history_view_cache_test.go RawHistoryFolder

1package vt
2
3import (
4	"testing"
5
6	"github.com/bnema/vev-vt/core"
7	"github.com/stretchr/testify/require"
8)
9
10func TestHistoryViewReusesUnchangedTail(t *testing.T) {
11	h := NewHistory(HistoryConfig{MaxRows: 8, ChunkRows: 4})
12	require.NoError(t, h.Append([]core.Cell{{Rune: 'a', Style: core.DefaultStyle()}}, LineBound{End: 1}))
13	first := h.View()
14	require.Same(t, first.chunks[0], h.View().chunks[0])
15	require.LessOrEqual(t, testing.AllocsPerRun(20, func() { _ = h.View() }), float64(1))
16	require.Same(t, first.chunks[0], h.SealAndView().chunks[0])
17}
18
19func TestHistoryTailCacheInvalidationPreservesRetainedViews(t *testing.T) {
20	for _, tt := range []struct {
21		name   string
22		mutate func(*History) error
23		want   int
24	}{
25		{"append", func(h *History) error {
26			return h.Append([]core.Cell{{Rune: 'c', Style: core.DefaultStyle()}}, LineBound{End: 1})
27		}, 3},
28		{"byte eviction", func(h *History) error {
29			return h.SetLimits(HistoryConfig{MaxBytes: core.StoredCellLogicalBytes + core.RowDescriptorLogicalBytes + core.StyleRecordLogicalBytes, ChunkRows: 4})
30		}, 1},
31		{"disable", func(h *History) error { return h.SetLimits(HistoryConfig{}) }, 0},
32		{"seal and row eviction", func(h *History) error { return h.SetLimits(HistoryConfig{MaxRows: 1, ChunkRows: 1}) }, 1},
33	} {
34		t.Run(tt.name, func(t *testing.T) {
35			h := NewHistory(HistoryConfig{MaxRows: 8, ChunkRows: 4})
36			for _, r := range "ab" {
37				require.NoError(t, h.Append([]core.Cell{{Rune: r, Style: core.DefaultStyle()}}, LineBound{End: 1}))
38			}
39			before := h.View()
40			snapshot := h.SnapshotView()
41			require.NoError(t, tt.mutate(h))
42			require.Equal(t, tt.want, h.View().Len())
43			require.Equal(t, 2, before.Len())
44			require.Equal(t, 'a', before.Cell(0, 0).Rune)
45			require.Equal(t, 'b', before.Cell(0, 1).Rune)
46			require.Equal(t, 'a', snapshot.Tail().Cell(0, 0).Rune)
47			require.Equal(t, 'b', snapshot.Tail().Cell(0, 1).Rune)
48		})
49	}
50}