+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;
+ }
+
+ if (rc == NULL)
+ {
+ rc = (rrd_cache_t *) malloc (sizeof (rrd_cache_t));
+ if (rc == NULL)
+ return (NULL);
+ rc->values_num = 0;
+ rc->values = NULL;
+ rc->first_value = 0;
+ }
+
+ rc->values = (char **) realloc ((void *) rc->values,
+ (rc->values_num + 1) * sizeof (char *));
+ if (rc->values == NULL)
+ {
+ syslog (LOG_ERR, "rrdtool plugin: realloc failed: %s",
+ strerror (errno));
+ free (rc);
+ if (le != NULL)
+ {
+ llist_remove (cache, le);
+ llentry_destroy (le);
+ }
+ return (NULL);
+ }
+
+ rc->values[rc->values_num] = strdup (value);
+ if (rc->values[rc->values_num] != NULL)
+ rc->values_num++;
+
+ if (rc->values_num == 1)
+ rc->first_value = time (NULL);
+
+ if ((cache != NULL) && (le == NULL))
+ {
+ le = llentry_create (filename, (void *) rc);
+ if (le != NULL)
+ llist_prepend (cache, le);
+ }
+
+ DBG ("rrd_cache_insert (%s, %s) = %p", filename, value, (void *) rc);
+
+ return (rc);
+} /* rrd_cache_t *rrd_cache_insert */
+
+static int rrd_write_cache_entry (const char *filename, rrd_cache_t *rc)
+{
+ char **argv;
+ int argc;
+
+ char *fn;
+ int status;
+
+ argc = rc->values_num + 2;
+ argv = (char **) malloc ((argc + 1) * sizeof (char *));
+ if (argv == NULL)
+ return (-1);
+
+ fn = strdup (filename);
+ if (fn == NULL)
+ {
+ free (argv);
+ return (-1);
+ }
+
+ argv[0] = "update";
+ argv[1] = fn;
+ memcpy (argv + 2, rc->values, rc->values_num * sizeof (char *));
+ argv[argc] = NULL;
+
+ DBG ("rrd_update (argc = %i, argv = %p)", argc, (void *) argv);
+
+ optind = 0; /* bug in librrd? */
+ rrd_clear_error ();
+ status = rrd_update (argc, argv);
+
+ free (argv);
+ free (fn);
+
+ free (rc->values);
+ rc->values = NULL;
+ rc->values_num = 0;
+
+ if (status != 0)
+ {
+ syslog (LOG_WARNING, "rrd_update failed: %s: %s",
+ filename, rrd_get_error ());
+ return (-1);
+ }
+
+ return (0);
+} /* int rrd_update_file */
+
+static void rrd_cache_flush (int timeout)
+{
+ llentry_t *le;
+ rrd_cache_t *rc;
+ time_t now;
+
+ if (cache == NULL)
+ return;
+
+ DBG ("Flushing cache, timeout = %i", timeout);
+
+ now = time (NULL);
+
+ /* Remove empty entries */
+ le = llist_head (cache);
+ while (le != NULL)
+ {
+ llentry_t *next = le->next;
+ rc = (rrd_cache_t *) le->value;
+ if (rc->values_num == 0)
+ {
+ DBG ("Removing cache entry for `%s'", le->key);
+ free (rc->values);
+ free (rc);
+ llist_remove (cache, le);
+ }
+ le = next;
+ }
+
+ /* Write timed out entries */
+ le = llist_head (cache);
+ while (le != NULL)
+ {
+ rc = (rrd_cache_t *) le->value;
+ if ((now - rc->first_value) >= timeout)
+ rrd_write_cache_entry (le->key, rc);
+
+ le = le->next;
+ }
+
+ cache_flush = now;
+} /* void rrd_cache_flush */
+