restore: reorganize progress bar code

The structure is now much more similar to that of the backup command.

internal/ui/restore/progress.go

@@ -0,0 +1,90 @@
+package restore
+
+import (
+	"sync"
+	"time"
+
+	"github.com/restic/restic/internal/ui/progress"
+)
+
+type Progress struct {
+	updater progress.Updater
+	m       sync.Mutex
+
+	progressInfoMap map[string]progressInfoEntry
+	filesFinished   uint64
+	filesTotal      uint64
+	allBytesWritten uint64
+	allBytesTotal   uint64
+	started         time.Time
+
+	printer ProgressPrinter
+}
+
+type progressInfoEntry struct {
+	bytesWritten uint64
+	bytesTotal   uint64
+}
+
+type term interface {
+	Print(line string)
+	SetStatus(lines []string)
+}
+
+type ProgressPrinter interface {
+	Update(filesFinished, filesTotal, allBytesWritten, allBytesTotal uint64, duration time.Duration)
+	Finish(filesFinished, filesTotal, allBytesWritten, allBytesTotal uint64, duration time.Duration)
+}
+
+func NewProgress(printer ProgressPrinter, interval time.Duration) *Progress {
+	p := &Progress{
+		progressInfoMap: make(map[string]progressInfoEntry),
+		started:         time.Now(),
+		printer:         printer,
+	}
+	p.updater = *progress.NewUpdater(interval, p.update)
+	return p
+}
+
+func (p *Progress) update(runtime time.Duration, final bool) {
+	p.m.Lock()
+	defer p.m.Unlock()
+
+	if !final {
+		p.printer.Update(p.filesFinished, p.filesTotal, p.allBytesWritten, p.allBytesTotal, runtime)
+	} else {
+		p.printer.Finish(p.filesFinished, p.filesTotal, p.allBytesWritten, p.allBytesTotal, runtime)
+	}
+}
+
+// AddFile starts tracking a new file with the given size
+func (p *Progress) AddFile(size uint64) {
+	p.m.Lock()
+	defer p.m.Unlock()
+
+	p.filesTotal++
+	p.allBytesTotal += size
+}
+
+// AddProgress accumulates the number of bytes written for a file
+func (p *Progress) AddProgress(name string, bytesWrittenPortion uint64, bytesTotal uint64) {
+	p.m.Lock()
+	defer p.m.Unlock()
+
+	entry, exists := p.progressInfoMap[name]
+	if !exists {
+		entry.bytesTotal = bytesTotal
+	}
+	entry.bytesWritten += bytesWrittenPortion
+	p.progressInfoMap[name] = entry
+
+	p.allBytesWritten += bytesWrittenPortion
+	if entry.bytesWritten == entry.bytesTotal {
+		delete(p.progressInfoMap, name)
+		p.filesFinished++
+	}
+}
+
+func (p *Progress) Finish() {
+	p.updater.Done()
+}