Golang Error.GetTxn方法代码示例

// requestLeaseAsync sends a transfer lease or lease request to the
// specified replica. The request is sent in an async task.
func (p *pendingLeaseRequest) requestLeaseAsync(
	repl *Replica,
	nextLeaseHolder roachpb.ReplicaDescriptor,
	reqLease roachpb.Lease,
	status LeaseStatus,
	leaseReq roachpb.Request,
) error {
	return repl.store.Stopper().RunAsyncTask(context.TODO(), func(ctx context.Context) {
		ctx = repl.AnnotateCtx(ctx)
		var pErr *roachpb.Error

		// If requesting an epoch-based lease & current state is expired,
		// potentially heartbeat our own liveness or increment epoch of
		// prior owner. Note we only do this if the previous lease was
		// epoch-based.
		if reqLease.Type() == roachpb.LeaseEpoch && status.state == leaseExpired &&
			status.lease.Type() == roachpb.LeaseEpoch {
			var err error
			// If this replica is previous & next lease holder, manually heartbeat to become live.
			if status.lease.OwnedBy(nextLeaseHolder.StoreID) &&
				repl.store.StoreID() == nextLeaseHolder.StoreID {
				if err = repl.store.cfg.NodeLiveness.Heartbeat(ctx, status.liveness); err != nil {
					log.Error(ctx, err)
				}
			} else if status.liveness.Epoch == *status.lease.Epoch {
				// If not owner, increment epoch if necessary to invalidate lease.
				if err = repl.store.cfg.NodeLiveness.IncrementEpoch(ctx, status.liveness); err != nil {
					log.Error(ctx, err)
				}
			}
			// Set error for propagation to all waiters below.
			if err != nil {
				pErr = roachpb.NewError(newNotLeaseHolderError(status.lease, repl.store.StoreID(), repl.Desc()))
			}
		}

		// Propose a RequestLease command and wait for it to apply.
		if pErr == nil {
			ba := roachpb.BatchRequest{}
			ba.Timestamp = repl.store.Clock().Now()
			ba.RangeID = repl.RangeID
			ba.Add(leaseReq)
			_, pErr = repl.Send(ctx, ba)
		}
		// We reset our state below regardless of whether we've gotten an error or
		// not, but note that an error is ambiguous - there's no guarantee that the
		// transfer will not still apply. That's OK, however, as the "in transfer"
		// state maintained by the pendingLeaseRequest is not relied on for
		// correctness (see repl.mu.minLeaseProposedTS), and resetting the state
		// is beneficial as it'll allow the replica to attempt to transfer again or
		// extend the existing lease in the future.

		// Send result of lease to all waiter channels.
		repl.mu.Lock()
		defer repl.mu.Unlock()
		for _, llChan := range p.llChans {
			// Don't send the same transaction object twice; this can lead to races.
			if pErr != nil {
				pErrClone := *pErr
				pErrClone.SetTxn(pErr.GetTxn())
				llChan <- &pErrClone
			} else {
				llChan <- nil
			}
		}
		p.llChans = p.llChans[:0]
		p.nextLease = roachpb.Lease{}
	})
}

// updateState updates the transaction state in both the success and
// error cases, applying those updates to the corresponding txnMeta
// object when adequate. It also updates certain errors with the
// updated transaction for use by client restarts.
func (tc *TxnCoordSender) updateState(
	ctx context.Context,
	startNS int64,
	ba roachpb.BatchRequest,
	br *roachpb.BatchResponse,
	pErr *roachpb.Error,
) *roachpb.Error {

	tc.Lock()
	defer tc.Unlock()

	if ba.Txn == nil {
		// Not a transactional request.
		return pErr
	}

	var newTxn roachpb.Transaction
	newTxn.Update(ba.Txn)
	if pErr == nil {
		newTxn.Update(br.Txn)
	} else if errTxn := pErr.GetTxn(); errTxn != nil {
		newTxn.Update(errTxn)
	}

	switch t := pErr.GetDetail().(type) {
	case *roachpb.OpRequiresTxnError:
		panic("OpRequiresTxnError must not happen at this level")
	case *roachpb.ReadWithinUncertaintyIntervalError:
		// If the reader encountered a newer write within the uncertainty
		// interval, we advance the txn's timestamp just past the last observed
		// timestamp from the node.
		restartTS, ok := newTxn.GetObservedTimestamp(pErr.OriginNode)
		if !ok {
			pErr = roachpb.NewError(errors.Errorf("no observed timestamp for node %d found on uncertainty restart", pErr.OriginNode))
		} else {
			newTxn.Timestamp.Forward(restartTS)
			newTxn.Restart(ba.UserPriority, newTxn.Priority, newTxn.Timestamp)
		}
	case *roachpb.TransactionAbortedError:
		// Increase timestamp if applicable.
		newTxn.Timestamp.Forward(pErr.GetTxn().Timestamp)
		newTxn.Priority = pErr.GetTxn().Priority
		// Clean up the freshly aborted transaction in defer(), avoiding a
		// race with the state update below.
		defer tc.cleanupTxnLocked(ctx, newTxn)
	case *roachpb.TransactionPushError:
		// Increase timestamp if applicable, ensuring that we're
		// just ahead of the pushee.
		newTxn.Timestamp.Forward(t.PusheeTxn.Timestamp)
		newTxn.Restart(ba.UserPriority, t.PusheeTxn.Priority-1, newTxn.Timestamp)
	case *roachpb.TransactionRetryError:
		// Increase timestamp so on restart, we're ahead of any timestamp
		// cache entries or newer versions which caused the restart.
		newTxn.Restart(ba.UserPriority, pErr.GetTxn().Priority, newTxn.Timestamp)
	case *roachpb.WriteTooOldError:
		newTxn.Restart(ba.UserPriority, newTxn.Priority, t.ActualTimestamp)
	case nil:
		// Nothing to do here, avoid the default case.
	default:
		// Do not clean up the transaction since we're leaving cancellation of
		// the transaction up to the client. For example, on seeing an error,
		// like TransactionStatusError or ConditionFailedError, the client
		// will call Txn.CleanupOnError() which will cleanup the transaction
		// and its intents. Therefore leave the transaction in the PENDING
		// state and do not call cleanTxnLocked().
	}

	txnID := *newTxn.ID

	txnMeta := tc.txns[txnID]
	// For successful transactional requests, keep the written intents and
	// the updated transaction record to be sent along with the reply.
	// The transaction metadata is created with the first writing operation.
	// A tricky edge case is that of a transaction which "fails" on the
	// first writing request, but actually manages to write some intents
	// (for example, due to being multi-range). In this case, there will
	// be an error, but the transaction will be marked as Writing and the
	// coordinator must track the state, for the client's retry will be
	// performed with a Writing transaction which the coordinator rejects
	// unless it is tracking it (on top of it making sense to track it;
	// after all, it **has** laid down intents and only the coordinator
	// can augment a potential EndTransaction call). See #3303.
	if txnMeta != nil || pErr == nil || newTxn.Writing {
		// Adding the intents even on error reduces the likelihood of dangling
		// intents blocking concurrent writers for extended periods of time.
		// See #3346.
		var keys []roachpb.Span
		if txnMeta != nil {
			keys = txnMeta.keys
		}
		ba.IntentSpanIterate(br, func(key, endKey roachpb.Key) {
			keys = append(keys, roachpb.Span{
				Key:    key,
				EndKey: endKey,
			})
		})
//.........这里部分代码省略.........