Golang proto.NewError函數代碼示例

// send runs the specified calls synchronously in a single batch and
// returns any errors.
func (db *DB) send(calls ...proto.Call) (pErr *proto.Error) {
	if len(calls) == 0 {
		return nil
	}

	if len(calls) == 1 {
		c := calls[0]
		// We only send BatchRequest. Everything else needs to go into one.
		if _, ok := calls[0].Args.(*proto.BatchRequest); ok {
			if c.Args.Header().UserPriority == nil && db.userPriority != 0 {
				c.Args.Header().UserPriority = gogoproto.Int32(db.userPriority)
			}
			resetClientCmdID(c.Args)
			_ = SendCall(db.sender, c)
			pErr = c.Reply.Header().Error
			if pErr != nil {
				if log.V(1) {
					log.Infof("failed %s: %s", c.Method(), pErr)
				}
			} else if c.Post != nil {
				pErr = proto.NewError(c.Post())
			}
			return pErr
		}
	}

	ba, br := &proto.BatchRequest{}, &proto.BatchResponse{}
	for _, call := range calls {
		ba.Add(call.Args)
	}
	pErr = db.send(proto.Call{Args: ba, Reply: br})

	// Recover from protobuf merge panics.
	defer func() {
		if r := recover(); r != nil {
			// Take care to log merge error and to return it if no error has
			// already been set.
			mergeErr := util.Errorf("unable to merge response: %s", r)
			log.Error(mergeErr)
			if pErr == nil {
				pErr = proto.NewError(mergeErr)
			}
		}
	}()

	// Transfer individual responses from batch response to prepared replies.
	for i, reply := range br.Responses {
		c := calls[i]
		gogoproto.Merge(c.Reply, reply.GetInner())
		if c.Post != nil {
			if e := c.Post(); e != nil && pErr != nil {
				pErr = proto.NewError(e)
			}
		}
	}
	return
}

// send runs the specified calls synchronously in a single batch and
// returns any errors. If the transaction is read-only or has already
// been successfully committed or aborted, a potential trailing
// EndTransaction call is silently dropped, allowing the caller to
// always commit or clean-up explicitly even when that may not be
// required (or even erroneous).
func (txn *Txn) send(calls ...proto.Call) *proto.Error {
	if txn.Proto.Status != proto.PENDING {
		return proto.NewError(util.Errorf("attempting to use %s transaction", txn.Proto.Status))
	}

	lastIndex := len(calls) - 1
	if lastIndex < 0 {
		return nil
	}

	lastReq := calls[lastIndex].Args
	// haveTxnWrite tracks intention to write. This is in contrast to
	// txn.Proto.Writing, which is set by the coordinator when the first
	// intent has been created, and which lives for the life of the
	// transaction.
	haveTxnWrite := proto.IsTransactionWrite(lastReq)

	for _, call := range calls[:lastIndex] {
		request := call.Args

		if req, ok := request.(*proto.EndTransactionRequest); ok {
			return proto.NewError(util.Errorf("%s sent as non-terminal call", req.Method()))
		}

		if !haveTxnWrite {
			haveTxnWrite = proto.IsTransactionWrite(request)
		}
	}

	endTxnRequest, haveEndTxn := lastReq.(*proto.EndTransactionRequest)
	needEndTxn := txn.Proto.Writing || haveTxnWrite
	elideEndTxn := haveEndTxn && !needEndTxn

	if elideEndTxn {
		calls = calls[:lastIndex]
	}

	pErr := txn.db.send(calls...)
	if elideEndTxn && pErr == nil {
		// This normally happens on the server and sent back in response
		// headers, but this transaction was optimized away. The caller may
		// still inspect the transaction struct, so we manually update it
		// here to emulate a true transaction.
		if endTxnRequest.Commit {
			txn.Proto.Status = proto.COMMITTED
		} else {
			txn.Proto.Status = proto.ABORTED
		}
	}
	return pErr
}

// sendAttempt gathers and rearranges the replicas, and makes an RPC call.
func (ds *DistSender) sendAttempt(trace *tracer.Trace, ba proto.BatchRequest, desc *proto.RangeDescriptor) (*proto.BatchResponse, *proto.Error) {
	defer trace.Epoch("sending RPC")()

	leader := ds.leaderCache.Lookup(proto.RangeID(desc.RangeID))

	// Try to send the call.
	replicas := newReplicaSlice(ds.gossip, desc)

	// Rearrange the replicas so that those replicas with long common
	// prefix of attributes end up first. If there's no prefix, this is a
	// no-op.
	order := ds.optimizeReplicaOrder(replicas)

	// If this request needs to go to a leader and we know who that is, move
	// it to the front.
	if !(proto.IsReadOnly(&ba) && ba.ReadConsistency == proto.INCONSISTENT) &&
		leader.StoreID > 0 {
		if i := replicas.FindReplica(leader.StoreID); i >= 0 {
			replicas.MoveToFront(i)
			order = rpc.OrderStable
		}
	}

	// TODO(tschottdorf) &ba -> ba
	resp, err := ds.sendRPC(trace, desc.RangeID, replicas, order, &ba)
	if err != nil {
		return nil, proto.NewError(err)
	}
	// Untangle the error from the received response.
	br := resp.(*proto.BatchResponse)
	pErr := br.Error
	br.Error = nil // scrub the response error
	return br, pErr
}

// getDescriptors looks up the range descriptor to use for a query over the
// key range [from,to), with the given lookupOptions. The range descriptor
// which contains the range in which the request should start its query is
// returned first; the returned bool is true in case the given range reaches
// outside the first descriptor.
// In case either of the descriptors is discovered stale, the returned closure
// should be called; it evicts the cache appropriately.
// Note that `from` and `to` are not necessarily Key and EndKey from a
// RequestHeader; it's assumed that they've been translated to key addresses
// already (via KeyAddress).
func (ds *DistSender) getDescriptors(from, to proto.Key, options lookupOptions) (*proto.RangeDescriptor, bool, func(), *proto.Error) {
	var desc *proto.RangeDescriptor
	var err error
	var descKey proto.Key
	if !options.useReverseScan {
		descKey = from
	} else {
		descKey = to
	}
	desc, err = ds.rangeCache.LookupRangeDescriptor(descKey, options)

	if err != nil {
		return nil, false, nil, proto.NewError(err)
	}

	// Checks whether need to get next range descriptor. If so, returns true.
	needAnother := func(desc *proto.RangeDescriptor, isReverse bool) bool {
		if isReverse {
			return from.Less(desc.StartKey)
		}
		return desc.EndKey.Less(to)
	}

	evict := func() {
		ds.rangeCache.EvictCachedRangeDescriptor(descKey, desc, options.useReverseScan)
	}

	return desc, needAnother(desc, options.useReverseScan), evict, nil
}

// Batch sends a request to Cockroach via RPC. Errors which are retryable are
// retried with backoff in a loop using the default retry options. Other errors
// sending the request are retried indefinitely using the same client command
// ID to avoid reporting failure when in fact the command may have gone through
// and been executed successfully. We retry here to eventually get through with
// the same client command ID and be given the cached response.
func (s *rpcSender) Send(ctx context.Context, ba proto.BatchRequest) (*proto.BatchResponse, *proto.Error) {
	var err error
	var br proto.BatchResponse
	for r := retry.Start(s.retryOpts); r.Next(); {
		select {
		case <-s.client.Healthy():
		default:
			err = fmt.Errorf("failed to send RPC request %s: client is unhealthy", method)
			log.Warning(err)
			continue
		}

		if err = s.client.Call(method, &ba, &br); err != nil {
			br.Reset() // don't trust anyone.
			// Assume all errors sending request are retryable. The actual
			// number of things that could go wrong is vast, but we don't
			// want to miss any which should in theory be retried with the
			// same client command ID. We log the error here as a warning so
			// there's visiblity that this is happening. Some of the errors
			// we'll sweep up in this net shouldn't be retried, but we can't
			// really know for sure which.
			log.Warningf("failed to send RPC request %s: %s", method, err)
			continue
		}

		// On successful post, we're done with retry loop.
		break
	}
	if err != nil {
		return nil, proto.NewError(err)
	}
	pErr := br.Error
	br.Error = nil
	return &br, pErr
}

// Send implements the client.Sender interface. The store is looked up from the
// store map if specified by the request; otherwise, the command is being
// executed locally, and the replica is determined via lookup through each
// store's LookupRange method. The latter path is taken only by unit tests.
func (ls *LocalSender) Send(ctx context.Context, ba proto.BatchRequest) (*proto.BatchResponse, *proto.Error) {
	trace := tracer.FromCtx(ctx)
	var store *storage.Store
	var err error

	// If we aren't given a Replica, then a little bending over
	// backwards here. This case applies exclusively to unittests.
	if ba.RangeID == 0 || ba.Replica.StoreID == 0 {
		var repl *proto.Replica
		var rangeID proto.RangeID
		rangeID, repl, err = ls.lookupReplica(ba.Key, ba.EndKey)
		if err == nil {
			ba.RangeID = rangeID
			ba.Replica = *repl
		}
	}

	ctx = log.Add(ctx,
		log.Method, ba.Method(), // TODO(tschottdorf): Method() always `Batch`.
		log.Key, ba.Key,
		log.RangeID, ba.RangeID)

	if err == nil {
		store, err = ls.GetStore(ba.Replica.StoreID)
	}

	var br *proto.BatchResponse
	if err != nil {
		return nil, proto.NewError(err)
	}
	// For calls that read data within a txn, we can avoid uncertainty
	// related retries in certain situations. If the node is in
	// "CertainNodes", we need not worry about uncertain reads any
	// more. Setting MaxTimestamp=Timestamp for the operation
	// accomplishes that. See proto.Transaction.CertainNodes for details.
	if ba.Txn != nil && ba.Txn.CertainNodes.Contains(ba.Replica.NodeID) {
		// MaxTimestamp = Timestamp corresponds to no clock uncertainty.
		trace.Event("read has no clock uncertainty")
		ba.Txn.MaxTimestamp = ba.Txn.Timestamp
	}
	// TODO(tschottdorf): &ba -> ba
	tmpR, pErr := store.ExecuteCmd(ctx, &ba)
	// TODO(tschottdorf): remove this dance once BatchResponse is returned.
	if tmpR != nil {
		br = tmpR.(*proto.BatchResponse)
		if br.Error != nil {
			panic(proto.ErrorUnexpectedlySet(store, br))
		}
	}
	return br, pErr
}

// TestRunTransactionRetryOnErrors verifies that the transaction
// is retried on the correct errors.
func TestRunTransactionRetryOnErrors(t *testing.T) {
	defer leaktest.AfterTest(t)
	testCases := []struct {
		err   error
		retry bool // Expect retry?
	}{
		{&proto.ReadWithinUncertaintyIntervalError{}, true},
		{&proto.TransactionAbortedError{}, true},
		{&proto.TransactionPushError{}, true},
		{&proto.TransactionRetryError{}, true},
		{&proto.RangeNotFoundError{}, false},
		{&proto.RangeKeyMismatchError{}, false},
		{&proto.TransactionStatusError{}, false},
	}

	for i, test := range testCases {
		count := 0
		db := newDB(newTestSender(func(ba proto.BatchRequest) (*proto.BatchResponse, *proto.Error) {

			if _, ok := ba.GetArg(proto.Put); ok {
				count++
				if count == 1 {
					return nil, proto.NewError(test.err)
				}
			}
			return &proto.BatchResponse{}, nil
		}, nil))
		db.txnRetryOptions.InitialBackoff = 1 * time.Millisecond
		err := db.Txn(func(txn *Txn) error {
			return txn.Put("a", "b")
		})
		if test.retry {
			if count != 2 {
				t.Errorf("%d: expected one retry; got %d", i, count-1)
			}
			if err != nil {
				t.Errorf("%d: expected success on retry; got %s", i, err)
			}
		} else {
			if count != 1 {
				t.Errorf("%d: expected no retries; got %d", i, count)
			}
			if reflect.TypeOf(err) != reflect.TypeOf(test.err) {
				t.Errorf("%d: expected error of type %T; got %T", i, test.err, err)
			}
		}
	}
}

// sendAndFill is a helper which sends the given batch and fills its results,
// returning the appropriate error which is either from the first failing call,
// or an "internal" error.
func sendAndFill(send func(...proto.Call) *proto.Error, b *Batch) *proto.Error {
	// Errors here will be attached to the results, so we will get them from
	// the call to fillResults in the regular case in which an individual call
	// fails. But send() also returns its own errors, so there's some dancing
	// here to do because we want to run fillResults() so that the individual
	// result gets initialized with an error from the corresponding call.
	pErr := send(b.calls...)
	if pErr != nil {
		// TODO(tschottdorf): give the error to fillResults or make sure in
		// some other way that fillResults knows it's only called to set the
		// keys.
		_ = b.fillResults()
		return pErr
	}
	return proto.NewError(b.fillResults())
}

// TestClientCommandID verifies that client command ID is set
// on call.
func TestClientCommandID(t *testing.T) {
	defer leaktest.AfterTest(t)
	count := 0
	db := NewDB(newTestSender(func(ba proto.BatchRequest) (*proto.BatchResponse, *proto.Error) {
		count++
		if ba.CmdID.WallTime == 0 {
			return nil, proto.NewError(util.Errorf("expected client command ID to be initialized"))
		}
		return ba.CreateReply().(*proto.BatchResponse), nil
	}, nil))
	if err := db.Put("a", "b"); err != nil {
		t.Error(err)
	}
	if count != 1 {
		t.Errorf("expected test sender to be invoked once; got %d", count)
	}
}

// TestAbortTransactionOnCommitErrors verifies that non-exec transactions are
// aborted on the correct errors.
func TestAbortTransactionOnCommitErrors(t *testing.T) {
	defer leaktest.AfterTest(t)

	testCases := []struct {
		err   error
		abort bool
	}{
		{&proto.ReadWithinUncertaintyIntervalError{}, true},
		{&proto.TransactionAbortedError{}, false},
		{&proto.TransactionPushError{}, true},
		{&proto.TransactionRetryError{}, true},
		{&proto.RangeNotFoundError{}, true},
		{&proto.RangeKeyMismatchError{}, true},
		{&proto.TransactionStatusError{}, true},
	}

	for _, test := range testCases {
		var commit, abort bool
		db := NewDB(newTestSender(func(ba proto.BatchRequest) (*proto.BatchResponse, *proto.Error) {

			switch t := ba.Requests[0].GetInner().(type) {
			case *proto.EndTransactionRequest:
				if t.Commit {
					commit = true
					return nil, proto.NewError(test.err)
				}
				abort = true
			}
			return &proto.BatchResponse{}, nil
		}, nil))

		txn := NewTxn(*db)
		_ = txn.Put("a", "b")
		_ = txn.Commit()

		if !commit {
			t.Errorf("%T: failed to find commit", test.err)
		}
		if test.abort && !abort {
			t.Errorf("%T: failed to find abort", test.err)
		} else if !test.abort && abort {
			t.Errorf("%T: found unexpected abort", test.err)
		}
	}
}

// TestTxnResetTxnOnAbort verifies transaction is reset on abort.
func TestTxnResetTxnOnAbort(t *testing.T) {
	defer leaktest.AfterTest(t)
	db := newDB(newTestSender(func(ba proto.BatchRequest) (*proto.BatchResponse, *proto.Error) {
		return nil, proto.NewError(&proto.TransactionAbortedError{
			Txn: *gogoproto.Clone(ba.Txn).(*proto.Transaction),
		})
	}, nil))

	txn := NewTxn(*db)
	_, pErr := txn.db.sender.Send(context.Background(), testPut())
	if _, ok := pErr.GoError().(*proto.TransactionAbortedError); !ok {
		t.Fatalf("expected TransactionAbortedError, got %v", pErr)
	}

	if len(txn.Proto.ID) != 0 {
		t.Errorf("expected txn to be cleared")
	}
}

// TestTxnRequestTxnTimestamp verifies response txn timestamp is
// always upgraded on successive requests.
func TestTxnRequestTxnTimestamp(t *testing.T) {
	defer leaktest.AfterTest(t)
	makeTS := func(walltime int64, logical int32) proto.Timestamp {
		return proto.ZeroTimestamp.Add(walltime, logical)
	}

	testPutReq := gogoproto.Clone(testPutReq).(*proto.PutRequest)

	testCases := []struct {
		expRequestTS, responseTS proto.Timestamp
	}{
		{makeTS(0, 0), makeTS(10, 0)},
		{makeTS(10, 0), makeTS(10, 1)},
		{makeTS(10, 1), makeTS(10, 0)},
		{makeTS(10, 1), makeTS(20, 1)},
		{makeTS(20, 1), makeTS(20, 1)},
		{makeTS(20, 1), makeTS(0, 0)},
		{makeTS(20, 1), makeTS(20, 1)},
	}

	var testIdx int
	db := NewDB(newTestSender(nil, func(ba proto.BatchRequest) (*proto.BatchResponse, *proto.Error) {
		test := testCases[testIdx]
		if !test.expRequestTS.Equal(ba.Txn.Timestamp) {
			return nil, proto.NewError(util.Errorf("%d: expected ts %s got %s", testIdx, test.expRequestTS, ba.Txn.Timestamp))
		}
		br := &proto.BatchResponse{}
		br.Txn = &proto.Transaction{}
		br.Txn.Update(ba.Txn) // copy
		br.Txn.Timestamp = test.responseTS
		return br, nil
	}))

	txn := NewTxn(*db)

	for testIdx = range testCases {
		if _, err := send(txn.db.sender, testPutReq); err != nil {
			t.Fatal(err)
		}
	}
}

// TODO(tschottdorf): this method is somewhat awkward but unless we want to
// give this error back to the client, our options are limited. We'll have to
// run the whole thing for them, or any restart will still end up at the client
// which will not be prepared to be handed a Txn.
func (tc *TxnCoordSender) resendWithTxn(ba proto.BatchRequest) (*proto.BatchResponse, *proto.Error) {
	// Run a one-off transaction with that single command.
	if log.V(1) {
		log.Infof("%s: auto-wrapping in txn and re-executing: ", ba)
	}
	tmpDB := client.NewDBWithPriority(tc, ba.GetUserPriority())
	br := &proto.BatchResponse{}
	if err := tmpDB.Txn(func(txn *client.Txn) error {
		txn.SetDebugName("auto-wrap", 0)
		b := &client.Batch{}
		for _, arg := range ba.Requests {
			req := arg.GetInner()
			call := proto.Call{Args: req, Reply: req.CreateReply()}
			b.InternalAddCall(call)
			br.Add(call.Reply)
		}
		return txn.CommitInBatch(b)
	}); err != nil {
		return nil, proto.NewError(err)
	}
	return br, nil
}

// TODO(tschottdorf): this method is somewhat awkward but unless we want to
// give this error back to the client, our options are limited. We'll have to
// run the whole thing for them, or any restart will still end up at the client
// which will not be prepared to be handed a Txn.
func (tc *TxnCoordSender) resendWithTxn(ba proto.BatchRequest) (*proto.BatchResponse, *proto.Error) {
	// Run a one-off transaction with that single command.
	if log.V(1) {
		log.Infof("%s: auto-wrapping in txn and re-executing: ", ba)
	}
	tmpDB := client.NewDBWithPriority(tc, ba.GetUserPriority())
	var br *proto.BatchResponse
	err := tmpDB.Txn(func(txn *client.Txn) error {
		txn.SetDebugName("auto-wrap", 0)
		b := &client.Batch{}
		for _, arg := range ba.Requests {
			req := arg.GetInner()
			b.InternalAddRequest(req)
		}
		var err error
		br, err = txn.CommitInBatchWithResponse(b)
		return err
	})
	if err != nil {
		return nil, proto.NewError(err)
	}
	br.Txn = nil // hide the evidence
	return br, nil
}

func TestNodeEventFeed(t *testing.T) {
	defer leaktest.AfterTest(t)

	nodeDesc := proto.NodeDescriptor{
		NodeID: proto.NodeID(99),
	}

	// A testCase corresponds to a single Store event type. Each case contains a
	// method which publishes a single event to the given storeEventPublisher,
	// and an expected result interface which should match the produced
	// event.
	testCases := []struct {
		publishTo func(status.NodeEventFeed)
		expected  interface{}
	}{
		{
			publishTo: func(nef status.NodeEventFeed) {
				nef.StartNode(nodeDesc, 100)
			},
			expected: &status.StartNodeEvent{
				Desc:      nodeDesc,
				StartedAt: 100,
			},
		},
		{
			publishTo: func(nef status.NodeEventFeed) {
				nef.CallComplete(wrap(proto.NewGet(proto.Key("abc"))), nil)
			},
			expected: &status.CallSuccessEvent{
				NodeID: proto.NodeID(1),
				Method: proto.Get,
			},
		},
		{
			publishTo: func(nef status.NodeEventFeed) {
				nef.CallComplete(wrap(proto.NewPut(proto.Key("abc"), proto.Value{Bytes: []byte("def")})), nil)
			},
			expected: &status.CallSuccessEvent{
				NodeID: proto.NodeID(1),
				Method: proto.Put,
			},
		},
		{
			publishTo: func(nef status.NodeEventFeed) {
				nef.CallComplete(wrap(proto.NewGet(proto.Key("abc"))), proto.NewError(util.Errorf("error")))
			},
			expected: &status.CallErrorEvent{
				NodeID: proto.NodeID(1),
				Method: proto.Batch,
			},
		},
		{
			publishTo: func(nef status.NodeEventFeed) {
				nef.CallComplete(wrap(proto.NewGet(proto.Key("abc"))), &proto.Error{
					Index:   &proto.ErrPosition{Index: 0},
					Message: "boo",
				})
			},
			expected: &status.CallErrorEvent{
				NodeID: proto.NodeID(1),
				Method: proto.Get,
			},
		},
	}

	// Compile expected events into a single slice.
	expectedEvents := make([]interface{}, len(testCases))
	for i := range testCases {
		expectedEvents[i] = testCases[i].expected
	}

	events := make([]interface{}, 0, len(expectedEvents))

	// Run test cases directly through a feed.
	stopper := stop.NewStopper()
	defer stopper.Stop()
	feed := util.NewFeed(stopper)
	feed.Subscribe(func(event interface{}) {
		events = append(events, event)
	})

	nodefeed := status.NewNodeEventFeed(proto.NodeID(1), feed)
	for _, tc := range testCases {
		tc.publishTo(nodefeed)
	}

	feed.Flush()

	if a, e := events, expectedEvents; !reflect.DeepEqual(a, e) {
		t.Errorf("received incorrect events.\nexpected: %v\nactual: %v", e, a)
	}
}