// TestTxnCoordSenderCleanupOnAborted verifies that if a txn receives a
// TransactionAbortedError, the coordinator cleans up the transaction.
func TestTxnCoordSenderCleanupOnAborted(t *testing.T) {
	defer leaktest.AfterTest(t)()
	s, sender := createTestDB(t)
	defer s.Stop()

	// Create a transaction with intent at "a".
	key := roachpb.Key("a")
	txn1 := client.NewTxn(context.Background(), *s.DB)
	txn1.InternalSetPriority(1)
	if err := txn1.Put(key, []byte("value")); err != nil {
		t.Fatal(err)
	}

	// Push the transaction (by writing key "a" with higher priority) to abort it.
	txn2 := client.NewTxn(context.Background(), *s.DB)
	txn2.InternalSetPriority(2)
	if err := txn2.Put(key, []byte("value2")); err != nil {
		t.Fatal(err)
	}

	// Now end the transaction and verify we've cleanup up, even though
	// end transaction failed.
	err := txn1.CommitOrCleanup()
	assertTransactionAbortedError(t, err)
	if err := txn2.CommitOrCleanup(); err != nil {
		t.Fatal(err)
	}
	verifyCleanup(key, sender, s.Eng, t)
}

// TestTxnInitialTimestamp verifies that the timestamp requested
// before the Txn is created is honored.
func TestTxnInitialTimestamp(t *testing.T) {
	defer leaktest.AfterTest(t)()
	s, sender := createTestDB(t)
	defer s.Stop()
	defer teardownHeartbeats(sender)

	txn := client.NewTxn(context.Background(), *s.DB)

	// Request a specific timestamp.
	refTimestamp := s.Clock.Now().Add(42, 69)
	txn.Proto.OrigTimestamp = refTimestamp

	// Put request will create a new transaction.
	key := roachpb.Key("key")
	txn.InternalSetPriority(10)
	txn.Proto.Isolation = enginepb.SNAPSHOT
	txn.Proto.Name = "test txn"
	if err := txn.Put(key, []byte("value")); err != nil {
		t.Fatal(err)
	}
	if txn.Proto.OrigTimestamp != refTimestamp {
		t.Errorf("expected txn orig ts to be %s; got %s", refTimestamp, txn.Proto.OrigTimestamp)
	}
	if txn.Proto.Timestamp != refTimestamp {
		t.Errorf("expected txn ts to be %s; got %s", refTimestamp, txn.Proto.Timestamp)
	}
}

// TestTxnCoordSenderAddIntentOnError verifies that intents are tracked if
// the transaction is, even on error.
func TestTxnCoordSenderAddIntentOnError(t *testing.T) {
	defer leaktest.AfterTest(t)()
	s, sender := createTestDB(t)
	defer s.Stop()

	// Create a transaction with intent at "a".
	key := roachpb.Key("x")
	txn := client.NewTxn(context.Background(), *s.DB)
	// Write so that the coordinator begins tracking this txn.
	if err := txn.Put("x", "y"); err != nil {
		t.Fatal(err)
	}
	err, ok := txn.CPut(key, []byte("x"), []byte("born to fail")).(*roachpb.ConditionFailedError)
	if !ok {
		t.Fatal(err)
	}
	sender.Lock()
	txnID := *txn.Proto.ID
	intentSpans, _ := roachpb.MergeSpans(sender.txns[txnID].keys)
	expSpans := []roachpb.Span{{Key: key, EndKey: []byte("")}}
	equal := !reflect.DeepEqual(intentSpans, expSpans)
	sender.Unlock()
	if err := txn.Rollback(); err != nil {
		t.Fatal(err)
	}
	if !equal {
		t.Fatalf("expected stored intents %v, got %v", expSpans, intentSpans)
	}
}

// TestTxnCoordSenderGCTimeout verifies that the coordinator cleans up extant
// transactions and intents after the lastUpdateNanos exceeds the timeout.
func TestTxnCoordSenderGCTimeout(t *testing.T) {
	defer leaktest.AfterTest(t)()
	s, sender := createTestDB(t)
	defer s.Stop()

	// Set heartbeat interval to 1ms for testing.
	sender.heartbeatInterval = 1 * time.Millisecond

	txn := client.NewTxn(context.Background(), *s.DB)
	key := roachpb.Key("a")
	if err := txn.Put(key, []byte("value")); err != nil {
		t.Fatal(err)
	}

	// Now, advance clock past the default client timeout.
	// Locking the TxnCoordSender to prevent a data race.
	sender.Lock()
	s.Manual.Increment(defaultClientTimeout.Nanoseconds() + 1)
	sender.Unlock()

	txnID := *txn.Proto.ID

	util.SucceedsSoon(t, func() error {
		// Locking the TxnCoordSender to prevent a data race.
		sender.Lock()
		_, ok := sender.txns[txnID]
		sender.Unlock()
		if ok {
			return errors.Errorf("expected garbage collection")
		}
		return nil
	})

	verifyCleanup(key, sender, s.Eng, t)
}

// TestTxnCoordIdempotentCleanup verifies that cleanupTxnLocked is idempotent.
func TestTxnCoordIdempotentCleanup(t *testing.T) {
	defer leaktest.AfterTest(t)()
	s, sender := createTestDB(t)
	defer s.Stop()
	defer teardownHeartbeats(sender)

	txn := client.NewTxn(context.Background(), *s.DB)
	ba := txn.NewBatch()
	ba.Put(roachpb.Key("a"), []byte("value"))
	if err := txn.Run(ba); err != nil {
		t.Fatal(err)
	}

	sender.Lock()
	// Clean up twice successively.
	sender.cleanupTxnLocked(context.Background(), txn.Proto)
	sender.cleanupTxnLocked(context.Background(), txn.Proto)
	sender.Unlock()

	// For good measure, try to commit (which cleans up once more if it
	// succeeds, which it may not if the previous cleanup has already
	// terminated the heartbeat goroutine)
	ba = txn.NewBatch()
	ba.AddRawRequest(&roachpb.EndTransactionRequest{})
	err := txn.Run(ba)
	if err != nil && !testutils.IsError(err, errNoState.Error()) {
		t.Fatal(err)
	}
}

// TestTxnCoordSenderBeginTransaction verifies that a command sent with a
// not-nil Txn with empty ID gets a new transaction initialized.
func TestTxnCoordSenderBeginTransaction(t *testing.T) {
	defer leaktest.AfterTest(t)()
	s, sender := createTestDB(t)
	defer s.Stop()
	defer teardownHeartbeats(sender)

	txn := client.NewTxn(context.Background(), *s.DB)

	// Put request will create a new transaction.
	key := roachpb.Key("key")
	txn.InternalSetPriority(10)
	txn.Proto.Isolation = enginepb.SNAPSHOT
	txn.Proto.Name = "test txn"
	if err := txn.Put(key, []byte("value")); err != nil {
		t.Fatal(err)
	}
	if txn.Proto.Name != "test txn" {
		t.Errorf("expected txn name to be %q; got %q", "test txn", txn.Proto.Name)
	}
	if txn.Proto.Priority != 10 {
		t.Errorf("expected txn priority 10; got %d", txn.Proto.Priority)
	}
	if !bytes.Equal(txn.Proto.Key, key) {
		t.Errorf("expected txn Key to match %q != %q", key, txn.Proto.Key)
	}
	if txn.Proto.Isolation != enginepb.SNAPSHOT {
		t.Errorf("expected txn isolation to be SNAPSHOT; got %s", txn.Proto.Isolation)
	}
}

// TestTxnCoordSenderMultipleTxns verifies correct operation with
// multiple outstanding transactions.
func TestTxnCoordSenderMultipleTxns(t *testing.T) {
	defer leaktest.AfterTest(t)()
	s, sender := createTestDB(t)
	defer s.Stop()
	defer teardownHeartbeats(sender)

	txn1 := client.NewTxn(context.Background(), *s.DB)
	txn2 := client.NewTxn(context.Background(), *s.DB)

	if err := txn1.Put(roachpb.Key("a"), []byte("value")); err != nil {
		t.Fatal(err)
	}
	if err := txn2.Put(roachpb.Key("b"), []byte("value")); err != nil {
		t.Fatal(err)
	}

	if len(sender.txns) != 2 {
		t.Errorf("expected length of transactions map to be 2; got %d", len(sender.txns))
	}
}

func backupRestoreTestSetup(
	t testing.TB, numAccounts int,
) (
	ctx context.Context,
	tempDir string,
	tc *testcluster.TestCluster,
	kvDB *client.DB,
	sqlDB *sqlutils.SQLRunner,
	cleanup func(),
) {
	ctx = context.Background()

	dir, dirCleanupFn := testutils.TempDir(t, 1)

	// Use ReplicationManual so we can force full replication, which is needed
	// to later move the leases around.
	tc = testcluster.StartTestCluster(t, backupRestoreClusterSize, base.TestClusterArgs{
		ReplicationMode: base.ReplicationManual,
	})
	sqlDB = sqlutils.MakeSQLRunner(t, tc.Conns[0])
	kvDB = tc.Server(0).KVClient().(*client.DB)

	sqlDB.Exec(bankCreateDatabase)
	sqlDB.Exec(bankCreateTable)
	for _, insert := range bankDataInsertStmts(numAccounts) {
		sqlDB.Exec(insert)
	}
	for _, split := range bankSplitStmts(numAccounts, backupRestoreDefaultRanges) {
		sqlDB.Exec(split)
	}

	targets := make([]testcluster.ReplicationTarget, backupRestoreClusterSize-1)
	for i := 1; i < backupRestoreClusterSize; i++ {
		targets[i-1] = tc.Target(i)
	}
	txn := client.NewTxn(ctx, *kvDB)
	rangeDescs, err := sql.AllRangeDescriptors(txn)
	if err != nil {
		t.Fatal(err)
	}
	for _, r := range rangeDescs {
		if _, err := tc.AddReplicas(r.StartKey.AsRawKey(), targets...); err != nil {
			t.Fatal(err)
		}
	}

	cleanupFn := func() {
		tc.Stopper().Stop()
		dirCleanupFn()
	}

	return ctx, dir, tc, kvDB, sqlDB, cleanupFn
}

func rebalanceLeases(t testing.TB, tc *testcluster.TestCluster) {
	kvDB := tc.Server(0).KVClient().(*client.DB)
	txn := client.NewTxn(context.Background(), *kvDB)
	rangeDescs, err := sql.AllRangeDescriptors(txn)
	if err != nil {
		t.Fatal(err)
	}
	for _, r := range rangeDescs {
		target := tc.Target(int(r.RangeID) % tc.NumServers())
		if err := tc.TransferRangeLease(r, target); err != nil {
			t.Fatal(err)
		}
	}
}

// TestTxnCoordSenderKeyRanges verifies that multiple requests to same or
// overlapping key ranges causes the coordinator to keep track only of
// the minimum number of ranges.
func TestTxnCoordSenderKeyRanges(t *testing.T) {
	defer leaktest.AfterTest(t)()
	ranges := []struct {
		start, end roachpb.Key
	}{
		{roachpb.Key("a"), roachpb.Key(nil)},
		{roachpb.Key("a"), roachpb.Key(nil)},
		{roachpb.Key("aa"), roachpb.Key(nil)},
		{roachpb.Key("b"), roachpb.Key(nil)},
		{roachpb.Key("aa"), roachpb.Key("c")},
		{roachpb.Key("b"), roachpb.Key("c")},
	}

	s, sender := createTestDB(t)
	defer s.Stop()
	defer teardownHeartbeats(sender)

	txn := client.NewTxn(context.Background(), *s.DB)
	for _, rng := range ranges {
		if rng.end != nil {
			if err := txn.DelRange(rng.start, rng.end); err != nil {
				t.Fatal(err)
			}
		} else {
			if err := txn.Put(rng.start, []byte("value")); err != nil {
				t.Fatal(err)
			}
		}
	}

	txnID := *txn.Proto.ID

	// Verify that the transaction metadata contains only two entries
	// in its "keys" range group. "a" and range "aa"-"c".
	txnMeta, ok := sender.txns[txnID]
	if !ok {
		t.Fatalf("expected a transaction to be created on coordinator")
	}
	keys, _ := roachpb.MergeSpans(txnMeta.keys)
	if len(keys) != 2 {
		t.Errorf("expected 2 entries in keys range group; got %v", keys)
	}
}

// TestTxnCoordSenderReleaseTxnMeta verifies that TxnCoordSender releases the
// txnMetadata after the txn has committed successfully.
func TestTxnCoordSenderReleaseTxnMeta(t *testing.T) {
	defer leaktest.AfterTest(t)()
	s, sender := createTestDB(t)
	defer s.Stop()
	defer teardownHeartbeats(sender)

	txn := client.NewTxn(context.Background(), *s.DB)
	ba := txn.NewBatch()
	ba.Put(roachpb.Key("a"), []byte("value"))
	ba.Put(roachpb.Key("b"), []byte("value"))
	if err := txn.CommitInBatch(ba); err != nil {
		t.Fatal(err)
	}

	txnID := *txn.Proto.ID

	if _, ok := sender.txns[txnID]; ok {
		t.Fatal("expected TxnCoordSender has released the txn")
	}
}

// TestTxnCoordSenderBeginTransactionMinPriority verifies that when starting
// a new transaction, a non-zero priority is treated as a minimum value.
func TestTxnCoordSenderBeginTransactionMinPriority(t *testing.T) {
	defer leaktest.AfterTest(t)()
	s, sender := createTestDB(t)
	defer s.Stop()
	defer teardownHeartbeats(sender)

	txn := client.NewTxn(context.Background(), *s.DB)

	// Put request will create a new transaction.
	key := roachpb.Key("key")
	txn.InternalSetPriority(10)
	txn.Proto.Isolation = enginepb.SNAPSHOT
	txn.Proto.Priority = 11
	if err := txn.Put(key, []byte("value")); err != nil {
		t.Fatal(err)
	}
	if prio := txn.Proto.Priority; prio != 11 {
		t.Errorf("expected txn priority 11; got %d", prio)
	}
}

// TestReadOnlyTxnObeysDeadline tests that read-only transactions obey the
// deadline.
func TestReadOnlyTxnObeysDeadline(t *testing.T) {
	defer leaktest.AfterTest(t)()
	s, _, _ := serverutils.StartServer(t, base.TestServerArgs{})
	defer s.Stopper().Stop()
	db := createTestClient(t, s)

	if err := db.Put(context.TODO(), "k", "v"); err != nil {
		t.Fatal(err)
	}

	// Use txn.Exec instead of db.Txn to disable auto retry.
	txn := client.NewTxn(context.TODO(), *db)
	if err := txn.Exec(client.TxnExecOptions{AutoRetry: false, AutoCommit: true}, func(txn *client.Txn, _ *client.TxnExecOptions) error {
		// Set deadline to sometime in the past.
		txn.UpdateDeadlineMaybe(hlc.Timestamp{WallTime: timeutil.Now().Add(-time.Second).UnixNano()})
		_, err := txn.Get("k")
		return err
	}); !testutils.IsError(err, "txn aborted") {
		t.Fatal(err)
	}
}

// TestTxnCoordSenderAddRequest verifies adding a request creates a
// transaction metadata and adding multiple requests with same
// transaction ID updates the last update timestamp.
func TestTxnCoordSenderAddRequest(t *testing.T) {
	defer leaktest.AfterTest(t)()
	s, sender := createTestDB(t)
	defer s.Stop()
	defer teardownHeartbeats(sender)

	txn := client.NewTxn(context.Background(), *s.DB)

	// Put request will create a new transaction.
	if err := txn.Put(roachpb.Key("a"), []byte("value")); err != nil {
		t.Fatal(err)
	}
	txnID := *txn.Proto.ID
	txnMeta, ok := sender.txns[txnID]
	if !ok {
		t.Fatal("expected a transaction to be created on coordinator")
	}
	if !txn.Proto.Writing {
		t.Fatal("txn is not marked as writing")
	}
	ts := txnMeta.getLastUpdate()

	// Advance time and send another put request. Lock the coordinator
	// to prevent a data race.
	sender.Lock()
	s.Manual.Increment(1)
	sender.Unlock()
	if err := txn.Put(roachpb.Key("a"), []byte("value")); err != nil {
		t.Fatal(err)
	}
	if len(sender.txns) != 1 {
		t.Errorf("expected length of transactions map to be 1; got %d", len(sender.txns))
	}
	txnMeta = sender.txns[txnID]
	if lu := txnMeta.getLastUpdate(); ts >= lu {
		t.Errorf("expected last update time to advance past %d; got %d", ts, lu)
	} else if un := s.Manual.UnixNano(); lu != un {
		t.Errorf("expected last update time to equal %d; got %d", un, lu)
	}
}

func TestTxnCoordSenderCancel(t *testing.T) {
	defer leaktest.AfterTest(t)()
	s, sender := createTestDB(t)
	defer s.Stop()

	ctx, cancel := context.WithCancel(context.Background())

	origSender := sender.wrapped
	sender.wrapped = client.SenderFunc(
		func(ctx context.Context, args roachpb.BatchRequest) (*roachpb.BatchResponse, *roachpb.Error) {
			if _, hasET := args.GetArg(roachpb.EndTransaction); hasET {
				// Cancel the transaction while also sending it along. This tickled a
				// data race in TxnCoordSender.tryAsyncAbort. See #7726.
				cancel()
			}
			return origSender.Send(ctx, args)
		})

	// Create a transaction with bunch of intents.
	txn := client.NewTxn(ctx, *s.DB)
	batch := txn.NewBatch()
	for i := 0; i < 100; i++ {
		key := roachpb.Key(fmt.Sprintf("%d", i))
		batch.Put(key, []byte("value"))
	}
	if err := txn.Run(batch); err != nil {
		t.Fatal(err)
	}

	// Commit the transaction. Note that we cancel the transaction when the
	// commit is sent which stresses the TxnCoordSender.tryAsyncAbort code
	// path. We'll either succeed, get a "does not exist" error, or get a
	// context canceled error. Anything else is unexpected.
	err := txn.CommitOrCleanup()
	if err != nil && err.Error() != context.Canceled.Error() &&
		!testutils.IsError(err, "does not exist") {
		t.Fatal(err)
	}
}

func TestTxnRestartCount(t *testing.T) {
	defer leaktest.AfterTest(t)()
	_, sender, cleanupFn := setupMetricsTest(t)
	defer cleanupFn()

	key := []byte("key-restart")
	value := []byte("value")
	db := client.NewDB(sender)

	// Start a transaction and do a GET. This forces a timestamp to be chosen for the transaction.
	txn := client.NewTxn(context.Background(), *db)
	if _, err := txn.Get(key); err != nil {
		t.Fatal(err)
	}

	// Outside of the transaction, read the same key as was read within the transaction. This
	// means that future attempts to write will increase the timestamp.
	if _, err := db.Get(context.TODO(), key); err != nil {
		t.Fatal(err)
	}

	// This put will lay down an intent, txn timestamp will increase beyond original.
	if err := txn.Put(key, value); err != nil {
		t.Fatal(err)
	}
	if !txn.Proto.OrigTimestamp.Less(txn.Proto.Timestamp) {
		t.Errorf("expected timestamp to increase: %s", txn.Proto)
	}

	// Commit (should cause restart metric to increase).
	err := txn.CommitOrCleanup()
	assertTransactionRetryError(t, err)

	teardownHeartbeats(sender)
	checkTxnMetrics(t, sender, "restart txn", 0, 0, 0, 1, 1)
}

func TestClusterFlow(t *testing.T) {
	defer leaktest.AfterTest(t)()
	const numRows = 100

	args := base.TestClusterArgs{ReplicationMode: base.ReplicationManual}
	tc := serverutils.StartTestCluster(t, 3, args)
	defer tc.Stopper().Stop()

	sumDigitsFn := func(row int) parser.Datum {
		sum := 0
		for row > 0 {
			sum += row % 10
			row /= 10
		}
		return parser.NewDInt(parser.DInt(sum))
	}

	sqlutils.CreateTable(t, tc.ServerConn(0), "t",
		"num INT PRIMARY KEY, digitsum INT, numstr STRING, INDEX s (digitsum)",
		numRows,
		sqlutils.ToRowFn(sqlutils.RowIdxFn, sumDigitsFn, sqlutils.RowEnglishFn))

	kvDB := tc.Server(0).KVClient().(*client.DB)
	desc := sqlbase.GetTableDescriptor(kvDB, "test", "t")
	makeIndexSpan := func(start, end int) TableReaderSpan {
		var span roachpb.Span
		prefix := roachpb.Key(sqlbase.MakeIndexKeyPrefix(desc, desc.Indexes[0].ID))
		span.Key = append(prefix, encoding.EncodeVarintAscending(nil, int64(start))...)
		span.EndKey = append(span.EndKey, prefix...)
		span.EndKey = append(span.EndKey, encoding.EncodeVarintAscending(nil, int64(end))...)
		return TableReaderSpan{Span: span}
	}

	// Set up table readers on three hosts feeding data into a join reader on
	// the third host. This is a basic test for the distributed flow
	// infrastructure, including local and remote streams.
	//
	// Note that the ranges won't necessarily be local to the table readers, but
	// that doesn't matter for the purposes of this test.

	// Start a span (useful to look at spans using Lighstep).
	sp, err := tracing.JoinOrNew(tracing.NewTracer(), nil, "cluster test")
	if err != nil {
		t.Fatal(err)
	}
	ctx := opentracing.ContextWithSpan(context.Background(), sp)
	defer sp.Finish()

	tr1 := TableReaderSpec{
		Table:         *desc,
		IndexIdx:      1,
		OutputColumns: []uint32{0, 1},
		Spans:         []TableReaderSpan{makeIndexSpan(0, 8)},
	}

	tr2 := TableReaderSpec{
		Table:         *desc,
		IndexIdx:      1,
		OutputColumns: []uint32{0, 1},
		Spans:         []TableReaderSpan{makeIndexSpan(8, 12)},
	}

	tr3 := TableReaderSpec{
		Table:         *desc,
		IndexIdx:      1,
		OutputColumns: []uint32{0, 1},
		Spans:         []TableReaderSpan{makeIndexSpan(12, 100)},
	}

	jr := JoinReaderSpec{
		Table:         *desc,
		OutputColumns: []uint32{2},
	}

	txn := client.NewTxn(ctx, *kvDB)
	fid := FlowID{uuid.MakeV4()}

	req1 := &SetupFlowRequest{Txn: txn.Proto}
	req1.Flow = FlowSpec{
		FlowID: fid,
		Processors: []ProcessorSpec{{
			Core: ProcessorCoreUnion{TableReader: &tr1},
			Output: []OutputRouterSpec{{
				Type: OutputRouterSpec_MIRROR,
				Streams: []StreamEndpointSpec{
					{StreamID: 0, Mailbox: &MailboxSpec{TargetAddr: tc.Server(2).ServingAddr()}},
				},
			}},
		}},
	}

	req2 := &SetupFlowRequest{Txn: txn.Proto}
	req2.Flow = FlowSpec{
		FlowID: fid,
		Processors: []ProcessorSpec{{
			Core: ProcessorCoreUnion{TableReader: &tr2},
			Output: []OutputRouterSpec{{
				Type: OutputRouterSpec_MIRROR,
				Streams: []StreamEndpointSpec{
					{StreamID: 1, Mailbox: &MailboxSpec{TargetAddr: tc.Server(2).ServingAddr()}},
//.........这里部分代码省略.........

// TestTxnCoordSenderTxnUpdatedOnError verifies that errors adjust the
// response transaction's timestamp and priority as appropriate.
func TestTxnCoordSenderTxnUpdatedOnError(t *testing.T) {
	defer leaktest.AfterTest(t)()
	origTS := makeTS(123, 0)
	plus10 := origTS.Add(10, 10)
	plus20 := plus10.Add(10, 0)
	testCases := []struct {
		pErr             *roachpb.Error
		expEpoch         uint32
		expPri           int32
		expTS, expOrigTS hlc.Timestamp
		nodeSeen         bool
	}{
		{
			// No error, so nothing interesting either.
			pErr:      nil,
			expEpoch:  0,
			expPri:    1,
			expTS:     origTS,
			expOrigTS: origTS,
		},
		{
			// On uncertainty error, new epoch begins and node is seen.
			// Timestamp moves ahead of the existing write.
			pErr: func() *roachpb.Error {
				pErr := roachpb.NewErrorWithTxn(
					roachpb.NewReadWithinUncertaintyIntervalError(hlc.ZeroTimestamp, hlc.ZeroTimestamp),
					&roachpb.Transaction{})
				const nodeID = 1
				pErr.GetTxn().UpdateObservedTimestamp(nodeID, plus10)
				pErr.OriginNode = nodeID
				return pErr
			}(),
			expEpoch:  1,
			expPri:    1,
			expTS:     plus10,
			expOrigTS: plus10,
			nodeSeen:  true,
		},
		{
			// On abort, nothing changes but we get a new priority to use for
			// the next attempt.
			pErr: roachpb.NewErrorWithTxn(&roachpb.TransactionAbortedError{},
				&roachpb.Transaction{
					TxnMeta: enginepb.TxnMeta{Timestamp: plus20, Priority: 10},
				}),
			expPri: 10,
		},
		{
			// On failed push, new epoch begins just past the pushed timestamp.
			// Additionally, priority ratchets up to just below the pusher's.
			pErr: roachpb.NewErrorWithTxn(&roachpb.TransactionPushError{
				PusheeTxn: roachpb.Transaction{
					TxnMeta: enginepb.TxnMeta{Timestamp: plus10, Priority: int32(10)},
				},
			},
				&roachpb.Transaction{}),
			expEpoch:  1,
			expPri:    9,
			expTS:     plus10,
			expOrigTS: plus10,
		},
		{
			// On retry, restart with new epoch, timestamp and priority.
			pErr: roachpb.NewErrorWithTxn(&roachpb.TransactionRetryError{},
				&roachpb.Transaction{
					TxnMeta: enginepb.TxnMeta{Timestamp: plus10, Priority: int32(10)},
				},
			),
			expEpoch:  1,
			expPri:    10,
			expTS:     plus10,
			expOrigTS: plus10,
		},
	}

	for i, test := range testCases {
		stopper := stop.NewStopper()

		manual := hlc.NewManualClock(origTS.WallTime)
		clock := hlc.NewClock(manual.UnixNano, 20*time.Nanosecond)

		senderFunc := func(_ context.Context, ba roachpb.BatchRequest) (*roachpb.BatchResponse, *roachpb.Error) {
			var reply *roachpb.BatchResponse
			if test.pErr == nil {
				reply = ba.CreateReply()
			}
			return reply, test.pErr
		}
		ambient := log.AmbientContext{Tracer: tracing.NewTracer()}
		ts := NewTxnCoordSender(
			ambient,
			senderFn(senderFunc),
			clock,
			false,
			stopper,
			MakeTxnMetrics(metric.TestSampleInterval),
		)
		db := client.NewDB(ts)
//.........这里部分代码省略.........

// TestTxnCoordSenderGCWithCancel verifies that the coordinator cleans up extant
// transactions and intents after transaction context is cancelled.
func TestTxnCoordSenderGCWithCancel(t *testing.T) {
	defer leaktest.AfterTest(t)()
	s, sender := createTestDB(t)
	defer s.Stop()

	// Set heartbeat interval to 1ms for testing.
	sender.heartbeatInterval = 1 * time.Millisecond

	ctx, cancel := context.WithCancel(context.Background())
	txn := client.NewTxn(ctx, *s.DB)
	key := roachpb.Key("a")
	if pErr := txn.Put(key, []byte("value")); pErr != nil {
		t.Fatal(pErr)
	}

	// Now, advance clock past the default client timeout.
	// Locking the TxnCoordSender to prevent a data race.
	sender.Lock()
	s.Manual.Increment(defaultClientTimeout.Nanoseconds() + 1)
	sender.Unlock()

	txnID := *txn.Proto.ID

	// Verify that the transaction is alive despite the timeout having been
	// exceeded.
	errStillActive := errors.New("transaction is still active")
	// TODO(dan): Figure out how to run the heartbeat manually instead of this.
	if err := util.RetryForDuration(1*time.Second, func() error {
		// Locking the TxnCoordSender to prevent a data race.
		sender.Lock()
		_, ok := sender.txns[txnID]
		sender.Unlock()
		if !ok {
			return nil
		}
		meta := &enginepb.MVCCMetadata{}
		ok, _, _, err := s.Eng.GetProto(engine.MakeMVCCMetadataKey(key), meta)
		if err != nil {
			t.Fatalf("error getting MVCC metadata: %s", err)
		}
		if !ok || meta.Txn == nil {
			return nil
		}
		return errStillActive
	}); err != errStillActive {
		t.Fatalf("expected transaction to be active, got: %v", err)
	}

	// After the context is cancelled, the transaction should be cleaned up.
	cancel()
	util.SucceedsSoon(t, func() error {
		// Locking the TxnCoordSender to prevent a data race.
		sender.Lock()
		_, ok := sender.txns[txnID]
		sender.Unlock()
		if ok {
			return errors.Errorf("expected garbage collection")
		}
		return nil
	})

	verifyCleanup(key, sender, s.Eng, t)
}

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

	s, sqlDB, kvDB := serverutils.StartServer(t, base.TestServerArgs{})
	defer s.Stopper().Stop()

	// Create a table where each row is:
	//
	//  |     a    |     b    |         sum         |         s           |
	//  |-----------------------------------------------------------------|
	//  | rowId/10 | rowId%10 | rowId/10 + rowId%10 | IntToEnglish(rowId) |

	aFn := func(row int) parser.Datum {
		return parser.NewDInt(parser.DInt(row / 10))
	}
	bFn := func(row int) parser.Datum {
		return parser.NewDInt(parser.DInt(row % 10))
	}
	sumFn := func(row int) parser.Datum {
		return parser.NewDInt(parser.DInt(row/10 + row%10))
	}

	sqlutils.CreateTable(t, sqlDB, "t",
		"a INT, b INT, sum INT, s STRING, PRIMARY KEY (a,b), INDEX bs (b,s)",
		99,
		sqlutils.ToRowFn(aFn, bFn, sumFn, sqlutils.RowEnglishFn))

	td := sqlbase.GetTableDescriptor(kvDB, "test", "t")

	makeIndexSpan := func(start, end int) TableReaderSpan {
		var span roachpb.Span
		prefix := roachpb.Key(sqlbase.MakeIndexKeyPrefix(td, td.Indexes[0].ID))
		span.Key = append(prefix, encoding.EncodeVarintAscending(nil, int64(start))...)
		span.EndKey = append(span.EndKey, prefix...)
		span.EndKey = append(span.EndKey, encoding.EncodeVarintAscending(nil, int64(end))...)
		return TableReaderSpan{Span: span}
	}

	testCases := []struct {
		spec     TableReaderSpec
		expected string
	}{
		{
			spec: TableReaderSpec{
				Filter:        Expression{Expr: "@3 < 5 AND @2 != 3"}, // sum < 5 && b != 3
				OutputColumns: []uint32{0, 1},
			},
			expected: "[[0 1] [0 2] [0 4] [1 0] [1 1] [1 2] [2 0] [2 1] [2 2] [3 0] [3 1] [4 0]]",
		},
		{
			spec: TableReaderSpec{
				Filter:        Expression{Expr: "@3 < 5 AND @2 != 3"},
				OutputColumns: []uint32{3}, // s
				HardLimit:     4,
			},
			expected: "[['one'] ['two'] ['four'] ['one-zero']]",
		},
		{
			spec: TableReaderSpec{
				IndexIdx:      1,
				Reverse:       true,
				Spans:         []TableReaderSpan{makeIndexSpan(4, 6)},
				Filter:        Expression{Expr: "@1 < 3"}, // sum < 8
				OutputColumns: []uint32{0, 1},
				SoftLimit:     1,
			},
			expected: "[[2 5] [1 5] [0 5] [2 4] [1 4] [0 4]]",
		},
	}

	for _, c := range testCases {
		ts := c.spec
		ts.Table = *td

		txn := client.NewTxn(context.Background(), *kvDB)
		flowCtx := FlowCtx{
			Context: context.Background(),
			evalCtx: &parser.EvalContext{},
			txn:     txn,
		}

		out := &RowBuffer{}
		tr, err := newTableReader(&flowCtx, &ts, out)
		if err != nil {
			t.Fatal(err)
		}
		tr.Run(nil)
		if out.err != nil {
			t.Fatal(out.err)
		}
		if !out.closed {
			t.Fatalf("output RowReceiver not closed")
		}
		if result := out.rows.String(); result != c.expected {
			t.Errorf("invalid results: %s, expected %s'", result, c.expected)
		}
	}
}