Add "proposed" optional flag to getValidatorsAt (#3531)

Signed-off-by: Ian Suvak <[email protected]>
Co-authored-by: Stephen Buttolph <[email protected]>

RELEASES.md

@@ -6,6 +6,7 @@
 
 - Added `platform.getL1Validator`
 - Added `platform.getProposedHeight`
+- Updated `platform.getValidatorsAt` to accept `"proposed"` as valid `height` input
 
 ### Configs
 

tests/e2e/p/l1.go

@@ -44,6 +44,7 @@ import (
 	p2ppb "github.com/ava-labs/avalanchego/proto/pb/p2p"
 	platformvmpb "github.com/ava-labs/avalanchego/proto/pb/platformvm"
 	snowvalidators "github.com/ava-labs/avalanchego/snow/validators"
+	platformapi "github.com/ava-labs/avalanchego/vms/platformvm/api"
 	platformvmvalidators "github.com/ava-labs/avalanchego/vms/platformvm/validators"
 	warpmessage "github.com/ava-labs/avalanchego/vms/platformvm/warp/message"
 )
@@ -156,7 +157,7 @@ var _ = e2e.DescribePChain("[L1]", func() {
 			height, err := pClient.GetHeight(tc.DefaultContext())
 			require.NoError(err)
 
-			subnetValidators, err := pClient.GetValidatorsAt(tc.DefaultContext(), subnetID, height)
+			subnetValidators, err := pClient.GetValidatorsAt(tc.DefaultContext(), subnetID, platformapi.Height(height))
 			require.NoError(err)
 			require.Equal(expectedValidators, subnetValidators)
 		}

tests/e2e/p/validator_sets.go

@@ -18,6 +18,8 @@ import (
 	"github.com/ava-labs/avalanchego/vms/platformvm"
 	"github.com/ava-labs/avalanchego/vms/platformvm/txs"
 	"github.com/ava-labs/avalanchego/vms/secp256k1fx"
+
+	platformapi "github.com/ava-labs/avalanchego/vms/platformvm/api"
 )
 
 var _ = e2e.DescribePChain("[Validator Sets]", func() {
@@ -101,7 +103,7 @@ var _ = e2e.DescribePChain("[Validator Sets]", func() {
 					validatorSet, err := pvmClient.GetValidatorsAt(
 						tc.DefaultContext(),
 						constants.PrimaryNetworkID,
-						height,
+						platformapi.Height(height),
 					)
 					require.NoError(err)
 					if observedValidatorSet == nil {

vms/platformvm/api/height.go

@@ -0,0 +1,49 @@
+// Copyright (C) 2019-2024, Ava Labs, Inc. All rights reserved.
+// See the file LICENSE for licensing terms.
+
+package api
+
+import (
+	"errors"
+	"math"
+
+	avajson "github.com/ava-labs/avalanchego/utils/json"
+)
+
+type Height avajson.Uint64
+
+const (
+	ProposedHeightFlag = "proposed"
+	ProposedHeight     = math.MaxUint64
+)
+
+var errInvalidHeight = errors.New("invalid height")
+
+func (h Height) MarshalJSON() ([]byte, error) {
+	if h == ProposedHeight {
+		return []byte(`"` + ProposedHeightFlag + `"`), nil
+	}
+	return avajson.Uint64(h).MarshalJSON()
+}
+
+func (h *Height) UnmarshalJSON(b []byte) error {
+	if string(b) == ProposedHeightFlag {
+		*h = ProposedHeight
+		return nil
+	}
+	err := (*avajson.Uint64)(h).UnmarshalJSON(b)
+	if err != nil {
+		return errInvalidHeight
+	}
+	// MaxUint64 is reserved for proposed height
+	// return an error if supplied numerically
+	if uint64(*h) == ProposedHeight {
+		*h = 0
+		return errInvalidHeight
+	}
+	return nil
+}
+
+func (h Height) IsProposed() bool {
+	return h == ProposedHeight
+}

vms/platformvm/api/height_test.go

@@ -0,0 +1,45 @@
+// Copyright (C) 2019-2024, Ava Labs, Inc. All rights reserved.
+// See the file LICENSE for licensing terms.
+
+package api
+
+import (
+	"strconv"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestMarshallHeight(t *testing.T) {
+	require := require.New(t)
+	h := Height(56)
+	bytes, err := h.MarshalJSON()
+	require.NoError(err)
+	require.Equal(`"56"`, string(bytes))
+
+	h = Height(ProposedHeight)
+	bytes, err = h.MarshalJSON()
+	require.NoError(err)
+	require.Equal(`"proposed"`, string(bytes))
+}
+
+func TestUnmarshallHeight(t *testing.T) {
+	require := require.New(t)
+
+	var h Height
+
+	require.NoError(h.UnmarshalJSON([]byte("56")))
+	require.Equal(Height(56), h)
+
+	require.NoError(h.UnmarshalJSON([]byte(ProposedHeightFlag)))
+	require.Equal(Height(ProposedHeight), h)
+	require.True(h.IsProposed())
+
+	err := h.UnmarshalJSON([]byte("invalid"))
+	require.ErrorIs(err, errInvalidHeight)
+	require.Equal(Height(0), h)
+
+	err = h.UnmarshalJSON([]byte(`"` + strconv.FormatUint(uint64(ProposedHeight), 10) + `"`))
+	require.ErrorIs(err, errInvalidHeight)
+	require.Equal(Height(0), h)
+}

vms/platformvm/client.go

@@ -21,6 +21,8 @@ import (
 	"github.com/ava-labs/avalanchego/vms/platformvm/fx"
 	"github.com/ava-labs/avalanchego/vms/platformvm/status"
 	"github.com/ava-labs/avalanchego/vms/secp256k1fx"
+
+	platformapi "github.com/ava-labs/avalanchego/vms/platformvm/api"
 )
 
 var _ Client = (*client)(nil)
@@ -119,11 +121,12 @@ type Client interface {
 	// GetTimestamp returns the current chain timestamp
 	GetTimestamp(ctx context.Context, options ...rpc.Option) (time.Time, error)
 	// GetValidatorsAt returns the weights of the validator set of a provided
-	// subnet at the specified height.
+	// subnet at the specified height or at proposerVM height if set to
+	// [platformapi.ProposedHeight]
 	GetValidatorsAt(
 		ctx context.Context,
 		subnetID ids.ID,
-		height uint64,
+		height platformapi.Height,
 		options ...rpc.Option,
 	) (map[ids.NodeID]*validators.GetValidatorOutput, error)
 	// GetBlock returns the block with the given id.
@@ -572,13 +575,13 @@ func (c *client) GetTimestamp(ctx context.Context, options ...rpc.Option) (time.
 func (c *client) GetValidatorsAt(
 	ctx context.Context,
 	subnetID ids.ID,
-	height uint64,
+	height platformapi.Height,
 	options ...rpc.Option,
 ) (map[ids.NodeID]*validators.GetValidatorOutput, error) {
 	res := &GetValidatorsAtReply{}
 	err := c.requester.SendRequest(ctx, "platform.getValidatorsAt", &GetValidatorsAtArgs{
 		SubnetID: subnetID,
-		Height:   json.Uint64(height),
+		Height:   height,
 	}, res, options...)
 	return res.Validators, err
 }

vms/platformvm/service.go

@@ -1792,8 +1792,8 @@ func (s *Service) GetTimestamp(_ *http.Request, _ *struct{}, reply *GetTimestamp
 
 // GetValidatorsAtArgs is the response from GetValidatorsAt
 type GetValidatorsAtArgs struct {
-	Height   avajson.Uint64 `json:"height"`
-	SubnetID ids.ID         `json:"subnetID"`
+	Height   platformapi.Height `json:"height"`
+	SubnetID ids.ID             `json:"subnetID"`
 }
 
 type jsonGetValidatorOutput struct {
@@ -1863,11 +1863,11 @@ type GetValidatorsAtReply struct {
 // GetValidatorsAt returns the weights of the validator set of a provided subnet
 // at the specified height.
 func (s *Service) GetValidatorsAt(r *http.Request, args *GetValidatorsAtArgs, reply *GetValidatorsAtReply) error {
-	height := uint64(args.Height)
 	s.vm.ctx.Log.Debug("API called",
 		zap.String("service", "platform"),
 		zap.String("method", "getValidatorsAt"),
-		zap.Uint64("height", height),
+		zap.Uint64("height", uint64(args.Height)),
+		zap.Bool("isProposed", args.Height.IsProposed()),
 		zap.Stringer("subnetID", args.SubnetID),
 	)
 
@@ -1876,6 +1876,14 @@ func (s *Service) GetValidatorsAt(r *http.Request, args *GetValidatorsAtArgs, re
 
 	ctx := r.Context()
 	var err error
+	height := uint64(args.Height)
+	if args.Height.IsProposed() {
+		height, err = s.vm.GetMinimumHeight(ctx)
+		if err != nil {
+			return fmt.Errorf("failed to get proposed height: %w", err)
+		}
+	}
+
 	reply.Validators, err = s.vm.GetValidatorSet(ctx, height, args.SubnetID)
 	if err != nil {
 		return fmt.Errorf("failed to get validator set: %w", err)

vms/platformvm/service.md

@@ -1891,13 +1891,14 @@ Get the validators and their weights of a Subnet or the Primary Network at a giv
 ```sh
 platform.getValidatorsAt(
     {
-        height: int,
+        height: [int|string],
         subnetID: string, // optional
     }
 )
 ```
 
-- `height` is the P-Chain height to get the validator set at.
+- `height` is the P-Chain height to get the validator set at, or the string literal "proposed"
+  to return the validator set at this node's ProposerVM height. 
 - `subnetID` is the Subnet ID to get the validator set of. If not given, gets validator set of the
   Primary Network.
 

vms/platformvm/service_test.go

@@ -819,6 +819,99 @@ func TestGetCurrentValidators(t *testing.T) {
 	}
 }
 
+func TestGetValidatorsAt(t *testing.T) {
+	require := require.New(t)
+	service, _ := defaultService(t, upgradetest.Latest)
+
+	genesis := genesistest.New(t, genesistest.Config{})
+
+	args := GetValidatorsAtArgs{}
+	response := GetValidatorsAtReply{}
+
+	service.vm.ctx.Lock.Lock()
+	lastAccepted := service.vm.manager.LastAccepted()
+	lastAcceptedBlk, err := service.vm.manager.GetBlock(lastAccepted)
+	require.NoError(err)
+
+	service.vm.ctx.Lock.Unlock()
+
+	// Confirm that it returns the genesis validators given the latest height
+	args.Height = pchainapi.Height(lastAcceptedBlk.Height())
+	require.NoError(service.GetValidatorsAt(&http.Request{}, &args, &response))
+	require.Len(response.Validators, len(genesis.Validators))
+
+	service.vm.ctx.Lock.Lock()
+
+	wallet := newWallet(t, service.vm, walletConfig{})
+	rewardsOwner := &secp256k1fx.OutputOwners{
+		Threshold: 1,
+		Addrs:     []ids.ShortID{ids.GenerateTestShortID()},
+	}
+
+	sk, err := bls.NewSecretKey()
+	require.NoError(err)
+
+	tx, err := wallet.IssueAddPermissionlessValidatorTx(
+		&txs.SubnetValidator{
+			Validator: txs.Validator{
+				NodeID: ids.GenerateTestNodeID(),
+				Start:  uint64(service.vm.clock.Time().Add(txexecutor.SyncBound).Unix()),
+				End:    uint64(service.vm.clock.Time().Add(txexecutor.SyncBound).Add(defaultMinStakingDuration).Unix()),
+				Wght:   service.vm.MinValidatorStake,
+			},
+			Subnet: constants.PrimaryNetworkID,
+		},
+		signer.NewProofOfPossession(sk),
+		service.vm.ctx.AVAXAssetID,
+		rewardsOwner,
+		rewardsOwner,
+		0,
+		common.WithMemo([]byte{}),
+	)
+
+	require.NoError(err)
+
+	service.vm.ctx.Lock.Unlock()
+	require.NoError(service.vm.Network.IssueTxFromRPC(tx))
+	service.vm.ctx.Lock.Lock()
+
+	block, err := service.vm.BuildBlock(context.Background())
+	require.NoError(err)
+
+	blk := block.(*blockexecutor.Block)
+	require.NoError(blk.Verify(context.Background()))
+
+	require.NoError(blk.Accept(context.Background()))
+	service.vm.ctx.Lock.Unlock()
+
+	newLastAccepted := service.vm.manager.LastAccepted()
+	newLastAcceptedBlk, err := service.vm.manager.GetBlock(newLastAccepted)
+	require.NoError(err)
+	require.NotEqual(newLastAccepted, lastAccepted)
+
+	// Confirm that it returns the genesis validators + the new validator given the latest height
+	args.Height = pchainapi.Height(newLastAcceptedBlk.Height())
+	require.NoError(service.GetValidatorsAt(&http.Request{}, &args, &response))
+	require.Len(response.Validators, len(genesis.Validators)+1)
+
+	// Confirm that [IsProposed] works. The proposed height should be the genesis height
+	args.Height = pchainapi.Height(pchainapi.ProposedHeight)
+	require.NoError(service.GetValidatorsAt(&http.Request{}, &args, &response))
+	require.Len(response.Validators, len(genesis.Validators))
+
+	service.vm.ctx.Lock.Lock()
+
+	// set clock beyond the [validators.recentlyAcceptedWindowTTL] to bump the
+	// proposerVM height
+	service.vm.clock.Set(newLastAcceptedBlk.Timestamp().Add(40 * time.Second))
+	service.vm.ctx.Lock.Unlock()
+
+	// Resending the same request with [IsProposed] set to true should now
+	// include the new validator
+	require.NoError(service.GetValidatorsAt(&http.Request{}, &args, &response))
+	require.Len(response.Validators, len(genesis.Validators)+1)
+}
+
 func TestGetTimestamp(t *testing.T) {
 	require := require.New(t)
 	service, _ := defaultService(t, upgradetest.Latest)