Add FCH

[a-thieme]

No description provided.

[Copilot]

Pull Request Overview

This PR adds a new FCH client for the NDN-FCH service, enabling HTTP queries to retrieve router information.

• Introduces core types (Request, Response, Router) with helper functions to apply defaults and build query URLs.
• Implements the Query function to perform HTTP requests and parse responses into routers.

Files not reviewed (1)

• go.mod: Language not supported

Comments suppressed due to low confidence (1)

std/ndn/fch/fch.go:47

• The function 'max' is referenced here but is not defined. Consider defining a helper function or using appropriate logic to ensure req.Count is at least 1.

req.Count = max(1, req.Count)

[Copilot]

The HTTP response body is not closed after reading, which could lead to resource leaks. Consider adding 'defer hRes.Body.Close()' after checking for a nil error.

[zjkmxy]

This comment is accurate. By document:

If the returned error is nil, the Response will contain a non-nil Body which the user is expected to close. If the Body is not both read to EOF and closed, the Client's underlying RoundTripper (typically Transport) may not be able to re-use a persistent TCP connection to the server for a subsequent "keep-alive" request.

io.ReadAll does not automatically close it.

[zjkmxy]

Tested with the following code and it works.

res, err := fch.Query(context.Background(), fch.Request{})
if err != nil {
	println(err)
} else {
	retJson, _ := json.Marshal(res)
	println(string(retJson))
}

[zjkmxy]

This comment is accurate. By document:

If the returned error is nil, the Response will contain a non-nil Body which the user is expected to close. If the Body is not both read to EOF and closed, the Client's underlying RoundTripper (typically Transport) may not be able to re-use a persistent TCP connection to the server for a subsequent "keep-alive" request.

io.ReadAll does not automatically close it.

[zjkmxy]

Personally, I don't like using a global variable.

[zjkmxy]

You don't need to write explicitly the values when using named result parameters.

[zjkmxy]

Why do not check if routers array is empty, but to check individual element instead?

[zjkmxy]

nit: Connect sounds too much like a function. Maybe rename to uri.