优化验证码加载方式，减少不必要的图片生成

internal/waf/captcha_test.go

@@ -0,0 +1,70 @@
+// Copyright 2023 GoEdge CDN goedge.cdn@gmail.com. All rights reserved. Official site: https://goedge.cn .
+
+package waf_test
+
+import (
+	"bytes"
+	"fmt"
+	"github.com/TeaOSLab/EdgeNode/internal/utils/testutils"
+	"github.com/dchest/captcha"
+	"runtime"
+	"testing"
+	"time"
+)
+
+func TestCaptchaMemory(t *testing.T) {
+	if !testutils.IsSingleTesting() {
+		return
+	}
+
+	var stat1 = &runtime.MemStats{}
+	runtime.ReadMemStats(stat1)
+
+	var count = 5_000
+	var before = time.Now()
+
+	for i := 0; i < count; i++ {
+		var id = captcha.NewLen(6)
+		var writer = &bytes.Buffer{}
+		err := captcha.WriteImage(writer, id, 200, 100)
+		if err != nil {
+			t.Fatal(err)
+		}
+		captcha.VerifyString(id, "abc")
+	}
+
+	var stat2 = &runtime.MemStats{}
+	runtime.ReadMemStats(stat2)
+	t.Log((stat2.HeapInuse-stat1.HeapInuse)>>20, "MB", fmt.Sprintf("%.0f QPS", float64(count)/time.Since(before).Seconds()))
+}
+
+func BenchmarkCaptcha_VerifyCode_100_50(b *testing.B) {
+	runtime.GOMAXPROCS(4)
+
+	b.RunParallel(func(pb *testing.PB) {
+		for pb.Next() {
+			var id = captcha.NewLen(6)
+			var writer = &bytes.Buffer{}
+			err := captcha.WriteImage(writer, id, 100, 50)
+			if err != nil {
+				b.Fatal(err)
+			}
+		}
+	})
+}
+
+func BenchmarkCaptcha_VerifyCode_200_100(b *testing.B) {
+	runtime.GOMAXPROCS(4)
+
+	b.RunParallel(func(pb *testing.PB) {
+		for pb.Next() {
+			var id = captcha.NewLen(6)
+			var writer = &bytes.Buffer{}
+			err := captcha.WriteImage(writer, id, 200, 100)
+			if err != nil {
+				b.Fatal(err)
+			}
+			_ = id
+		}
+	})
+}