Исходники и презентации

lessons/slices_and_arrays/dirty_slice/creation_test.go

@@ -0,0 +1,31 @@
+package main
+
+import (
+	"strings"
+	"testing"
+	"unsafe"
+)
+
+// go test -bench=. creation_test.go
+
+func makeDirty(size int) []byte {
+	var sb strings.Builder
+	sb.Grow(size)
+
+	pointer := unsafe.StringData(sb.String())
+	return unsafe.Slice(pointer, size)
+}
+
+var Result []byte
+
+func BenchmarkMake(b *testing.B) {
+	for i := 0; i < b.N; i++ {
+		Result = make([]byte, 0, 10<<20)
+	}
+}
+
+func BenchmarkMakeDirty(b *testing.B) {
+	for i := 0; i < b.N; i++ {
+		Result = makeDirty(10 << 20)
+	}
+}