Add ReadBenchFS to test linear read speed

samples/mount_readbenchfs/mount.go

@@ -0,0 +1,46 @@
+package main
+
+import (
+	"context"
+	"flag"
+	"github.com/jacobsa/fuse"
+	"github.com/jacobsa/fuse/samples/readbenchfs"
+	"log"
+	"os"
+)
+
+var fMountPoint = flag.String("mount_point", "", "Path to mount point.")
+var fReadOnly = flag.Bool("read_only", false, "Mount in read-only mode.")
+var fDebug = flag.Bool("debug", false, "Enable debug logging.")
+
+func main() {
+	flag.Parse()
+
+	server, err := readbenchfs.NewReadBenchServer()
+	if err != nil {
+		log.Fatalf("makeFS: %v", err)
+	}
+
+	// Mount the file system.
+	if *fMountPoint == "" {
+		log.Fatalf("You must set --mount_point.")
+	}
+
+	cfg := &fuse.MountConfig{
+		ReadOnly: *fReadOnly,
+	}
+
+	if *fDebug {
+		cfg.DebugLogger = log.New(os.Stderr, "fuse: ", 0)
+	}
+
+	mfs, err := fuse.Mount(*fMountPoint, server, cfg)
+	if err != nil {
+		log.Fatalf("Mount: %v", err)
+	}
+
+	// Wait for it to be unmounted.
+	if err = mfs.Join(context.Background()); err != nil {
+		log.Fatalf("Join: %v", err)
+	}
+}

samples/readbenchfs/readbenchfs.go

@@ -0,0 +1,167 @@
+// Copyright 2021 Vitaliy Filippov
+//
+// 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 readbenchfs
+
+import (
+	"golang.org/x/net/context"
+	"io"
+	"math/rand"
+	"os"
+
+	"github.com/jacobsa/fuse"
+	"github.com/jacobsa/fuse/fuseops"
+	"github.com/jacobsa/fuse/fuseutil"
+)
+
+type readBenchFS struct {
+	fuseutil.NotImplementedFileSystem
+	buf []byte
+}
+
+// 1 TB
+const fileSize = 1024 * 1024 * 1024 * 1024
+
+var _ fuseutil.FileSystem = &readBenchFS{}
+
+// Create a file system that mirrors an existing physical path, in a readonly mode
+
+func NewReadBenchServer() (server fuse.Server, err error) {
+	// 1 GB of random data to exceed CPU cache
+	buf := make([]byte, 1024*1024*1024)
+	rand.Read(buf)
+	server = fuseutil.NewFileSystemServer(&readBenchFS{
+		buf: buf,
+	})
+	return
+}
+
+func (fs *readBenchFS) StatFS(ctx context.Context, op *fuseops.StatFSOp) error {
+	return nil
+}
+
+func (fs *readBenchFS) LookUpInode(ctx context.Context, op *fuseops.LookUpInodeOp) error {
+	if op.Name == "test" {
+		op.Entry = fuseops.ChildInodeEntry{
+			Child: 2,
+			Attributes: fuseops.InodeAttributes{
+				Size:  fileSize,
+				Nlink: 1,
+				Mode:  0444,
+			},
+		}
+		return nil
+	}
+	return fuse.ENOENT
+}
+
+func (fs *readBenchFS) GetInodeAttributes(ctx context.Context, op *fuseops.GetInodeAttributesOp) error {
+	if op.Inode == 1 {
+		op.Attributes = fuseops.InodeAttributes{
+			Nlink: 1,
+			Mode:  0755 | os.ModeDir,
+		}
+		return nil
+	} else if op.Inode == 2 {
+		op.Attributes = fuseops.InodeAttributes{
+			Size:  fileSize,
+			Nlink: 1,
+			Mode:  0444,
+		}
+		return nil
+	}
+	return fuse.ENOENT
+}
+
+func (fs *readBenchFS) OpenDir(ctx context.Context, op *fuseops.OpenDirOp) error {
+	// Allow opening any directory.
+	return nil
+}
+
+func (fs *readBenchFS) ReadDir(ctx context.Context, op *fuseops.ReadDirOp) error {
+	if op.Inode != 1 {
+		return fuse.ENOENT
+	}
+	if op.Offset > 0 {
+		return nil
+	}
+	entries := []fuseutil.Dirent{
+		fuseutil.Dirent{
+			Offset: 1,
+			Inode:  2,
+			Name:   "test",
+			Type:   fuseutil.DT_File,
+		},
+	}
+	for _, e := range entries[op.Offset:] {
+		n := fuseutil.WriteDirent(op.Dst[op.BytesRead:], e)
+		if n == 0 {
+			break
+		}
+		op.BytesRead += n
+	}
+	return nil
+}
+
+func (fs *readBenchFS) OpenFile(ctx context.Context, op *fuseops.OpenFileOp) error {
+	// Allow opening any file.
+	return nil
+}
+
+func (fs *readBenchFS) ReadFile(ctx context.Context, op *fuseops.ReadFileOp) error {
+	if op.Offset > fileSize {
+		return io.EOF
+	}
+	end := op.Offset + int64(len(op.Dst))
+	if end > fileSize {
+		end = fileSize
+	}
+	buflen := int64(len(fs.buf))
+	for pos := op.Offset; pos < end; {
+		s := pos % buflen
+		e := buflen
+		if e-s > end-pos {
+			e = s + end - pos
+		}
+		copy(op.Dst[pos-op.Offset:], fs.buf[s:])
+		pos = op.Offset + e
+	}
+	//op.Data = [][]byte{ contents[op.Offset : end] }
+	op.BytesRead = int(end - op.Offset)
+	return nil
+}
+
+func (fs *readBenchFS) ReleaseDirHandle(ctx context.Context, op *fuseops.ReleaseDirHandleOp) error {
+	return nil
+}
+
+func (fs *readBenchFS) GetXattr(ctx context.Context, op *fuseops.GetXattrOp) error {
+	return nil
+}
+
+func (fs *readBenchFS) ListXattr(ctx context.Context, op *fuseops.ListXattrOp) error {
+	return nil
+}
+
+func (fs *readBenchFS) ForgetInode(ctx context.Context, op *fuseops.ForgetInodeOp) error {
+	return nil
+}
+
+func (fs *readBenchFS) ReleaseFileHandle(ctx context.Context, op *fuseops.ReleaseFileHandleOp) error {
+	return nil
+}
+
+func (fs *readBenchFS) FlushFile(ctx context.Context, op *fuseops.FlushFileOp) error {
+	return nil
+}