stats: Use only one filter for stats and exports

Since there is no way to have a exported-only metric (i.e., all metrics are
used for statistics calculations), the exported metrics are always a subset
of all metrics.  Additionally, since exported metrics have a non-NULL
exporter info while stats-only metrics have a NULL, it is very easy to check
if a given metric shoud be exported or not.

We can combine these facts and simplify the event matching.  We can simply
match against the "all metrics" filter, perform the statistics, and then
export the event if needed.

This reduces the CPU load quite dramatically since we are no longer
duplicating the matching for exported metrics.  Stats-only metrics shouldn't
see any measurable difference in performance.

diff --git a/src/stats/stats-metrics.c b/src/stats/stats-metrics.c
index f4de66dd2fc09b2e095f70ed1c08cdbad88ca982..1122ef2bc1f7e93f46007ad5ac66ef4c2af3cc40 100644 (file)
--- a/src/stats/stats-metrics.c
+++ b/src/stats/stats-metrics.c
@@ -15,9 +15,7 @@
 
 struct stats_metrics {
        pool_t pool;
-       struct event_filter *stats_filter; /* stats-only */
-       struct event_filter *export_filter; /* export-only */
-       struct event_filter *combined_filter; /* stats & export */
+       struct event_filter *filter; /* stats & export */
        ARRAY(struct exporter *) exporters;
        ARRAY(struct metric *) metrics;
 };
@@ -114,11 +112,10 @@ static void stats_metrics_add_set(struct stats_metrics *metrics,
 
        array_push_back(&metrics->metrics, &metric);
 
-       event_filter_merge_with_context(metrics->stats_filter, set->parsed_filter, metric);
-       event_filter_merge_with_context(metrics->combined_filter, set->parsed_filter, metric);
+       event_filter_merge_with_context(metrics->filter, set->parsed_filter, metric);
 
        /*
-        * Done with statistics setup, now onto exporter setup
+        * Metrics may also be exported - make sure exporter info is set
         */
 
        if (set->exporter[0] == '\0')
@@ -153,8 +150,6 @@ static void stats_metrics_add_set(struct stats_metrics *metrics,
                else
                        i_warning("Ignoring unknown exporter include '%s'", *tmp);
        }
-
-       event_filter_merge_with_context(metrics->export_filter, set->parsed_filter, metric);
 }
 
 static void
@@ -194,9 +189,7 @@ struct stats_metrics *stats_metrics_init(const struct stats_settings *set)
 
        metrics = p_new(pool, struct stats_metrics, 1);
        metrics->pool = pool;
-       metrics->stats_filter = event_filter_create();
-       metrics->export_filter = event_filter_create();
-       metrics->combined_filter = event_filter_create();
+       metrics->filter = event_filter_create();
        stats_metrics_add_from_settings(metrics, set);
        return metrics;
 }
@@ -231,9 +224,7 @@ void stats_metrics_deinit(struct stats_metrics **_metrics)
 
        array_foreach(&metrics->metrics, metricp)
                stats_metric_free(*metricp);
-       event_filter_unref(&metrics->stats_filter);
-       event_filter_unref(&metrics->export_filter);
-       event_filter_unref(&metrics->combined_filter);
+       event_filter_unref(&metrics->filter);
        pool_unref(&metrics->pool);
 }
 
@@ -260,7 +251,7 @@ void stats_metrics_reset(struct stats_metrics *metrics)
 struct event_filter *
 stats_metrics_get_event_filter(struct stats_metrics *metrics)
 {
-       return metrics->combined_filter;
+       return metrics->filter;
 }
 
 static struct metric *
@@ -554,17 +545,15 @@ void stats_metrics_event(struct stats_metrics *metrics, struct event *event,
        event_get_last_duration(event, &duration);
        event_add_int(event, STATS_EVENT_FIELD_NAME_DURATION, duration);
 
-       /* process stats */
-       iter = event_filter_match_iter_init(metrics->stats_filter, event, ctx);
+       /* process stats & exports */
+       iter = event_filter_match_iter_init(metrics->filter, event, ctx);
        while ((metric = event_filter_match_iter_next(iter)) != NULL) T_BEGIN {
+               /* every metric is fed into stats */
                stats_metric_event(metric, event, metrics->pool);
-       } T_END;
-       event_filter_match_iter_deinit(&iter);
 
-       /* process exports */
-       iter = event_filter_match_iter_init(metrics->export_filter, event, ctx);
-       while ((metric = event_filter_match_iter_next(iter)) != NULL) T_BEGIN {
-               stats_export_event(metric, event);
+               /* some metrics are exported */
+               if (metric->export_info.exporter != NULL)
+                       stats_export_event(metric, event);
        } T_END;
        event_filter_match_iter_deinit(&iter);
 }