func (db *DB) mpoolGet(n int) *memDB {
var mdb *memdb.DB
select {
case mdb = <-db.memPool:
default:
}
if mdb == nil || mdb.Capacity() < n {
mdb = memdb.New(db.s.icmp, maxInt(db.s.o.GetWriteBuffer(), n))
}
return &memDB{
db: db,
DB: mdb,
}
}
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
}
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
}
// NewMemDbBuffer creates a new memDbBuffer.
func NewMemDbBuffer() MemBuffer {
return &memDbBuffer{db: memdb.New(comparer.DefaultComparer, 4*1024)}
}