Add SoV state struct (#3370)

Signed-off-by: Dhruba Basu <[email protected]>
Co-authored-by: dhrubabasu <[email protected]>

vms/platformvm/state/subnet_only_validator.go

@@ -0,0 +1,96 @@
+// Copyright (C) 2019-2024, Ava Labs, Inc. All rights reserved.
+// See the file LICENSE for licensing terms.
+
+package state
+
+import (
+	"fmt"
+
+	"github.com/google/btree"
+
+	"github.com/ava-labs/avalanchego/database"
+	"github.com/ava-labs/avalanchego/ids"
+	"github.com/ava-labs/avalanchego/vms/platformvm/block"
+)
+
+var _ btree.LessFunc[*SubnetOnlyValidator] = (*SubnetOnlyValidator).Less
+
+type SubnetOnlyValidator struct {
+	// ValidationID is not serialized because it is used as the key in the
+	// database, so it doesn't need to be stored in the value.
+	ValidationID ids.ID
+
+	SubnetID ids.ID     `serialize:"true"`
+	NodeID   ids.NodeID `serialize:"true"`
+
+	// PublicKey is the uncompressed BLS public key of the validator. It is
+	// guaranteed to be populated.
+	PublicKey []byte `serialize:"true"`
+
+	// StartTime is the unix timestamp, in seconds, when this validator was
+	// added to the set.
+	StartTime uint64 `serialize:"true"`
+
+	// Weight of this validator. It can be updated when the MinNonce is
+	// increased. If the weight is being set to 0, the validator is being
+	// removed.
+	Weight uint64 `serialize:"true"`
+
+	// MinNonce is the smallest nonce that can be used to modify this
+	// validator's weight. It is initially set to 0 and is set to one higher
+	// than the last nonce used. It is not valid to use nonce MaxUint64 unless
+	// the weight is being set to 0, which removes the validator from the set.
+	MinNonce uint64 `serialize:"true"`
+
+	// EndAccumulatedFee is the amount of globally accumulated fees that can
+	// accrue before this validator must be deactivated. It is equal to the
+	// amount of fees this validator is willing to pay plus the amount of
+	// globally accumulated fees when this validator started validating.
+	EndAccumulatedFee uint64 `serialize:"true"`
+}
+
+// Less determines a canonical ordering of *SubnetOnlyValidators based on their
+// EndAccumulatedFees and ValidationIDs.
+//
+// Returns true if:
+//
+//  1. This validator has a lower EndAccumulatedFee than the other.
+//  2. This validator has an equal EndAccumulatedFee to the other and has a
+//     lexicographically lower ValidationID.
+func (v *SubnetOnlyValidator) Less(o *SubnetOnlyValidator) bool {
+	switch {
+	case v.EndAccumulatedFee < o.EndAccumulatedFee:
+		return true
+	case o.EndAccumulatedFee < v.EndAccumulatedFee:
+		return false
+	default:
+		return v.ValidationID.Compare(o.ValidationID) == -1
+	}
+}
+
+func getSubnetOnlyValidator(db database.KeyValueReader, validationID ids.ID) (*SubnetOnlyValidator, error) {
+	bytes, err := db.Get(validationID[:])
+	if err != nil {
+		return nil, err
+	}
+
+	vdr := &SubnetOnlyValidator{
+		ValidationID: validationID,
+	}
+	if _, err = block.GenesisCodec.Unmarshal(bytes, vdr); err != nil {
+		return nil, fmt.Errorf("failed to unmarshal SubnetOnlyValidator: %w", err)
+	}
+	return vdr, err
+}
+
+func putSubnetOnlyValidator(db database.KeyValueWriter, vdr *SubnetOnlyValidator) error {
+	bytes, err := block.GenesisCodec.Marshal(block.CodecVersion, vdr)
+	if err != nil {
+		return fmt.Errorf("failed to marshal SubnetOnlyValidator: %w", err)
+	}
+	return db.Put(vdr.ValidationID[:], bytes)
+}
+
+func deleteSubnetOnlyValidator(db database.KeyValueDeleter, validationID ids.ID) error {
+	return db.Delete(validationID[:])
+}

vms/platformvm/state/subnet_only_validator_test.go

@@ -0,0 +1,113 @@
+// Copyright (C) 2019-2024, Ava Labs, Inc. All rights reserved.
+// See the file LICENSE for licensing terms.
+
+package state
+
+import (
+	"math/rand"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+
+	"github.com/ava-labs/avalanchego/database"
+	"github.com/ava-labs/avalanchego/database/memdb"
+	"github.com/ava-labs/avalanchego/ids"
+	"github.com/ava-labs/avalanchego/utils/crypto/bls"
+)
+
+func TestSubnetOnlyValidator_Less(t *testing.T) {
+	tests := []struct {
+		name  string
+		v     *SubnetOnlyValidator
+		o     *SubnetOnlyValidator
+		equal bool
+	}{
+		{
+			name: "v.EndAccumulatedFee < o.EndAccumulatedFee",
+			v: &SubnetOnlyValidator{
+				ValidationID:      ids.GenerateTestID(),
+				EndAccumulatedFee: 1,
+			},
+			o: &SubnetOnlyValidator{
+				ValidationID:      ids.GenerateTestID(),
+				EndAccumulatedFee: 2,
+			},
+			equal: false,
+		},
+		{
+			name: "v.EndAccumulatedFee = o.EndAccumulatedFee, v.ValidationID < o.ValidationID",
+			v: &SubnetOnlyValidator{
+				ValidationID:      ids.ID{0},
+				EndAccumulatedFee: 1,
+			},
+			o: &SubnetOnlyValidator{
+				ValidationID:      ids.ID{1},
+				EndAccumulatedFee: 1,
+			},
+			equal: false,
+		},
+		{
+			name: "v.EndAccumulatedFee = o.EndAccumulatedFee, v.ValidationID = o.ValidationID",
+			v: &SubnetOnlyValidator{
+				ValidationID:      ids.ID{0},
+				EndAccumulatedFee: 1,
+			},
+			o: &SubnetOnlyValidator{
+				ValidationID:      ids.ID{0},
+				EndAccumulatedFee: 1,
+			},
+			equal: true,
+		},
+	}
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			require := require.New(t)
+
+			less := test.v.Less(test.o)
+			require.Equal(!test.equal, less)
+
+			greater := test.o.Less(test.v)
+			require.False(greater)
+		})
+	}
+}
+
+func TestSubnetOnlyValidator_DatabaseHelpers(t *testing.T) {
+	require := require.New(t)
+	db := memdb.New()
+
+	sk, err := bls.NewSecretKey()
+	require.NoError(err)
+
+	vdr := &SubnetOnlyValidator{
+		ValidationID:      ids.GenerateTestID(),
+		SubnetID:          ids.GenerateTestID(),
+		NodeID:            ids.GenerateTestNodeID(),
+		PublicKey:         bls.PublicKeyToUncompressedBytes(bls.PublicFromSecretKey(sk)),
+		StartTime:         rand.Uint64(), // #nosec G404
+		Weight:            rand.Uint64(), // #nosec G404
+		MinNonce:          rand.Uint64(), // #nosec G404
+		EndAccumulatedFee: rand.Uint64(), // #nosec G404
+	}
+
+	// Validator hasn't been put on disk yet
+	gotVdr, err := getSubnetOnlyValidator(db, vdr.ValidationID)
+	require.ErrorIs(err, database.ErrNotFound)
+	require.Nil(gotVdr)
+
+	// Place the validator on disk
+	require.NoError(putSubnetOnlyValidator(db, vdr))
+
+	// Verify that the validator can be fetched from disk
+	gotVdr, err = getSubnetOnlyValidator(db, vdr.ValidationID)
+	require.NoError(err)
+	require.Equal(vdr, gotVdr)
+
+	// Remove the validator from disk
+	require.NoError(deleteSubnetOnlyValidator(db, vdr.ValidationID))
+
+	// Verify that the validator has been removed from disk
+	gotVdr, err = getSubnetOnlyValidator(db, vdr.ValidationID)
+	require.ErrorIs(err, database.ErrNotFound)
+	require.Nil(gotVdr)
+}