server: terminal width should fallback to 80x25. (#1895)

Some environments might disable access to `/dev/tty`, fall
back to '80' in such scenarios.

Move to 'cheggaaa/pb' package for better cross platform
support on fetching terminal width.

Fixes #1891

vendor/github.com/cheggaaa/pb/format.go

@@ -0,0 +1,87 @@
+package pb
+
+import (
+	"fmt"
+	"strings"
+	"time"
+)
+
+type Units int
+
+const (
+	// U_NO are default units, they represent a simple value and are not formatted at all.
+	U_NO Units = iota
+	// U_BYTES units are formatted in a human readable way (b, Bb, Mb, ...)
+	U_BYTES
+	// U_DURATION units are formatted in a human readable way (3h14m15s)
+	U_DURATION
+)
+
+func Format(i int64) *formatter {
+	return &formatter{n: i}
+}
+
+type formatter struct {
+	n      int64
+	unit   Units
+	width  int
+	perSec bool
+}
+
+func (f *formatter) Value(n int64) *formatter {
+	f.n = n
+	return f
+}
+
+func (f *formatter) To(unit Units) *formatter {
+	f.unit = unit
+	return f
+}
+
+func (f *formatter) Width(width int) *formatter {
+	f.width = width
+	return f
+}
+
+func (f *formatter) PerSec() *formatter {
+	f.perSec = true
+	return f
+}
+
+func (f *formatter) String() (out string) {
+	switch f.unit {
+	case U_BYTES:
+		out = formatBytes(f.n)
+	case U_DURATION:
+		d := time.Duration(f.n)
+		if d > time.Hour*24 {
+			out = fmt.Sprintf("%dd", d/24/time.Hour)
+			d -= (d / time.Hour / 24) * (time.Hour * 24)
+		}
+		out = fmt.Sprintf("%s%v", out, d)
+	default:
+		out = fmt.Sprintf(fmt.Sprintf("%%%dd", f.width), f.n)
+	}
+	if f.perSec {
+		out += "/s"
+	}
+	return
+}
+
+// Convert bytes to human readable string. Like a 2 MB, 64.2 KB, 52 B
+func formatBytes(i int64) (result string) {
+	switch {
+	case i > (1024 * 1024 * 1024 * 1024):
+		result = fmt.Sprintf("%.02f TB", float64(i)/1024/1024/1024/1024)
+	case i > (1024 * 1024 * 1024):
+		result = fmt.Sprintf("%.02f GB", float64(i)/1024/1024/1024)
+	case i > (1024 * 1024):
+		result = fmt.Sprintf("%.02f MB", float64(i)/1024/1024)
+	case i > 1024:
+		result = fmt.Sprintf("%.02f KB", float64(i)/1024)
+	default:
+		result = fmt.Sprintf("%d B", i)
+	}
+	result = strings.Trim(result, " ")
+	return
+}