test(resize): guard reflow rendering performance

commit: 804097528a61932b70ef35afc8e4dac0b513962d
author: brice · 3mo ago · 2026-07-15 15:34 UTC
parent: 56e46d3
signature: GPG VerifiedCD88F9E564E0102646FB6077A1A07C7C7C3E349D · arch-gpg Verified for the committer email

3 files · +66 -0

M internal/usecase/daemon/output_state_stream_test.go +30 -0


@@ -77,6 +77,36 @@ func drawOutputState(t testing.T, stream outputStateStream, frame renderer.Fra
77	77		return stream.frame(data, reset, echoAck), true, nil
78	78		}
79	79
	80	+	// A resize is a state reset, but it must not turn subsequent idle or damaged
	81	+	// renders into full frames.
	82	+	func TestOutputStateStreamResizeFrameThenNoopAndDamageAreDifferential(t *testing.T) {
	83	+	screen := vt.NewScreen(4, 2)
	84	+	screen.Write([]byte("abcd"))
	85	+	screen.ClearDamage()
	86	+	screen.Resize(6, 2)
	87	+
	88	+	stream := newOutputStateStream()
	89	+	resized, ok, err := drawOutputState(t, stream, screen.Frame, screen.Damage(), true, 0)
	90	+	require.NoError(t, err)
	91	+	require.True(t, ok)
	92	+	resizeOutput, err := ports.UnmarshalOutput(resized.Payload)
	93	+	require.NoError(t, err)
	94	+	require.Zero(t, resizeOutput.BaseStateNum, "resize must emit the one reset frame")
	95	+	screen.ClearDamage()
	96	+
	97	+	_, ok, err = drawOutputState(t, stream, screen.Frame, screen.Damage(), false, 0)
	98	+	require.NoError(t, err)
	99	+	require.False(t, ok, "an unchanged render after resize must emit nothing")
	100	+
	101	+	screen.Frame.Set(0, 0, renderer.Cell{Rune: 'x', Style: renderer.DefaultStyle()})
	102	+	damaged, ok, err := drawOutputState(t, stream, screen.Frame, []renderer.Damage{{Kind: renderer.DamageText, Width: 1, Height: 1}}, false, 0)
	103	+	require.NoError(t, err)
	104	+	require.True(t, ok)
	105	+	damageOutput, err := ports.UnmarshalOutput(damaged.Payload)
	106	+	require.NoError(t, err)
	107	+	require.Equal(t, resizeOutput.NewStateNum, damageOutput.BaseStateNum, "later damage must remain incremental")
	108	+	}
	109	+
80	110		func TestOutputStateStreamDefaultsAndNormalizesWindow(t *testing.T) {
81	111		require.Equal(t, uint64(8), newOutputStateStream().maxOutstanding)
82	112		require.Equal(t, uint64(8), newOutputStateStream(0).maxOutstanding)


@@ -77,6 +77,36 @@ func drawOutputState(t testing.T, stream outputStateStream, frame renderer.Fra
77	return stream.frame(data, reset, echoAck), true, nil	77		return stream.frame(data, reset, echoAck), true, nil
78	}	78		}
79		79
		80	+	// A resize is a state reset, but it must not turn subsequent idle or damaged
		81	+	// renders into full frames.
		82	+	func TestOutputStateStreamResizeFrameThenNoopAndDamageAreDifferential(t *testing.T) {
		83	+	screen := vt.NewScreen(4, 2)
		84	+	screen.Write([]byte("abcd"))
		85	+	screen.ClearDamage()
		86	+	screen.Resize(6, 2)
		87	+
		88	+	stream := newOutputStateStream()
		89	+	resized, ok, err := drawOutputState(t, stream, screen.Frame, screen.Damage(), true, 0)
		90	+	require.NoError(t, err)
		91	+	require.True(t, ok)
		92	+	resizeOutput, err := ports.UnmarshalOutput(resized.Payload)
		93	+	require.NoError(t, err)
		94	+	require.Zero(t, resizeOutput.BaseStateNum, "resize must emit the one reset frame")
		95	+	screen.ClearDamage()
		96	+
		97	+	_, ok, err = drawOutputState(t, stream, screen.Frame, screen.Damage(), false, 0)
		98	+	require.NoError(t, err)
		99	+	require.False(t, ok, "an unchanged render after resize must emit nothing")
		100	+
		101	+	screen.Frame.Set(0, 0, renderer.Cell{Rune: 'x', Style: renderer.DefaultStyle()})
		102	+	damaged, ok, err := drawOutputState(t, stream, screen.Frame, []renderer.Damage{{Kind: renderer.DamageText, Width: 1, Height: 1}}, false, 0)
		103	+	require.NoError(t, err)
		104	+	require.True(t, ok)
		105	+	damageOutput, err := ports.UnmarshalOutput(damaged.Payload)
		106	+	require.NoError(t, err)
		107	+	require.Equal(t, resizeOutput.NewStateNum, damageOutput.BaseStateNum, "later damage must remain incremental")
		108	+	}
		109	+
80	func TestOutputStateStreamDefaultsAndNormalizesWindow(t *testing.T) {	110		func TestOutputStateStreamDefaultsAndNormalizesWindow(t *testing.T) {
81	require.Equal(t, uint64(8), newOutputStateStream().maxOutstanding)	111		require.Equal(t, uint64(8), newOutputStateStream().maxOutstanding)
82	require.Equal(t, uint64(8), newOutputStateStream(0).maxOutstanding)	112		require.Equal(t, uint64(8), newOutputStateStream(0).maxOutstanding)

M internal/usecase/daemon/transactional_resize_test.go +3 -0


@@ -357,6 +357,9 @@ func TestTransactionalResizeObsoleteTimerCallbacksCommitOnlyLatestEpoch(t *testi
357	357		// through S2 immediately (subject to ACK/sync gates).
358	358		frame := <-frames
359	359		require.Equal(t, ports.MsgOutput, frame.Type, "the committed epoch emits a full frame")
	360	+	output, err := ports.UnmarshalOutput(frame.Payload)
	361	+	require.NoError(t, err)
	362	+	require.Zero(t, output.BaseStateNum, "the accepted resize frame must reset the renderer state")
360	363		select {
361	364		case extra := <-frames:
362	365		t.Fatalf("obsolete epoch emitted an additional frame: %#v", extra)


@@ -357,6 +357,9 @@ func TestTransactionalResizeObsoleteTimerCallbacksCommitOnlyLatestEpoch(t *testi
357	// through S2 immediately (subject to ACK/sync gates).	357		// through S2 immediately (subject to ACK/sync gates).
358	frame := <-frames	358		frame := <-frames
359	require.Equal(t, ports.MsgOutput, frame.Type, "the committed epoch emits a full frame")	359		require.Equal(t, ports.MsgOutput, frame.Type, "the committed epoch emits a full frame")
		360	+	output, err := ports.UnmarshalOutput(frame.Payload)
		361	+	require.NoError(t, err)
		362	+	require.Zero(t, output.BaseStateNum, "the accepted resize frame must reset the renderer state")
360	select {	363		select {
361	case extra := <-frames:	364		case extra := <-frames:
362	t.Fatalf("obsolete epoch emitted an additional frame: %#v", extra)	365		t.Fatalf("obsolete epoch emitted an additional frame: %#v", extra)

M pkg/vt/benchmark_test.go +33 -0

@@ -1,6 +1,7 @@
1	1		package vt
2	2
3	3		import (
	4	+	"bytes"
4	5		"testing"
5	6
6	7		"github.com/bnema/vev/pkg/renderer"

@@ -159,6 +160,38 @@ func benchmarkHistory(t testing.TB, rows, width, chunkRows int) *History {
159	160		return history
160	161		}
161	162
	163	+	// BenchmarkScreenResizeReflowViewport verifies resize only visits the live
	164	+	// viewport. The 10K-history variant must track the control rather than history
	165	+	// length; history is deliberately populated without changing the viewport.
	166	+	func BenchmarkScreenResizeReflowViewport(b *testing.B) {
	167	+	b.Run("control", func(b *testing.B) { benchmarkScreenResizeReflow(b, 0) })
	168	+	b.Run("10k-history", func(b *testing.B) { benchmarkScreenResizeReflow(b, 10_000) })
	169	+	}
	170	+
	171	+	func benchmarkScreenResizeReflow(b *testing.B, historyRows int) {
	172	+	b.Helper()
	173	+	s := NewScreenWithHistory(120, 40, HistoryConfig{MaxRows: historyRows + 500})
	174	+	if historyRows > 0 {
	175	+	for range historyRows {
	176	+	s.history.Append(make([]renderer.Cell, 120))
	177	+	}
	178	+	}
	179	+	s.Write(bytes.Repeat([]byte("x"), 120*39))
	180	+	s.ClearDamage()
	181	+	sizes := [2][2]int{{80, 40}, {120, 40}}
	182	+
	183	+	b.ReportAllocs()
	184	+	b.ResetTimer()
	185	+	for i := 0; b.Loop(); i++ {
	186	+	s.Resize(sizes[i%len(sizes)][0], sizes[i%len(sizes)][1])
	187	+	s.ClearDamage()
	188	+	}
	189	+	b.StopTimer()
	190	+	if got := s.History(); historyRows > 0 && got.Len() < historyRows {
	191	+	b.Fatalf("resize discarded retained history rows: got %d want at least %d", got.Len(), historyRows)
	192	+	}
	193	+	}
	194	+
162	195		func BenchmarkScreenShellRedrawBurst(b *testing.B) {
163	196		chunk := []byte("\r\x1b[K❯ abc\x1b[90m autosuggestion\x1b[39m\r\x1b[5C")
164	197		b.ReportAllocs()

@@ -1,6 +1,7 @@
1	package vt	1		package vt
2		2
3	import (	3		import (
		4	+	"bytes"
4	"testing"	5		"testing"
5		6
6	"github.com/bnema/vev/pkg/renderer"	7		"github.com/bnema/vev/pkg/renderer"

@@ -159,6 +160,38 @@ func benchmarkHistory(t testing.TB, rows, width, chunkRows int) *History {
159	return history	160		return history
160	}	161		}
161		162
		163	+	// BenchmarkScreenResizeReflowViewport verifies resize only visits the live
		164	+	// viewport. The 10K-history variant must track the control rather than history
		165	+	// length; history is deliberately populated without changing the viewport.
		166	+	func BenchmarkScreenResizeReflowViewport(b *testing.B) {
		167	+	b.Run("control", func(b *testing.B) { benchmarkScreenResizeReflow(b, 0) })
		168	+	b.Run("10k-history", func(b *testing.B) { benchmarkScreenResizeReflow(b, 10_000) })
		169	+	}
		170	+
		171	+	func benchmarkScreenResizeReflow(b *testing.B, historyRows int) {
		172	+	b.Helper()
		173	+	s := NewScreenWithHistory(120, 40, HistoryConfig{MaxRows: historyRows + 500})
		174	+	if historyRows > 0 {
		175	+	for range historyRows {
		176	+	s.history.Append(make([]renderer.Cell, 120))
		177	+	}
		178	+	}
		179	+	s.Write(bytes.Repeat([]byte("x"), 120*39))
		180	+	s.ClearDamage()
		181	+	sizes := [2][2]int{{80, 40}, {120, 40}}
		182	+
		183	+	b.ReportAllocs()
		184	+	b.ResetTimer()
		185	+	for i := 0; b.Loop(); i++ {
		186	+	s.Resize(sizes[i%len(sizes)][0], sizes[i%len(sizes)][1])
		187	+	s.ClearDamage()
		188	+	}
		189	+	b.StopTimer()
		190	+	if got := s.History(); historyRows > 0 && got.Len() < historyRows {
		191	+	b.Fatalf("resize discarded retained history rows: got %d want at least %d", got.Len(), historyRows)
		192	+	}
		193	+	}
		194	+
162	func BenchmarkScreenShellRedrawBurst(b *testing.B) {	195		func BenchmarkScreenShellRedrawBurst(b *testing.B) {
163	chunk := []byte("\r\x1b[K❯ abc\x1b[90m autosuggestion\x1b[39m\r\x1b[5C")	196		chunk := []byte("\r\x1b[K❯ abc\x1b[90m autosuggestion\x1b[39m\r\x1b[5C")
164	b.ReportAllocs()	197		b.ReportAllocs()