// NewWriter creates a new initialized table writer for the file.
//
// Table writer is not goroutine-safe.
func NewWriter(f io.Writer, o *opt.Options) *Writer {
w := &Writer{
writer: f,
cmp: o.GetComparer(),
filter: o.GetFilter(),
compression: o.GetCompression(),
blockSize: o.GetBlockSize(),
comparerScratch: make([]byte, 0),
}
// data block
w.dataBlock.restartInterval = o.GetBlockRestartInterval()
// The first 20-bytes are used for encoding block handle.
w.dataBlock.scratch = w.scratch[20:]
// index block
w.indexBlock.restartInterval = 1
w.indexBlock.scratch = w.scratch[20:]
// filter block
if w.filter != nil {
w.filterBlock.generator = w.filter.NewGenerator()
w.filterBlock.flush(0)
}
return w
}
func recoverTable(s *session, o *opt.Options) error {
o = dupOptions(o)
// Mask StrictReader, lets StrictRecovery doing its job.
o.Strict &= ^opt.StrictReader
// Get all tables and sort it by file number.
fds, err := s.stor.List(storage.TypeTable)
if err != nil {
return err
}
sortFds(fds)
var (
maxSeq uint64
recoveredKey, goodKey, corruptedKey, corruptedBlock, droppedTable int
// We will drop corrupted table.
strict = o.GetStrict(opt.StrictRecovery)
noSync = o.GetNoSync()
rec = &sessionRecord{}
bpool = util.NewBufferPool(o.GetBlockSize() + 5)
)
buildTable := func(iter iterator.Iterator) (tmpFd storage.FileDesc, size int64, err error) {
tmpFd = s.newTemp()
writer, err := s.stor.Create(tmpFd)
if err != nil {
return
}
defer func() {
writer.Close()
if err != nil {
s.stor.Remove(tmpFd)
tmpFd = storage.FileDesc{}
}
}()
// Copy entries.
tw := table.NewWriter(writer, o)
for iter.Next() {
key := iter.Key()
if validInternalKey(key) {
err = tw.Append(key, iter.Value())
if err != nil {
return
}
}
}
err = iter.Error()
if err != nil {
return
}
err = tw.Close()
if err != nil {
return
}
if !noSync {
err = writer.Sync()
if err != nil {
return
}
}
size = int64(tw.BytesLen())
return
}
recoverTable := func(fd storage.FileDesc) error {
s.logf("table@recovery recovering @%d", fd.Num)
reader, err := s.stor.Open(fd)
if err != nil {
return err
}
var closed bool
defer func() {
if !closed {
reader.Close()
}
}()
// Get file size.
size, err := reader.Seek(0, 2)
if err != nil {
return err
}
var (
tSeq uint64
tgoodKey, tcorruptedKey, tcorruptedBlock int
imin, imax []byte
)
tr, err := table.NewReader(reader, size, fd, nil, bpool, o)
if err != nil {
return err
}
iter := tr.NewIterator(nil, nil)
if itererr, ok := iter.(iterator.ErrorCallbackSetter); ok {
itererr.SetErrorCallback(func(err error) {
if errors.IsCorrupted(err) {
s.logf("table@recovery block corruption @%d %q", fd.Num, err)
tcorruptedBlock++
}
})
}
// Scan the table.
for iter.Next() {
key := iter.Key()
_, seq, _, kerr := parseInternalKey(key)
if kerr != nil {
tcorruptedKey++
continue
}
tgoodKey++
if seq > tSeq {
tSeq = seq
}
if imin == nil {
imin = append([]byte{}, key...)
}
imax = append(imax[:0], key...)
}
if err := iter.Error(); err != nil {
iter.Release()
return err
}
iter.Release()
goodKey += tgoodKey
corruptedKey += tcorruptedKey
corruptedBlock += tcorruptedBlock
if strict && (tcorruptedKey > 0 || tcorruptedBlock > 0) {
droppedTable++
s.logf("table@recovery dropped @%d Gk·%d Ck·%d Cb·%d S·%d Q·%d", fd.Num, tgoodKey, tcorruptedKey, tcorruptedBlock, size, tSeq)
return nil
}
if tgoodKey > 0 {
if tcorruptedKey > 0 || tcorruptedBlock > 0 {
// Rebuild the table.
s.logf("table@recovery rebuilding @%d", fd.Num)
iter := tr.NewIterator(nil, nil)
tmpFd, newSize, err := buildTable(iter)
iter.Release()
if err != nil {
return err
}
closed = true
reader.Close()
if err := s.stor.Rename(tmpFd, fd); err != nil {
return err
}
size = newSize
}
if tSeq > maxSeq {
maxSeq = tSeq
}
recoveredKey += tgoodKey
// Add table to level 0.
rec.addTable(0, fd.Num, size, imin, imax)
s.logf("table@recovery recovered @%d Gk·%d Ck·%d Cb·%d S·%d Q·%d", fd.Num, tgoodKey, tcorruptedKey, tcorruptedBlock, size, tSeq)
} else {
droppedTable++
s.logf("table@recovery unrecoverable @%d Ck·%d Cb·%d S·%d", fd.Num, tcorruptedKey, tcorruptedBlock, size)
}
return nil
}
// Recover all tables.
if len(fds) > 0 {
s.logf("table@recovery F·%d", len(fds))
// Mark file number as used.
s.markFileNum(fds[len(fds)-1].Num)
for _, fd := range fds {
if err := recoverTable(fd); err != nil {
return err
}
}
s.logf("table@recovery recovered F·%d N·%d Gk·%d Ck·%d Q·%d", len(fds), recoveredKey, goodKey, corruptedKey, maxSeq)
}
// Set sequence number.
rec.setSeqNum(maxSeq)
// Create new manifest.
if err := s.create(); err != nil {
return err
}
// Commit.
return s.commit(rec)
}