tsweb: move some comments, add a TODO
@@ -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
+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.
//
-// 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 {
+ // 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
}
