Restored the FileSystem interface in a new form.

doc.go

@@ -19,7 +19,10 @@
 //  *  The fuseops package, which defines the operations that fuse might send
 //     to your userspace daemon.
 //
-//  *  The Server interface, which a type in your daemon must implement.
+//  *  The Server interface, which your daemon must implement.
+//
+//  *  fuseutil.NewFileSystemServer, which offers a convenient way to implement
+//     the Server interface.
 //
 //  *  Mount, a function that allows for mounting a Server as a file system.
 //

fuseutil/file_system.go

+// Copyright 2015 Google Inc. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package fuseutil
+
+import (
+	"io"
+
+	"github.com/jacobsa/fuse"
+	"github.com/jacobsa/fuse/fuseops"
+)
+
+// An interface with a method for each op type in the fuseops package. This can
+// be used in conjunction with NewFileSystemServer to avoid writing a "dispatch
+// loop" that switches on op types, instead receiving typed method calls
+// directly.
+//
+// Each method should fill in appropriate response fields for the supplied op
+// and return an error status, but not call Repand.
+//
+// See NotImplementedFileSystem for a convenient way to embed default
+// implementations for methods you don't care about.
+type FileSystem interface {
+	Init(*fuseops.InitOp) error
+	LookUpInode(*fuseops.LookUpInodeOp) error
+	GetInodeAttributes(*fuseops.GetInodeAttributesOp) error
+	SetInodeAttributes(*fuseops.SetInodeAttributesOp) error
+	ForgetInode(*fuseops.ForgetInodeOp) error
+	MkDir(*fuseops.MkDirOp) error
+	CreateFile(*fuseops.CreateFileOp) error
+	RmDir(*fuseops.RmDirOp) error
+	Unlink(*fuseops.UnlinkOp) error
+	OpenDir(*fuseops.OpenDirOp) error
+	ReadDir(*fuseops.ReadDirOp) error
+	ReleaseDirHandle(*fuseops.ReleaseDirHandleOp) error
+	OpenFile(*fuseops.OpenFileOp) error
+	ReadFile(*fuseops.ReadFileOp) error
+	WriteFile(*fuseops.WriteFileOp) error
+	SyncFile(*fuseops.SyncFileOp) error
+	FlushFile(*fuseops.FlushFileOp) error
+	ReleaseFileHandle(*fuseops.ReleaseFileHandleOp) error
+}
+
+// Create a fuse.Server that serves ops by calling the associated FileSystem
+// method and then calling Op.Respond with the resulting error. Unsupported ops
+// are responded to directly with ENOSYS.
+func NewFileSystemServer(fs FileSystem) fuse.Server {
+	return fileSystemServer{fs}
+}
+
+type fileSystemServer struct {
+	fs FileSystem
+}
+
+func (s fileSystemServer) ServeOps(c *fuse.Connection) {
+	for {
+		op, err := c.ReadOp()
+		if err == io.EOF {
+			break
+		}
+
+		if err != nil {
+			panic(err)
+		}
+
+		switch typed := op.(type) {
+		default:
+			op.Respond(fuse.ENOSYS)
+
+		case *fuseops.InitOp:
+			op.Respond(s.fs.Init(typed))
+
+		case *fuseops.LookUpInodeOp:
+			op.Respond(s.fs.LookUpInode(typed))
+
+		case *fuseops.GetInodeAttributesOp:
+			op.Respond(s.fs.GetInodeAttributes(typed))
+
+		case *fuseops.SetInodeAttributesOp:
+			op.Respond(s.fs.SetInodeAttributes(typed))
+
+		case *fuseops.ForgetInodeOp:
+			op.Respond(s.fs.ForgetInode(typed))
+
+		case *fuseops.MkDirOp:
+			op.Respond(s.fs.MkDir(typed))
+
+		case *fuseops.CreateFileOp:
+			op.Respond(s.fs.CreateFile(typed))
+
+		case *fuseops.RmDirOp:
+			op.Respond(s.fs.RmDir(typed))
+
+		case *fuseops.UnlinkOp:
+			op.Respond(s.fs.Unlink(typed))
+
+		case *fuseops.OpenDirOp:
+			op.Respond(s.fs.OpenDir(typed))
+
+		case *fuseops.ReadDirOp:
+			op.Respond(s.fs.ReadDir(typed))
+
+		case *fuseops.ReleaseDirHandleOp:
+			op.Respond(s.fs.ReleaseDirHandle(typed))
+
+		case *fuseops.OpenFileOp:
+			op.Respond(s.fs.OpenFile(typed))
+
+		case *fuseops.ReadFileOp:
+			op.Respond(s.fs.ReadFile(typed))
+
+		case *fuseops.WriteFileOp:
+			op.Respond(s.fs.WriteFile(typed))
+
+		case *fuseops.SyncFileOp:
+			op.Respond(s.fs.SyncFile(typed))
+
+		case *fuseops.FlushFileOp:
+			op.Respond(s.fs.FlushFile(typed))
+
+		case *fuseops.ReleaseFileHandleOp:
+			op.Respond(s.fs.ReleaseFileHandle(typed))
+		}
+	}
+}

fuseutil/not_implemented_file_system.go

+// Copyright 2015 Google Inc. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package fuseutil
+
+import (
+	"github.com/jacobsa/fuse"
+	"github.com/jacobsa/fuse/fuseops"
+)
+
+// A FileSystem that returns fuse.ENOSYS for all methods. Embed this in your
+// struct to inherit default implementations for the methods you don't care
+// about, ensuring your struct will continue to implement FileSystem even as
+// new methods are added.
+type NotImplementedFileSystem struct {
+}
+
+var _ FileSystem = &NotImplementedFileSystem{}
+
+func (fs *NotImplementedFileSystem) Init(
+	op *fuseops.InitOp) error {
+	return fuse.ENOSYS
+}
+
+func (fs *NotImplementedFileSystem) LookUpInode(
+	op *fuseops.LookUpInodeOp) error {
+	return fuse.ENOSYS
+}
+
+func (fs *NotImplementedFileSystem) GetInodeAttributes(
+	op *fuseops.GetInodeAttributesOp) error {
+	return fuse.ENOSYS
+}
+
+func (fs *NotImplementedFileSystem) SetInodeAttributes(
+	op *fuseops.SetInodeAttributesOp) error {
+	return fuse.ENOSYS
+}
+
+func (fs *NotImplementedFileSystem) ForgetInode(
+	op *fuseops.ForgetInodeOp) error {
+	return fuse.ENOSYS
+}
+
+func (fs *NotImplementedFileSystem) MkDir(
+	op *fuseops.MkDirOp) error {
+	return fuse.ENOSYS
+}
+
+func (fs *NotImplementedFileSystem) CreateFile(
+	op *fuseops.CreateFileOp) error {
+	return fuse.ENOSYS
+}
+
+func (fs *NotImplementedFileSystem) RmDir(
+	op *fuseops.RmDirOp) error {
+	return fuse.ENOSYS
+}
+
+func (fs *NotImplementedFileSystem) Unlink(
+	op *fuseops.UnlinkOp) error {
+	return fuse.ENOSYS
+}
+
+func (fs *NotImplementedFileSystem) OpenDir(
+	op *fuseops.OpenDirOp) error {
+	return fuse.ENOSYS
+}
+
+func (fs *NotImplementedFileSystem) ReadDir(
+	op *fuseops.ReadDirOp) error {
+	return fuse.ENOSYS
+}
+
+func (fs *NotImplementedFileSystem) ReleaseDirHandle(
+	op *fuseops.ReleaseDirHandleOp) error {
+	return fuse.ENOSYS
+}
+
+func (fs *NotImplementedFileSystem) OpenFile(
+	op *fuseops.OpenFileOp) error {
+	return fuse.ENOSYS
+}
+
+func (fs *NotImplementedFileSystem) ReadFile(
+	op *fuseops.ReadFileOp) error {
+	return fuse.ENOSYS
+}
+
+func (fs *NotImplementedFileSystem) WriteFile(
+	op *fuseops.WriteFileOp) error {
+	return fuse.ENOSYS
+}
+
+func (fs *NotImplementedFileSystem) SyncFile(
+	op *fuseops.SyncFileOp) error {
+	return fuse.ENOSYS
+}
+
+func (fs *NotImplementedFileSystem) FlushFile(
+	op *fuseops.FlushFileOp) error {
+	return fuse.ENOSYS
+}
+
+func (fs *NotImplementedFileSystem) ReleaseFileHandle(
+	op *fuseops.ReleaseFileHandleOp) error {
+	return fuse.ENOSYS
+}