* int uc_get_hits */
810 int uc_set_hits (const data_set_t *ds, const value_list_t *vl, int hits)
812 char name[6 * DATA_MAX_NAME_LEN];
813 cache_entry_t *ce = NULL;
816 if (FORMAT_VL (name, sizeof (name), vl) != 0)
818 ERROR ("uc_get_state: FORMAT_VL failed.");
819 return (STATE_ERROR);
822 pthread_mutex_lock (&cache_lock);
824 if (c_avl_get (cache_tree, name, (void *) &ce) == 0)
831 pthread_mutex_unlock (&cache_lock);
834 } /* int uc_set_hits */
836 int uc_inc_hits (const data_set_t *ds, const value_list_t *vl, int step)
838 char name[6 * DATA_MAX_NAME_LEN];
839 cache_entry_t *ce = NULL;
842 if (FORMAT_VL (name, sizeof (name), vl) != 0)
844 ERROR ("uc_get_state: FORMAT_VL failed.");
845 return (STATE_ERROR);
848 pthread_mutex_lock (&cache_lock);
850 if (c_avl_get (cache_tree, name, (void *) &ce) == 0)
854 ce->hits = ret + step;
857 pthread_mutex_unlock (&cache_lock);
860 } /* int uc_inc_hits */
863 * Meta data interface
865 /* XXX: This function will acquire `cache_lock' but will not free it! */
866 static meta_data_t *uc_get_meta (const value_list_t *vl) /* {{{ */
868 char name[6 * DATA_MAX_NAME_LEN];
869 cache_entry_t *ce = NULL;
872 status = FORMAT_VL (name, sizeof (name), vl);
875 ERROR ("utils_cache: uc_get_meta: FORMAT_VL failed.");
879 pthread_mutex_lock (&cache_lock);
881 status = c_avl_get (cache_tree, name, (void *) &ce);
884 pthread_mutex_unlock (&cache_lock);
889 if (ce->meta == NULL)
890 ce->meta = meta_data_create ();
892 if (ce->meta == NULL)
893 pthread_mutex_unlock (&cache_lock);
896 } /* }}} meta_data_t *uc_get_meta */
898 /* Sorry about this preprocessor magic, but it really makes this file much
900 #define UC_WRAP(wrap_function) { \
903 meta = uc_get_meta (vl); \
904 if (meta == NULL) return (-1); \
905 status = wrap_function (meta, key); \
906 pthread_mutex_unlock (&cache_lock); \
909 int uc_meta_data_exists (const value_list_t *vl, const char *key)
910 UC_WRAP (meta_data_exists)
912 int uc_meta_data_delete (const value_list_t *vl, const char *key)
913 UC_WRAP (meta_data_delete)
916 /* We need a new version of this macro because the following functions take
918 #define UC_WRAP(wrap_function) { \
921 meta = uc_get_meta (vl); \
922 if (meta == NULL) return (-1); \
923 status = wrap_function (meta, key, value); \
924 pthread_mutex_unlock (&cache_lock); \
927 int uc_meta_data_add_string (const value_list_t *vl,
930 UC_WRAP(meta_data_add_string)
931 int uc_meta_data_add_signed_int (const value_list_t *vl,
934 UC_WRAP(meta_data_add_signed_int)
935 int uc_meta_data_add_unsigned_int (const value_list_t *vl,
938 UC_WRAP(meta_data_add_unsigned_int)
939 int uc_meta_data_add_double (const value_list_t *vl,
942 UC_WRAP(meta_data_add_double)
943 int uc_meta_data_add_boolean (const value_list_t *vl,
946 UC_WRAP(meta_data_add_boolean)
948 int uc_meta_data_get_string (const value_list_t *vl,
951 UC_WRAP(meta_data_get_string)
952 int uc_meta_data_get_signed_int (const value_list_t *vl,
955 UC_WRAP(meta_data_get_signed_int)
956 int uc_meta_data_get_unsigned_int (const value_list_t *vl,
959 UC_WRAP(meta_data_get_unsigned_int)
960 int uc_meta_data_get_double (const value_list_t *vl,
963 UC_WRAP(meta_data_get_double)
964 int uc_meta_data_get_boolean (const value_list_t *vl,
967 UC_WRAP(meta_data_get_boolean)
970 /* vim: set sw=2 ts=8 sts=2 tw=78 : */