lib: event filter - Avoid using event name wildcard matching when not needed

If the right hand side of an event name comparison is not using any
wildcards, we can compare using strcmp() instead of the more expensive
wildcard_match().

This wildcard matching avoidance change speeds up matching quite a bit.
When the desired comparison is *not* a wildcard match (i.e., the filter is
'event=abc'), microbenchmarks show at least a 30% speedup in filter matching
speed.  When the comparison includes a wildcard (i.e., the filter is
'event=abc*'), microbenchmarks show approximately 0.4% filer matching
slowdown.

Since there are so many non-wildcard matches in a typical filter, this is a
very good trade-off.

diff --git a/src/lib/event-filter-parser.y b/src/lib/event-filter-parser.y
index 03477763a84185532834baf3c0f36738af0edc30..640b48bc0587e289bacdfce2bbc67dff5c929c3a 100644 (file)
--- a/src/lib/event-filter-parser.y
+++ b/src/lib/event-filter-parser.y
@@ -10,6 +10,7 @@
 
 %{
 #include "lib.h"
+#include "wildcard-match.h"
 #include "lib-event-private.h"
 #include "event-filter-private.h"
 
@@ -58,6 +59,8 @@ static struct event_filter_node *key_value(struct event_filter_parser_state *sta
                i_unreached();
        case EVENT_FILTER_NODE_TYPE_EVENT_NAME_WILDCARD:
                node->str = p_strdup(state->pool, b);
+               if (wildcard_is_literal(node->str))
+                       node->type = EVENT_FILTER_NODE_TYPE_EVENT_NAME_EXACT;
                state->has_event_name = TRUE;
                break;
        case EVENT_FILTER_NODE_TYPE_EVENT_SOURCE_LOCATION: {
@@ -100,6 +103,8 @@ static struct event_filter_node *key_value(struct event_filter_parser_state *sta
                        node->field.value.intmax = INT_MIN;
                }
                break;
+       case EVENT_FILTER_NODE_TYPE_EVENT_NAME_EXACT:
+               i_unreached();
        }
 
        return node;

diff --git a/src/lib/event-filter-private.h b/src/lib/event-filter-private.h
index 632ae46ca74f443adc60fffd37521c4508ca7a49..e5f05ea0a1c9d51ef6f0421cb9e3f1cc745c8ae8 100644 (file)
--- a/src/lib/event-filter-private.h
+++ b/src/lib/event-filter-private.h
@@ -20,6 +20,7 @@ enum event_filter_node_type {
        EVENT_FILTER_NODE_TYPE_LOGIC = 1, /* children */
 
        /* leaf nodes */
+       EVENT_FILTER_NODE_TYPE_EVENT_NAME_EXACT, /* str */
        EVENT_FILTER_NODE_TYPE_EVENT_NAME_WILDCARD, /* str */
        EVENT_FILTER_NODE_TYPE_EVENT_SOURCE_LOCATION, /* str + int */
        EVENT_FILTER_NODE_TYPE_EVENT_CATEGORY, /* cat */

diff --git a/src/lib/event-filter.c b/src/lib/event-filter.c
index 315aa0f397ba7c0d3710744cefa03aca66e18466..49f3d3e908a433380d5109ea90b2663e7d67d5f0 100644 (file)
--- a/src/lib/event-filter.c
+++ b/src/lib/event-filter.c
@@ -290,6 +290,8 @@ void event_filter_add(struct event_filter *filter,
                node->type = EVENT_FILTER_NODE_TYPE_EVENT_NAME_WILDCARD;
                node->op = EVENT_FILTER_OP_CMP_EQ;
                node->str = p_strdup(filter->pool, query->name);
+               if (wildcard_is_literal(query->name))
+                       node->type = EVENT_FILTER_NODE_TYPE_EVENT_NAME_EXACT;
 
                add_node(filter->pool, &expr, node, EVENT_FILTER_OP_AND);
        }
@@ -435,6 +437,7 @@ event_filter_export_query_expr(const struct event_filter_query_internal *query,
                }
                str_append_c(dest, ')');
                break;
+       case EVENT_FILTER_NODE_TYPE_EVENT_NAME_EXACT:
        case EVENT_FILTER_NODE_TYPE_EVENT_NAME_WILDCARD:
                str_append(dest, "event");
                str_append(dest, event_filter_export_query_expr_op(node->op));
@@ -631,6 +634,9 @@ event_filter_query_match_cmp(struct event_filter_node *node,
        switch (node->type) {
                case EVENT_FILTER_NODE_TYPE_LOGIC:
                        i_unreached();
+               case EVENT_FILTER_NODE_TYPE_EVENT_NAME_EXACT:
+                       return (event->sending_name != NULL) &&
+                              strcmp(event->sending_name, node->str) == 0;
                case EVENT_FILTER_NODE_TYPE_EVENT_NAME_WILDCARD:
                        return (event->sending_name != NULL) &&
                               wildcard_match(event->sending_name, node->str);
@@ -806,6 +812,7 @@ event_filter_query_update_category(struct event_filter_query_internal *query,
                event_filter_query_update_category(query, node->children[0], category, add);
                event_filter_query_update_category(query, node->children[1], category, add);
                break;
+       case EVENT_FILTER_NODE_TYPE_EVENT_NAME_EXACT:
        case EVENT_FILTER_NODE_TYPE_EVENT_NAME_WILDCARD:
        case EVENT_FILTER_NODE_TYPE_EVENT_SOURCE_LOCATION:
        case EVENT_FILTER_NODE_TYPE_EVENT_FIELD: