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package sliderule
import (
"crypto/tls"
"errors"
"fmt"
"net/http"
neturl "net/url"
"tildegit.org/tjp/sliderule/finger"
"tildegit.org/tjp/sliderule/gemini"
"tildegit.org/tjp/sliderule/gopher"
"tildegit.org/tjp/sliderule/internal/types"
"tildegit.org/tjp/sliderule/spartan"
)
type protocolClient interface {
RoundTrip(*Request) (*Response, error)
IsRedirect(*Response) bool
}
// Client is a multi-protocol client which handles all protocols known to sliderule.
type Client struct {
MaxRedirects int
protos map[string]protocolClient
}
const DefaultMaxRedirects int = 5
var ExceededMaxRedirects = errors.New("Client: exceeded MaxRedirects")
// NewClient builds a Client object.
//
// tlsConf may be nil, in which case gemini requests connections will not be made
// with any client certificate.
func NewClient(tlsConf *tls.Config) Client {
hc := httpClient{}
return Client{
protos: map[string]protocolClient{
"finger": finger.Client{},
"gopher": gopher.Client{},
"gemini": gemini.NewClient(tlsConf),
"spartan": spartan.NewClient(),
"http": hc,
"https": hc,
},
MaxRedirects: DefaultMaxRedirects,
}
}
// RoundTrip sends a single request and returns the repsonse.
//
// If the response is a redirect it will be returned, rather than fetched.
func (c Client) RoundTrip(request *Request) (*Response, error) {
pc, ok := c.protos[request.Scheme]
if !ok {
return nil, fmt.Errorf("unrecognized protocol: %s", request.Scheme)
}
return pc.RoundTrip(request)
}
// Fetch collects a resource from a URL including following any redirects.
func (c Client) Fetch(url string) (*Response, error) {
u, err := neturl.Parse(url)
if err != nil {
return nil, err
}
for i := 0; i <= c.MaxRedirects; i += 1 {
response, err := c.RoundTrip(&types.Request{URL: u})
if err != nil {
return nil, err
}
if !c.protos[u.Scheme].IsRedirect(response) {
return response, nil
}
prev := u
u, err = neturl.Parse(getRedirectLocation(u.Scheme, response.Meta))
if err != nil {
return nil, err
}
if u.Scheme == "" {
u.Scheme = prev.Scheme
}
}
return nil, ExceededMaxRedirects
}
func getRedirectLocation(proto string, meta any) string {
switch proto {
case "gemini", "spartan":
return meta.(string)
case "http", "https":
return meta.(http.Header).Get("Location")
}
return ""
}
type httpClient struct{}
func (hc httpClient) RoundTrip(request *Request) (*Response, error) {
hreq, err := http.NewRequest("GET", request.URL.String(), nil)
if err != nil {
return nil, err
}
hresp, err := http.DefaultTransport.RoundTrip(hreq)
if err != nil {
return nil, err
}
return &Response{
Status: Status(hresp.StatusCode),
Meta: hresp.Header,
Body: hresp.Body,
}, nil
}
func (hc httpClient) IsRedirect(response *Response) bool {
return response.Meta.(http.Header).Get("Location") != ""
}
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