// Create new memdb and froze the old one; need external synchronization.
// newMem only called synchronously by the writer.
func (db *DB) newMem(n int) (mem *memdb.DB, err error) {
num := db.s.allocFileNum()
file := db.s.getJournalFile(num)
w, err := file.Create()
if err != nil {
db.s.reuseFileNum(num)
return
}
db.memMu.Lock()
defer db.memMu.Unlock()
if db.journal == nil {
db.journal = journal.NewWriter(w)
} else {
db.journal.Reset(w)
db.journalWriter.Close()
db.frozenJournalFile = db.journalFile
}
db.journalWriter = w
db.journalFile = file
db.frozenMem = db.mem
db.mem = memdb.New(db.s.icmp, maxInt(db.s.o.GetWriteBuffer(), n))
mem = db.mem
// The seq only incremented by the writer. And whoever called newMem
// should hold write lock, so no need additional synchronization here.
db.frozenSeq = db.seq
return
}
// Create new memdb and froze the old one; need external synchronization.
// newMem only called synchronously by the writer.
func (d *DB) newMem() (mem *memdb.DB, err error) {
s := d.s
num := s.allocFileNum()
file := s.getJournalFile(num)
w, err := file.Create()
if err != nil {
s.reuseFileNum(num)
return
}
d.memMu.Lock()
if d.journal == nil {
d.journal = journal.NewWriter(w)
} else {
d.journal.Reset(w)
d.journalWriter.Close()
d.frozenJournalFile = d.journalFile
}
d.journalWriter = w
d.journalFile = file
d.frozenMem = d.mem
d.mem = memdb.New(s.cmp, toPercent(d.s.o.GetWriteBuffer(), kWriteBufferPercent))
mem = d.mem
// The seq only incremented by the writer.
d.frozenSeq = d.seq
d.memMu.Unlock()
return
}
// Create a new manifest file; need external synchronization.
func (s *session) newManifest(rec *sessionRecord, v *version) (err error) {
num := s.allocFileNum()
file := s.stor.GetFile(num, storage.TypeManifest)
writer, err := file.Create()
if err != nil {
return
}
jw := journal.NewWriter(writer)
if v == nil {
v = s.version_NB()
}
if rec == nil {
rec = new(sessionRecord)
}
s.fillRecord(rec, true)
v.fillRecord(rec)
defer func() {
if err == nil {
s.recordCommited(rec)
if s.manifest != nil {
s.manifest.Close()
}
if s.manifestWriter != nil {
s.manifestWriter.Close()
}
if s.manifestFile != nil {
s.manifestFile.Remove()
}
s.manifestFile = file
s.manifestWriter = writer
s.manifest = jw
} else {
writer.Close()
file.Remove()
s.reuseFileNum(num)
}
}()
w, err := jw.Next()
if err != nil {
return
}
err = rec.encode(w)
if err != nil {
return
}
err = jw.Flush()
if err != nil {
return
}
err = s.stor.SetManifest(file)
return
}