cmd/htpacker: swap out progress bar library

Switch to a simpler progress bar library. I've been having trouble tracking
down a panic that seemed to affect the prior code; the new code is much
easier and uses far fewer async channels and things.

cmd/htpacker/progress.go

@@ -0,0 +1,131 @@
+package main
+
+import (
+	"bytes"
+	"slices"
+	"sync"
+
+	"github.com/gosuri/uiprogress"
+	"src.lwithers.me.uk/go/htpack/cmd/htpacker/packer"
+)
+
+type uiProgress struct {
+	p                          *uiprogress.Progress
+	uncompressed, gzip, brotli *uiProgressBar
+}
+
+func newUiProgress(ftp packer.FilesToPack) *uiProgress {
+	up := &uiProgress{
+		p: uiprogress.New(),
+	}
+
+	up.uncompressed = newUiProgressBar(up.p, len(ftp), "uncompressed")
+	var nGzip, nBrotli int
+	for _, f := range ftp {
+		if !f.DisableCompression && !f.DisableGzip {
+			nGzip++
+		}
+		if !f.DisableCompression && !f.DisableBrotli {
+			nBrotli++
+		}
+	}
+	if nGzip > 0 {
+		up.gzip = newUiProgressBar(up.p, nGzip, "gzip")
+	}
+	if nBrotli > 0 {
+		up.brotli = newUiProgressBar(up.p, nGzip, "brotli")
+	}
+
+	up.p.Start()
+	return up
+}
+
+func (up *uiProgress) Count(_ int) {
+}
+
+func (up *uiProgress) Begin(filename, compression string) {
+	up.bar(compression).begin(filename)
+}
+
+func (up *uiProgress) End(filename, compression string) {
+	up.bar(compression).end(filename)
+}
+
+func (up *uiProgress) bar(compression string) *uiProgressBar {
+	switch compression {
+	case "uncompressed":
+		return up.uncompressed
+	case "gzip":
+		return up.gzip
+	case "brotli":
+		return up.brotli
+	}
+	return nil
+}
+
+func (up *uiProgress) Complete() {
+	up.p.Stop()
+}
+
+type uiProgressBar struct {
+	bar      *uiprogress.Bar
+	lock     sync.Mutex
+	inflight []string
+}
+
+func newUiProgressBar(p *uiprogress.Progress, total int, compression string) *uiProgressBar {
+	bar := &uiProgressBar{
+		bar: p.AddBar(total).AppendCompleted(),
+	}
+
+	var buf bytes.Buffer
+	bar.bar.PrependFunc(func(*uiprogress.Bar) string {
+		bar.lock.Lock()
+		defer bar.lock.Unlock()
+		buf.Reset()
+		buf.WriteString(compression)
+		if len(bar.inflight) > 0 {
+			buf.WriteString(" (")
+			for i, f := range bar.inflight {
+				if i > 0 {
+					buf.WriteString(", ")
+				}
+				buf.WriteString(f)
+			}
+			buf.WriteRune(')')
+		}
+		if buf.Len() < 40 {
+			buf.WriteString("                                        ")
+			buf.Truncate(40)
+		} else if buf.Len() > 40 {
+			buf.Truncate(39)
+			buf.WriteString("…")
+		}
+		return buf.String()
+	})
+
+	return bar
+}
+
+func (bar *uiProgressBar) begin(filename string) {
+	if bar == nil {
+		return
+	}
+	bar.lock.Lock()
+	defer bar.lock.Unlock()
+
+	bar.inflight = append(bar.inflight, filename)
+}
+
+func (bar *uiProgressBar) end(filename string) {
+	if bar == nil {
+		return
+	}
+	bar.lock.Lock()
+	defer bar.lock.Unlock()
+
+	bar.bar.Incr()
+	if idx := slices.Index(bar.inflight, filename); idx != -1 {
+		bar.inflight = slices.Delete(bar.inflight, idx, idx+1)
+	}
+}