func (c *cMem) flush(mem *memdb.DB, level int) error {
s := c.s
// Write memdb to table
t, n, err := s.tops.createFrom(mem.NewIterator(nil))
if err != nil {
return err
}
if level < 0 {
level = s.version_NB().pickLevel(t.min.ukey(), t.max.ukey())
}
c.rec.addTableFile(level, t)
s.logf("mem@flush created L%d@%d N·%d S·%s %q:%q", level, t.file.Num(), n, shortenb(int(t.size)), t.min, t.max)
c.level = level
return nil
}
func (b *Batch) revertMemReplay(to *memdb.DB) error {
return b.decodeRec(func(i int, t vType, key, value []byte) {
ikey := newIKey(key, b.seq+uint64(i), t)
to.Delete(ikey)
})
}
func (d *DB) recoverJournal() error {
s := d.s
icmp := s.cmp
ff0, err := s.getFiles(storage.TypeJournal)
if err != nil {
return err
}
ff1 := files(ff0)
ff1.sort()
ff2 := make([]storage.File, 0, len(ff1))
for _, file := range ff1 {
if file.Num() >= s.stJournalNum || file.Num() == s.stPrevJournalNum {
s.markFileNum(file.Num())
ff2 = append(ff2, file)
}
}
var jr *journal.Reader
var of storage.File
var mem *memdb.DB
batch := new(Batch)
cm := newCMem(s)
buf := new(util.Buffer)
// Options.
strict := s.o.GetStrict(opt.StrictJournal)
checksum := s.o.GetStrict(opt.StrictJournalChecksum)
writeBuffer := s.o.GetWriteBuffer()
recoverJournal := func(file storage.File) error {
s.logf("journal@recovery recovering @%d", file.Num())
reader, err := file.Open()
if err != nil {
return err
}
defer reader.Close()
if jr == nil {
jr = journal.NewReader(reader, dropper{s, file}, strict, checksum)
} else {
jr.Reset(reader, dropper{s, file}, strict, checksum)
}
if of != nil {
if mem.Len() > 0 {
if err := cm.flush(mem, 0); err != nil {
return err
}
}
if err := cm.commit(file.Num(), d.seq); err != nil {
return err
}
cm.reset()
of.Remove()
of = nil
}
// Reset 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 strict {
return err
}
continue
}
if err := batch.decode(buf.Bytes()); err != nil {
return err
}
if err := batch.memReplay(mem); err != nil {
return err
}
d.seq = batch.seq + uint64(batch.len())
if mem.Size() >= writeBuffer {
// Large enough, flush it.
if err := cm.flush(mem, 0); err != nil {
return err
}
// Reset memdb.
mem.Reset()
}
}
of = file
return nil
}
// Recover all journals.
if len(ff2) > 0 {
s.logf("journal@recovery F·%d", len(ff2))
mem = memdb.New(icmp, toPercent(writeBuffer, kWriteBufferPercent))
for _, file := range ff2 {
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 := d.newMem(); err != nil {
return err
}
// Commit.
if err := cm.commit(d.journalFile.Num(), d.seq); err != nil {
return err
}
// Remove the last journal.
if of != nil {
of.Remove()
}
return nil
}