X github.com/jacobsa/fuse vs github.com/hanwen/go-fuse

Out of the box github.com/jacobsa/fuse turned out to be ~ 1.6x slower
than github.com/hanwen/go-fuse.

with github.com/hanwen/go-fuse:

	.../github.com/hanwen/go-fuse/example/benchmark-read-throughput$ md5sum ~/mnt/tmp/file.txt
	f4cbd65f70761c9c5306d9301422af02  /home/kirr/mnt/tmp/file.txt

	.../github.com/hanwen/go-fuse/example/benchmark-read-throughput$ go run readbench.go -bs 128 -limit 30000 ~/mnt/tmp/file.txt
	block size 128 kb: 30000.4 MB in 9.704823906s: 3091.29 MBs/s

with github.com/jacobsa/fuse

	.../github.com/hanwen/go-fuse/example/benchmark-read-throughput$ md5sum ~/mnt/tmp/hello
	f4cbd65f70761c9c5306d9301422af02  /home/kirr/mnt/tmp/hello

	.../github.com/hanwen/go-fuse/example/benchmark-read-throughput$ go run readbench.go -bs 128 -limit 30000 ~/mnt/tmp/hello
	block size 128 kb: 30000.4 MB in 15.701199318s: 1910.71 MBs/s

See also go-fuse@0aff2383

See also https://github.com/hanwen/go-fuse/issues/192#issuecomment-338198877

samples/hellofs/hello_fs.go

@@ -17,8 +17,10 @@ package hellofs
 import (
 	"context"
 	"io"
+	"io/ioutil"
 	"os"
-	"strings"
+	//"strings"
+	"bytes"
 
 	"github.com/jacobsa/fuse"
 	"github.com/jacobsa/fuse/fuseops"
@@ -66,7 +68,18 @@ type inodeInfo struct {
 }
 
 // We have a fixed directory structure.
-var gInodeInfo = map[fuseops.InodeID]inodeInfo{
+var gInodeInfo map[fuseops.InodeID]inodeInfo
+var data []byte
+
+func init() {
+	var err error
+	data, err = ioutil.ReadFile("/boot/initrd.img-4.16.0-2-amd64")
+	if err != nil {
+		panic(err)
+	}
+
+
+	gInodeInfo  = map[fuseops.InodeID]inodeInfo{
 	// root
 	rootInode: inodeInfo{
 		attributes: fuseops.InodeAttributes{
@@ -95,7 +108,8 @@ var gInodeInfo = map[fuseops.InodeID]inodeInfo{
 		attributes: fuseops.InodeAttributes{
 			Nlink: 1,
 			Mode:  0444,
-			Size:  uint64(len("Hello, world!")),
+			//Size:  uint64(len("Hello, world!")),
+			Size:  uint64(len(data)),
 		},
 	},
 
@@ -121,9 +135,11 @@ var gInodeInfo = map[fuseops.InodeID]inodeInfo{
 		attributes: fuseops.InodeAttributes{
 			Nlink: 1,
 			Mode:  0444,
-			Size:  uint64(len("Hello, world!")),
+			//Size:  uint64(len("Hello, world!")),
+			Size:  uint64(len(data)),
 		},
 	},
+	}
 }
 
 func findChildInode(
@@ -254,8 +270,28 @@ func (fs *helloFS) OpenFile(
 func (fs *helloFS) ReadFile(
 	ctx context.Context,
 	op *fuseops.ReadFileOp) (err error) {
+
+	ldata := int64(len(data))
+
+	if op.Offset >= ldata {
+		op.BytesRead = 0
+		return nil
+	}
+
+	end := op.Offset + int64(len(op.Dst))
+	if end > ldata {
+		end = ldata
+	}
+
+	op.BytesRead = copy(op.Dst, data[op.Offset:end])
+	return nil
+
+
+
+
 	// Let io.ReaderAt deal with the semantics.
-	reader := strings.NewReader("Hello, world!")
+	//reader := strings.NewReader("Hello, world!")
+	reader := bytes.NewReader(data)
 
 	op.BytesRead, err = reader.ReadAt(op.Dst, op.Offset)
 

samples/ktest/ktest.go

+package main
+
+import (
+	"context"
+	"flag"
+	"log"
+	"os"
+
+	"github.com/jacobsa/fuse"
+	"github.com/jacobsa/fuse/samples/hellofs"
+	"github.com/jacobsa/timeutil"
+)
+
+
+func main() {
+	flag.Parse()
+	if len(flag.Args()) != 1 {
+		log.Fatalf("usage: %s <mntpt>", os.Args[0])
+	}
+	mntpt := flag.Args()[0]
+
+	server, err := hellofs.NewHelloFS(timeutil.RealClock())
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	mfs, err := fuse.Mount(mntpt, server, &fuse.MountConfig{})
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	err = mfs.Join(context.Background())
+	if err != nil {
+		log.Fatal(err)
+	}
+}

[Kirill Smelkov]

.