client: URI is always parsed

[stokito]

To perform an HTTP requests each time the SetRequestURIBytes() must be called. But internally the method just saves an URL and it is then parsed inside of parseURI():

func (req *Request) parseURI() error {
	if req.parsedURI {
		return nil
	}
	req.parsedURI = true
	return req.uri.parse(req.Header.Host(), req.Header.RequestURI(), req.isTLS)
}

My application has a bunch of fixed URLs like http://example.com/api/ and I can call the req.uri.parse() only once on initialization. And then I would like to just set this fasthttp.URI objects before sending the request with a new method SetRequestURI(preparsedUri).

Is any reason why this wasn't implemented? Will you implement this or accept a PR with such functionality?

[erikdubbelboer]

To be honest I'm not sure why it was implemented like that. Yes I would accept a PR to support such functionality.

[stokito]

Thank you for merging, this should be useful if we have a base URI that can be copied and some part can be changed.
But I found even a better way for my case when API endpoint is static:

0. Create a separate request pool for each API endpoint
1. Create a request manually and set URI and headers
2. Execute the request
3. Put the request back to pool but without calling the Reset()
4. Next time when the request will be taken from the pool it will already have a parsed URI and headers. You just need to override a body

var requestPool sync.Pool

func main() {
        reqBody := []byte("{\"id\": 1}")
        // AcquireRequest
	reqV := requestPool.Get()
	var req *fasthttp.Request
	if reqV != nil {
		req = reqV.(*fasthttp.Request)
	} else {
		req = &fasthttp.Request{}
		req.SetRequestURIBytes("http://example.com/api/v1/")
		req.Header.SetMethod(fasthttp.MethodPost)
		req.Header.SetContentType("application/json")
	}
	resp := fasthttp.AcquireResponse()
	req.SetBodyRaw(reqBody)
	err := fasthttp.Do(req, resp)
	// Same as fasthttp.ReleaseRequest but without reset
	requestPool.Put(req)
	fasthttp.ReleaseResponse(resp)
}

I hope this solution may be useful for someone. Interesting if there is any way to make it easier to use.
Maybe we remove the `Reset()` on release and leave this for users. Also we may create a separate type for pools so users may create their own instead of using a global pool.
This is just some thoughts and I don't think that fasthhtp should be changed for now.