posts/delegating-handler

[TechWatching]

Written on 28/10/2019 14:02:44

URL: https://techwatching.dev/posts/delegating-handler

[TechWatching]

Comment written by Gerald Maale on 29/05/2021 10:37:48

Hi,
Don't you think using IMemoryCache stores the token in the entire server where notwithstanding who logs in, the token is not actually representing the new user logging in. You consider revising this.

[TechWatching]

Comment written by Alex Pavlenko on 07/07/2021 02:46:29

If this is the inner service that should be used for entire application, why not?

[TechWatching]

Comment written by Alexandre on 22/08/2021 22:53:54

Good remark but in my sample the call to the API is made as a Service, not as a User: in that case caching the token for the whole server is what I want. But I agree with you,in other cases involving multiple users the implementation should be modified a bit.

[mohammadshahabrafiq]

Hello Alexandre,

First of all, thank you for the article. Very informative. As I was reading it I noticed there maybe a race condition in the code.

So in the UserApiAuthenticationService class the body of conditional if (!_memoryCache.TryGetValue("Token", out string token)) could potentially be executed by more than one thread at the same time. If multiple threads hit the this same line of code at same time then you will get multiple cache misses.

See here for more details.

This might be the desired behaviour which is fine but just wanted to make the readers aware of this.

[TechWatching]

I don't think it is really a problem for the use case in my sample but that is good to know for other use cases. I did not know about that so thanks for the link and for making the other readers aware. 👍

[aghazadehm]

Hi,
If the service gets token in body !!! what I do ?
Payload: { "Token": "token", "Data": "..." }

[TechWatching]

You can also you http message handlers and modify the body of the request to add the token