core/rawdb: support starting offset for future deletion

This commit is contained in:
Martin Holst Swende 2019-04-14 21:25:32 +02:00 committed by Péter Szilágyi
parent 80469bea0c
commit 331de17e4d
No known key found for this signature in database
GPG Key ID: E9AE538CEDF8293D
2 changed files with 175 additions and 30 deletions

@ -81,9 +81,14 @@ type freezerTable struct {
head *os.File // File descriptor for the data head of the table
files map[uint32]*os.File // open files
headId uint32 // number of the currently active head file
tailId uint32 // number of the earliest file
index *os.File // File descriptor for the indexEntry file of the table
items uint64 // Number of items stored in the table
// In the case that old items are deleted (from the tail), we use itemOffset
// to count how many historic items have gone missing.
items uint64 // Number of items stored in the table (including items removed from tail)
itemOffset uint32 // Offset (number of discarded items)
headBytes uint32 // Number of bytes written to the head file
readMeter metrics.Meter // Meter for measuring the effective amount of data read
writeMeter metrics.Meter // Meter for measuring the effective amount of data written
@ -164,10 +169,19 @@ func (t *freezerTable) repair() error {
// Open the head file
var (
firstIndex indexEntry
lastIndex indexEntry
contentSize int64
contentExp int64
)
// Read index zero, determine what file is the earliest
// and what item offset to use
t.index.ReadAt(buffer, 0)
firstIndex.unmarshalBinary(buffer)
t.tailId = firstIndex.offset
t.itemOffset = firstIndex.filenum
t.index.ReadAt(buffer, offsetsSize-indexEntrySize)
lastIndex.unmarshalBinary(buffer)
t.head, err = t.openFile(lastIndex.filenum, os.O_RDWR|os.O_CREATE|os.O_APPEND)
@ -225,7 +239,7 @@ func (t *freezerTable) repair() error {
return err
}
// Update the item and byte counters and return
t.items = uint64(offsetsSize/indexEntrySize - 1) // last indexEntry points to the end of the data file
t.items = uint64(t.itemOffset) + uint64(offsetsSize/indexEntrySize-1) // last indexEntry points to the end of the data file
t.headBytes = uint32(contentSize)
t.headId = lastIndex.filenum
@ -245,7 +259,7 @@ func (t *freezerTable) preopen() (err error) {
// The repair might have already opened (some) files
t.releaseFilesAfter(0, false)
// Open all except head in RDONLY
for i := uint32(0); i < t.headId; i++ {
for i := uint32(t.tailId); i < t.headId; i++ {
if _, err = t.openFile(i, os.O_RDONLY); err != nil {
return err
}
@ -259,7 +273,8 @@ func (t *freezerTable) preopen() (err error) {
func (t *freezerTable) truncate(items uint64) error {
t.lock.Lock()
defer t.lock.Unlock()
// If out item count is corrent, don't do anything
// If our item count is correct, don't do anything
if atomic.LoadUint64(&t.items) <= items {
return nil
}
@ -275,6 +290,7 @@ func (t *freezerTable) truncate(items uint64) error {
}
var expected indexEntry
expected.unmarshalBinary(buffer)
// We might need to truncate back to older files
if expected.filenum != t.headId {
// If already open for reading, force-reopen for writing
@ -290,7 +306,6 @@ func (t *freezerTable) truncate(items uint64) error {
t.head = newHead
atomic.StoreUint32(&t.headId, expected.filenum)
}
if err := t.head.Truncate(int64(expected.offset)); err != nil {
return err
}
@ -330,9 +345,9 @@ func (t *freezerTable) openFile(num uint32, flag int) (f *os.File, err error) {
if f, exist = t.files[num]; !exist {
var name string
if t.noCompression {
name = fmt.Sprintf("%s.%d.rdat", t.name, num)
name = fmt.Sprintf("%s.%04d.rdat", t.name, num)
} else {
name = fmt.Sprintf("%s.%d.cdat", t.name, num)
name = fmt.Sprintf("%s.%04d.cdat", t.name, num)
}
f, err = os.OpenFile(filepath.Join(t.path, name), flag, 0644)
if err != nil {
@ -376,11 +391,13 @@ func (t *freezerTable) Append(item uint64, blob []byte) error {
t.lock.RLock()
// Ensure the table is still accessible
if t.index == nil || t.head == nil {
t.lock.RUnlock()
return errClosed
}
// Ensure only the next item can be written, nothing else
if atomic.LoadUint64(&t.items) != item {
panic(fmt.Sprintf("appending unexpected item: want %d, have %d", t.items, item))
t.lock.RUnlock()
return fmt.Errorf("appending unexpected item: want %d, have %d", t.items, item)
}
// Encode the blob and write it into the data file
if !t.noCompression {
@ -461,13 +478,20 @@ func (t *freezerTable) Retrieve(item uint64) ([]byte, error) {
if atomic.LoadUint64(&t.items) <= item {
return nil, errOutOfBounds
}
// Ensure the item was not deleted from the tail either
offset := atomic.LoadUint32(&t.itemOffset)
if uint64(offset) > item {
return nil, errOutOfBounds
}
t.lock.RLock()
startOffset, endOffset, filenum, err := t.getBounds(item)
startOffset, endOffset, filenum, err := t.getBounds(item - uint64(offset))
if err != nil {
t.lock.RUnlock()
return nil, err
}
dataFile, exist := t.files[filenum]
if !exist {
t.lock.RUnlock()
return nil, fmt.Errorf("missing data file %d", filenum)
}
// Retrieve the data itself, decompress and return
@ -499,3 +523,26 @@ func (t *freezerTable) Sync() error {
}
return t.head.Sync()
}
// printIndex is a debug print utility function for testing
func (t *freezerTable) printIndex() {
buf := make([]byte, indexEntrySize)
fmt.Printf("|-----------------|\n")
fmt.Printf("| fileno | offset |\n")
fmt.Printf("|--------+--------|\n")
for i := uint64(0); ; i++ {
if _, err := t.index.ReadAt(buf, int64(i*indexEntrySize)); err != nil {
break
}
var entry indexEntry
entry.unmarshalBinary(buf)
fmt.Printf("| %03d | %03d | \n", entry.filenum, entry.offset)
if i > 100 {
fmt.Printf(" ... \n")
break
}
}
fmt.Printf("|-----------------|\n")
}

@ -19,12 +19,13 @@ package rawdb
import (
"bytes"
"fmt"
"github.com/ethereum/go-ethereum/metrics"
"math/rand"
"os"
"path/filepath"
"testing"
"time"
"github.com/ethereum/go-ethereum/metrics"
)
func init() {
@ -32,10 +33,10 @@ func init() {
}
// Gets a chunk of data, filled with 'b'
func getChunk(size int, b byte) []byte {
func getChunk(size int, b int) []byte {
data := make([]byte, size)
for i, _ := range data {
data[i] = b
data[i] = byte(b)
}
return data
}
@ -61,7 +62,7 @@ func TestFreezerBasics(t *testing.T) {
}
defer f.Close()
// Write 15 bytes 255 times, results in 85 files
for x := byte(0); x < 255; x++ {
for x := 0; x < 255; x++ {
data := getChunk(15, x)
f.Append(uint64(x), data)
}
@ -74,7 +75,7 @@ func TestFreezerBasics(t *testing.T) {
//db[1] = 010101010101010101010101010101
//db[2] = 020202020202020202020202020202
for y := byte(0); y < 255; y++ {
for y := 0; y < 255; y++ {
exp := getChunk(15, y)
got, err := f.Retrieve(uint64(y))
if err != nil {
@ -84,6 +85,11 @@ func TestFreezerBasics(t *testing.T) {
t.Fatalf("test %d, got \n%x != \n%x", y, got, exp)
}
}
// Check that we cannot read too far
_, err = f.Retrieve(uint64(255))
if err != errOutOfBounds {
t.Fatal(err)
}
}
// TestFreezerBasicsClosing tests same as TestFreezerBasics, but also closes and reopens the freezer between
@ -102,18 +108,15 @@ func TestFreezerBasicsClosing(t *testing.T) {
t.Fatal(err)
}
// Write 15 bytes 255 times, results in 85 files
for x := byte(0); x < 255; x++ {
for x := 0; x < 255; x++ {
data := getChunk(15, x)
f.Append(uint64(x), data)
f.Close()
f, err = newCustomTable(os.TempDir(), fname, m1, m2, 50, true)
if err != nil {
t.Fatal(err)
}
}
defer f.Close()
for y := byte(0); y < 255; y++ {
for y := 0; y < 255; y++ {
exp := getChunk(15, y)
got, err := f.Retrieve(uint64(y))
if err != nil {
@ -142,7 +145,7 @@ func TestFreezerRepairDanglingHead(t *testing.T) {
t.Fatal(err)
}
// Write 15 bytes 255 times
for x := byte(0); x < 0xff; x++ {
for x := 0; x < 255; x++ {
data := getChunk(15, x)
f.Append(uint64(x), data)
}
@ -190,7 +193,7 @@ func TestFreezerRepairDanglingHeadLarge(t *testing.T) {
t.Fatal(err)
}
// Write 15 bytes 255 times
for x := byte(0); x < 0xff; x++ {
for x := 0; x < 0xff; x++ {
data := getChunk(15, x)
f.Append(uint64(x), data)
}
@ -223,7 +226,7 @@ func TestFreezerRepairDanglingHeadLarge(t *testing.T) {
t.Errorf("Expected error for missing index entry")
}
// We should now be able to store items again, from item = 1
for x := byte(1); x < 0xff; x++ {
for x := 1; x < 0xff; x++ {
data := getChunk(15, ^x)
f.Append(uint64(x), data)
}
@ -232,7 +235,7 @@ func TestFreezerRepairDanglingHeadLarge(t *testing.T) {
// And if we open it, we should now be able to read all of them (new values)
{
f, _ := newCustomTable(os.TempDir(), fname, rm, wm, 50, true)
for y := byte(1); y < 255; y++ {
for y := 1; y < 255; y++ {
exp := getChunk(15, ^y)
got, err := f.Retrieve(uint64(y))
if err != nil {
@ -257,7 +260,7 @@ func TestSnappyDetection(t *testing.T) {
t.Fatal(err)
}
// Write 15 bytes 255 times
for x := byte(0); x < 0xff; x++ {
for x := 0; x < 0xff; x++ {
data := getChunk(15, x)
f.Append(uint64(x), data)
}
@ -308,7 +311,7 @@ func TestFreezerRepairDanglingIndex(t *testing.T) {
t.Fatal(err)
}
// Write 15 bytes 9 times : 150 bytes
for x := byte(0); x < 9; x++ {
for x := 0; x < 9; x++ {
data := getChunk(15, x)
f.Append(uint64(x), data)
}
@ -321,7 +324,7 @@ func TestFreezerRepairDanglingIndex(t *testing.T) {
// File sizes should be 45, 45, 45 : items[3, 3, 3)
}
// Crop third file
fileToCrop := filepath.Join(os.TempDir(), fmt.Sprintf("%s.2.rdat", fname))
fileToCrop := filepath.Join(os.TempDir(), fmt.Sprintf("%s.0002.rdat", fname))
// Truncate third file: 45 ,45, 20
{
if err := assertFileSize(fileToCrop, 45); err != nil {
@ -365,7 +368,7 @@ func TestFreezerTruncate(t *testing.T) {
t.Fatal(err)
}
// Write 15 bytes 30 times
for x := byte(0); x < 30; x++ {
for x := 0; x < 30; x++ {
data := getChunk(15, x)
f.Append(uint64(x), data)
}
@ -416,7 +419,7 @@ func TestFreezerRepairFirstFile(t *testing.T) {
f.Close()
}
// Truncate the file in half
fileToCrop := filepath.Join(os.TempDir(), fmt.Sprintf("%s.1.rdat", fname))
fileToCrop := filepath.Join(os.TempDir(), fmt.Sprintf("%s.0001.rdat", fname))
{
if err := assertFileSize(fileToCrop, 40); err != nil {
t.Fatal(err)
@ -463,7 +466,7 @@ func TestFreezerReadAndTruncate(t *testing.T) {
t.Fatal(err)
}
// Write 15 bytes 30 times
for x := byte(0); x < 30; x++ {
for x := 0; x < 30; x++ {
data := getChunk(15, x)
f.Append(uint64(x), data)
}
@ -489,7 +492,7 @@ func TestFreezerReadAndTruncate(t *testing.T) {
// Now, truncate back to zero
f.truncate(0)
// Write the data again
for x := byte(0); x < 30; x++ {
for x := 0; x < 30; x++ {
data := getChunk(15, ^x)
if err := f.Append(uint64(x), data); err != nil {
t.Fatalf("error %v", err)
@ -499,6 +502,101 @@ func TestFreezerReadAndTruncate(t *testing.T) {
}
}
func TestOffset(t *testing.T) {
t.Parallel()
wm, rm := metrics.NewMeter(), metrics.NewMeter()
fname := fmt.Sprintf("offset-%d", rand.Uint64())
{ // Fill table
f, err := newCustomTable(os.TempDir(), fname, rm, wm, 40, true)
if err != nil {
t.Fatal(err)
}
// Write 6 x 20 bytes, splitting out into three files
f.Append(0, getChunk(20, 0xFF))
f.Append(1, getChunk(20, 0xEE))
f.Append(2, getChunk(20, 0xdd))
f.Append(3, getChunk(20, 0xcc))
f.Append(4, getChunk(20, 0xbb))
f.Append(5, getChunk(20, 0xaa))
f.printIndex()
f.Close()
}
// Now crop it.
{
// delete files 0 and 1
for i := 0; i < 2; i++ {
p := filepath.Join(os.TempDir(), fmt.Sprintf("%v.%04d.rdat", fname, i))
if err := os.Remove(p); err != nil {
t.Fatal(err)
}
}
// Read the index file
p := filepath.Join(os.TempDir(), fmt.Sprintf("%v.ridx", fname))
indexFile, err := os.OpenFile(p, os.O_RDWR, 0644)
if err != nil {
t.Fatal(err)
}
indexBuf := make([]byte, 7*indexEntrySize)
indexFile.Read(indexBuf)
// Update the index file, so that we store
// [ file = 2, offset = 4 ] at index zero
tailId := uint32(2) // First file is 2
itemOffset := uint32(4) // We have removed four items
zeroIndex := indexEntry{
offset: tailId,
filenum: itemOffset,
}
buf := zeroIndex.marshallBinary()
// Overwrite index zero
copy(indexBuf, buf)
// Remove the four next indices by overwriting
copy(indexBuf[indexEntrySize:], indexBuf[indexEntrySize*5:])
indexFile.WriteAt(indexBuf, 0)
// Need to truncate the moved index items
indexFile.Truncate(indexEntrySize * (1 + 2))
indexFile.Close()
}
// Now open again
{
f, err := newCustomTable(os.TempDir(), fname, rm, wm, 40, true)
if err != nil {
t.Fatal(err)
}
f.printIndex()
// It should allow writing item 6
f.Append(6, getChunk(20, 0x99))
// It should be fine to fetch 4,5,6
if got, err := f.Retrieve(4); err != nil {
t.Fatal(err)
} else if exp := getChunk(20, 0xbb); !bytes.Equal(got, exp) {
t.Fatalf("expected %x got %x", exp, got)
}
if got, err := f.Retrieve(5); err != nil {
t.Fatal(err)
} else if exp := getChunk(20, 0xaa); !bytes.Equal(got, exp) {
t.Fatalf("expected %x got %x", exp, got)
}
if got, err := f.Retrieve(6); err != nil {
t.Fatal(err)
} else if exp := getChunk(20, 0x99); !bytes.Equal(got, exp) {
t.Fatalf("expected %x got %x", exp, got)
}
// It should error at 0, 1,2,3
for i := 0; i < 4; i++ {
if _, err := f.Retrieve(uint64(i)); err == nil {
t.Fatal("expected err")
}
}
}
}
// TODO (?)
// - test that if we remove several head-files, aswell as data last data-file,
// the index is truncated accordingly