示例#1
0
文件: db.go 项目: XuHuaiyu/tidb
func (db *DB) recoverJournalRO() error {
	// Get all journals and sort it by file number.
	rawFds, err := db.s.stor.List(storage.TypeJournal)
	if err != nil {
		return err
	}
	sortFds(rawFds)

	// Journals that will be recovered.
	var fds []storage.FileDesc
	for _, fd := range rawFds {
		if fd.Num >= db.s.stJournalNum || fd.Num == db.s.stPrevJournalNum {
			fds = append(fds, fd)
		}
	}

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

		mdb = memdb.New(db.s.icmp, writeBuffer)
	)

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

		var (
			jr    *journal.Reader
			buf   = &util.Buffer{}
			batch = &Batch{}
		)

		for _, fd := range fds {
			db.logf("journal@recovery recovering @%d", fd.Num)

			fr, err := db.s.stor.Open(fd)
			if err != nil {
				return err
			}

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

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

					fr.Close()
					return errors.SetFd(err, fd)
				}

				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.SetFd(err, fd)
				}
				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.SetFd(err, fd)
				}

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

			fr.Close()
		}
	}

	// Set memDB.
	db.mem = &memDB{db: db, DB: mdb, ref: 1}

	return nil
}
示例#2
0
文件: db.go 项目: XuHuaiyu/tidb
func (db *DB) recoverJournal() error {
	// Get all journals and sort it by file number.
	rawFds, err := db.s.stor.List(storage.TypeJournal)
	if err != nil {
		return err
	}
	sortFds(rawFds)

	// Journals that will be recovered.
	var fds []storage.FileDesc
	for _, fd := range rawFds {
		if fd.Num >= db.s.stJournalNum || fd.Num == db.s.stPrevJournalNum {
			fds = append(fds, fd)
		}
	}

	var (
		ofd storage.FileDesc // Obsolete file.
		rec = &sessionRecord{}
	)

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

		// Mark file number as used.
		db.s.markFileNum(fds[len(fds)-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 _, fd := range fds {
			db.logf("journal@recovery recovering @%d", fd.Num)

			fr, err := db.s.stor.Open(fd)
			if err != nil {
				return err
			}

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

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

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

				db.s.stor.Remove(ofd)
				ofd = storage.FileDesc{}
			}

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

					fr.Close()
					return errors.SetFd(err, fd)
				}

				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.SetFd(err, fd)
				}
				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.SetFd(err, fd)
				}

				// 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()
			ofd = fd
		}

		// 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.journalFd.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 !ofd.Nil() {
		db.s.stor.Remove(ofd)
	}

	return nil
}