🐛 Get unexpected results from cache

[reloadzz]

Fiber version
github.com/gofiber/fiber/v2 v2.18.0
Issue description
Get unexpected results from cache
Code snippet

package test

import (
	"fmt"
	"io/ioutil"
	"net/http"
	"net/http/httptest"
	"strconv"
	"testing"
	"time"

	"github.com/gofiber/fiber/v2"
	"github.com/gofiber/fiber/v2/middleware/cache"
	"github.com/gofiber/utils"
)

func Test_Fiber_Cache(t *testing.T) {
	app := fiber.New()

	app.Use(cache.New(cache.Config{
		CacheControl: true,
		Expiration:   10 * time.Second,
	}))

	app.Get("/:id", func(c *fiber.Ctx) error {
		// log.Println(c.Params("id"))
		return c.SendString(c.Params("id"))
	})

	for {
		for i := 0; i < 10; i++ {
			func(id int) {
				rsp, err := app.Test(httptest.NewRequest(http.MethodGet, fmt.Sprintf("/%d", id), nil))
				utils.AssertEqual(t, nil, err)

				defer rsp.Body.Close()

				idFromServ, err := ioutil.ReadAll(rsp.Body)
				utils.AssertEqual(t, nil, err)

				a, err := strconv.Atoi(string(idFromServ))
				utils.AssertEqual(t, nil, err)

				// SomeTimes,The id is not equal with a
				utils.AssertEqual(t, id, a)
			}(i)
		}
	}
}

[reloadzz]

KeyGenerator: func(c *fiber.Ctx) string {
	return utils.CopyString(c.Path())
},

this works well,but don't know why

[ReneWerner87]

in the example you use the memory as storage for the cache, there the path from the context is used directly, because we have a reference here to save allocations in the next request, this memory area is linked and the cache key changes

as you rightly noticed, we should make a copy of the string, this will slow down the middleware a bit, but should be ok

[reloadzz]

ok,thank you