// maybeBeginTxn begins a new transaction if a txn has been specified
// in the request but has a nil ID. The new transaction is initialized
// using the name and isolation in the otherwise uninitialized txn.
// The Priority, if non-zero is used as a minimum.
func (tc *TxnCoordSender) maybeBeginTxn(header *proto.RequestHeader) {
if header.Txn != nil {
if len(header.Txn.ID) == 0 {
newTxn := proto.NewTransaction(header.Txn.Name, keys.KeyAddress(header.Key), header.GetUserPriority(),
header.Txn.Isolation, tc.clock.Now(), tc.clock.MaxOffset().Nanoseconds())
// Use existing priority as a minimum. This is used on transaction
// aborts to ratchet priority when creating successor transaction.
if newTxn.Priority < header.Txn.Priority {
newTxn.Priority = header.Txn.Priority
}
header.Txn = newTxn
}
}
}
// updateForBatch updates the first argument (the header of a request contained
// in a batch) from the second one (the batch header), returning an error when
// inconsistencies are found.
// It is checked that the individual call does not have a User, UserPriority
// or Txn set that differs from the batch's.
func updateForBatch(aHeader *proto.RequestHeader, bHeader proto.RequestHeader) error {
// Disallow transaction, user and priority on individual calls, unless
// equal.
if aHeader.User != "" && aHeader.User != bHeader.User {
return util.Error("conflicting user on call in batch")
}
if aPrio := aHeader.GetUserPriority(); aPrio != proto.Default_RequestHeader_UserPriority && aPrio != bHeader.GetUserPriority() {
return util.Error("conflicting user priority on call in batch")
}
if aHeader.Txn != nil && !aHeader.Txn.Equal(bHeader.Txn) {
return util.Error("conflicting transaction in transactional batch")
}
aHeader.User = bHeader.User
aHeader.UserPriority = bHeader.UserPriority
aHeader.Txn = bHeader.Txn
return nil
}
// updateResponseTxn updates the response txn based on the response
// timestamp and error. The timestamp may have changed upon
// encountering a newer write or read. Both the timestamp and the
// priority may change depending on error conditions.
func (tc *TxnCoordSender) updateResponseTxn(argsHeader *proto.RequestHeader, replyHeader *proto.ResponseHeader) {
// Move txn timestamp forward to response timestamp if applicable.
if replyHeader.Txn.Timestamp.Less(replyHeader.Timestamp) {
replyHeader.Txn.Timestamp = replyHeader.Timestamp
}
// Take action on various errors.
switch t := replyHeader.GoError().(type) {
case *proto.ReadWithinUncertaintyIntervalError:
// Mark the host as certain. See the protobuf comment for
// Transaction.CertainNodes for details.
replyHeader.Txn.CertainNodes.Add(argsHeader.Replica.NodeID)
// If the reader encountered a newer write within the uncertainty
// interval, move the timestamp forward, just past that write or
// up to MaxTimestamp, whichever comes first.
var candidateTS proto.Timestamp
if t.ExistingTimestamp.Less(replyHeader.Txn.MaxTimestamp) {
candidateTS = t.ExistingTimestamp
candidateTS.Logical++
} else {
candidateTS = replyHeader.Txn.MaxTimestamp
}
// Only change the timestamp if we're moving it forward.
if replyHeader.Txn.Timestamp.Less(candidateTS) {
replyHeader.Txn.Timestamp = candidateTS
}
replyHeader.Txn.Restart(argsHeader.GetUserPriority(), replyHeader.Txn.Priority, replyHeader.Txn.Timestamp)
case *proto.TransactionAbortedError:
// Increase timestamp if applicable.
if replyHeader.Txn.Timestamp.Less(t.Txn.Timestamp) {
replyHeader.Txn.Timestamp = t.Txn.Timestamp
}
replyHeader.Txn.Priority = t.Txn.Priority
case *proto.TransactionPushError:
// Increase timestamp if applicable.
if replyHeader.Txn.Timestamp.Less(t.PusheeTxn.Timestamp) {
replyHeader.Txn.Timestamp = t.PusheeTxn.Timestamp
replyHeader.Txn.Timestamp.Logical++ // ensure this txn's timestamp > other txn
}
replyHeader.Txn.Restart(argsHeader.GetUserPriority(), t.PusheeTxn.Priority-1, replyHeader.Txn.Timestamp)
case *proto.TransactionRetryError:
// Increase timestamp if applicable.
if replyHeader.Txn.Timestamp.Less(t.Txn.Timestamp) {
replyHeader.Txn.Timestamp = t.Txn.Timestamp
}
replyHeader.Txn.Restart(argsHeader.GetUserPriority(), t.Txn.Priority, replyHeader.Txn.Timestamp)
}
}
// updateForBatch updates the first argument (the header of a request contained
// in a batch) from the second one (the batch header), returning an error when
// inconsistencies are found.
// It is checked that the individual call does not have a User, UserPriority
// or Txn set that differs from the batch's.
func updateForBatch(args proto.Request, bHeader proto.RequestHeader) error {
// Disallow transaction, user and priority on individual calls, unless
// equal.
aHeader := args.Header()
if aHeader.User != "" && aHeader.User != bHeader.User {
return util.Error("conflicting user on call in batch")
}
if aPrio := aHeader.GetUserPriority(); aPrio != proto.Default_RequestHeader_UserPriority && aPrio != bHeader.GetUserPriority() {
return util.Error("conflicting user priority on call in batch")
}
aHeader.User = bHeader.User
aHeader.UserPriority = bHeader.UserPriority
// Only allow individual transactions on the requests of a batch if
// - the batch is non-transactional,
// - the individual transaction does not write intents, and
// - the individual transaction is initialized.
// The main usage of this is to allow mass-resolution of intents, which
// entails sending a non-txn batch of transactional InternalResolveIntent.
if aHeader.Txn != nil && !aHeader.Txn.Equal(bHeader.Txn) {
if len(aHeader.Txn.ID) == 0 || proto.IsTransactionWrite(args) || bHeader.Txn != nil {
return util.Error("conflicting transaction in transactional batch")
}
} else {
aHeader.Txn = bHeader.Txn
}
return nil
}
// UpdateForBatch updates the first argument (the header of a request contained
// in a batch) from the second one (the batch header), returning an error when
// inconsistencies are found.
// It is checked that the individual call does not have a UserPriority
// or Txn set that differs from the batch's.
// TODO(tschottdorf): will go with #2143.
func updateForBatch(args proto.Request, bHeader proto.RequestHeader) error {
// Disallow transaction, user and priority on individual calls, unless
// equal.
aHeader := args.Header()
if aPrio := aHeader.GetUserPriority(); aPrio != proto.Default_RequestHeader_UserPriority && aPrio != bHeader.GetUserPriority() {
return util.Errorf("conflicting user priority on call in batch")
}
aHeader.UserPriority = bHeader.UserPriority
aHeader.Txn = bHeader.Txn // reqs always take Txn from batch
return nil
}