Use a 2 minute rolling average

3 files changed, 21 insertions, 20 deletions

diff --git a/go.mod b/go.mod
index 03223e0..24fe437 100644
--- a/go.mod
+++ b/go.mod
@@ -3,8 +3,8 @@ module gitlab.com/rhogenson/progress-bar
 go 1.24.1
 
 require (
-	gitlab.com/rhogenson/vecdeque v0.0.0-20250405212855-dfc639535656
-	golang.org/x/term v0.30.0
+	gitlab.com/rhogenson/vecdeque v0.0.0-20250406001322-9e21d75e8d13
+	golang.org/x/term v0.31.0
 )
 
 require golang.org/x/sys v0.32.0 // indirect
diff --git a/go.sum b/go.sum
index aaaaccc..c219b71 100644
--- a/go.sum
+++ b/go.sum
@@ -1,6 +1,6 @@
-gitlab.com/rhogenson/vecdeque v0.0.0-20250405212855-dfc639535656 h1:doc1SOczGwCrlM79hCNRuIY5P72zj+iCSYqAQ4v4+Pg=
-gitlab.com/rhogenson/vecdeque v0.0.0-20250405212855-dfc639535656/go.mod h1:i++skCmDHJAQbyC5LqvJbehbEGCiO8EkrsPon6h0Jgo=
+gitlab.com/rhogenson/vecdeque v0.0.0-20250406001322-9e21d75e8d13 h1:KzxZ53VHLj1w4DsYcbdIjNFPTcnc4UtBA79KoXkdgP0=
+gitlab.com/rhogenson/vecdeque v0.0.0-20250406001322-9e21d75e8d13/go.mod h1:i++skCmDHJAQbyC5LqvJbehbEGCiO8EkrsPon6h0Jgo=
 golang.org/x/sys v0.32.0 h1:s77OFDvIQeibCmezSnk/q6iAfkdiQaJi4VzroCFrN20=
 golang.org/x/sys v0.32.0/go.mod h1:BJP2sWEmIv4KK5OTEluFJCKSidICx8ciO85XgH3Ak8k=
-golang.org/x/term v0.30.0 h1:PQ39fJZ+mfadBm0y5WlL4vlM7Sx1Hgf13sMIY2+QS9Y=
-golang.org/x/term v0.30.0/go.mod h1:NYYFdzHoI5wRh/h5tDMdMqCqPJZEuNqVR5xJLd/n67g=
+golang.org/x/term v0.31.0 h1:erwDkOK1Msy6offm1mOgvspSkslFnIGsFnxOKoufg3o=
+golang.org/x/term v0.31.0/go.mod h1:R4BeIy7D95HzImkxGkTW1UQTtP54tio2RyHz7PwK0aw=
diff --git a/progress.go b/progress.go
index 11821c1..2d78cef 100644
--- a/progress.go
+++ b/progress.go
@@ -28,8 +28,6 @@ import (
 	"golang.org/x/term"
 )
 
-const measurements = 20
-
 type measurement struct {
 	t time.Time
 	i int
@@ -40,19 +38,15 @@ type Bar struct {
 	max          int
 	measurements vecdeque.DQ[measurement]
 	cols         int
+	secondPrint  bool
 }
 
 func New(max int) *Bar {
-	b := &Bar{max: max}
-	b.measurements.Grow(measurements)
-	return b
+	return &Bar{max: max}
 }
 
 // Set sets the current value to val.
 func (b *Bar) Set(val int) {
-	if b.measurements.Len() == measurements {
-		b.measurements.PopFront()
-	}
 	b.measurements.PushBack(measurement{time.Now(), val})
 }
 
@@ -62,6 +56,10 @@ func (b *Bar) Print() {
 		return
 	}
 
+	now := time.Now()
+	for b.measurements.Len() > 1 && now.Sub(b.measurements.Get(0).t) > 2*time.Minute {
+		b.measurements.PopFront()
+	}
 	first := b.measurements.Get(0)
 	last := b.measurements.Get(b.measurements.Len() - 1)
 	deltaT := last.t.Sub(first.t)
@@ -71,16 +69,19 @@ func (b *Bar) Print() {
 		eta = time.Duration(float64(b.max-last.i) / float64(delta) * float64(deltaT))
 	}
 
-	p := last.i * b.cols / b.max
+	if b.secondPrint {
+		fmt.Fprint(os.Stderr, "\033[2F\033[J")
+	}
+	b.secondPrint = true
 	if b.cols == 0 {
 		var err error
 		if b.cols, _, err = term.GetSize(int(os.Stderr.Fd())); err != nil {
-			fmt.Fprintf(os.Stderr, "Warning: unable to determine terminal size: %s\n", err)
-		} else {
-			fmt.Fprintf(os.Stderr, "%s>\n", strings.Repeat("=", max(p-1, 0)))
+			fmt.Fprintf(os.Stderr, "Unable to determine terminal size: %s\n", err)
 		}
-	} else {
-		fmt.Fprintf(os.Stderr, "\033[2F\033[J%s>\n", strings.Repeat("=", max(p-1, 0)))
+	}
+	p := last.i * b.cols / b.max
+	if b.cols > 0 {
+		fmt.Fprintf(os.Stderr, "%s>\n", strings.Repeat("=", max(p-1, 0)))
 	}
 	if eta < 0 {
 		fmt.Fprintln(os.Stderr, "ETA: calculating...")