freezer: implement split files for data

* freezer: implement split files for data

* freezer: add tests

* freezer: close old head-file when opening next

* freezer: fix truncation

* freezer: more testing around close/open

* rawdb/freezer: address review concerns

* freezer: fix minor review concerns

* freezer: fix remaining concerns + testcases around truncation

* freezer: docs

* freezer: implement multithreading

* core/rawdb: fix freezer nitpicks + change offsets to uint32

* freezer: preopen files, simplify lock constructs

* freezer: delete files during truncation
This commit is contained in:
Martin Holst Swende 2019-03-26 12:28:23 +01:00 committed by Péter Szilágyi
parent 006c21efc7
commit b69bdc2a4f
No known key found for this signature in database
GPG Key ID: E9AE538CEDF8293D
2 changed files with 816 additions and 96 deletions

View File

@ -1,4 +1,4 @@
// Copyright 2018 The go-ethereum Authors
// Copyright 2019 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
@ -23,6 +23,7 @@ import (
"os"
"path/filepath"
"sync"
"sync/atomic"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/log"
@ -40,16 +41,47 @@ var (
errOutOfBounds = errors.New("out of bounds")
)
// indexEntry contains the number/id of the file that the data resides in, aswell as the
// offset within the file to the end of the data
// In serialized form, the filenum is stored as uint16.
type indexEntry struct {
filenum uint32 // stored as uint16 ( 2 bytes)
offset uint32 // stored as uint32 ( 4 bytes)
}
const indexEntrySize = 6
// unmarshallBinary deserializes binary b into the rawIndex entry.
func (i *indexEntry) unmarshalBinary(b []byte) error {
i.filenum = uint32(binary.BigEndian.Uint16(b[:2]))
i.offset = binary.BigEndian.Uint32(b[2:6])
return nil
}
// marshallBinary serializes the rawIndex entry into binary.
func (i *indexEntry) marshallBinary() []byte {
b := make([]byte, indexEntrySize)
binary.BigEndian.PutUint16(b[:2], uint16(i.filenum))
binary.BigEndian.PutUint32(b[2:6], i.offset)
return b
}
// freezerTable represents a single chained data table within the freezer (e.g. blocks).
// It consists of a data file (snappy encoded arbitrary data blobs) and an index
// It consists of a data file (snappy encoded arbitrary data blobs) and an indexEntry
// file (uncompressed 64 bit indices into the data file).
type freezerTable struct {
content *os.File // File descriptor for the data content of the table
offsets *os.File // File descriptor for the index file of the table
noCompression bool // if true, disables snappy compression. Note: does not work retroactively
maxFileSize uint32 // Max file size for data-files
name string
path string
items uint64 // Number of items stored in the table
bytes uint64 // Number of content bytes stored in the table
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
index *os.File // File descriptor for the indexEntry file of the table
items uint64 // Number of items stored in the table
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
@ -57,149 +89,231 @@ type freezerTable struct {
lock sync.RWMutex // Mutex protecting the data file descriptors
}
// newTable opens a freezer table, creating the data and index files if they are
// newTable opens a freezer table with default settings - 2G files and snappy compression
func newTable(path string, name string, readMeter metrics.Meter, writeMeter metrics.Meter) (*freezerTable, error) {
return newCustomTable(path, name, readMeter, writeMeter, 2*1000*1000*1000, false)
}
// newCustomTable opens a freezer table, creating the data and index files if they are
// non existent. Both files are truncated to the shortest common length to ensure
// they don't go out of sync.
func newTable(path string, name string, readMeter metrics.Meter, writeMeter metrics.Meter) (*freezerTable, error) {
// Ensure the containing directory exists and open the two data files
func newCustomTable(path string, name string, readMeter metrics.Meter, writeMeter metrics.Meter, maxFilesize uint32, noCompression bool) (*freezerTable, error) {
// Ensure the containing directory exists and open the indexEntry file
if err := os.MkdirAll(path, 0755); err != nil {
return nil, err
}
content, err := os.OpenFile(filepath.Join(path, name+".dat"), os.O_RDWR|os.O_CREATE|os.O_APPEND, 0644)
if err != nil {
return nil, err
var idxName string
if noCompression {
// raw idx
idxName = fmt.Sprintf("%s.ridx", name)
} else {
// compressed idx
idxName = fmt.Sprintf("%s.cidx", name)
}
offsets, err := os.OpenFile(filepath.Join(path, name+".idx"), os.O_RDWR|os.O_CREATE|os.O_APPEND, 0644)
offsets, err := os.OpenFile(filepath.Join(path, idxName), os.O_RDWR|os.O_CREATE|os.O_APPEND, 0644)
if err != nil {
content.Close()
return nil, err
}
// Create the table and repair any past inconsistency
tab := &freezerTable{
content: content,
offsets: offsets,
readMeter: readMeter,
writeMeter: writeMeter,
logger: log.New("database", path, "table", name),
index: offsets,
files: make(map[uint32]*os.File),
readMeter: readMeter,
writeMeter: writeMeter,
name: name,
path: path,
logger: log.New("database", path, "table", name),
noCompression: noCompression,
maxFileSize: maxFilesize,
}
if err := tab.repair(); err != nil {
offsets.Close()
content.Close()
tab.Close()
return nil, err
}
return tab, nil
}
// repair cross checks the content and the offsets file and truncates them to
// repair cross checks the head and the index file and truncates them to
// be in sync with each other after a potential crash / data loss.
func (t *freezerTable) repair() error {
// Create a temporary offset buffer to init files with and read offsts into
offset := make([]byte, 8)
// Create a temporary offset buffer to init files with and read indexEntry into
buffer := make([]byte, indexEntrySize)
// If we've just created the files, initialize the offsets with the 0 index
stat, err := t.offsets.Stat()
// If we've just created the files, initialize the index with the 0 indexEntry
stat, err := t.index.Stat()
if err != nil {
return err
}
if stat.Size() == 0 {
if _, err := t.offsets.Write(offset); err != nil {
if _, err := t.index.Write(buffer); err != nil {
return err
}
}
// Ensure the offsets are a multiple of 8 bytes
if overflow := stat.Size() % 8; overflow != 0 {
t.offsets.Truncate(stat.Size() - overflow) // New file can't trigger this path
// Ensure the index is a multiple of indexEntrySize bytes
if overflow := stat.Size() % indexEntrySize; overflow != 0 {
t.index.Truncate(stat.Size() - overflow) // New file can't trigger this path
}
// Retrieve the file sizes and prepare for truncation
if stat, err = t.offsets.Stat(); err != nil {
if stat, err = t.index.Stat(); err != nil {
return err
}
offsetsSize := stat.Size()
if stat, err = t.content.Stat(); err != nil {
// Open the head file
var (
lastIndex indexEntry
contentSize int64
contentExp int64
)
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)
if err != nil {
return err
}
contentSize := stat.Size()
if stat, err = t.head.Stat(); err != nil {
return err
}
contentSize = stat.Size()
// Keep truncating both files until they come in sync
t.offsets.ReadAt(offset, offsetsSize-8)
contentExp := int64(binary.LittleEndian.Uint64(offset))
contentExp = int64(lastIndex.offset)
for contentExp != contentSize {
// Truncate the content file to the last offset pointer
// Truncate the head file to the last offset pointer
if contentExp < contentSize {
t.logger.Warn("Truncating dangling content", "indexed", common.StorageSize(contentExp), "stored", common.StorageSize(contentSize))
if err := t.content.Truncate(contentExp); err != nil {
t.logger.Warn("Truncating dangling head", "indexed", common.StorageSize(contentExp), "stored", common.StorageSize(contentSize))
if err := t.head.Truncate(contentExp); err != nil {
return err
}
contentSize = contentExp
}
// Truncate the offsets to point within the content file
// Truncate the index to point within the head file
if contentExp > contentSize {
t.logger.Warn("Truncating dangling offsets", "indexed", common.StorageSize(contentExp), "stored", common.StorageSize(contentSize))
if err := t.offsets.Truncate(offsetsSize - 8); err != nil {
t.logger.Warn("Truncating dangling indexes", "indexed", common.StorageSize(contentExp), "stored", common.StorageSize(contentSize))
if err := t.index.Truncate(offsetsSize - indexEntrySize); err != nil {
return err
}
offsetsSize -= 8
t.offsets.ReadAt(offset, offsetsSize-8)
contentExp = int64(binary.LittleEndian.Uint64(offset))
offsetsSize -= indexEntrySize
t.index.ReadAt(buffer, offsetsSize-indexEntrySize)
var newLastIndex indexEntry
newLastIndex.unmarshalBinary(buffer)
// We might have slipped back into an earlier head-file here
if newLastIndex.filenum != lastIndex.filenum {
// release earlier opened file
t.releaseFile(lastIndex.filenum)
t.head, err = t.openFile(newLastIndex.filenum, os.O_RDWR|os.O_CREATE|os.O_APPEND)
if stat, err = t.head.Stat(); err != nil {
// TODO, anything more we can do here?
// A data file has gone missing...
return err
}
contentSize = stat.Size()
}
lastIndex = newLastIndex
contentExp = int64(lastIndex.offset)
}
}
// Ensure all reparation changes have been written to disk
if err := t.offsets.Sync(); err != nil {
if err := t.index.Sync(); err != nil {
return err
}
if err := t.content.Sync(); err != nil {
if err := t.head.Sync(); err != nil {
return err
}
// Update the item and byte counters and return
t.items = uint64(offsetsSize/8 - 1) // last index points to the end of the data file
t.bytes = uint64(contentSize)
t.items = uint64(offsetsSize/indexEntrySize - 1) // last indexEntry points to the end of the data file
t.headBytes = uint32(contentSize)
t.headId = lastIndex.filenum
t.logger.Debug("Chain freezer table opened", "items", t.items, "size", common.StorageSize(t.bytes))
// Close opened files and preopen all files
if err := t.preopen(); err != nil {
return err
}
t.logger.Debug("Chain freezer table opened", "items", t.items, "size", common.StorageSize(t.headBytes))
return nil
}
// preopen opens all files that the freezer will need. This method should be called from an init-context,
// since it assumes that it doesn't have to bother with locking
// The rationale for doing preopen is to not have to do it from within Retrieve, thus not needing to ever
// obtain a write-lock within Retrieve.
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++ {
if _, err = t.openFile(i, os.O_RDONLY); err != nil {
return err
}
}
// Open head in read/write
t.head, err = t.openFile(t.headId, os.O_RDWR|os.O_CREATE|os.O_APPEND)
return err
}
// truncate discards any recent data above the provided threashold number.
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 t.items <= items {
if atomic.LoadUint64(&t.items) <= items {
return nil
}
// Something's out of sync, truncate the table's offset index
t.logger.Warn("Truncating freezer table", "items", t.items, "limit", items)
if err := t.offsets.Truncate(int64(items+1) * 8); err != nil {
if err := t.index.Truncate(int64(items+1) * indexEntrySize); err != nil {
return err
}
// Calculate the new expected size of the data file and truncate it
offset := make([]byte, 8)
t.offsets.ReadAt(offset, int64(items)*8)
expected := binary.LittleEndian.Uint64(offset)
buffer := make([]byte, indexEntrySize)
if _, err := t.index.ReadAt(buffer, int64(items*indexEntrySize)); err != nil {
return err
}
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
t.releaseFile(expected.filenum)
newHead, err := t.openFile(expected.filenum, os.O_RDWR|os.O_CREATE|os.O_APPEND)
if err != nil {
return err
}
// release any files _after the current head -- both the previous head
// and any files which may have been opened for reading
t.releaseFilesAfter(expected.filenum, true)
// set back the historic head
t.head = newHead
atomic.StoreUint32(&t.headId, expected.filenum)
}
if err := t.content.Truncate(int64(expected)); err != nil {
if err := t.head.Truncate(int64(expected.offset)); err != nil {
return err
}
// All data files truncated, set internal counters and return
t.items, t.bytes = items, expected
atomic.StoreUint64(&t.items, items)
atomic.StoreUint32(&t.headBytes, expected.offset)
return nil
}
// Close unmaps all active memory mapped regions.
// Close closes all opened files.
func (t *freezerTable) Close() error {
t.lock.Lock()
defer t.lock.Unlock()
var errs []error
if err := t.offsets.Close(); err != nil {
if err := t.index.Close(); err != nil {
errs = append(errs, err)
}
t.offsets = nil
t.index = nil
if err := t.content.Close(); err != nil {
errs = append(errs, err)
for _, f := range t.files {
if err := f.Close(); err != nil {
errs = append(errs, err)
}
}
t.content = nil
t.head = nil
if errs != nil {
return fmt.Errorf("%v", errs)
@ -207,78 +321,173 @@ func (t *freezerTable) Close() error {
return nil
}
// Append injects a binary blob at the end of the freezer table. The item index
// openFile assumes that the write-lock is held by the caller
func (t *freezerTable) openFile(num uint32, flag int) (f *os.File, err error) {
var exist bool
if f, exist = t.files[num]; !exist {
var name string
if t.noCompression {
name = fmt.Sprintf("%s.%d.rdat", t.name, num)
} else {
name = fmt.Sprintf("%s.%d.cdat", t.name, num)
}
f, err = os.OpenFile(filepath.Join(t.path, name), flag, 0644)
if err != nil {
return nil, err
}
t.files[num] = f
}
return f, err
}
// releaseFile closes a file, and removes it from the open file cache.
// Assumes that the caller holds the write lock
func (t *freezerTable) releaseFile(num uint32) {
if f, exist := t.files[num]; exist {
delete(t.files, num)
f.Close()
}
}
// releaseFilesAfter closes all open files with a higher number, and optionally also deletes the files
func (t *freezerTable) releaseFilesAfter(num uint32, remove bool) {
for fnum, f := range t.files {
if fnum > num {
delete(t.files, fnum)
f.Close()
if remove {
os.Remove(f.Name())
}
}
}
}
// Append injects a binary blob at the end of the freezer table. The item number
// is a precautionary parameter to ensure data correctness, but the table will
// reject already existing data.
//
// Note, this method will *not* flush any data to disk so be sure to explicitly
// fsync before irreversibly deleting data from the database.
func (t *freezerTable) Append(item uint64, blob []byte) error {
// Read lock prevents competition with truncate
t.lock.RLock()
// Ensure the table is still accessible
if t.offsets == nil || t.content == nil {
if t.index == nil || t.head == nil {
return errClosed
}
// Ensure only the next item can be written, nothing else
if t.items != item {
if atomic.LoadUint64(&t.items) != item {
panic(fmt.Sprintf("appending unexpected item: want %d, have %d", t.items, item))
}
// Encode the blob and write it into the data file
blob = snappy.Encode(nil, blob)
if _, err := t.content.Write(blob); err != nil {
if !t.noCompression {
blob = snappy.Encode(nil, blob)
}
bLen := uint32(len(blob))
if t.headBytes+bLen < bLen ||
t.headBytes+bLen > t.maxFileSize {
// we need a new file, writing would overflow
t.lock.RUnlock()
t.lock.Lock()
nextId := atomic.LoadUint32(&t.headId) + 1
// We open the next file in truncated mode -- if this file already
// exists, we need to start over from scratch on it
newHead, err := t.openFile(nextId, os.O_RDWR|os.O_CREATE|os.O_TRUNC)
if err != nil {
t.lock.Unlock()
return err
}
// Close old file, and reopen in RDONLY mode
t.releaseFile(t.headId)
t.openFile(t.headId, os.O_RDONLY)
// Swap out the current head
t.head = newHead
atomic.StoreUint32(&t.headBytes, 0)
atomic.StoreUint32(&t.headId, nextId)
t.lock.Unlock()
t.lock.RLock()
}
defer t.lock.RUnlock()
if _, err := t.head.Write(blob); err != nil {
return err
}
t.bytes += uint64(len(blob))
offset := make([]byte, 8)
binary.LittleEndian.PutUint64(offset, t.bytes)
if _, err := t.offsets.Write(offset); err != nil {
return err
newOffset := atomic.AddUint32(&t.headBytes, bLen)
idx := indexEntry{
filenum: atomic.LoadUint32(&t.headId),
offset: newOffset,
}
t.items++
t.writeMeter.Mark(int64(len(blob) + 8)) // 8 = 1 x 8 byte offset
// Write indexEntry
t.index.Write(idx.marshallBinary())
t.writeMeter.Mark(int64(bLen + indexEntrySize))
atomic.AddUint64(&t.items, 1)
return nil
}
// Retrieve looks up the data offset of an item with the given index and retrieves
// getBounds returns the indexes for the item
// returns start, end, filenumber and error
func (t *freezerTable) getBounds(item uint64) (uint32, uint32, uint32, error) {
var startIdx, endIdx indexEntry
buffer := make([]byte, indexEntrySize)
if _, err := t.index.ReadAt(buffer, int64(item*indexEntrySize)); err != nil {
return 0, 0, 0, err
}
startIdx.unmarshalBinary(buffer)
if _, err := t.index.ReadAt(buffer, int64((item+1)*indexEntrySize)); err != nil {
return 0, 0, 0, err
}
endIdx.unmarshalBinary(buffer)
if startIdx.filenum != endIdx.filenum {
// If a piece of data 'crosses' a data-file,
// it's actually in one piece on the second data-file.
// We return a zero-indexEntry for the second file as start
return 0, endIdx.offset, endIdx.filenum, nil
}
return startIdx.offset, endIdx.offset, endIdx.filenum, nil
}
// Retrieve looks up the data offset of an item with the given number and retrieves
// the raw binary blob from the data file.
func (t *freezerTable) Retrieve(item uint64) ([]byte, error) {
t.lock.RLock()
defer t.lock.RUnlock()
// Ensure the table and the item is accessible
if t.offsets == nil || t.content == nil {
if t.index == nil || t.head == nil {
return nil, errClosed
}
if t.items <= item {
if atomic.LoadUint64(&t.items) <= item {
return nil, errOutOfBounds
}
// Item reachable, retrieve the data content boundaries
offset := make([]byte, 8)
if _, err := t.offsets.ReadAt(offset, int64(item*8)); err != nil {
t.lock.RLock()
startOffset, endOffset, filenum, err := t.getBounds(item)
if err != nil {
return nil, err
}
start := binary.LittleEndian.Uint64(offset)
if _, err := t.offsets.ReadAt(offset, int64((item+1)*8)); err != nil {
return nil, err
dataFile, exist := t.files[filenum]
if !exist {
return nil, fmt.Errorf("missing data file %d", filenum)
}
end := binary.LittleEndian.Uint64(offset)
// Retrieve the data itself, decompress and return
blob := make([]byte, end-start)
if _, err := t.content.ReadAt(blob, int64(start)); err != nil {
blob := make([]byte, endOffset-startOffset)
if _, err := dataFile.ReadAt(blob, int64(startOffset)); err != nil {
t.lock.RUnlock()
return nil, err
}
t.readMeter.Mark(int64(len(blob) + 16)) // 16 = 2 x 8 byte offset
t.lock.RUnlock()
t.readMeter.Mark(int64(len(blob) + 2*indexEntrySize))
if t.noCompression {
return blob, nil
}
return snappy.Decode(nil, blob)
}
// Sync pushes any pending data from memory out to disk. This is an expensive
// operation, so use it with care.
func (t *freezerTable) Sync() error {
if err := t.offsets.Sync(); err != nil {
if err := t.index.Sync(); err != nil {
return err
}
return t.content.Sync()
return t.head.Sync()
}

View File

@ -0,0 +1,511 @@
// Copyright 2018 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
package rawdb
import (
"bytes"
"fmt"
"github.com/ethereum/go-ethereum/metrics"
"math/rand"
"os"
"path/filepath"
"testing"
"time"
)
func init() {
rand.Seed(time.Now().Unix())
}
// Gets a chunk of data, filled with 'b'
func getChunk(size int, b byte) []byte {
data := make([]byte, size)
for i, _ := range data {
data[i] = b
}
return data
}
func print(t *testing.T, f *freezerTable, item uint64) {
a, err := f.Retrieve(item)
if err != nil {
t.Fatal(err)
}
fmt.Printf("db[%d] = %x\n", item, a)
}
// TestFreezerBasics test initializing a freezertable from scratch, writing to the table,
// and reading it back.
func TestFreezerBasics(t *testing.T) {
t.Parallel()
// set cutoff at 50 bytes
f, err := newCustomTable(os.TempDir(),
fmt.Sprintf("unittest-%d", rand.Uint64()),
metrics.NewMeter(), metrics.NewMeter(), 50, true)
if err != nil {
t.Fatal(err)
}
defer f.Close()
// Write 15 bytes 255 times, results in 85 files
for x := byte(0); x < 255; x++ {
data := getChunk(15, x)
f.Append(uint64(x), data)
}
//print(t, f, 0)
//print(t, f, 1)
//print(t, f, 2)
//
//db[0] = 000000000000000000000000000000
//db[1] = 010101010101010101010101010101
//db[2] = 020202020202020202020202020202
for y := byte(0); y < 255; y++ {
exp := getChunk(15, y)
got, err := f.Retrieve(uint64(y))
if err != nil {
t.Fatal(err)
}
if !bytes.Equal(got, exp) {
t.Fatalf("test %d, got \n%x != \n%x", y, got, exp)
}
}
}
// TestFreezerBasicsClosing tests same as TestFreezerBasics, but also closes and reopens the freezer between
// every operation
func TestFreezerBasicsClosing(t *testing.T) {
t.Parallel()
// set cutoff at 50 bytes
var (
fname = fmt.Sprintf("basics-close-%d", rand.Uint64())
m1, m2 = metrics.NewMeter(), metrics.NewMeter()
f *freezerTable
err error
)
f, err = newCustomTable(os.TempDir(), fname, m1, m2, 50, true)
if err != nil {
t.Fatal(err)
}
// Write 15 bytes 255 times, results in 85 files
for x := byte(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++ {
exp := getChunk(15, y)
got, err := f.Retrieve(uint64(y))
if err != nil {
t.Fatal(err)
}
if !bytes.Equal(got, exp) {
t.Fatalf("test %d, got \n%x != \n%x", y, got, exp)
}
f.Close()
f, err = newCustomTable(os.TempDir(), fname, m1, m2, 50, true)
if err != nil {
t.Fatal(err)
}
}
}
// TestFreezerRepairDanglingHead tests that we can recover if index entries are removed
func TestFreezerRepairDanglingHead(t *testing.T) {
t.Parallel()
wm, rm := metrics.NewMeter(), metrics.NewMeter()
fname := fmt.Sprintf("dangling_headtest-%d", rand.Uint64())
{ // Fill table
f, err := newCustomTable(os.TempDir(), fname, rm, wm, 50, true)
if err != nil {
t.Fatal(err)
}
// Write 15 bytes 255 times
for x := byte(0); x < 0xff; x++ {
data := getChunk(15, x)
f.Append(uint64(x), data)
}
// The last item should be there
if _, err = f.Retrieve(0xfe); err != nil {
t.Fatal(err)
}
f.Close()
}
// open the index
idxFile, err := os.OpenFile(filepath.Join(os.TempDir(), fmt.Sprintf("%s.ridx", fname)), os.O_RDWR, 0644)
if err != nil {
t.Fatalf("Failed to open index file: %v", err)
}
// Remove 4 bytes
stat, err := idxFile.Stat()
if err != nil {
t.Fatalf("Failed to stat index file: %v", err)
}
idxFile.Truncate(stat.Size() - 4)
idxFile.Close()
// Now open it again
{
f, err := newCustomTable(os.TempDir(), fname, rm, wm, 50, true)
// The last item should be missing
if _, err = f.Retrieve(0xff); err == nil {
t.Errorf("Expected error for missing index entry")
}
// The one before should still be there
if _, err = f.Retrieve(0xfd); err != nil {
t.Fatalf("Expected no error, got %v", err)
}
}
}
// TestFreezerRepairDanglingHeadLarge tests that we can recover if very many index entries are removed
func TestFreezerRepairDanglingHeadLarge(t *testing.T) {
t.Parallel()
wm, rm := metrics.NewMeter(), metrics.NewMeter()
fname := fmt.Sprintf("dangling_headtest-%d", rand.Uint64())
{ // Fill a table and close it
f, err := newCustomTable(os.TempDir(), fname, wm, rm, 50, true)
if err != nil {
t.Fatal(err)
}
// Write 15 bytes 255 times
for x := byte(0); x < 0xff; x++ {
data := getChunk(15, x)
f.Append(uint64(x), data)
}
// The last item should be there
if _, err = f.Retrieve(f.items - 1); err == nil {
if err != nil {
t.Fatal(err)
}
}
f.Close()
}
// open the index
idxFile, err := os.OpenFile(filepath.Join(os.TempDir(), fmt.Sprintf("%s.ridx", fname)), os.O_RDWR, 0644)
if err != nil {
t.Fatalf("Failed to open index file: %v", err)
}
// Remove everything but the first item, and leave data unaligned
// 0-indexEntry, 1-indexEntry, corrupt-indexEntry
idxFile.Truncate(indexEntrySize + indexEntrySize + indexEntrySize/2)
idxFile.Close()
// Now open it again
{
f, err := newCustomTable(os.TempDir(), fname, rm, wm, 50, true)
// The first item should be there
if _, err = f.Retrieve(0); err != nil {
t.Fatal(err)
}
// The second item should be missing
if _, err = f.Retrieve(1); err == nil {
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++ {
data := getChunk(15, ^x)
f.Append(uint64(x), data)
}
f.Close()
}
// 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++ {
exp := getChunk(15, ^y)
got, err := f.Retrieve(uint64(y))
if err != nil {
t.Fatal(err)
}
if !bytes.Equal(got, exp) {
t.Fatalf("test %d, got \n%x != \n%x", y, got, exp)
}
}
}
}
// TestSnappyDetection tests that we fail to open a snappy database and vice versa
func TestSnappyDetection(t *testing.T) {
t.Parallel()
wm, rm := metrics.NewMeter(), metrics.NewMeter()
fname := fmt.Sprintf("snappytest-%d", rand.Uint64())
// Open with snappy
{
f, err := newCustomTable(os.TempDir(), fname, wm, rm, 50, true)
if err != nil {
t.Fatal(err)
}
// Write 15 bytes 255 times
for x := byte(0); x < 0xff; x++ {
data := getChunk(15, x)
f.Append(uint64(x), data)
}
f.Close()
}
// Open without snappy
{
f, err := newCustomTable(os.TempDir(), fname, wm, rm, 50, false)
if _, err = f.Retrieve(0); err == nil {
f.Close()
t.Fatalf("expected empty table")
}
}
// Open with snappy
{
f, err := newCustomTable(os.TempDir(), fname, wm, rm, 50, true)
// There should be 255 items
if _, err = f.Retrieve(0xfe); err != nil {
f.Close()
t.Fatalf("expected no error, got %v", err)
}
}
}
func assertFileSize(f string, size int64) error {
stat, err := os.Stat(f)
if err != nil {
return err
}
if stat.Size() != size {
return fmt.Errorf("error, expected size %d, got %d", size, stat.Size())
}
return nil
}
// TestFreezerRepairDanglingIndex checks that if the index has more entries than there are data,
// the index is repaired
func TestFreezerRepairDanglingIndex(t *testing.T) {
t.Parallel()
wm, rm := metrics.NewMeter(), metrics.NewMeter()
fname := fmt.Sprintf("dangling_indextest-%d", rand.Uint64())
{ // Fill a table and close it
f, err := newCustomTable(os.TempDir(), fname, wm, rm, 50, true)
if err != nil {
t.Fatal(err)
}
// Write 15 bytes 9 times : 150 bytes
for x := byte(0); x < 9; x++ {
data := getChunk(15, x)
f.Append(uint64(x), data)
}
// The last item should be there
if _, err = f.Retrieve(f.items - 1); err != nil {
f.Close()
t.Fatal(err)
}
f.Close()
// 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))
// Truncate third file: 45 ,45, 20
{
if err := assertFileSize(fileToCrop, 45); err != nil {
t.Fatal(err)
}
file, err := os.OpenFile(fileToCrop, os.O_RDWR, 0644)
if err != nil {
t.Fatal(err)
}
file.Truncate(20)
file.Close()
}
// Open db it again
// It should restore the file(s) to
// 45, 45, 15
// with 3+3+1 items
{
f, err := newCustomTable(os.TempDir(), fname, wm, rm, 50, true)
if err != nil {
t.Fatal(err)
}
if f.items != 7 {
f.Close()
t.Fatalf("expected %d items, got %d", 7, f.items)
}
if err := assertFileSize(fileToCrop, 15); err != nil {
t.Fatal(err)
}
}
}
func TestFreezerTruncate(t *testing.T) {
t.Parallel()
wm, rm := metrics.NewMeter(), metrics.NewMeter()
fname := fmt.Sprintf("truncation-%d", rand.Uint64())
{ // Fill table
f, err := newCustomTable(os.TempDir(), fname, rm, wm, 50, true)
if err != nil {
t.Fatal(err)
}
// Write 15 bytes 30 times
for x := byte(0); x < 30; x++ {
data := getChunk(15, x)
f.Append(uint64(x), data)
}
// The last item should be there
if _, err = f.Retrieve(f.items - 1); err != nil {
t.Fatal(err)
}
f.Close()
}
// Reopen, truncate
{
f, err := newCustomTable(os.TempDir(), fname, rm, wm, 50, true)
if err != nil {
t.Fatal(err)
}
defer f.Close()
f.truncate(10) // 150 bytes
if f.items != 10 {
t.Fatalf("expected %d items, got %d", 10, f.items)
}
// 45, 45, 45, 15 -- bytes should be 15
if f.headBytes != 15 {
t.Fatalf("expected %d bytes, got %d", 15, f.headBytes)
}
}
}
// TestFreezerRepairFirstFile tests a head file with the very first item only half-written.
// That will rewind the index, and _should_ truncate the head file
func TestFreezerRepairFirstFile(t *testing.T) {
t.Parallel()
wm, rm := metrics.NewMeter(), metrics.NewMeter()
fname := fmt.Sprintf("truncationfirst-%d", rand.Uint64())
{ // Fill table
f, err := newCustomTable(os.TempDir(), fname, rm, wm, 50, true)
if err != nil {
t.Fatal(err)
}
// Write 80 bytes, splitting out into two files
f.Append(0, getChunk(40, 0xFF))
f.Append(1, getChunk(40, 0xEE))
// The last item should be there
if _, err = f.Retrieve(f.items - 1); err != nil {
t.Fatal(err)
}
f.Close()
}
// Truncate the file in half
fileToCrop := filepath.Join(os.TempDir(), fmt.Sprintf("%s.1.rdat", fname))
{
if err := assertFileSize(fileToCrop, 40); err != nil {
t.Fatal(err)
}
file, err := os.OpenFile(fileToCrop, os.O_RDWR, 0644)
if err != nil {
t.Fatal(err)
}
file.Truncate(20)
file.Close()
}
// Reopen
{
f, err := newCustomTable(os.TempDir(), fname, wm, rm, 50, true)
if err != nil {
t.Fatal(err)
}
if f.items != 1 {
f.Close()
t.Fatalf("expected %d items, got %d", 0, f.items)
}
// Write 40 bytes
f.Append(1, getChunk(40, 0xDD))
f.Close()
// Should have been truncated down to zero and then 40 written
if err := assertFileSize(fileToCrop, 40); err != nil {
t.Fatal(err)
}
}
}
// TestFreezerReadAndTruncate tests:
// - we have a table open
// - do some reads, so files are open in readonly
// - truncate so those files are 'removed'
// - check that we did not keep the rdonly file descriptors
func TestFreezerReadAndTruncate(t *testing.T) {
t.Parallel()
wm, rm := metrics.NewMeter(), metrics.NewMeter()
fname := fmt.Sprintf("read_truncate-%d", rand.Uint64())
{ // Fill table
f, err := newCustomTable(os.TempDir(), fname, rm, wm, 50, true)
if err != nil {
t.Fatal(err)
}
// Write 15 bytes 30 times
for x := byte(0); x < 30; x++ {
data := getChunk(15, x)
f.Append(uint64(x), data)
}
// The last item should be there
if _, err = f.Retrieve(f.items - 1); err != nil {
t.Fatal(err)
}
f.Close()
}
// Reopen and read all files
{
f, err := newCustomTable(os.TempDir(), fname, wm, rm, 50, true)
if err != nil {
t.Fatal(err)
}
if f.items != 30 {
f.Close()
t.Fatalf("expected %d items, got %d", 0, f.items)
}
for y := byte(0); y < 30; y++ {
f.Retrieve(uint64(y))
}
// Now, truncate back to zero
f.truncate(0)
// Write the data again
for x := byte(0); x < 30; x++ {
data := getChunk(15, ^x)
if err := f.Append(uint64(x), data); err != nil {
t.Fatalf("error %v", err)
}
}
f.Close()
}
}
// TODO (?)
// - test that if we remove several head-files, aswell as data last data-file,
// the index is truncated accordingly
// Right now, the freezer would fail on these conditions:
// 1. have data files d0, d1, d2, d3
// 2. remove d2,d3
//
// However, all 'normal' failure modes arising due to failing to sync() or save a file should be
// handled already, and the case described above can only (?) happen if an external process/user
// deletes files from the filesystem.