Refactor: A faster DomainMatcher implementation (#348)

Co-authored-by: DarthVader <61409963+darsvador@users.noreply.github.com>

common/strmatcher/benchmark_test.go

@@ -8,6 +8,19 @@ import (
 	. "github.com/xtls/xray-core/common/strmatcher"
 )
 
+func BenchmarkACAutomaton(b *testing.B) {
+	ac := NewACAutomaton()
+	for i := 1; i <= 1024; i++ {
+		ac.Add(strconv.Itoa(i)+".v2ray.com", Domain)
+	}
+	ac.Build()
+
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		_ = ac.Match("0.v2ray.com")
+	}
+}
+
 func BenchmarkDomainMatcherGroup(b *testing.B) {
 	g := new(DomainMatcherGroup)