Add sfdupes implementation: scan, report, and trees subcommands

progress.go

@@ -0,0 +1,123 @@
+package main
+
+import (
+	"fmt"
+	"os"
+	"time"
+
+	"github.com/schollz/progressbar/v3"
+)
+
+// plainInterval is the minimum time between progress lines when stderr
+// is not a TTY.
+const plainInterval = 5 * time.Second
+
+// stderrIsTTY reports whether stderr is attached to a terminal.
+func stderrIsTTY() bool {
+	fi, err := os.Stderr.Stat()
+	if err != nil {
+		return false
+	}
+	return fi.Mode()&os.ModeCharDevice != 0
+}
+
+// progress renders one scan pass's progress on stderr. On a TTY it
+// delegates to the progressbar library (spinner style when the total is
+// unknown, full bar with count/percent/rate/elapsed/ETA otherwise). When
+// stderr is not a TTY it emits no ANSI redraws: it prints a plain
+// one-line update no more often than every plainInterval.
+//
+// All methods must be called from the main goroutine only.
+type progress struct {
+	label string
+	total int64 // -1 when unknown (walk pass)
+	bar   *progressbar.ProgressBar
+	count int64
+	start time.Time
+	last  time.Time
+}
+
+func newProgress(label string, total int64) *progress {
+	p := &progress{label: label, total: total, start: time.Now()}
+	if !stderrIsTTY() {
+		return p
+	}
+	opts := []progressbar.Option{
+		progressbar.OptionSetWriter(os.Stderr),
+		progressbar.OptionSetDescription(label),
+		progressbar.OptionShowCount(),
+		progressbar.OptionShowIts(),
+		progressbar.OptionSetItsString("files"),
+		progressbar.OptionSetElapsedTime(true),
+		progressbar.OptionThrottle(100 * time.Millisecond),
+	}
+	if total >= 0 {
+		opts = append(opts,
+			progressbar.OptionSetPredictTime(true),
+			progressbar.OptionShowElapsedTimeOnFinish(),
+		)
+	} else {
+		opts = append(opts,
+			progressbar.OptionSetPredictTime(false),
+			progressbar.OptionSpinnerType(14),
+		)
+	}
+	p.bar = progressbar.NewOptions64(total, opts...)
+	return p
+}
+
+// increment records one completed item and refreshes the display.
+func (p *progress) increment() {
+	p.count++
+	if p.bar != nil {
+		_ = p.bar.Add(1)
+		return
+	}
+	if time.Since(p.last) >= plainInterval {
+		p.last = time.Now()
+		fmt.Fprintln(os.Stderr, p.plainLine())
+	}
+}
+
+// warnf prints a one-line warning to stderr without corrupting the bar.
+func (p *progress) warnf(format string, args ...any) {
+	if p.bar != nil {
+		_ = p.bar.Clear()
+	}
+	fmt.Fprintf(os.Stderr, format+"\n", args...)
+}
+
+// finish terminates the pass's display.
+func (p *progress) finish() {
+	if p.bar != nil {
+		_ = p.bar.Finish()
+		fmt.Fprintln(os.Stderr)
+		return
+	}
+	fmt.Fprintln(os.Stderr, p.plainLine())
+}
+
+// plainLine formats a non-TTY progress line.
+func (p *progress) plainLine() string {
+	elapsed := time.Since(p.start)
+	if p.total < 0 {
+		return fmt.Sprintf("%s: %d files, elapsed %s",
+			p.label, p.count, elapsed.Round(time.Second))
+	}
+	pct := 100.0
+	if p.total > 0 {
+		pct = 100 * float64(p.count) / float64(p.total)
+	}
+	rate := 0.0
+	if s := elapsed.Seconds(); s > 0 {
+		rate = float64(p.count) / s
+	}
+	eta := "?"
+	if rate > 0 && p.count <= p.total {
+		remaining := time.Duration(float64(p.total-p.count) / rate * float64(time.Second))
+		eta = remaining.Round(time.Second).String()
+	}
+	return fmt.Sprintf("%s: [%d/%d] %.0f%% %.0f files/s elapsed %s eta %s",
+		p.label, p.count, p.total, pct, rate,
+		elapsed.Round(time.Second), eta)
+}