Ejemplo n.º 1
0
func (db *DB) recoverJournal() error {
	// Get all journals and sort it by file number.
	allJournalFiles, err := db.s.getFiles(storage.TypeJournal)
	if err != nil {
		return err
	}
	files(allJournalFiles).sort()

	// Journals that will be recovered.
	var recJournalFiles []storage.File
	for _, jf := range allJournalFiles {
		if jf.Num() >= db.s.stJournalNum || jf.Num() == db.s.stPrevJournalNum {
			recJournalFiles = append(recJournalFiles, jf)
		}
	}

	var (
		of  storage.File // Obsolete file.
		rec = &sessionRecord{}
	)

	// Recover journals.
	if len(recJournalFiles) > 0 {
		db.logf("[email protected] F·%d", len(recJournalFiles))

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

		var (
			// Options.
			strict      = db.s.o.GetStrict(opt.StrictJournal)
			checksum    = db.s.o.GetStrict(opt.StrictJournalChecksum)
			writeBuffer = db.s.o.GetWriteBuffer()

			jr    *journal.Reader
			mdb   = memdb.New(db.s.icmp, writeBuffer)
			buf   = &util.Buffer{}
			batch = &Batch{}
		)

		for _, jf := range recJournalFiles {
			db.logf("[email protected] recovering @%d", jf.Num())

			fr, err := jf.Open()
			if err != nil {
				return err
			}

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

			// Flush memdb and remove obsolete journal file.
			if of != nil {
				if mdb.Len() > 0 {
					if _, err := db.s.flushMemdb(rec, mdb, -1); err != nil {
						fr.Close()
						return err
					}
				}

				rec.setJournalNum(jf.Num())
				rec.setSeqNum(db.seq)
				if err := db.s.commit(rec); err != nil {
					fr.Close()
					return err
				}
				rec.resetAddedTables()

				of.Remove()
				of = nil
			}

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

					fr.Close()
					return errors.SetFile(err, jf)
				}

				buf.Reset()
				if _, err := buf.ReadFrom(r); err != nil {
					if err == io.ErrUnexpectedEOF {
						// This is error returned due to corruption, with strict == false.
						continue
					}

					fr.Close()
					return errors.SetFile(err, jf)
				}
				if err := batch.memDecodeAndReplay(db.seq, buf.Bytes(), mdb); err != nil {
					if !strict && errors.IsCorrupted(err) {
						db.s.logf("journal error: %v (skipped)", err)
						// We won't apply sequence number as it might be corrupted.
						continue
					}

					fr.Close()
					return errors.SetFile(err, jf)
				}

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

				// Flush it if large enough.
				if mdb.Size() >= writeBuffer {
					if _, err := db.s.flushMemdb(rec, mdb, 0); err != nil {
						fr.Close()
						return err
					}

					mdb.Reset()
				}
			}

			fr.Close()
			of = jf
		}

		// Flush the last memdb.
		if mdb.Len() > 0 {
			if _, err := db.s.flushMemdb(rec, mdb, 0); err != nil {
				return err
			}
		}
	}

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

	// Commit.
	rec.setJournalNum(db.journalFile.Num())
	rec.setSeqNum(db.seq)
	if err := db.s.commit(rec); err != nil {
		// Close journal on error.
		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
}
Ejemplo n.º 2
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("[email protected] 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 errors.SetFile(err, file)
			}

			buf.Reset()
			if _, err := buf.ReadFrom(r); err != nil {
				if err == io.ErrUnexpectedEOF {
					// This is error returned due to corruption, with strict == false.
					continue
				} else {
					return errors.SetFile(err, file)
				}
			}
			if err := batch.memDecodeAndReplay(db.seq, buf.Bytes(), mem); err != nil {
				if strict || !errors.IsCorrupted(err) {
					return errors.SetFile(err, file)
				} else {
					db.s.logf("journal error: %v (skipped)", err)
					// We won't apply sequence number as it might be corrupted.
					continue
				}
			}

			// 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("[email protected] 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
}