From fa67d36eb4ef20d3b1988b153c86e57c19ed2e2b Mon Sep 17 00:00:00 2001 From: Florian Forster Date: Thu, 15 Feb 2007 12:10:09 +0100 Subject: [PATCH] rrdtool plugin: Use the AVL-tree to implement the cache. --- src/rrdtool.c | 137 +++++++++++++++++++++++++++++++++----------------- 1 file changed, 90 insertions(+), 47 deletions(-) diff --git a/src/rrdtool.c b/src/rrdtool.c index beb5a73e..1c7d6629 100644 --- a/src/rrdtool.c +++ b/src/rrdtool.c @@ -22,7 +22,7 @@ #include "collectd.h" #include "plugin.h" #include "common.h" -#include "utils_llist.h" +#include "utils_avltree.h" #include "utils_debug.h" /* @@ -76,16 +76,18 @@ static int rra_types_num = 3; static const char *config_keys[] = { "CacheTimeout", + "CacheFlush", "DataDir", NULL }; -static int config_keys_num = 2; +static int config_keys_num = 3; static char *datadir = NULL; -static int cache_timeout = 0; -static time_t cache_flush; -static llist_t *cache = NULL; +static int cache_timeout = 0; +static int cache_flush_timeout = 0; +static time_t cache_flush_last; +static avl_tree_t *cache = NULL; /* * * * * * * * * * * WARNING: Magic * @@ -410,14 +412,9 @@ static rrd_cache_t *rrd_cache_insert (const char *filename, const char *value) { rrd_cache_t *rc = NULL; - llentry_t *le = NULL; if (cache != NULL) - { - le = llist_search (cache, filename); - if (le != NULL) - rc = (rrd_cache_t *) le->value; - } + avl_get (cache, filename, (void *) &rc); if (rc == NULL) { @@ -435,12 +432,13 @@ static rrd_cache_t *rrd_cache_insert (const char *filename, { syslog (LOG_ERR, "rrdtool plugin: realloc failed: %s", strerror (errno)); - free (rc); - if (le != NULL) + if (cache != NULL) { - llist_remove (cache, le); - llentry_destroy (le); + void *cache_key = NULL; + avl_remove (cache, filename, &cache_key, NULL); + sfree (cache_key); } + free (rc); return (NULL); } @@ -451,11 +449,21 @@ static rrd_cache_t *rrd_cache_insert (const char *filename, if (rc->values_num == 1) rc->first_value = time (NULL); - if ((cache != NULL) && (le == NULL)) + /* Insert if this is the first value */ + if ((cache != NULL) && (rc->values_num == 1)) { - le = llentry_create (filename, (void *) rc); - if (le != NULL) - llist_prepend (cache, le); + void *cache_key = strdup (filename); + + if (cache_key == NULL) + { + syslog (LOG_ERR, "rrdtool plugin: strdup failed: %s", + strerror (errno)); + sfree (rc->values); + sfree (rc); + return (NULL); + } + + avl_insert (cache, cache_key, rc); } DBG ("rrd_cache_insert (%s, %s) = %p", filename, value, (void *) rc); @@ -513,10 +521,16 @@ static int rrd_write_cache_entry (const char *filename, rrd_cache_t *rc) static void rrd_cache_flush (int timeout) { - llentry_t *le; rrd_cache_t *rc; time_t now; + char **keys = NULL; + int keys_num = 0; + + char *key; + avl_iterator_t *iter; + int i; + if (cache == NULL) return; @@ -524,34 +538,48 @@ static void rrd_cache_flush (int timeout) now = time (NULL); - /* Remove empty entries */ - le = llist_head (cache); - while (le != NULL) + /* Build a list of entries to be flushed */ + iter = avl_get_iterator (cache); + while (avl_iterator_next (iter, (void *) &key, (void *) &rc) == 0) { - llentry_t *next = le->next; - rc = (rrd_cache_t *) le->value; - if (rc->values_num == 0) + DBG ("key = %s; age = %i;", key, now - rc->first_value); + if ((now - rc->first_value) >= timeout) { - DBG ("Removing cache entry for `%s'", le->key); - free (rc->values); - free (rc); - llist_remove (cache, le); + keys = (char **) realloc ((void *) keys, + (keys_num + 1) * sizeof (char *)); + if (keys == NULL) + { + DBG ("realloc failed: %s", strerror (errno)); + syslog (LOG_ERR, "rrdtool plugin: " + "realloc failed: %s", + strerror (errno)); + avl_iterator_destroy (iter); + return; + } + keys[keys_num] = key; + keys_num++; } - le = next; - } - - /* Write timed out entries */ - le = llist_head (cache); - while (le != NULL) + } /* while (avl_iterator_next) */ + avl_iterator_destroy (iter); + + for (i = 0; i < keys_num; i++) { - rc = (rrd_cache_t *) le->value; - if ((now - rc->first_value) >= timeout) - rrd_write_cache_entry (le->key, rc); + if (avl_remove (cache, keys[i], NULL, (void *) &rc) != 0) + { + DBG ("avl_remove (%s) failed.", keys[i]); + continue; + } - le = le->next; - } + rrd_write_cache_entry (keys[i], rc); + sfree (keys[i]); keys[i] = NULL; + sfree (rc->values); + sfree (rc); + } /* for (i = 0..keys_num) */ - cache_flush = now; + free (keys); + DBG ("Flushed %i value(s)", keys_num); + + cache_flush_last = now; } /* void rrd_cache_flush */ static int rrd_write (const data_set_t *ds, const value_list_t *vl) @@ -608,13 +636,13 @@ static int rrd_write (const data_set_t *ds, const value_list_t *vl) if ((now - rc->first_value) >= cache_timeout) rrd_write_cache_entry (filename, rc); - if ((time (NULL) - cache_flush) >= cache_timeout) + if ((now - cache_flush_last) >= cache_flush_timeout) { - rrd_cache_flush (cache_timeout); + rrd_cache_flush (cache_flush_timeout); } return (0); -} /* int rrd_dispatch */ +} /* int rrd_write */ static int rrd_config (const char *key, const char *val) { @@ -629,6 +657,17 @@ static int rrd_config (const char *key, const char *val) } cache_timeout = tmp; } + else if (strcasecmp ("CacheFlush", key) == 0) + { + int tmp = atoi (val); + if (tmp < 0) + { + fprintf (stderr, "rrdtool: `CacheFlush' must " + "be greater than 0.\n"); + return (1); + } + cache_flush_timeout = tmp; + } else if (strcasecmp ("DataDir", key) == 0) { if (datadir != NULL) @@ -668,11 +707,15 @@ static int rrd_init (void) if (cache_timeout < 2) { cache_timeout = 0; + cache_flush_timeout = 0; } else { - cache = llist_create (); - cache_flush = time (NULL); + if (cache_flush_timeout < cache_timeout) + cache_flush_timeout = 10 * cache_timeout; + + cache = avl_create ((int (*) (const void *, const void *)) strcmp); + cache_flush_last = time (NULL); plugin_register_shutdown ("rrdtool", rrd_shutdown); } return (0); -- 2.30.2