Beispiel #1
0
func applyTxn(kv dstorage.KV, le lease.Lessor, rt *pb.TxnRequest) (*pb.TxnResponse, error) {
	var revision int64

	ok := true
	for _, c := range rt.Compare {
		if revision, ok = applyCompare(kv, c); !ok {
			break
		}
	}

	var reqs []*pb.RequestUnion
	if ok {
		reqs = rt.Success
	} else {
		reqs = rt.Failure
	}

	if err := checkRequestLeases(le, reqs); err != nil {
		return nil, err
	}
	if err := checkRequestRange(kv, reqs); err != nil {
		return nil, err
	}

	// When executing the operations of txn, we need to hold the txn lock.
	// So the reader will not see any intermediate results.
	txnID := kv.TxnBegin()
	defer func() {
		err := kv.TxnEnd(txnID)
		if err != nil {
			panic(fmt.Sprint("unexpected error when closing txn", txnID))
		}
	}()

	resps := make([]*pb.ResponseUnion, len(reqs))
	for i := range reqs {
		resps[i] = applyUnion(txnID, kv, reqs[i])
	}

	if len(resps) != 0 {
		revision += 1
	}

	txnResp := &pb.TxnResponse{}
	txnResp.Header = &pb.ResponseHeader{}
	txnResp.Header.Revision = revision
	txnResp.Responses = resps
	txnResp.Succeeded = ok
	return txnResp, nil
}
Beispiel #2
0
func applyTxn(kv dstorage.KV, le lease.Lessor, rt *pb.TxnRequest) (*pb.TxnResponse, error) {
	var revision int64

	txnID := kv.TxnBegin()
	defer func() {
		err := kv.TxnEnd(txnID)
		if err != nil {
			panic(fmt.Sprint("unexpected error when closing txn", txnID))
		}
	}()

	ok := true
	for _, c := range rt.Compare {
		if revision, ok = applyCompare(txnID, kv, c); !ok {
			break
		}
	}

	// TODO: check potential errors before actually applying anything

	var reqs []*pb.RequestUnion
	if ok {
		reqs = rt.Success
	} else {
		reqs = rt.Failure
	}

	if err := checkRequestLeases(le, reqs); err != nil {
		return nil, err
	}

	resps := make([]*pb.ResponseUnion, len(reqs))
	for i := range reqs {
		resps[i] = applyUnion(txnID, kv, reqs[i])
	}

	if len(resps) != 0 {
		revision += 1
	}

	txnResp := &pb.TxnResponse{}
	txnResp.Header = &pb.ResponseHeader{}
	txnResp.Header.Revision = revision
	txnResp.Responses = resps
	txnResp.Succeeded = ok
	return txnResp, nil
}