Add example/statfs/ for profiling pathfs.

example/statfs/main.go

+package main
+
+import (
+	"flag"
+	"fmt"
+	"github.com/hanwen/go-fuse/fuse"
+	"github.com/hanwen/go-fuse/benchmark"
+	"io"
+	"log"
+	"os"
+	"os/exec"
+	"runtime"
+	"runtime/pprof"
+	"strings"
+	"time"
+)
+
+var _ = log.Printf
+
+func main() {
+	// Scans the arg list and sets up flags
+	debug := flag.Bool("debug", false, "print debugging messages.")
+	latencies := flag.Bool("latencies", false, "record operation latencies.")
+	profile := flag.String("profile", "", "record cpu profile.")
+	mem_profile := flag.String("mem-profile", "", "record memory profile.")
+	command := flag.String("run", "", "run this command after mounting.")
+	ttl := flag.Float64("ttl", 1.0, "attribute/entry cache TTL.")
+	flag.Parse()
+	if flag.NArg() < 2 {
+		fmt.Fprintf(os.Stderr, "usage: %s MOUNTPOINT FILENAMES-FILE\n", os.Args[0])
+		os.Exit(2)
+	}
+
+	var profFile, memProfFile io.Writer
+	var err error
+	if *profile != "" {
+		profFile, err = os.Create(*profile)
+		if err != nil {
+			log.Fatalf("os.Create: %v", err)
+		}
+	}
+	if *mem_profile != "" {
+		memProfFile, err = os.Create(*mem_profile)
+		if err != nil {
+			log.Fatalf("os.Create: %v", err)
+		}
+	}
+	fs := benchmark.NewStatFs()
+	lines := benchmark.ReadLines(flag.Arg(1))
+	for _, l := range lines {
+		fs.AddFile(l)
+	}
+	nfs := fuse.NewPathNodeFs(fs, nil)
+	opts := &fuse.FileSystemOptions{
+		AttrTimeout: time.Duration(*ttl * float64(time.Second)),
+		EntryTimeout: time.Duration(*ttl * float64(time.Second)),
+	}
+	state, _, err := fuse.MountNodeFileSystem(flag.Arg(0), nfs, opts)
+	if err != nil {
+		fmt.Printf("Mount fail: %v\n", err)
+		os.Exit(1)
+	}
+ 	
+	state.SetRecordStatistics(*latencies)
+	state.Debug = *debug
+	runtime.GC()
+	if profFile != nil {
+		pprof.StartCPUProfile(profFile)
+		defer pprof.StopCPUProfile()
+	}
+
+	if *command != "" {
+		args := strings.Split(*command, " ")
+		cmd := exec.Command(args[0], args[1:]...)
+		cmd.Stdout = os.Stdout
+		cmd.Start()
+	}
+	
+	state.Loop()
+	if memProfFile != nil {
+		pprof.WriteHeapProfile(memProfFile)
+	}
+}