コード例 #1
0
ファイル: table.go プロジェクト: XuHuaiyu/tidb
// Creates an empty table and returns table writer.
func (t *tOps) create() (*tWriter, error) {
	fd := storage.FileDesc{storage.TypeTable, t.s.allocFileNum()}
	fw, err := t.s.stor.Create(fd)
	if err != nil {
		return nil, err
	}
	return &tWriter{
		t:  t,
		fd: fd,
		w:  fw,
		tw: table.NewWriter(fw, t.s.o.Options),
	}, nil
}
コード例 #2
0
ファイル: db.go プロジェクト: XuHuaiyu/tidb
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("[email protected] 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("[email protected] 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("[email protected] 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("[email protected] 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("[email protected] recovered @%d Gk·%d Ck·%d Cb·%d S·%d Q·%d", fd.Num, tgoodKey, tcorruptedKey, tcorruptedBlock, size, tSeq)
		} else {
			droppedTable++
			s.logf("[email protected] unrecoverable @%d Ck·%d Cb·%d S·%d", fd.Num, tcorruptedKey, tcorruptedBlock, size)
		}

		return nil
	}

	// Recover all tables.
	if len(fds) > 0 {
		s.logf("[email protected] 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("[email protected] 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)
}