swarm/api: url scheme bzz-hash to get hashes of swarm content (#15238)

Update URI to support bzz-hash scheme and handle such HTTP requests by
responding with hash of the content as a text/plain response.

swarm/api/http/server.go

@@ -290,9 +290,12 @@ func (s *Server) HandleDelete(w http.ResponseWriter, r *Request) {
 	fmt.Fprint(w, newKey)
 }
 
-// HandleGetRaw handles a GET request to bzzr://<key> and responds with
-// the raw content stored at the given storage key
-func (s *Server) HandleGetRaw(w http.ResponseWriter, r *Request) {
+// HandleGet handles a GET request to
+// - bzzr://<key> and responds with the raw content stored at the
+//   given storage key
+// - bzz-hash://<key> and responds with the hash of the content stored
+//   at the given storage key as a text/plain response
+func (s *Server) HandleGet(w http.ResponseWriter, r *Request) {
 	key, err := s.api.Resolve(r.uri)
 	if err != nil {
 		s.Error(w, r, fmt.Errorf("error resolving %s: %s", r.uri.Addr, err))
@@ -345,6 +348,8 @@ func (s *Server) HandleGetRaw(w http.ResponseWriter, r *Request) {
 		return
 	}
 
+	switch {
+	case r.uri.Raw():
 		// allow the request to overwrite the content type using a query
 		// parameter
 		contentType := "application/octet-stream"
@@ -354,6 +359,11 @@ func (s *Server) HandleGetRaw(w http.ResponseWriter, r *Request) {
 		w.Header().Set("Content-Type", contentType)
 
 		http.ServeContent(w, &r.Request, "", time.Now(), reader)
+	case r.uri.Hash():
+		w.Header().Set("Content-Type", "text/plain")
+		w.WriteHeader(http.StatusOK)
+		fmt.Fprint(w, key)
+	}
 }
 
 // HandleGetFiles handles a GET request to bzz:/<manifest> with an Accept
@@ -616,8 +626,8 @@ func (s *Server) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 		s.HandleDelete(w, req)
 
 	case "GET":
-		if uri.Raw() {
-			s.HandleGetRaw(w, req)
+		if uri.Raw() || uri.Hash() {
+			s.HandleGet(w, req)
 			return
 		}
 

swarm/api/http/server_test.go

@@ -33,7 +33,7 @@ import (
 	"github.com/ethereum/go-ethereum/swarm/testutil"
 )
 
-func TestBzzrGetPath(t *testing.T) {
+func TestBzzGetPath(t *testing.T) {
 
 	var err error
 
@@ -104,16 +104,47 @@ func TestBzzrGetPath(t *testing.T) {
 		}
 	}
 
+	for k, v := range testrequests {
+		var resp *http.Response
+		var respbody []byte
+
+		url := srv.URL + "/bzz-hash:/"
+		if k[:] != "" {
+			url += common.ToHex(key[0])[2:] + "/" + k[1:]
+		}
+		resp, err = http.Get(url)
+		if err != nil {
+			t.Fatalf("Request failed: %v", err)
+		}
+		defer resp.Body.Close()
+		respbody, err = ioutil.ReadAll(resp.Body)
+
+		if string(respbody) != key[v].String() {
+			isexpectedfailrequest := false
+
+			for _, r := range expectedfailrequests {
+				if k[:] == r {
+					isexpectedfailrequest = true
+				}
+			}
+			if !isexpectedfailrequest {
+				t.Fatalf("Response body does not match, expected: %v, got %v", key[v], string(respbody))
+			}
+		}
+	}
+
 	nonhashtests := []string{
 		srv.URL + "/bzz:/name",
 		srv.URL + "/bzzi:/nonhash",
 		srv.URL + "/bzzr:/nonhash",
+		srv.URL + "/bzz-hash:/nonhash",
 	}
 
 	nonhashresponses := []string{
 		"error resolving name: no DNS to resolve name: "name"",
 		"error resolving nonhash: immutable address not a content hash: "nonhash"",
 		"error resolving nonhash: no DNS to resolve name: "nonhash"",
+		"error resolving nonhash: no DNS to resolve name: "nonhash"",
 	}
 
 	for i, url := range nonhashtests {

swarm/api/uri.go

@@ -30,6 +30,8 @@ type URI struct {
 	// * bzzr - raw swarm content
 	// * bzzi - immutable URI of an entry in a swarm manifest
 	//          (address is not resolved)
+	// * bzz-hash - hash of swarm content
+	//
 	Scheme string
 
 	// Addr is either a hexadecimal storage key or it an address which
@@ -50,7 +52,7 @@ type URI struct {
 // * <scheme>://<addr>
 // * <scheme>://<addr>/<path>
 //
-// with scheme one of bzz, bzzr or bzzi
+// with scheme one of bzz, bzzr, bzzi or bzz-hash
 func Parse(rawuri string) (*URI, error) {
 	u, err := url.Parse(rawuri)
 	if err != nil {
@@ -60,7 +62,7 @@ func Parse(rawuri string) (*URI, error) {
 
 	// check the scheme is valid
 	switch uri.Scheme {
-	case "bzz", "bzzi", "bzzr":
+	case "bzz", "bzzi", "bzzr", "bzz-hash":
 	default:
 		return nil, fmt.Errorf("unknown scheme %q", u.Scheme)
 	}
@@ -91,6 +93,10 @@ func (u *URI) Immutable() bool {
 	return u.Scheme == "bzzi"
 }
 
+func (u *URI) Hash() bool {
+	return u.Scheme == "bzz-hash"
+}
+
 func (u *URI) String() string {
 	return u.Scheme + ":/" + u.Addr + "/" + u.Path
 }

swarm/api/uri_test.go

@@ -28,6 +28,7 @@ func TestParseURI(t *testing.T) {
 		expectErr       bool
 		expectRaw       bool
 		expectImmutable bool
+		expectHash      bool
 	}
 	tests := []test{
 		{
@@ -95,6 +96,16 @@ func TestParseURI(t *testing.T) {
 			uri:       "bzz://abc123/path/to/entry",
 			expectURI: &URI{Scheme: "bzz", Addr: "abc123", Path: "path/to/entry"},
 		},
+		{
+			uri:        "bzz-hash:",
+			expectURI:  &URI{Scheme: "bzz-hash"},
+			expectHash: true,
+		},
+		{
+			uri:        "bzz-hash:/",
+			expectURI:  &URI{Scheme: "bzz-hash"},
+			expectHash: true,
+		},
 	}
 	for _, x := range tests {
 		actual, err := Parse(x.uri)
@@ -116,5 +127,8 @@ func TestParseURI(t *testing.T) {
 		if actual.Immutable() != x.expectImmutable {
 			t.Fatalf("expected %s immutable to be %t, got %t", x.uri, x.expectImmutable, actual.Immutable())
 		}
+		if actual.Hash() != x.expectHash {
+			t.Fatalf("expected %s hash to be %t, got %t", x.uri, x.expectHash, actual.Hash())
+		}
 	}
 }