ctx.userValues is shared across different request matches causing unpredictable results?
gsych opened this issue · comments
Hi there! :)
I've prepared a short snippet program localizing the issue:
go.mod:
module test
go 1.14
require (
github.com/fasthttp/router v1.2.4
github.com/valyala/fasthttp v1.15.1
)main.go:
package main
import (
httprouter "github.com/fasthttp/router"
"github.com/valyala/fasthttp"
)
func main() {
router := httprouter.New()
var s string
router.GET("/api/v1/path/special-path", func(ctx *fasthttp.RequestCtx) {
println("from GET: " + s)
})
router.PATCH("/api/v1/path/{id}", func(ctx *fasthttp.RequestCtx) {
s = ctx.UserValue("id").(string)
println("from PATCH: " + s)
})
err := fasthttp.ListenAndServe("127.0.0.1:8080", router.Handler)
if err != nil {
panic(err)
}
}Then I make the following requests, one after another:
curl --location --request PATCH 'http://127.0.0.1:8080/api/v1/path/aaabbbcccdddzzz'
curl --location --request GET 'http://127.0.0.1:8080/api/v1/path/special-path'
The output I expect to see:
from PATCH: aaabbbcccdddzzz
from GET: aaabbbcccdddzzz
The actual output:
from PATCH: aaabbbcccdddzzz
from GET: special-pathzzz
As you can see the special-path path part overwrites part of the aaabbbcccdddzzz word.
Hi @savsgio !
Thank you for your reply. Yes, it was clear why this happens from the beginning. Still, I think there should be a note about that in the documentation or a comment to the UserValue func or anywhere else, otherwise in my opinion it's really misleading. I've spent several hours trying to figure out why the hell I have a data corruption and never had a second thought that I actually have to allocate a new copy. Having a proper allocation in the UserValue usage example would definitely prevent this.
Thank you for your effort!
Hi @gsych,
Sorry for remove my answer, but i think the better solution it's save a copy directly to the user values and avoid confusions in a future.
I will upload the fix now.
Fixed 😉
Thanks for your issue!
Superb!
