use interface for ReadResultFd

fuse/api.go

@@ -112,6 +112,11 @@ type ReadResult interface {
 	Done()
 }
 
+type ReadResultFd interface {
+	ReadResult
+	ReadFd() uintptr
+}
+
 type MountOptions struct {
 	AllowOther bool
 

fuse/opcode.go

@@ -396,7 +396,7 @@ func doRead(server *Server, req *request) {
 	}
 
 	req.readResult, req.status = server.fileSystem.Read(req.cancel, in, buf)
-	if fd, ok := req.readResult.(*readResultFd); ok {
+	if fd, ok := req.readResult.(ReadResultFd); ok {
 		req.fdData = fd
 		req.flatData = nil
 	} else if req.readResult != nil && req.status.Ok() {

fuse/read.go

@@ -30,10 +30,6 @@ func ReadResultData(b []byte) ReadResult {
 	return &readResultData{b}
 }
 
-func ReadResultFd(fd uintptr, off int64, sz int) ReadResult {
-	return &readResultFd{fd, off, sz}
-}
-
 // ReadResultFd is the read return for zero-copy file data.
 type readResultFd struct {
 	// Splice from the following file.

fuse/request.go

@@ -36,7 +36,7 @@ type request struct {
 	// Output data.
 	status   Status
 	flatData []byte
-	fdData   *readResultFd
+	fdData   ReadResultFd
 	slices   [][]byte
 
 	// In case of read, keep read result here so we can call

fuse/splice_darwin.go

@@ -12,6 +12,6 @@ func (s *Server) setSplice() {
 	s.canSplice = false
 }
 
-func (ms *Server) trySplice(header []byte, req *request, fdData *readResultFd) error {
+func (ms *Server) trySplice(header []byte, req *request, fdData ReadResultFd) error {
 	return fmt.Errorf("unimplemented")
 }

fuse/splice_linux.go

@@ -19,16 +19,16 @@ func (s *Server) setSplice() {
 //
 // This is a four-step process:
 //
-//	1) Splice data form fdData.Fd into the "pair1" pipe buffer --> pair1: [payload]
-//	   Now we know the actual payload length and can
+//  1. Splice data form fdData.Fd into the "pair1" pipe buffer --> pair1: [payload]
+//     Now we know the actual payload length and can
 //     construct the reply header
-//	2) Write header into the "pair2" pipe buffer               --> pair2: [header]
-//	4) Splice data from "pair1" into "pair2"                   --> pair2: [header][payload]
-//	3) Splice the data from "pair2" into /dev/fuse
+//  2. Write header into the "pair2" pipe buffer               --> pair2: [header]
+//  4. Splice data from "pair1" into "pair2"                   --> pair2: [header][payload]
+//  3. Splice the data from "pair2" into /dev/fuse
 //
 // This dance is neccessary because header and payload cannot be split across
 // two splices and we cannot seek in a pipe buffer.
-func (ms *Server) trySplice(header []byte, req *request, fdData *readResultFd) error {
+func (ms *Server) trySplice(header []byte, req *request, fdData ReadResultFd) error {
 	// Get a pair of connected pipes
 	pair, err := splice.Get()
 	if err != nil {
@@ -56,7 +56,7 @@ func (ms *Server) trySplice(header []byte, req *request, fdData *readResultFd) e
 	}
 
 	// Write data into pair2
-	n, err = pair.LoadFrom(fdData.Fd, payloadLen)
+	n, err = pair.LoadFrom(fdData.ReadFd(), payloadLen)
 	if err != nil {
 		return err
 	}