Exemplo n.º 1
0
// Get returns the value for a specified key.
func (r *Range) Get(batch engine.Engine, args proto.GetRequest) (proto.GetResponse, []proto.Intent, error) {
	var reply proto.GetResponse

	val, intents, err := engine.MVCCGet(batch, args.Key, args.Timestamp, args.ReadConsistency == proto.CONSISTENT, args.Txn)
	reply.Value = val
	return reply, intents, err
}
Exemplo n.º 2
0
// Get returns the value for a specified key.
func (r *Range) Get(batch engine.Engine, args *proto.GetRequest, reply *proto.GetResponse) []proto.Intent {
	val, intents, err := engine.MVCCGet(batch, args.Key, args.Timestamp, args.ReadConsistency == proto.CONSISTENT, args.Txn)
	reply.Value = val
	reply.SetGoError(err)
	return intents
}
Exemplo n.º 3
0
// Get returns the value for a specified key.
func (r *Range) Get(args *proto.GetRequest, reply *proto.GetResponse) {
	val, err := r.engine.Get(args.Key)
	reply.Value = proto.Value{Bytes: val}
	reply.SetGoError(err)
}
Exemplo n.º 4
0
// Get returns the value for a specified key.
func (r *Range) Get(args *proto.GetRequest, reply *proto.GetResponse) {
	val, err := r.mvcc.Get(args.Key, args.Timestamp, args.Txn)
	reply.Value = val
	reply.SetGoError(err)
}
Exemplo n.º 5
0
// verifyUncertainty writes values to a key in 5ns intervals and then launches
// a transaction at each value's timestamp reading that value with
// the maximumOffset given, verifying in the process that the correct values
// are read (usually after one transaction restart).
func verifyUncertainty(concurrency int, maxOffset time.Duration, t *testing.T) {
	db, _, clock, _, lSender, transport, err := createTestDB()
	if err != nil {
		t.Fatal(err)
	}
	defer transport.Close()

	txnOpts := &client.TransactionOptions{
		Name: "test",
	}

	key := []byte("key-test")
	// wgStart waits for all transactions to line up, wgEnd has the main
	// function wait for them to finish.
	var wgStart, wgEnd sync.WaitGroup
	wgStart.Add(concurrency + 1)
	wgEnd.Add(concurrency)

	// Initial high offset to allow for future writes.
	clock.SetMaxOffset(999 * time.Nanosecond)
	for i := 0; i < concurrency; i++ {
		value := []byte(fmt.Sprintf("value-%d", i))
		// Values will be written with 5ns spacing.
		futureTS := clock.Now().Add(5, 0)
		clock.Update(futureTS)
		// Expected number of versions skipped.
		skipCount := int(maxOffset) / 5
		if i+skipCount >= concurrency {
			skipCount = concurrency - i - 1
		}
		readValue := []byte(fmt.Sprintf("value-%d", i+skipCount))
		pr := proto.PutResponse{}
		db.Call(proto.Put, &proto.PutRequest{
			RequestHeader: proto.RequestHeader{
				Key: key,
			},
			Value: proto.Value{Bytes: value},
		}, &pr)
		if err := pr.GoError(); err != nil {
			t.Errorf("%d: got write error: %v", i, err)
		}
		gr := proto.GetResponse{}
		db.Call(proto.Get, &proto.GetRequest{
			RequestHeader: proto.RequestHeader{
				Key:       key,
				Timestamp: clock.Now(),
			},
		}, &gr)
		if gr.GoError() != nil || gr.Value == nil || !bytes.Equal(gr.Value.Bytes, value) {
			t.Fatalf("%d: expected success reading value %+v: %v", i, gr.Value, gr.GoError())
		}

		go func(i int) {
			defer wgEnd.Done()
			wgStart.Done()
			// Wait until the other goroutines are running.
			wgStart.Wait()

			txnManual := hlc.NewManualClock(futureTS.WallTime)
			txnClock := hlc.NewClock(txnManual.UnixNano)
			// Make sure to incorporate the logical component if the wall time
			// hasn't changed (i=0). The logical component will change
			// internally in a way we can't track, but we want to be just
			// ahead.
			txnClock.Update(futureTS.Add(0, 999))
			// The written values are spaced out in intervals of 5ns, so
			// setting <5ns here should make do without any restarts while
			// higher values require roughly offset/5 restarts.
			txnClock.SetMaxOffset(maxOffset)

			sender := NewTxnCoordSender(lSender, txnClock, false)
			txnDB := client.NewKV(sender, nil)
			txnDB.User = storage.UserRoot

			if err := txnDB.RunTransaction(txnOpts, func(txn *client.KV) error {
				// Read within the transaction.
				gr := proto.GetResponse{}
				txn.Call(proto.Get, &proto.GetRequest{
					RequestHeader: proto.RequestHeader{
						Key:       key,
						Timestamp: futureTS,
					},
				}, &gr)
				if err := gr.GoError(); err != nil {
					if _, ok := gr.GoError().(*proto.ReadWithinUncertaintyIntervalError); ok {
						return err
					}
					return util.Errorf("unexpected read error of type %s: %v", reflect.TypeOf(err), err)
				}
				if gr.Value == nil || gr.Value.Bytes == nil {
					return util.Errorf("no value read")
				}
				if !bytes.Equal(gr.Value.Bytes, readValue) {
					return util.Errorf("%d: read wrong value %q at %v, wanted %q", i, gr.Value.Bytes, futureTS, readValue)
				}
				return nil
			}); err != nil {
				t.Error(err)
			}
		}(i)
	}
	// Kick the goroutines loose.
	wgStart.Done()
	// Wait for the goroutines to finish.
	wgEnd.Wait()
}