txscript: Add benchmark for IsNullData

txscript/bench_test.go

@@ -312,3 +312,18 @@ func BenchmarkIsWitnessScriptHash(b *testing.B) {
 		_ = IsPayToWitnessScriptHash(script)
 	}
 }
+
+// BenchmarkIsNullDataScript benchmarks how long it takes to analyze a very
+// large script to determine if it is a standard nulldata script.
+func BenchmarkIsNullDataScript(b *testing.B) {
+	script, err := genComplexScript()
+	if err != nil {
+		b.Fatalf("failed to create benchmark script: %v", err)
+	}
+
+	b.ResetTimer()
+	b.ReportAllocs()
+	for i := 0; i < b.N; i++ {
+		_ = IsNullData(script)
+	}
+}

txscript/script.go

@@ -151,6 +151,16 @@ func isWitnessProgram(pops []parsedOpcode) bool {
 		(len(pops[1].data) >= 2 && len(pops[1].data) <= 40)
 }
 
+// IsNullData returns true if the passed script is a null data script, false
+// otherwise.
+func IsNullData(script []byte) bool {
+	pops, err := parseScript(script)
+	if err != nil {
+		return false
+	}
+	return isNullData(pops)
+}
+
 // ExtractWitnessProgramInfo attempts to extract the witness program version,
 // as well as the witness program itself from the passed script.
 func ExtractWitnessProgramInfo(script []byte) (int, []byte, error) {