Ejemplo n.º 1
0
func (bra *badReadAction) combine(action *msgs.Action, rmBal *rmBallot, txnId *common.TxnId, clockElem uint64) {
	newActionType := action.Which()
	braActionType := bra.action.Which()

	switch {
	case braActionType != msgs.ACTION_READ && newActionType != msgs.ACTION_READ:
		// They're both writes in some way. Just order the txns
		if clockElem > bra.clockElem || (clockElem == bra.clockElem && bra.txnId.Compare(txnId) == common.LT) {
			bra.set(action, rmBal, txnId, clockElem)
		}

	case braActionType == msgs.ACTION_READ && newActionType == msgs.ACTION_READ:
		braRead := bra.action.Read()
		newRead := action.Read()
		clockElem--
		// If they read the same version, we really don't care.
		if !bytes.Equal(braRead.Version(), newRead.Version()) {
			// They read different versions, but which version was the latter?
			if clockElem > bra.clockElem {
				bra.set(action, rmBal, common.MakeTxnId(newRead.Version()), clockElem)
			}
		}

	case braActionType == msgs.ACTION_READ:
		if bytes.Equal(bra.txnId[:], txnId[:]) {
			// The write will obviously be in the past of the
			// existing read, but it's better to have the write
			// as we can update the client with the actual
			// value.
			bra.set(action, rmBal, txnId, clockElem)
		} else if clockElem > bra.clockElem {
			// The write is after than the read
			bra.set(action, rmBal, txnId, clockElem)
		}

	default: // Existing is not a read, but new is a read.
		newRead := action.Read()
		clockElem--
		// If the read is a read of the existing write, better to keep the write
		if !bytes.Equal(bra.txnId[:], newRead.Version()) {
			if clockElem > bra.clockElem {
				// The read must be of some value which was written after our existing write.
				bra.set(action, rmBal, common.MakeTxnId(newRead.Version()), clockElem)
			}
		}
	}
}
Ejemplo n.º 2
0
func (sts *SimpleTxnSubmitter) translateRead(action *msgs.Action, clientAction *cmsgs.ClientAction) {
	action.SetRead()
	clientRead := clientAction.Read()
	read := action.Read()
	read.SetVersion(clientRead.Version())
}