jldb/mdb/txaggregator.go
2023-10-13 11:43:27 +02:00

93 lines
1.2 KiB
Go

package mdb
/*
type txAggregator struct {
Stop chan struct{}
Done *sync.WaitGroup
ModChan chan txMod
W *cswal.Writer
Index *pagefile.Index
Snapshot *atomic.Pointer[Snapshot]
}
func (p txAggregator) Run() {
defer p.Done.Done()
defer p.W.Close()
var (
tx *Snapshot
mod txMod
rec cswal.Record
err error
toNotify = make([]chan error, 0, 1024)
)
READ_FIRST:
toNotify = toNotify[:0]
select {
case mod = <-p.ModChan:
goto BEGIN
case <-p.Stop:
goto END
}
BEGIN:
tx = p.Snapshot.Load().begin()
goto APPLY_MOD
CLONE:
tx = tx.clone()
goto APPLY_MOD
APPLY_MOD:
if err = mod.Update(tx); err != nil {
mod.Resp <- err
goto ROLLBACK
}
toNotify = append(toNotify, mod.Resp)
goto NEXT
ROLLBACK:
if len(toNotify) == 0 {
goto READ_FIRST
}
tx = tx.rollback()
goto NEXT
NEXT:
select {
case mod = <-p.ModChan:
goto CLONE
default:
goto WRITE
}
WRITE:
rec, err = writeChangesToWAL(tx.changes, p.Index, p.W)
if err == nil {
tx.seqNum = rec.SeqNum
tx.updatedAt = rec.CreatedAt
tx.setReadOnly()
p.Snapshot.Store(tx)
}
for i := range toNotify {
toNotify[i] <- err
}
goto READ_FIRST
END:
}
*/