fix metadata generator

cmd/cachectl/main.go

@@ -3,15 +3,19 @@
 package main
 
 import (
+	"cachefs/pkg/provider"
 	"cachefs/pkg/provider/parse"
 	"encoding/hex"
 	"errors"
 	"flag"
 	"fmt"
 	"io"
+	"math"
 	"os"
 	"path/filepath"
 	"strings"
+	"sync/atomic"
+	"time"
 )
 
 var (
@@ -176,7 +180,52 @@ func cp(args []string) (err error) {
 		return
 	}
 	defer df.Close()
-	_, err = io.Copy(df, sf)
+	fi, err := sf.Stat()
+	if err != nil {
+		return
+	}
+	r := &progressReader{
+		f:    sf,
+		done: make(chan struct{}),
+		size: fi.Size(),
+	}
+	go r.PrintProgress()
+	_, err = io.Copy(df, r)
+	close(r.done)
+	return
+}
+
+type progressReader struct {
+	f    provider.File
+	done chan struct{}
+	size int64
+	n    int64
+}
+
+func (p *progressReader) Read(b []byte) (n int, err error) {
+	n, err = p.f.Read(b)
+	atomic.AddInt64(&p.n, int64(n))
+	return
+}
+
+func (p *progressReader) ReadAt(b []byte, off int64) (n int, err error) {
+	n, err = p.f.ReadAt(b, off)
+	atomic.AddInt64(&p.n, int64(n))
+	return
+}
+
+func (p *progressReader) PrintProgress() {
+	for {
+		select {
+		case <-p.done:
+			fmt.Println()
+			return
+		case <-time.After(time.Millisecond * 500):
+		}
+		n := atomic.LoadInt64(&p.n)
+		percent := int(math.Round(float64(n) / float64(p.size) * 100))
+		fmt.Printf("progress: %d / %d %d%%\r", n, p.size, percent)
+	}
 	return
 }