Immutable blocks with mmap reads

Flush sealed head chunks to ULID-named block directories on disk. Each
block contains CRC'd chunk segment files (mmap'd for reads), a binary
index (symbol table, series, postings with TOC), and a meta.json written
last as the immutability gate. WAL is truncated after block fsync,
preserving the crash-safety ording invariant.
This commit is contained in:
2026-07-04 14:59:39 -04:00
parent 376d3faf25
commit 42b03db2fa
16 changed files with 2176 additions and 2 deletions
+332
View File
@@ -0,0 +1,332 @@
package block
import (
"math"
"math/rand"
"os"
"path/filepath"
"testing"
"git.dvdt.dev/david/ingot/internal/chunkenc"
"git.dvdt.dev/david/ingot/labels"
"github.com/stretchr/testify/assert"
"github.com/stretchr/testify/require"
)
type sample struct {
t int64
vBits uint64
}
func s(t int64, v float64) sample { return sample{t, math.Float64bits(v)} }
// makeChunk creates a chunk with the given samples and returns its raw bytes.
func makeChunk(t *testing.T, samples []sample) []byte {
t.Helper()
c := chunkenc.NewXORChunk()
a, err := c.Appender()
require.NoError(t, err)
for _, s := range samples {
a.Append(s.t, math.Float64frombits(s.vBits))
}
return append([]byte(nil), c.Bytes()...)
}
// collectIterator reads all samples from a ChunkIterator.
func collectIterator(t *testing.T, it chunkenc.ChunkIterator) []sample {
t.Helper()
var out []sample
for it.Next() {
ts, v := it.At()
out = append(out, sample{ts, math.Float64bits(v)})
}
require.NoError(t, it.Err())
return out
}
func TestBlockRoundTrip(t *testing.T) {
tests := []struct {
name string
series []struct {
ref uint64
labels []labels.Label
samples []sample
}
}{
{
name: "single_series_single_chunk",
series: []struct {
ref uint64
labels []labels.Label
samples []sample
}{
{
ref: 1,
labels: []labels.Label{{Name: "__name__", Value: "temp"}},
samples: []sample{
s(1000, 71.3), s(1015, 71.4), s(1030, 71.5),
},
},
},
},
{
name: "multiple_series",
series: []struct {
ref uint64
labels []labels.Label
samples []sample
}{
{
ref: 1,
labels: []labels.Label{{Name: "__name__", Value: "temp"}, {Name: "room", Value: "office"}},
samples: []sample{
s(1000, 71.3), s(1015, 71.4), s(1030, 71.5),
},
},
{
ref: 2,
labels: []labels.Label{{Name: "__name__", Value: "humidity"}, {Name: "room", Value: "office"}},
samples: []sample{
s(1000, 55.0), s(1015, 54.5), s(1030, 54.0),
},
},
},
},
{
name: "large_chunk",
series: []struct {
ref uint64
labels []labels.Label
samples []sample
}{
{
ref: 1,
labels: []labels.Label{{Name: "__name__", Value: "counter"}},
samples: func() []sample {
rnd := rand.New(rand.NewSource(42))
out := make([]sample, 120)
ts, v := int64(0), 0.0
for i := range out {
out[i] = s(ts, v)
ts += 15000 + int64(rnd.Intn(100)) - 50
v += rnd.Float64()
}
return out
}(),
},
},
},
}
for _, tc := range tests {
t.Run(tc.name, func(t *testing.T) {
dataDir := t.TempDir()
// Build SeriesFlush data.
var flushData []SeriesFlush
for _, s := range tc.series {
data := makeChunk(t, s.samples)
minT, maxT := s.samples[0].t, s.samples[len(s.samples)-1].t
flushData = append(flushData, SeriesFlush{
Ref: s.ref,
Labels: s.labels,
Chunks: []ChunkData{{MinT: minT, MaxT: maxT, Data: data}},
})
}
// Write block.
ulid, err := Flush(dataDir, flushData)
require.NoError(t, err)
require.NotEmpty(t, ulid)
// Open block for reading.
blockDir := filepath.Join(dataDir, ulid)
r, err := Open(blockDir)
require.NoError(t, err)
defer r.Close()
// Verify meta.
assert.Equal(t, ulid, r.Meta.ULID)
assert.Equal(t, 1, r.Meta.Version)
assert.Equal(t, len(tc.series), r.Meta.Stats.NumSeries)
assert.Equal(t, len(tc.series), r.Meta.Stats.NumChunks)
// Verify each series' data via iteration.
for _, s := range tc.series {
it, err := r.SeriesChunkIterator(s.ref, math.MinInt64, math.MaxInt64)
require.NoError(t, err)
got := collectIterator(t, it)
require.Equal(t, len(s.samples), len(got), "ref %d sample count", s.ref)
for i, want := range s.samples {
assert.Equal(t, want.t, got[i].t, "ref %d sample %d t", s.ref, i)
assert.Equal(t, want.vBits, got[i].vBits, "ref %d sample %d v", s.ref, i)
}
}
// Verify postings.
for _, s := range tc.series {
for _, l := range s.labels {
refs := r.Postings(l.Name, l.Value)
assert.Contains(t, refs, s.ref, "postings for %s=%s", l.Name, l.Value)
}
}
// Verify labels lookup.
for _, s := range tc.series {
ls, ok := r.Labels(s.ref)
assert.True(t, ok)
assert.Equal(t, s.labels, ls)
}
})
}
}
func TestBlockMultipleChunksPerSeries(t *testing.T) {
dataDir := t.TempDir()
chunk1Samples := []sample{s(1000, 1.0), s(1015, 2.0), s(1030, 3.0)}
chunk2Samples := []sample{s(2000, 4.0), s(2015, 5.0), s(2030, 6.0)}
allSamples := append(chunk1Samples, chunk2Samples...)
flushData := []SeriesFlush{
{
Ref: 1,
Labels: []labels.Label{{Name: "__name__", Value: "temp"}},
Chunks: []ChunkData{
{MinT: 1000, MaxT: 1030, Data: makeChunk(t, chunk1Samples)},
{MinT: 2000, MaxT: 2030, Data: makeChunk(t, chunk2Samples)},
},
},
}
ulid, err := Flush(dataDir, flushData)
require.NoError(t, err)
r, err := Open(filepath.Join(dataDir, ulid))
require.NoError(t, err)
defer r.Close()
// Full range.
it, err := r.SeriesChunkIterator(1, math.MinInt64, math.MaxInt64)
require.NoError(t, err)
got := collectIterator(t, it)
require.Equal(t, len(allSamples), len(got))
for i, want := range allSamples {
assert.Equal(t, want.t, got[i].t, "sample %d t", i)
assert.Equal(t, want.vBits, got[i].vBits, "sample %d v", i)
}
// Query only second chunk's range.
it, err = r.SeriesChunkIterator(1, 2000, 3000)
require.NoError(t, err)
got = collectIterator(t, it)
require.Equal(t, len(chunk2Samples), len(got))
for i, want := range chunk2Samples {
assert.Equal(t, want.t, got[i].t, "sample %d t", i)
assert.Equal(t, want.vBits, got[i].vBits, "sample %d v", i)
}
// Query with no overlap.
it, err = r.SeriesChunkIterator(1, 5000, 6000)
require.NoError(t, err)
got = collectIterator(t, it)
assert.Empty(t, got)
// Unknown ref.
it, err = r.SeriesChunkIterator(999, math.MinInt64, math.MaxInt64)
require.NoError(t, err)
assert.False(t, it.Next())
}
func TestBlockMetaTimeBounds(t *testing.T) {
dataDir := t.TempDir()
flushData := []SeriesFlush{
{
Ref: 1,
Labels: []labels.Label{{Name: "__name__", Value: "a"}},
Chunks: []ChunkData{{MinT: 500, MaxT: 1000, Data: makeChunk(t, []sample{s(500, 1.0), s(1000, 2.0)})}},
},
{
Ref: 2,
Labels: []labels.Label{{Name: "__name__", Value: "b"}},
Chunks: []ChunkData{{MinT: 200, MaxT: 800, Data: makeChunk(t, []sample{s(200, 3.0), s(800, 4.0)})}},
},
}
ulid, err := Flush(dataDir, flushData)
require.NoError(t, err)
r, err := Open(filepath.Join(dataDir, ulid))
require.NoError(t, err)
defer r.Close()
assert.Equal(t, int64(200), r.Meta.MinTime)
assert.Equal(t, int64(1000), r.Meta.MaxTime)
}
func TestULIDRoundTrip(t *testing.T) {
for i := 0; i < 100; i++ {
u := newULID()
assert.Equal(t, 26, len(u), "ULID length")
// Should parse without error.
_, err := parseULID(u)
assert.NoError(t, err, "parse ULID %q", u)
}
}
func TestCorruptChunkCRC(t *testing.T) {
dataDir := t.TempDir()
samples := []sample{s(1000, 71.3), s(1015, 71.4)}
flushData := []SeriesFlush{
{
Ref: 1,
Labels: []labels.Label{{Name: "__name__", Value: "temp"}},
Chunks: []ChunkData{{MinT: 1000, MaxT: 1015, Data: makeChunk(t, samples)}},
},
}
ulid, err := Flush(dataDir, flushData)
require.NoError(t, err)
// Open block, find the chunk ref, then corrupt the chunk file.
blockDir := filepath.Join(dataDir, ulid)
r, err := Open(blockDir)
require.NoError(t, err)
series := r.Series()
require.Equal(t, 1, len(series))
chunkRef := series[0].Chunks[0].Ref
r.Close()
// Corrupt chunk data on disk.
chunkSeg := chunkRef.Segment()
chunkPath := filepath.Join(blockDir, chunksDirName, segmentName(int(chunkSeg)))
// Read, corrupt a data byte, write back.
chunkFile, err := readFileBytes(chunkPath)
require.NoError(t, err)
off := int(chunkRef.Offset()) + chunkEntryHeaderLen + 1 // corrupt a data byte
if off < len(chunkFile) {
chunkFile[off] ^= 0xFF
}
require.NoError(t, writeFileBytes(chunkPath, chunkFile))
// Re-open and try to read the corrupt chunk.
r, err = Open(blockDir)
require.NoError(t, err)
defer r.Close()
_, err = r.ChunkIterator(chunkRef)
assert.Equal(t, ErrCorruptChunk, err)
}
func readFileBytes(path string) ([]byte, error) {
return os.ReadFile(path)
}
func writeFileBytes(path string, data []byte) error {
return os.WriteFile(path, data, 0644)
}