ceremonyclient/pebble/record/record_test.go

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2024-01-03 07:31:42 +00:00
// Copyright 2011 The LevelDB-Go and Pebble Authors. All rights reserved. Use
// of this source code is governed by a BSD-style license that can be found in
// the LICENSE file.
package record
import (
"bytes"
"encoding/binary"
"fmt"
"io"
"math"
"strings"
"testing"
"time"
"github.com/cockroachdb/errors"
"github.com/cockroachdb/pebble/internal/base"
"github.com/prometheus/client_golang/prometheus"
"github.com/stretchr/testify/require"
"golang.org/x/exp/rand"
)
func short(s string) string {
if len(s) < 64 {
return s
}
return fmt.Sprintf("%s...(skipping %d bytes)...%s", s[:20], len(s)-40, s[len(s)-20:])
}
// big returns a string of length n, composed of repetitions of partial.
func big(partial string, n int) string {
return strings.Repeat(partial, n/len(partial)+1)[:n]
}
type recordWriter interface {
WriteRecord([]byte) (int64, error)
Close() error
}
func testGeneratorWriter(
t *testing.T, reset func(), gen func() (string, bool), newWriter func(io.Writer) recordWriter,
) {
buf := new(bytes.Buffer)
reset()
w := newWriter(buf)
for {
s, ok := gen()
if !ok {
break
}
if _, err := w.WriteRecord([]byte(s)); err != nil {
t.Fatalf("Write: %v", err)
}
}
if err := w.Close(); err != nil {
t.Fatalf("Close: %v", err)
}
reset()
r := NewReader(buf, 0 /* logNum */)
for {
s, ok := gen()
if !ok {
break
}
rr, err := r.Next()
if err != nil {
t.Fatalf("reader.Next: %v", err)
}
x, err := io.ReadAll(rr)
if err != nil {
t.Fatalf("ReadAll: %v", err)
}
if string(x) != s {
t.Fatalf("got %q, want %q", short(string(x)), short(s))
}
}
if _, err := r.Next(); err != io.EOF {
t.Fatalf("got %v, want %v", err, io.EOF)
}
}
func testGenerator(t *testing.T, reset func(), gen func() (string, bool)) {
t.Run("Writer", func(t *testing.T) {
testGeneratorWriter(t, reset, gen, func(w io.Writer) recordWriter {
return NewWriter(w)
})
})
t.Run("LogWriter", func(t *testing.T) {
testGeneratorWriter(t, reset, gen, func(w io.Writer) recordWriter {
return NewLogWriter(w, 0 /* logNum */, LogWriterConfig{
WALFsyncLatency: prometheus.NewHistogram(prometheus.HistogramOpts{})})
})
})
}
func testLiterals(t *testing.T, s []string) {
var i int
reset := func() {
i = 0
}
gen := func() (string, bool) {
if i == len(s) {
return "", false
}
i++
return s[i-1], true
}
testGenerator(t, reset, gen)
}
func TestMany(t *testing.T) {
const n = 1e5
var i int
reset := func() {
i = 0
}
gen := func() (string, bool) {
if i == n {
return "", false
}
i++
return fmt.Sprintf("%d.", i-1), true
}
testGenerator(t, reset, gen)
}
func TestRandom(t *testing.T) {
const n = 1e2
var (
i int
r *rand.Rand
)
reset := func() {
i, r = 0, rand.New(rand.NewSource(0))
}
gen := func() (string, bool) {
if i == n {
return "", false
}
i++
return strings.Repeat(string(uint8(i)), r.Intn(2*blockSize+16)), true
}
testGenerator(t, reset, gen)
}
func TestBasic(t *testing.T) {
testLiterals(t, []string{
strings.Repeat("a", 1000),
strings.Repeat("b", 97270),
strings.Repeat("c", 8000),
})
}
func TestBoundary(t *testing.T) {
for i := blockSize - 16; i < blockSize+16; i++ {
s0 := big("abcd", i)
for j := blockSize - 16; j < blockSize+16; j++ {
s1 := big("ABCDE", j)
testLiterals(t, []string{s0, s1})
testLiterals(t, []string{s0, "", s1})
testLiterals(t, []string{s0, "x", s1})
}
}
}
func TestFlush(t *testing.T) {
buf := new(bytes.Buffer)
w := NewWriter(buf)
// Write a couple of records. Everything should still be held
// in the record.Writer buffer, so that buf.Len should be 0.
w0, _ := w.Next()
w0.Write([]byte("0"))
w1, _ := w.Next()
w1.Write([]byte("11"))
if got, want := buf.Len(), 0; got != want {
t.Fatalf("buffer length #0: got %d want %d", got, want)
}
// Flush the record.Writer buffer, which should yield 17 bytes.
// 17 = 2*7 + 1 + 2, which is two headers and 1 + 2 payload bytes.
require.NoError(t, w.Flush())
if got, want := buf.Len(), 17; got != want {
t.Fatalf("buffer length #1: got %d want %d", got, want)
}
// Do another write, one that isn't large enough to complete the block.
// The write should not have flowed through to buf.
w2, _ := w.Next()
w2.Write(bytes.Repeat([]byte("2"), 10000))
if got, want := buf.Len(), 17; got != want {
t.Fatalf("buffer length #2: got %d want %d", got, want)
}
// Flushing should get us up to 10024 bytes written.
// 10024 = 17 + 7 + 10000.
require.NoError(t, w.Flush())
if got, want := buf.Len(), 10024; got != want {
t.Fatalf("buffer length #3: got %d want %d", got, want)
}
// Do a bigger write, one that completes the current block.
// We should now have 32768 bytes (a complete block), without
// an explicit flush.
w3, _ := w.Next()
w3.Write(bytes.Repeat([]byte("3"), 40000))
if got, want := buf.Len(), 32768; got != want {
t.Fatalf("buffer length #4: got %d want %d", got, want)
}
// Flushing should get us up to 50038 bytes written.
// 50038 = 10024 + 2*7 + 40000. There are two headers because
// the one record was split into two chunks.
require.NoError(t, w.Flush())
if got, want := buf.Len(), 50038; got != want {
t.Fatalf("buffer length #5: got %d want %d", got, want)
}
// Check that reading those records give the right lengths.
r := NewReader(buf, 0 /* logNum */)
wants := []int64{1, 2, 10000, 40000}
for i, want := range wants {
rr, _ := r.Next()
n, err := io.Copy(io.Discard, rr)
if err != nil {
t.Fatalf("read #%d: %v", i, err)
}
if n != want {
t.Fatalf("read #%d: got %d bytes want %d", i, n, want)
}
}
}
func TestNonExhaustiveRead(t *testing.T) {
const n = 100
buf := new(bytes.Buffer)
p := make([]byte, 10)
rnd := rand.New(rand.NewSource(1))
w := NewWriter(buf)
for i := 0; i < n; i++ {
length := len(p) + rnd.Intn(3*blockSize)
s := string(uint8(i)) + "123456789abcdefgh"
_, _ = w.WriteRecord([]byte(big(s, length)))
}
if err := w.Close(); err != nil {
t.Fatalf("Close: %v", err)
}
r := NewReader(buf, 0 /* logNum */)
for i := 0; i < n; i++ {
rr, _ := r.Next()
_, err := io.ReadFull(rr, p)
if err != nil {
t.Fatalf("ReadFull: %v", err)
}
want := string(uint8(i)) + "123456789"
if got := string(p); got != want {
t.Fatalf("read #%d: got %q want %q", i, got, want)
}
}
}
func TestStaleReader(t *testing.T) {
buf := new(bytes.Buffer)
w := NewWriter(buf)
_, err := w.WriteRecord([]byte("0"))
require.NoError(t, err)
_, err = w.WriteRecord([]byte("11"))
require.NoError(t, err)
require.NoError(t, w.Close())
r := NewReader(buf, 0 /* logNum */)
r0, err := r.Next()
require.NoError(t, err)
r1, err := r.Next()
require.NoError(t, err)
p := make([]byte, 1)
if _, err := r0.Read(p); err == nil || !strings.Contains(err.Error(), "stale") {
t.Fatalf("stale read #0: unexpected error: %v", err)
}
if _, err := r1.Read(p); err != nil {
t.Fatalf("fresh read #1: got %v want nil error", err)
}
if p[0] != '1' {
t.Fatalf("fresh read #1: byte contents: got '%c' want '1'", p[0])
}
}
type testRecords struct {
records [][]byte // The raw value of each record.
offsets []int64 // The offset of each record within buf, derived from writer.LastRecordOffset.
buf []byte // The serialized records form of all records.
}
// makeTestRecords generates test records of specified lengths.
// The first record will consist of repeating 0x00 bytes, the next record of
// 0x01 bytes, and so forth. The values will loop back to 0x00 after 0xff.
func makeTestRecords(recordLengths ...int) (*testRecords, error) {
ret := &testRecords{}
ret.records = make([][]byte, len(recordLengths))
ret.offsets = make([]int64, len(recordLengths))
for i, n := range recordLengths {
ret.records[i] = bytes.Repeat([]byte{byte(i)}, n)
}
buf := new(bytes.Buffer)
w := NewWriter(buf)
for i, rec := range ret.records {
wRec, err := w.Next()
if err != nil {
return nil, err
}
// Alternate between one big write and many small writes.
cSize := 8
if i&1 == 0 {
cSize = len(rec)
}
for ; len(rec) > cSize; rec = rec[cSize:] {
if _, err := wRec.Write(rec[:cSize]); err != nil {
return nil, err
}
}
if _, err := wRec.Write(rec); err != nil {
return nil, err
}
ret.offsets[i], err = w.LastRecordOffset()
if err != nil {
return nil, err
}
}
if err := w.Close(); err != nil {
return nil, err
}
ret.buf = buf.Bytes()
return ret, nil
}
// corruptBlock corrupts the checksum of the record that starts at the
// specified block offset. The number of the block offset is 0 based.
func corruptBlock(buf []byte, blockNum int) {
// Ensure we always permute at least 1 byte of the checksum.
if buf[blockSize*blockNum] == 0x00 {
buf[blockSize*blockNum] = 0xff
} else {
buf[blockSize*blockNum] = 0x00
}
buf[blockSize*blockNum+1] = 0x00
buf[blockSize*blockNum+2] = 0x00
buf[blockSize*blockNum+3] = 0x00
}
func TestRecoverNoOp(t *testing.T) {
recs, err := makeTestRecords(
blockSize-legacyHeaderSize,
blockSize-legacyHeaderSize,
blockSize-legacyHeaderSize,
)
if err != nil {
t.Fatalf("makeTestRecords: %v", err)
}
r := NewReader(bytes.NewReader(recs.buf), 0 /* logNum */)
_, err = r.Next()
if err != nil || r.err != nil {
t.Fatalf("reader.Next: %v reader.err: %v", err, r.err)
}
seq, begin, end, n := r.seq, r.begin, r.end, r.n
// Should be a no-op since r.err == nil.
r.recover()
// r.err was nil, nothing should have changed.
if seq != r.seq || begin != r.begin || end != r.end || n != r.n {
t.Fatal("reader.Recover when no error existed, was not a no-op")
}
}
func TestBasicRecover(t *testing.T) {
recs, err := makeTestRecords(
blockSize-legacyHeaderSize,
blockSize-legacyHeaderSize,
blockSize-legacyHeaderSize,
)
if err != nil {
t.Fatalf("makeTestRecords: %v", err)
}
// Corrupt the checksum of the second record r1 in our file.
corruptBlock(recs.buf, 1)
underlyingReader := bytes.NewReader(recs.buf)
r := NewReader(underlyingReader, 0 /* logNum */)
// The first record r0 should be read just fine.
r0, err := r.Next()
if err != nil {
t.Fatalf("Next: %v", err)
}
r0Data, err := io.ReadAll(r0)
if err != nil {
t.Fatalf("ReadAll: %v", err)
}
if !bytes.Equal(r0Data, recs.records[0]) {
t.Fatal("Unexpected output in r0's data")
}
// The next record should have a checksum mismatch.
_, err = r.Next()
if err == nil {
t.Fatal("Expected an error while reading a corrupted record")
}
if err != ErrInvalidChunk {
t.Fatalf("Unexpected error returned: %v", err)
}
// Recover from that checksum mismatch.
r.recover()
currentOffset, err := underlyingReader.Seek(0, io.SeekCurrent)
if err != nil {
t.Fatalf("current offset: %v", err)
}
if currentOffset != blockSize*2 {
t.Fatalf("current offset: got %d, want %d", currentOffset, blockSize*2)
}
// The third record r2 should be read just fine.
r2, err := r.Next()
if err != nil {
t.Fatalf("Next: %v", err)
}
r2Data, err := io.ReadAll(r2)
if err != nil {
t.Fatalf("ReadAll: %v", err)
}
if !bytes.Equal(r2Data, recs.records[2]) {
t.Fatal("Unexpected output in r2's data")
}
}
func TestRecoverSingleBlock(t *testing.T) {
// The first record will be blockSize * 3 bytes long. Since each block has
// a 7 byte header, the first record will roll over into 4 blocks.
recs, err := makeTestRecords(
blockSize*3,
blockSize-legacyHeaderSize,
blockSize/2,
)
if err != nil {
t.Fatalf("makeTestRecords: %v", err)
}
// Corrupt the checksum for the portion of the first record that exists in
// the 4th block.
corruptBlock(recs.buf, 3)
// The first record should fail, but only when we read deeper beyond the
// first block.
r := NewReader(bytes.NewReader(recs.buf), 0 /* logNum */)
r0, err := r.Next()
if err != nil {
t.Fatalf("Next: %v", err)
}
// Reading deeper should yield a checksum mismatch.
_, err = io.ReadAll(r0)
if err == nil {
t.Fatal("Expected a checksum mismatch error, got nil")
}
if err != ErrInvalidChunk {
t.Fatalf("Unexpected error returned: %v", err)
}
// Recover from that checksum mismatch.
r.recover()
// All of the data in the second record r1 is lost because the first record
// r0 shared a partial block with it. The second record also overlapped
// into the block with the third record r2. Recovery should jump to that
// block, skipping over the end of the second record and start parsing the
// third record.
r2, err := r.Next()
if err != nil {
t.Fatalf("Next: %v", err)
}
r2Data, _ := io.ReadAll(r2)
if !bytes.Equal(r2Data, recs.records[2]) {
t.Fatal("Unexpected output in r2's data")
}
}
func TestRecoverMultipleBlocks(t *testing.T) {
recs, err := makeTestRecords(
// The first record will consume 3 entire blocks but a fraction of the 4th.
blockSize*3,
// The second record will completely fill the remainder of the 4th block.
3*(blockSize-legacyHeaderSize)-2*blockSize-2*legacyHeaderSize,
// Consume the entirety of the 5th block.
blockSize-legacyHeaderSize,
// Consume the entirety of the 6th block.
blockSize-legacyHeaderSize,
// Consume roughly half of the 7th block.
blockSize/2,
)
if err != nil {
t.Fatalf("makeTestRecords: %v", err)
}
// Corrupt the checksum for the portion of the first record that exists in the 4th block.
corruptBlock(recs.buf, 3)
// Now corrupt the two blocks in a row that correspond to recs.records[2:4].
corruptBlock(recs.buf, 4)
corruptBlock(recs.buf, 5)
// The first record should fail, but only when we read deeper beyond the first block.
r := NewReader(bytes.NewReader(recs.buf), 0 /* logNum */)
r0, err := r.Next()
if err != nil {
t.Fatalf("Next: %v", err)
}
// Reading deeper should yield a checksum mismatch.
_, err = io.ReadAll(r0)
if err == nil {
t.Fatal("Exptected a checksum mismatch error, got nil")
}
if err != ErrInvalidChunk {
t.Fatalf("Unexpected error returned: %v", err)
}
// Recover from that checksum mismatch.
r.recover()
// All of the data in the second record is lost because the first
// record shared a partial block with it. The following two records
// have corrupted checksums as well, so the call above to r.Recover
// should result in r.Next() being a reader to the 5th record.
r4, err := r.Next()
if err != nil {
t.Fatalf("Next: %v", err)
}
r4Data, _ := io.ReadAll(r4)
if !bytes.Equal(r4Data, recs.records[4]) {
t.Fatal("Unexpected output in r4's data")
}
}
// verifyLastBlockRecover reads each record from recs expecting that the
// last record will be corrupted. It will then try Recover and verify that EOF
// is returned.
func verifyLastBlockRecover(recs *testRecords) error {
r := NewReader(bytes.NewReader(recs.buf), 0 /* logNum */)
// Loop to one element larger than the number of records to verify EOF.
for i := 0; i < len(recs.records)+1; i++ {
_, err := r.Next()
switch i {
case len(recs.records) - 1:
if err == nil {
return errors.New("Expected a checksum mismatch error, got nil")
}
r.recover()
case len(recs.records):
if err != io.EOF {
return errors.Errorf("Expected io.EOF, got %v", err)
}
default:
if err != nil {
return errors.Errorf("Next: %v", err)
}
}
}
return nil
}
func TestRecoverLastPartialBlock(t *testing.T) {
recs, err := makeTestRecords(
// The first record will consume 3 entire blocks but a fraction of the 4th.
blockSize*3,
// The second record will completely fill the remainder of the 4th block.
3*(blockSize-legacyHeaderSize)-2*blockSize-2*legacyHeaderSize,
// Consume roughly half of the 5th block.
blockSize/2,
)
if err != nil {
t.Fatalf("makeTestRecords: %v", err)
}
// Corrupt the 5th block.
corruptBlock(recs.buf, 4)
// Verify Recover works when the last block is corrupted.
if err := verifyLastBlockRecover(recs); err != nil {
t.Fatalf("verifyLastBlockRecover: %v", err)
}
}
func TestRecoverLastCompleteBlock(t *testing.T) {
recs, err := makeTestRecords(
// The first record will consume 3 entire blocks but a fraction of the 4th.
blockSize*3,
// The second record will completely fill the remainder of the 4th block.
3*(blockSize-legacyHeaderSize)-2*blockSize-2*legacyHeaderSize,
// Consume the entire 5th block.
blockSize-legacyHeaderSize,
)
if err != nil {
t.Fatalf("makeTestRecords: %v", err)
}
// Corrupt the 5th block.
corruptBlock(recs.buf, 4)
// Verify Recover works when the last block is corrupted.
if err := verifyLastBlockRecover(recs); err != nil {
t.Fatalf("verifyLastBlockRecover: %v", err)
}
}
func TestReaderOffset(t *testing.T) {
recs, err := makeTestRecords(
blockSize*2,
400,
500,
600,
700,
800,
9000,
1000,
)
if err != nil {
t.Fatalf("makeTestRecords: %v", err)
}
// The first record should fail, but only when we read deeper beyond the first block.
r := NewReader(bytes.NewReader(recs.buf), 0 /* logNum */)
for i, offset := range recs.offsets {
if offset != r.Offset() {
t.Fatalf("%d: expected offset %d, but found %d", i, offset, r.Offset())
}
rec, err := r.Next()
if err != nil {
t.Fatalf("Next: %v", err)
}
if _, err = io.ReadAll(rec); err != nil {
t.Fatalf("ReadAll: %v", err)
}
}
}
func TestSeekRecord(t *testing.T) {
recs, err := makeTestRecords(
// The first record will consume 3 entire blocks but a fraction of the 4th.
blockSize*3,
// The second record will completely fill the remainder of the 4th block.
3*(blockSize-legacyHeaderSize)-2*blockSize-2*legacyHeaderSize,
// Consume the entirety of the 5th block.
blockSize-legacyHeaderSize,
// Consume the entirety of the 6th block.
blockSize-legacyHeaderSize,
// Consume roughly half of the 7th block.
blockSize/2,
)
if err != nil {
t.Fatalf("makeTestRecords: %v", err)
}
r := NewReader(bytes.NewReader(recs.buf), 0 /* logNum */)
// Seek to a valid block offset, but within a multiblock record. This should cause the next call to
// Next after SeekRecord to return the next valid FIRST/FULL chunk of the subsequent record.
err = r.seekRecord(blockSize)
if err != nil {
t.Fatalf("SeekRecord: %v", err)
}
rec, err := r.Next()
if err != nil {
t.Fatalf("Next: %v", err)
}
rData, _ := io.ReadAll(rec)
if !bytes.Equal(rData, recs.records[1]) {
t.Fatalf("Unexpected output in record 1's data, got %v want %v", rData, recs.records[1])
}
// Seek 3 bytes into the second block, which is still in the middle of the first record, but not
// at a valid chunk boundary. Should result in an error upon calling r.Next.
err = r.seekRecord(blockSize + 3)
if err != nil {
t.Fatalf("SeekRecord: %v", err)
}
if _, err = r.Next(); err == nil {
t.Fatalf("Expected an error seeking to an invalid chunk boundary")
}
r.recover()
// Seek to the fifth block and verify all records can be read as appropriate.
err = r.seekRecord(blockSize * 4)
if err != nil {
t.Fatalf("SeekRecord: %v", err)
}
check := func(i int) {
for ; i < len(recs.records); i++ {
rec, err := r.Next()
if err != nil {
t.Fatalf("Next: %v", err)
}
rData, _ := io.ReadAll(rec)
if !bytes.Equal(rData, recs.records[i]) {
t.Fatalf("Unexpected output in record #%d's data, got %v want %v", i, rData, recs.records[i])
}
}
}
check(2)
// Seek back to the fourth block, and read all subsequent records and verify them.
err = r.seekRecord(blockSize * 3)
if err != nil {
t.Fatalf("SeekRecord: %v", err)
}
check(1)
// Now seek past the end of the file and verify it causes an error.
err = r.seekRecord(1 << 20)
if err == nil {
t.Fatalf("Seek past the end of a file didn't cause an error")
}
if err != io.ErrUnexpectedEOF {
t.Fatalf("Seeking past EOF raised unexpected error: %v", err)
}
r.recover() // Verify recovery works.
// Validate the current records are returned after seeking to a valid offset.
err = r.seekRecord(blockSize * 4)
if err != nil {
t.Fatalf("SeekRecord: %v", err)
}
check(2)
}
func TestLastRecordOffset(t *testing.T) {
recs, err := makeTestRecords(
// The first record will consume 3 entire blocks but a fraction of the 4th.
blockSize*3,
// The second record will completely fill the remainder of the 4th block.
3*(blockSize-legacyHeaderSize)-2*blockSize-2*legacyHeaderSize,
// Consume the entirety of the 5th block.
blockSize-legacyHeaderSize,
// Consume the entirety of the 6th block.
blockSize-legacyHeaderSize,
// Consume roughly half of the 7th block.
blockSize/2,
)
if err != nil {
t.Fatalf("makeTestRecords: %v", err)
}
wants := []int64{0, 98332, 131072, 163840, 196608}
for i, got := range recs.offsets {
if want := wants[i]; got != want {
t.Errorf("record #%d: got %d, want %d", i, got, want)
}
}
}
func TestNoLastRecordOffset(t *testing.T) {
buf := new(bytes.Buffer)
w := NewWriter(buf)
defer w.Close()
if _, err := w.LastRecordOffset(); err != ErrNoLastRecord {
t.Fatalf("Expected ErrNoLastRecord, got: %v", err)
}
require.NoError(t, w.Flush())
if _, err := w.LastRecordOffset(); err != ErrNoLastRecord {
t.Fatalf("LastRecordOffset: got: %v, want ErrNoLastRecord", err)
}
_, err := w.WriteRecord([]byte("testrecord"))
require.NoError(t, err)
if off, err := w.LastRecordOffset(); err != nil {
t.Fatalf("LastRecordOffset: %v", err)
} else if off != 0 {
t.Fatalf("LastRecordOffset: got %d, want 0", off)
}
}
func TestInvalidLogNum(t *testing.T) {
var buf bytes.Buffer
w := NewLogWriter(&buf, 1, LogWriterConfig{
WALFsyncLatency: prometheus.NewHistogram(prometheus.HistogramOpts{})})
for i := 0; i < 10; i++ {
s := fmt.Sprintf("%04d\n", i)
_, err := w.WriteRecord([]byte(s))
require.NoError(t, err)
}
require.NoError(t, w.Close())
{
r := NewReader(bytes.NewReader(buf.Bytes()), 1)
for i := 0; i < 10; i++ {
rr, err := r.Next()
require.NoError(t, err)
x, err := io.ReadAll(rr)
require.NoError(t, err)
s := fmt.Sprintf("%04d\n", i)
if s != string(x) {
t.Fatalf("expected %s, but found %s", s, x)
}
}
if _, err := r.Next(); err != io.EOF {
t.Fatalf("expected EOF, but found %s", err)
}
}
{
r := NewReader(bytes.NewReader(buf.Bytes()), 2)
if _, err := r.Next(); err != io.EOF {
t.Fatalf("expected %s, but found %s\n", io.EOF, err)
}
}
}
func TestSize(t *testing.T) {
var buf bytes.Buffer
zeroes := make([]byte, 8<<10)
w := NewWriter(&buf)
for i := 0; i < 100; i++ {
n := rand.Intn(len(zeroes))
_, err := w.WriteRecord(zeroes[:n])
require.NoError(t, err)
require.NoError(t, w.Flush())
if buf.Len() != int(w.Size()) {
t.Fatalf("expected %d, but found %d", buf.Len(), w.Size())
}
}
require.NoError(t, w.Close())
}
type limitedWriter struct {
io.Writer
limit int
}
func (w *limitedWriter) Write(p []byte) (n int, err error) {
w.limit--
if w.limit < 0 {
return len(p), nil
}
return w.Writer.Write(p)
}
func TestRecycleLog(t *testing.T) {
const min = 16
const max = 4096
rnd := rand.New(rand.NewSource(uint64(time.Now().UnixNano())))
randBlock := func() []byte {
data := make([]byte, rand.Intn(max-min)+min)
tmp := data
for len(tmp) >= 8 {
binary.LittleEndian.PutUint64(tmp, rand.Uint64())
tmp = tmp[8:]
}
r := rand.Uint64()
for i := 0; i < len(tmp); i++ {
tmp[i] = byte(r)
r >>= 8
}
return data
}
// Recycle a log file 100 times, writing a random number of records filled
// with random data.
backing := make([]byte, 1<<20)
for i := 1; i <= 100; i++ {
blocks := rnd.Intn(100)
limitedBuf := &limitedWriter{
Writer: bytes.NewBuffer(backing[:0]),
limit: blocks,
}
w := NewLogWriter(limitedBuf, base.DiskFileNum(i), LogWriterConfig{
WALFsyncLatency: prometheus.NewHistogram(prometheus.HistogramOpts{})})
sizes := make([]int, 10+rnd.Intn(100))
for j := range sizes {
data := randBlock()
if _, err := w.WriteRecord(data); err != nil {
t.Fatalf("%d/%d: %v", i, j, err)
}
sizes[j] = len(data)
}
if err := w.Close(); err != nil {
t.Fatalf("%d: %v", i, err)
}
r := NewReader(bytes.NewReader(backing), base.DiskFileNum(i))
for j := range sizes {
rr, err := r.Next()
if err != nil {
// If we limited output then an EOF, zeroed, or invalid chunk is expected.
if limitedBuf.limit < 0 && (err == io.EOF || err == ErrZeroedChunk || err == ErrInvalidChunk) {
break
}
t.Fatalf("%d/%d: %v", i, j, err)
}
x, err := io.ReadAll(rr)
if err != nil {
// If we limited output then an EOF, zeroed, or invalid chunk is expected.
if limitedBuf.limit < 0 && (err == io.EOF || err == ErrZeroedChunk || err == ErrInvalidChunk) {
break
}
t.Fatalf("%d/%d: %v", i, j, err)
}
if sizes[j] != len(x) {
t.Fatalf("%d/%d: expected record %d, but found %d", i, j, sizes[j], len(x))
}
}
if _, err := r.Next(); err != io.EOF && err != ErrZeroedChunk && err != ErrInvalidChunk {
t.Fatalf("%d: expected EOF, but found %v", i, err)
}
}
}
func TestTruncatedLog(t *testing.T) {
backing := make([]byte, 2*blockSize)
w := NewLogWriter(bytes.NewBuffer(backing[:0]), base.DiskFileNum(1), LogWriterConfig{
WALFsyncLatency: prometheus.NewHistogram(prometheus.HistogramOpts{})})
// Write a record that spans 2 blocks.
_, err := w.WriteRecord(bytes.Repeat([]byte("s"), blockSize+100))
require.NoError(t, err)
require.NoError(t, w.Close())
// Create a reader only for the first block.
r := NewReader(bytes.NewReader(backing[:blockSize]), base.DiskFileNum(1))
rr, err := r.Next()
require.NoError(t, err)
_, err = io.ReadAll(rr)
require.EqualValues(t, err, io.ErrUnexpectedEOF)
}
func TestRecycleLogWithPartialBlock(t *testing.T) {
backing := make([]byte, 27)
w := NewLogWriter(bytes.NewBuffer(backing[:0]), base.DiskFileNum(1), LogWriterConfig{
WALFsyncLatency: prometheus.NewHistogram(prometheus.HistogramOpts{})})
// Will write a chunk with 11 byte header + 5 byte payload.
_, err := w.WriteRecord([]byte("aaaaa"))
require.NoError(t, err)
// Close will write a 11-byte EOF chunk.
require.NoError(t, w.Close())
w = NewLogWriter(bytes.NewBuffer(backing[:0]), base.DiskFileNum(2), LogWriterConfig{
WALFsyncLatency: prometheus.NewHistogram(prometheus.HistogramOpts{})})
// Will write a chunk with 11 byte header + 1 byte payload.
_, err = w.WriteRecord([]byte("a"))
require.NoError(t, err)
// Close will write a 11-byte EOF chunk.
require.NoError(t, w.Close())
r := NewReader(bytes.NewReader(backing), base.DiskFileNum(2))
_, err = r.Next()
require.NoError(t, err)
// 4 bytes left, which are not enough for even the legacy header.
if _, err = r.Next(); err != io.EOF {
t.Fatalf("unexpected error: %v", err)
}
}
func TestRecycleLogNumberOverflow(t *testing.T) {
// We truncate log numbers to 32-bits when writing to the WAL. Test log
// recycling at the wraparound point, ensuring that EOF chunks are
// interpreted correctly.
backing := make([]byte, 27)
w := NewLogWriter(bytes.NewBuffer(backing[:0]), base.DiskFileNum(math.MaxUint32), LogWriterConfig{
WALFsyncLatency: prometheus.NewHistogram(prometheus.HistogramOpts{})})
// Will write a chunk with 11 byte header + 5 byte payload.
_, err := w.WriteRecord([]byte("aaaaa"))
require.NoError(t, err)
// Close will write a 11-byte EOF chunk.
require.NoError(t, w.Close())
w = NewLogWriter(bytes.NewBuffer(backing[:0]), base.DiskFileNum(math.MaxUint32+1), LogWriterConfig{
WALFsyncLatency: prometheus.NewHistogram(prometheus.HistogramOpts{})})
// Will write a chunk with 11 byte header + 1 byte payload.
_, err = w.WriteRecord([]byte("a"))
require.NoError(t, err)
// Close will write a 11-byte EOF chunk.
require.NoError(t, w.Close())
r := NewReader(bytes.NewReader(backing), base.DiskFileNum(math.MaxUint32+1))
_, err = r.Next()
require.NoError(t, err)
// 4 bytes left, which are not enough for even the legacy header.
if _, err = r.Next(); err != io.EOF {
t.Fatalf("unexpected error: %v", err)
}
}
func TestRecycleLogWithPartialRecord(t *testing.T) {
const recordSize = (blockSize * 3) / 2
// Write a record that is larger than the log block size.
backing1 := make([]byte, 2*blockSize)
w := NewLogWriter(bytes.NewBuffer(backing1[:0]), base.DiskFileNum(1), LogWriterConfig{
WALFsyncLatency: prometheus.NewHistogram(prometheus.HistogramOpts{})})
_, err := w.WriteRecord(bytes.Repeat([]byte("a"), recordSize))
require.NoError(t, err)
require.NoError(t, w.Close())
// Write another record to a new incarnation of the WAL that is larger than
// the block size.
backing2 := make([]byte, 2*blockSize)
w = NewLogWriter(bytes.NewBuffer(backing2[:0]), base.DiskFileNum(2), LogWriterConfig{
WALFsyncLatency: prometheus.NewHistogram(prometheus.HistogramOpts{})})
_, err = w.WriteRecord(bytes.Repeat([]byte("b"), recordSize))
require.NoError(t, err)
require.NoError(t, w.Close())
// Copy the second block from the first WAL to the second block of the second
// WAL. This produces a scenario where it appears we crashed after writing
// the first block of the second WAL, but before writing the second block.
copy(backing2[blockSize:], backing1[blockSize:])
// Verify that we can't read a partial record from the second WAL.
r := NewReader(bytes.NewReader(backing2), base.DiskFileNum(2))
rr, err := r.Next()
require.NoError(t, err)
_, err = io.ReadAll(rr)
require.Equal(t, err, ErrInvalidChunk)
}
func BenchmarkRecordWrite(b *testing.B) {
for _, size := range []int{8, 16, 32, 64, 256, 1028, 4096, 65_536} {
b.Run(fmt.Sprintf("size=%d", size), func(b *testing.B) {
w := NewLogWriter(io.Discard, 0 /* logNum */, LogWriterConfig{
WALFsyncLatency: prometheus.NewHistogram(prometheus.HistogramOpts{})})
defer w.Close()
buf := make([]byte, size)
b.SetBytes(int64(len(buf)))
b.ResetTimer()
for i := 0; i < b.N; i++ {
if _, err := w.WriteRecord(buf); err != nil {
b.Fatal(err)
}
}
b.StopTimer()
})
}
}