perf: avoid per-event string allocations in event filters (task 394)

2 files changed, 12 insertions, 4 deletions

diff --git a/internal/eventfilter.go b/internal/eventfilter.go
index d49e612..43a8f51 100644
--- a/internal/eventfilter.go
+++ b/internal/eventfilter.go
@@ -1,6 +1,7 @@
 package internal
 
 import (
+	"bytes"
 	"fmt"
 	"strings"
 
@@ -11,8 +12,10 @@ import (
 type eventFilter struct {
 	commFilterEnable bool
 	commFilter       string
+	commFilterBytes  []byte
 	pathFilterEnable bool
 	pathFilter       string
+	pathFilterBytes  []byte
 }
 
 func newEventFilter(commFilter, pathFilter string) (*eventFilter, error) {
@@ -24,6 +27,7 @@ func newEventFilter(commFilter, pathFilter string) (*eventFilter, error) {
 		}
 		ef.commFilterEnable = true
 		ef.commFilter = commFilter
+		ef.commFilterBytes = []byte(commFilter)
 	}
 
 	if pathFilter != "" {
@@ -32,6 +36,7 @@ func newEventFilter(commFilter, pathFilter string) (*eventFilter, error) {
 		}
 		ef.pathFilterEnable = true
 		ef.pathFilter = pathFilter
+		ef.pathFilterBytes = []byte(pathFilter)
 	}
 
 	return &ef, nil
@@ -48,11 +53,11 @@ func (ef *eventFilter) eventPair(ev *event.Pair) bool {
 }
 
 func (ef *eventFilter) openEvent(ev *types.OpenEvent) (*types.OpenEvent, bool) {
-	if ef.commFilterEnable && !strings.Contains(string(ev.Comm[:]), ef.commFilter) {
+	if ef.commFilterEnable && !bytes.Contains(ev.Comm[:], ef.commFilterBytes) {
 		return ev, false
 	}
 
-	if ef.pathFilterEnable && !strings.Contains(string(ev.Filename[:]), ef.pathFilter) {
+	if ef.pathFilterEnable && !bytes.Contains(ev.Filename[:], ef.pathFilterBytes) {
 		return ev, false
 	}
 	return ev, true
@@ -60,14 +65,14 @@ func (ef *eventFilter) openEvent(ev *types.OpenEvent) (*types.OpenEvent, bool) {
 
 func (ef *eventFilter) pathEvent(ev *types.PathEvent) (*types.PathEvent, bool) {
 	if ef.pathFilterEnable {
-		return ev, strings.Contains(string(ev.Pathname[:]), ef.pathFilter)
+		return ev, bytes.Contains(ev.Pathname[:], ef.pathFilterBytes)
 	}
 	return ev, true
 }
 
 func (ef *eventFilter) nameEvent(ev *types.NameEvent) (*types.NameEvent, bool) {
 	if ef.pathFilterEnable {
-		return ev, strings.Contains(string(ev.Oldname[:]), ef.pathFilter) || strings.Contains(string(ev.Newname[:]), ef.pathFilter)
+		return ev, bytes.Contains(ev.Oldname[:], ef.pathFilterBytes) || bytes.Contains(ev.Newname[:], ef.pathFilterBytes)
 	}
 	return ev, true
 }
diff --git a/internal/eventloop_filter_test.go b/internal/eventloop_filter_test.go
index e9fa91b..6418adf 100644
--- a/internal/eventloop_filter_test.go
+++ b/internal/eventloop_filter_test.go
@@ -475,6 +475,7 @@ func TestCommFilterToggle(t *testing.T) {
 			filter: &eventFilter{
 				commFilterEnable: true,
 				commFilter:       "test",
+				commFilterBytes:  []byte("test"),
 			},
 			enterEvs:      make(map[uint32]*event.Pair),
 			files:         make(map[int32]file.File),
@@ -507,8 +508,10 @@ func newEventLoopWithFilter(commFilter, pathFilter string) *eventLoop {
 		filter: &eventFilter{
 			commFilterEnable: commFilter != "",
 			commFilter:       commFilter,
+			commFilterBytes:  []byte(commFilter),
 			pathFilterEnable: pathFilter != "",
 			pathFilter:       pathFilter,
+			pathFilterBytes:  []byte(pathFilter),
 		},
 		enterEvs:      make(map[uint32]*event.Pair),
 		files:         make(map[int32]file.File),