tsweb: move some comments, add a TODO

This commit is contained in:
Brad Fitzpatrick 2020-03-18 09:53:14 -07:00
parent df4636567f
commit 6de37f4cc0

View File

@ -141,19 +141,17 @@ func stripPort(hostport string) string {
// Handler is like net/http.Handler, but the handler can return an
// error instead of writing to its ResponseWriter.
//
// ServeHTTPErr should behave like http.Handler.ServeHTTP, except that
// it can choose to return an error instead of writing to its
// http.ResponseWriter.
//
// Callers of Handler should handle an error by serving a 500 error to
// the user. The error details should not be sent to the client, as
// they may contain sensitive information.
//
// In addition, if the returned error is an HTTPError, callers should
// use the HTTP response code and message as the response to the
// client.
type Handler interface {
// ServeHTTPErr is like http.Handler.ServeHTTP, except that
// it can choose to return an error instead of writing to its
// http.ResponseWriter.
//
// If ServeHTTPErr returns an error, it caller should handle
// an error by serving an HTTP 500 response to the user. The
// error details should not be sent to the client, as they may
// contain sensitive information. If the error is an
// HTTPError, though, callers should use the HTTP response
// code and message as the response to the client.
ServeHTTPErr(http.ResponseWriter, *http.Request) error
}
@ -179,10 +177,19 @@ func (h handler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
if err == context.Canceled {
// No need to inform client, but still log the
// cancellation.
//
// TODO(bradfitz): this 499 thing is weird and
// undocumented. Also, shouldn't it be "err != nil &&
// r.Context().Err() == context.Canceled" instead? If
// they just return an error, it could've been from
// the handler's own context cancel.
msg.HTTP.Code = 499 // nginx convention: Client Closed Request
msg.Err = err
} else if hErr, ok := err.(HTTPError); ok {
msg.HTTP.Code = hErr.Code
if msg.HTTP.Code == 0 {
msg.HTTP.Code = 500
}
msg.Err = hErr.Err
msg.Msg = hErr.Msg
http.Error(w, hErr.Msg, hErr.Code)
@ -209,8 +216,10 @@ func StdHandler(h Handler, logf logger.Logf) http.Handler {
}
// HTTPError is an error with embedded HTTP response information.
//
// It is the error type to be (optionally) used by Handler.ServeHTTPErr.
type HTTPError struct {
Code int // HTTP response code to send to client
Code int // HTTP response code to send to client; 0 means means 500
Msg string // Response body to send to client
Err error // Detailed error to log on the server
}