add benchmarks for 2 funcs in utils.go

comparing map[rune]bool with map[rune]struct{}

lib/utils_test.go

@@ -0,0 +1,81 @@
+package passgen
+
+import (
+	"math/rand"
+	"testing"
+)
+
+func removeDuplicateRunes_2(list []rune) []rune {
+	set := map[rune]struct{}{}
+	newlist := make([]rune, 0, len(list))
+	for _, c := range list {
+		if _, ok := set[c]; ok {
+			continue
+		}
+		set[c] = struct{}{}
+		newlist = append(newlist, c)
+	}
+	return newlist
+}
+
+func excludeCharsASCII_2(exclude []rune) []rune {
+	ex_set := map[rune]struct{}{}
+	for _, c := range exclude {
+		ex_set[c] = struct{}{}
+	}
+	list := make([]rune, 0, 95)
+	for ci := 32; ci < 127; ci++ {
+		c := rune(ci)
+		if _, ok := ex_set[c]; ok {
+			continue
+		}
+		list = append(list, c)
+	}
+	return list
+}
+
+func Benchmark_removeDuplicateRunes(b *testing.B) {
+	listLength := 100
+	count := b.N * 10000
+	lists := make([][]rune, count)
+	for i := 0; i < count; i++ {
+		list := make([]rune, listLength)
+		for j := 0; j < listLength; j++ {
+			list[j] = rune(rand.Intn(256))
+		}
+		lists[i] = list
+	}
+	b.Run("map[rune]bool", func(b *testing.B) {
+		for _, list := range lists {
+			removeDuplicateRunes(list)
+		}
+	})
+	b.Run("map[rune]struct{}", func(b *testing.B) {
+		for _, list := range lists {
+			removeDuplicateRunes_2(list)
+		}
+	})
+}
+
+func Benchmark_excludeCharsASCII(b *testing.B) {
+	listLength := 100
+	count := b.N * 10000
+	lists := make([][]rune, count)
+	for i := 0; i < count; i++ {
+		list := make([]rune, listLength)
+		for j := 0; j < listLength; j++ {
+			list[j] = rune(rand.Intn(256))
+		}
+		lists[i] = list
+	}
+	b.Run("map[rune]bool", func(b *testing.B) {
+		for _, list := range lists {
+			excludeCharsASCII(list)
+		}
+	})
+	b.Run("map[rune]struct{}", func(b *testing.B) {
+		for _, list := range lists {
+			excludeCharsASCII_2(list)
+		}
+	})
+}