net/http: add Pattern field and set value with matched pattern string

Author: sillydong

src/net/http/request.go

@@ -320,6 +320,10 @@ type Request struct {
 	// redirects.
 	Response *Response
 
+	// Pattern is saving the pattern string of the matching handler.
+	// This field is also available for third-party routers.
+	Pattern string
+
 	// ctx is either the client or server context. It should only
 	// be modified via copying the whole Request using Clone or WithContext.
 	// It is unexported to prevent people from using Context wrong
@@ -1561,39 +1565,3 @@ func (r *Request) requiresHTTP1() bool {
 	return hasToken(r.Header.Get("Connection"), "upgrade") &&
 		ascii.EqualFold(r.Header.Get("Upgrade"), "websocket")
 }
-
-// SetPattern parses a string into a Pattern and set in Request.
-// The string's syntax is
-//
-//	[METHOD] [HOST]/[PATH]
-//
-// where:
-//   - METHOD is an HTTP method
-//   - HOST is a hostname
-//   - PATH consists of slash-separated segments, where each segment is either
-//     a literal or a wildcard of the form "{name}", "{name...}", or "{$}".
-//
-// METHOD, HOST and PATH are all optional; that is, the string can be "/".
-// If METHOD is present, it must be followed by at least one space or tab.
-// Wildcard names must be valid Go identifiers.
-// The "{$}" and "{name...}" wildcard must occur at the end of PATH.
-// PATH may end with a '/'.
-// Wildcard names in a path must be distinct.
-func (r *Request) SetPattern(s string) error {
-	pat, err := parsePattern(s)
-	if err != nil {
-		return err
-	}
-	r.pat = pat
-	return nil
-}
-
-// Pattern returns the pattern that matched this request, if the request
-// resulted from matching a pattern registered on a ServeMux.
-// Otherwise, it returns the empty string.
-func (r *Request) Pattern() string {
-	if r.pat == nil {
-		return ""
-	}
-	return r.pat.str
-}

src/net/http/request_test.go

@@ -1568,8 +1568,8 @@ func TestPathValueAndPattern(t *testing.T) {
 					t.Errorf("%q, %q: got %q, want %q", test.pattern, name, got, want)
 				}
 			}
-			if r.Pattern() != test.pattern {
-				t.Errorf("pattern: got %s, want %s", r.Pattern(), test.pattern)
+			if r.Pattern != test.pattern {
+				t.Errorf("pattern: got %s, want %s", r.Pattern, test.pattern)
 			}
 		})
 		server := httptest.NewServer(mux)
@@ -1655,25 +1655,3 @@ func TestStatus(t *testing.T) {
 		}
 	}
 }
-
-func TestSetPattern(t *testing.T) {
-	patterns := []string{
-		"GET /",
-		"HEAD /test",
-		"/",
-		"/foo/bar",
-		"GET /foo/{b...}",
-		"GET /{f}",
-	}
-
-	req := new(Request)
-	for _, pattern := range patterns {
-		err := req.SetPattern(pattern)
-		if err != nil {
-			t.Fatal(err)
-		}
-		if req.Pattern() != pattern {
-			t.Errorf("pattern doesn't match, got %s, want %s", req.Pattern(), pattern)
-		}
-	}
-}

src/net/http/server.go

@@ -2682,7 +2682,7 @@ func (mux *ServeMux) ServeHTTP(w ResponseWriter, r *Request) {
 	if use121 {
 		h, _ = mux.mux121.findHandler(r)
 	} else {
-		h, _, r.pat, r.matches = mux.findHandler(r)
+		h, r.Pattern, r.pat, r.matches = mux.findHandler(r)
 	}
 	h.ServeHTTP(w, r)
 }