Example #1
0
func (db *DB) recoverJournal() error {
	// Get all tables and sort it by file number.
	journalFiles_, err := db.s.getFiles(storage.TypeJournal)
	if err != nil {
		return err
	}
	journalFiles := files(journalFiles_)
	journalFiles.sort()

	// Discard older journal.
	prev := -1
	for i, file := range journalFiles {
		if file.Num() >= db.s.stJournalNum {
			if prev >= 0 {
				i--
				journalFiles[i] = journalFiles[prev]
			}
			journalFiles = journalFiles[i:]
			break
		} else if file.Num() == db.s.stPrevJournalNum {
			prev = i
		}
	}

	var jr *journal.Reader
	var of storage.File
	var mem *memdb.DB
	batch := new(Batch)
	cm := newCMem(db.s)
	buf := new(util.Buffer)
	// Options.
	strict := db.s.o.GetStrict(opt.StrictJournal)
	checksum := db.s.o.GetStrict(opt.StrictJournalChecksum)
	writeBuffer := db.s.o.GetWriteBuffer()
	recoverJournal := func(file storage.File) error {
		db.logf("journal@recovery recovering @%d", file.Num())
		reader, err := file.Open()
		if err != nil {
			return err
		}
		defer reader.Close()

		// Create/reset journal reader instance.
		if jr == nil {
			jr = journal.NewReader(reader, dropper{db.s, file}, strict, checksum)
		} else {
			jr.Reset(reader, dropper{db.s, file}, strict, checksum)
		}

		// Flush memdb and remove obsolete journal file.
		if of != nil {
			if mem.Len() > 0 {
				if err := cm.flush(mem, 0); err != nil {
					return err
				}
			}
			if err := cm.commit(file.Num(), db.seq); err != nil {
				return err
			}
			cm.reset()
			of.Remove()
			of = nil
		}

		// Replay journal to memdb.
		mem.Reset()
		for {
			r, err := jr.Next()
			if err != nil {
				if err == io.EOF {
					break
				}
				return err
			}

			buf.Reset()
			if _, err := buf.ReadFrom(r); err != nil {
				if err == io.ErrUnexpectedEOF {
					continue
				} else {
					return err
				}
			}
			if err := batch.decode(buf.Bytes()); err != nil {
				return err
			}
			if err := batch.memReplay(mem); err != nil {
				return err
			}

			// Save sequence number.
			db.seq = batch.seq + uint64(batch.len())

			// Flush it if large enough.
			if mem.Size() >= writeBuffer {
				if err := cm.flush(mem, 0); err != nil {
					return err
				}
				mem.Reset()
			}
		}

		of = file
		return nil
	}

	// Recover all journals.
	if len(journalFiles) > 0 {
		db.logf("journal@recovery F·%d", len(journalFiles))

		// Mark file number as used.
		db.s.markFileNum(journalFiles[len(journalFiles)-1].Num())

		mem = memdb.New(db.s.icmp, writeBuffer)
		for _, file := range journalFiles {
			if err := recoverJournal(file); err != nil {
				return err
			}
		}

		// Flush the last journal.
		if mem.Len() > 0 {
			if err := cm.flush(mem, 0); err != nil {
				return err
			}
		}
	}

	// Create a new journal.
	if _, err := db.newMem(0); err != nil {
		return err
	}

	// Commit.
	if err := cm.commit(db.journalFile.Num(), db.seq); err != nil {
		// Close journal.
		if db.journal != nil {
			db.journal.Close()
			db.journalWriter.Close()
		}
		return err
	}

	// Remove the last obsolete journal file.
	if of != nil {
		of.Remove()
	}

	return nil
}
Example #2
0
// Recover a database session; need external synchronization.
func (s *session) recover() (err error) {
	defer func() {
		if os.IsNotExist(err) {
			// Don't return os.ErrNotExist if the underlying storage contains
			// other files that belong to LevelDB. So the DB won't get trashed.
			if files, _ := s.stor.GetFiles(storage.TypeAll); len(files) > 0 {
				err = ErrCorrupted{Type: CorruptedManifest, Err: errors.New("leveldb: manifest file missing")}
			}
		}
	}()

	file, err := s.stor.GetManifest()
	if err != nil {
		return
	}

	reader, err := file.Open()
	if err != nil {
		return
	}
	defer reader.Close()
	strict := s.o.GetStrict(opt.StrictManifest)
	jr := journal.NewReader(reader, dropper{s, file}, strict, true)

	staging := s.version_NB().newStaging()
	rec := &sessionRecord{}
	for {
		var r io.Reader
		r, err = jr.Next()
		if err != nil {
			if err == io.EOF {
				err = nil
				break
			}
			return
		}

		err = rec.decode(r)
		if err == nil {
			// save compact pointers
			for _, r := range rec.compactionPointers {
				s.stCptrs[r.level] = iKey(r.ikey)
			}
			// commit record to version staging
			staging.commit(rec)
		} else if strict {
			return ErrCorrupted{Type: CorruptedManifest, Err: err}
		} else {
			s.logf("manifest error: %v (skipped)", err)
		}
		rec.resetCompactionPointers()
		rec.resetAddedTables()
		rec.resetDeletedTables()
	}

	switch {
	case !rec.has(recComparer):
		return ErrCorrupted{Type: CorruptedManifest, Err: errors.New("leveldb: manifest missing comparer name")}
	case rec.comparer != s.icmp.uName():
		return ErrCorrupted{Type: CorruptedManifest, Err: errors.New("leveldb: comparer mismatch, " + "want '" + s.icmp.uName() + "', " + "got '" + rec.comparer + "'")}
	case !rec.has(recNextNum):
		return ErrCorrupted{Type: CorruptedManifest, Err: errors.New("leveldb: manifest missing next file number")}
	case !rec.has(recJournalNum):
		return ErrCorrupted{Type: CorruptedManifest, Err: errors.New("leveldb: manifest missing journal file number")}
	case !rec.has(recSeq):
		return ErrCorrupted{Type: CorruptedManifest, Err: errors.New("leveldb: manifest missing seq number")}
	}

	s.manifestFile = file
	s.setVersion(staging.finish())
	s.setFileNum(rec.nextNum)
	s.recordCommited(rec)
	return nil
}