perf(copy): gate large-history allocations

commit: 25d9db5d5a6d5563cddae780982ab63c3bc61999
author: brice · 3mo ago · 2026-07-11 06:24 UTC
parent: 70ae2be
signature: GPG VerifiedCD88F9E564E0102646FB6077A1A07C7C7C3E349D · arch-gpg Verified for the committer email

3 files · +61 -0

M docs/performance.md +18 -0


@@ -59,6 +59,24 @@ context:
59	59		} > /tmp/vev-history-before.txt 2>&1
60	60		```
61	61
	62	+	## Immutable document allocation gate
	63	+
	64	+	The copy-mode document retains an immutable view of existing scrollback rows and
	65	+	clones only the visible frame. Visual-search models share that document; cloning
	66	+	a model copies only its mutable input and match state. Check those two paths at
	67	+	10,000 history rows with:
	68	+
	69	+	```sh
	70	+	go test ./internal/usecase/copy ./internal/usecase/visualsearch -run '^$' -bench '^(BenchmarkNewSnapshot10KRows\|BenchmarkVisualSearchClone10KRows)$' -benchtime=1s -count=5 -benchmem
	71	+	```
	72	+
	73	+	Treat `allocs/op` and `B/op` as allocation gates: compare the complete repeated
	74	+	output with the accepted baseline before merging, and investigate any increase.
	75	+	This scope does not yet include an incremental/full-text search index: queries
	76	+	still scan the immutable document and produce a fresh match list. Coordinator
	77	+	behavior, chunk encoding, compression, GC tuning, and real Unix-socket, SSH, or
	78	+	UDP impairment/latency remain out of scope.
	79	+
62	80		## Lower-level smoke baseline
63	81
64	82		Use this command to check renderer, VT, IPC, and daemon microbenchmarks without


@@ -59,6 +59,24 @@ context:
59	} > /tmp/vev-history-before.txt 2>&1	59		} > /tmp/vev-history-before.txt 2>&1
60	```	60		```
61		61
		62	+	## Immutable document allocation gate
		63	+
		64	+	The copy-mode document retains an immutable view of existing scrollback rows and
		65	+	clones only the visible frame. Visual-search models share that document; cloning
		66	+	a model copies only its mutable input and match state. Check those two paths at
		67	+	10,000 history rows with:
		68	+
		69	+	```sh
		70	+	go test ./internal/usecase/copy ./internal/usecase/visualsearch -run '^$' -bench '^(BenchmarkNewSnapshot10KRows\|BenchmarkVisualSearchClone10KRows)$' -benchtime=1s -count=5 -benchmem
		71	+	```
		72	+
		73	+	Treat `allocs/op` and `B/op` as allocation gates: compare the complete repeated
		74	+	output with the accepted baseline before merging, and investigate any increase.
		75	+	This scope does not yet include an incremental/full-text search index: queries
		76	+	still scan the immutable document and produce a fresh match list. Coordinator
		77	+	behavior, chunk encoding, compression, GC tuning, and real Unix-socket, SSH, or
		78	+	UDP impairment/latency remain out of scope.
		79	+
62	## Lower-level smoke baseline	80		## Lower-level smoke baseline
63		81
64	Use this command to check renderer, VT, IPC, and daemon microbenchmarks without	82		Use this command to check renderer, VT, IPC, and daemon microbenchmarks without

M internal/usecase/copy/mode_test.go +25 -0


@@ -10,6 +10,8 @@ import (
10	10		"github.com/stretchr/testify/require"
11	11		)
12	12
	13	+	var benchmarkSnapshotSink Snapshot
	14	+
13	15		func snapshot(lines []string, height int) Snapshot {
14	16		rows := make([][]renderer.Cell, len(lines))
15	17		for i, line := range lines {

@@ -476,6 +478,29 @@ func TestOSC52FromBase64(t *testing.T) {
476	478		}
477	479		}
478	480
	481	+	func BenchmarkNewSnapshot10KRows(b *testing.B) {
	482	+	const (
	483	+	width = 120
	484	+	height = 40
	485	+	historyRows = 10_000
	486	+	)
	487	+
	488	+	scrollback := NewScrollback(historyRows)
	489	+	for range historyRows {
	490	+	scrollback.Append(row(strings.Repeat("x", width)))
	491	+	}
	492	+	screen := renderer.NewFrame(width, height)
	493	+	for y := range height {
	494	+	copy(screen.Row(y), row(strings.Repeat("s", width)))
	495	+	}
	496	+
	497	+	b.ReportAllocs()
	498	+	b.ResetTimer()
	499	+	for b.Loop() {
	500	+	benchmarkSnapshotSink = NewSnapshot(scrollback, screen)
	501	+	}
	502	+	}
	503	+
479	504		func decodeOSC52Chunk(t *testing.T, chunk []byte) []byte {
480	505		t.Helper()
481	506		s := string(chunk)


@@ -10,6 +10,8 @@ import (
10	"github.com/stretchr/testify/require"	10		"github.com/stretchr/testify/require"
11	)	11		)
12		12
		13	+	var benchmarkSnapshotSink Snapshot
		14	+
13	func snapshot(lines []string, height int) Snapshot {	15		func snapshot(lines []string, height int) Snapshot {
14	rows := make([][]renderer.Cell, len(lines))	16		rows := make([][]renderer.Cell, len(lines))
15	for i, line := range lines {	17		for i, line := range lines {

@@ -476,6 +478,29 @@ func TestOSC52FromBase64(t *testing.T) {
476	}	478		}
477	}	479		}
478		480
		481	+	func BenchmarkNewSnapshot10KRows(b *testing.B) {
		482	+	const (
		483	+	width = 120
		484	+	height = 40
		485	+	historyRows = 10_000
		486	+	)
		487	+
		488	+	scrollback := NewScrollback(historyRows)
		489	+	for range historyRows {
		490	+	scrollback.Append(row(strings.Repeat("x", width)))
		491	+	}
		492	+	screen := renderer.NewFrame(width, height)
		493	+	for y := range height {
		494	+	copy(screen.Row(y), row(strings.Repeat("s", width)))
		495	+	}
		496	+
		497	+	b.ReportAllocs()
		498	+	b.ResetTimer()
		499	+	for b.Loop() {
		500	+	benchmarkSnapshotSink = NewSnapshot(scrollback, screen)
		501	+	}
		502	+	}
		503	+
479	func decodeOSC52Chunk(t *testing.T, chunk []byte) []byte {	504		func decodeOSC52Chunk(t *testing.T, chunk []byte) []byte {
480	t.Helper()	505		t.Helper()
481	s := string(chunk)	506		s := string(chunk)

M internal/usecase/visualsearch/model_test.go +18 -0


@@ -11,6 +11,8 @@ import (
11	11		"github.com/bnema/vev/pkg/renderer"
12	12		)
13	13
	14	+	var benchmarkModelSink *Model
	15	+
14	16		func testSnapshot(lines ...string) scopy.Snapshot {
15	17		rows := make([][]renderer.Cell, len(lines))
16	18		for i, line := range lines {

@@ -105,6 +107,22 @@ func TestVisualSearchRenderShowsInputAndLineResults(t *testing.T) {
105	107		require.Contains(t, text, "2:6 beta alpha")
106	108		}
107	109
	110	+	func BenchmarkVisualSearchClone10KRows(b *testing.B) {
	111	+	const historyRows = 10_000
	112	+
	113	+	lines := make([]string, historyRows)
	114	+	for i := range lines {
	115	+	lines[i] = "immutable history row"
	116	+	}
	117	+	model := New(testSnapshot(lines...))
	118	+
	119	+	b.ReportAllocs()
	120	+	b.ResetTimer()
	121	+	for b.Loop() {
	122	+	benchmarkModelSink = model.Clone()
	123	+	}
	124	+	}
	125	+
108	126		func rowText(row []renderer.Cell) string {
109	127		var b strings.Builder
110	128		for _, c := range row {


@@ -11,6 +11,8 @@ import (
11	"github.com/bnema/vev/pkg/renderer"	11		"github.com/bnema/vev/pkg/renderer"
12	)	12		)
13		13
		14	+	var benchmarkModelSink *Model
		15	+
14	func testSnapshot(lines ...string) scopy.Snapshot {	16		func testSnapshot(lines ...string) scopy.Snapshot {
15	rows := make([][]renderer.Cell, len(lines))	17		rows := make([][]renderer.Cell, len(lines))
16	for i, line := range lines {	18		for i, line := range lines {

@@ -105,6 +107,22 @@ func TestVisualSearchRenderShowsInputAndLineResults(t *testing.T) {
105	require.Contains(t, text, "2:6 beta alpha")	107		require.Contains(t, text, "2:6 beta alpha")
106	}	108		}
107		109
		110	+	func BenchmarkVisualSearchClone10KRows(b *testing.B) {
		111	+	const historyRows = 10_000
		112	+
		113	+	lines := make([]string, historyRows)
		114	+	for i := range lines {
		115	+	lines[i] = "immutable history row"
		116	+	}
		117	+	model := New(testSnapshot(lines...))
		118	+
		119	+	b.ReportAllocs()
		120	+	b.ResetTimer()
		121	+	for b.Loop() {
		122	+	benchmarkModelSink = model.Clone()
		123	+	}
		124	+	}
		125	+
108	func rowText(row []renderer.Cell) string {	126		func rowText(row []renderer.Cell) string {
109	var b strings.Builder	127		var b strings.Builder
110	for _, c := range row {	128		for _, c := range row {