Allow Foundation subsidy to be waived

consensus/state.go

@@ -97,13 +97,13 @@ func (n *Network) GenesisState() State {
 		ChildTarget:    n.InitialTarget,
 		SiafundPool:    types.ZeroCurrency,
 
-		OakTime:                   0,
-		OakTarget:                 intToTarget(maxTarget),
-		FoundationPrimaryAddress:  n.HardforkFoundation.PrimaryAddress,
-		FoundationFailsafeAddress: n.HardforkFoundation.FailsafeAddress,
-		TotalWork:                 Work{invTarget(intToTarget(maxTarget))},
-		Difficulty:                Work{invTarget(n.InitialTarget)},
-		OakWork:                   Work{invTarget(intToTarget(maxTarget))},
+		OakTime:                     0,
+		OakTarget:                   intToTarget(maxTarget),
+		FoundationSubsidyAddress:    n.HardforkFoundation.PrimaryAddress,
+		FoundationManagementAddress: n.HardforkFoundation.FailsafeAddress,
+		TotalWork:                   Work{invTarget(intToTarget(maxTarget))},
+		Difficulty:                  Work{invTarget(n.InitialTarget)},
+		OakWork:                     Work{invTarget(intToTarget(maxTarget))},
 	}
 }
 
@@ -121,8 +121,8 @@ type State struct {
 	OakTime   time.Duration `json:"oakTime"`
 	OakTarget types.BlockID `json:"oakTarget"`
 	// Foundation hardfork state
-	FoundationPrimaryAddress  types.Address `json:"foundationPrimaryAddress"`
-	FoundationFailsafeAddress types.Address `json:"foundationFailsafeAddress"`
+	FoundationSubsidyAddress    types.Address `json:"foundationSubsidyAddress"`
+	FoundationManagementAddress types.Address `json:"foundationManagementAddress"`
 	// v2 hardfork state
 	TotalWork    Work               `json:"totalWork"`
 	Difficulty   Work               `json:"difficulty"`
@@ -143,8 +143,8 @@ func (s State) EncodeTo(e *types.Encoder) {
 
 	e.WriteUint64(uint64(s.OakTime))
 	s.OakTarget.EncodeTo(e)
-	s.FoundationPrimaryAddress.EncodeTo(e)
-	s.FoundationFailsafeAddress.EncodeTo(e)
+	s.FoundationSubsidyAddress.EncodeTo(e)
+	s.FoundationManagementAddress.EncodeTo(e)
 	s.TotalWork.EncodeTo(e)
 	s.Difficulty.EncodeTo(e)
 	s.OakWork.EncodeTo(e)
@@ -164,8 +164,8 @@ func (s *State) DecodeFrom(d *types.Decoder) {
 
 	s.OakTime = time.Duration(d.ReadUint64())
 	s.OakTarget.DecodeFrom(d)
-	s.FoundationPrimaryAddress.DecodeFrom(d)
-	s.FoundationFailsafeAddress.DecodeFrom(d)
+	s.FoundationSubsidyAddress.DecodeFrom(d)
+	s.FoundationManagementAddress.DecodeFrom(d)
 	s.TotalWork.DecodeFrom(d)
 	s.Difficulty.DecodeFrom(d)
 	s.OakWork.DecodeFrom(d)
@@ -257,22 +257,23 @@ func (s State) AncestorDepth() uint64 {
 }
 
 // FoundationSubsidy returns the Foundation subsidy output for the child block.
-// If no subsidy is due, the returned output has a value of zero.
 func (s State) FoundationSubsidy() (sco types.SiacoinOutput, exists bool) {
-	sco.Address = s.FoundationPrimaryAddress
-
+	if s.FoundationSubsidyAddress == types.VoidAddress {
+		return types.SiacoinOutput{}, false
+	}
+	sco.Address = s.FoundationSubsidyAddress
 	subsidyPerBlock := types.Siacoins(30000)
 	blocksPerYear := uint64(365 * 24 * time.Hour / s.BlockInterval())
 	blocksPerMonth := blocksPerYear / 12
 	hardforkHeight := s.Network.HardforkFoundation.Height
 	if s.childHeight() < hardforkHeight || (s.childHeight()-hardforkHeight)%blocksPerMonth != 0 {
-		sco.Value = types.ZeroCurrency
+		return types.SiacoinOutput{}, false
 	} else if s.childHeight() == hardforkHeight {
 		sco.Value = subsidyPerBlock.Mul64(blocksPerYear)
 	} else {
 		sco.Value = subsidyPerBlock.Mul64(blocksPerMonth)
 	}
-	return sco, !sco.Value.IsZero()
+	return sco, true
 }
 
 // NonceFactor is the factor by which all block nonces must be divisible.
@@ -342,6 +343,9 @@ func (s State) V2TransactionWeight(txn types.V2Transaction) uint64 {
 		a.EncodeTo(e)
 	}
 	e.Write(txn.ArbitraryData)
+	if txn.NewFoundationAddress != nil {
+		txn.NewFoundationAddress.EncodeTo(e)
+	}
 	e.Flush()
 	return uint64(wc.n)
 }
@@ -588,16 +592,16 @@ func (s State) AttestationSigHash(a types.Attestation) types.Hash256 {
 
 // A MidState represents the state of the chain within a block.
 type MidState struct {
-	base               State
-	created            map[types.ElementID]int // indices into element slices
-	spends             map[types.ElementID]types.TransactionID
-	revs               map[types.FileContractID]*types.FileContractElement
-	res                map[types.FileContractID]bool
-	v2revs             map[types.FileContractID]*types.V2FileContractElement
-	v2res              map[types.FileContractID]types.V2FileContractResolutionType
-	siafundPool        types.Currency
-	foundationPrimary  types.Address
-	foundationFailsafe types.Address
+	base                 State
+	created              map[types.ElementID]int // indices into element slices
+	spends               map[types.ElementID]types.TransactionID
+	revs                 map[types.FileContractID]*types.FileContractElement
+	res                  map[types.FileContractID]bool
+	v2revs               map[types.FileContractID]*types.V2FileContractElement
+	v2res                map[types.FileContractID]types.V2FileContractResolutionType
+	siafundPool          types.Currency
+	foundationSubsidy    types.Address
+	foundationManagement types.Address
 
 	// elements created/updated by block
 	sces   []types.SiacoinElement
@@ -650,16 +654,16 @@ func (ms *MidState) isCreated(id types.ElementID) bool {
 // NewMidState constructs a MidState initialized to the provided base state.
 func NewMidState(s State) *MidState {
 	return &MidState{
-		base:               s,
-		created:            make(map[types.ElementID]int),
-		spends:             make(map[types.ElementID]types.TransactionID),
-		revs:               make(map[types.FileContractID]*types.FileContractElement),
-		res:                make(map[types.FileContractID]bool),
-		v2revs:             make(map[types.FileContractID]*types.V2FileContractElement),
-		v2res:              make(map[types.FileContractID]types.V2FileContractResolutionType),
-		siafundPool:        s.SiafundPool,
-		foundationPrimary:  s.FoundationPrimaryAddress,
-		foundationFailsafe: s.FoundationFailsafeAddress,
+		base:                 s,
+		created:              make(map[types.ElementID]int),
+		spends:               make(map[types.ElementID]types.TransactionID),
+		revs:                 make(map[types.FileContractID]*types.FileContractElement),
+		res:                  make(map[types.FileContractID]bool),
+		v2revs:               make(map[types.FileContractID]*types.V2FileContractElement),
+		v2res:                make(map[types.FileContractID]types.V2FileContractResolutionType),
+		siafundPool:          s.SiafundPool,
+		foundationSubsidy:    s.FoundationSubsidyAddress,
+		foundationManagement: s.FoundationManagementAddress,
 	}
 }
 

consensus/update.go

@@ -509,8 +509,8 @@ func (ms *MidState) ApplyTransaction(txn types.Transaction, ts V1TransactionSupp
 			if bytes.HasPrefix(arb, types.SpecifierFoundation[:]) {
 				var update types.FoundationAddressUpdate
 				update.DecodeFrom(types.NewBufDecoder(arb[len(types.SpecifierFoundation):]))
-				ms.foundationPrimary = update.NewPrimary
-				ms.foundationFailsafe = update.NewFailsafe
+				ms.foundationSubsidy = update.NewPrimary
+				ms.foundationManagement = update.NewFailsafe
 			}
 		}
 	}
@@ -568,8 +568,13 @@ func (ms *MidState) ApplyV2Transaction(txn types.V2Transaction) {
 		})
 	}
 	if txn.NewFoundationAddress != nil {
-		ms.foundationPrimary = *txn.NewFoundationAddress
-		ms.foundationFailsafe = *txn.NewFoundationAddress
+		// The subsidy may be waived by sending it to the void address. In this
+		// case, the management address is not updated (as this would
+		// permanently disable the subsidy).
+		ms.foundationSubsidy = *txn.NewFoundationAddress
+		if *txn.NewFoundationAddress != types.VoidAddress {
+			ms.foundationManagement = *txn.NewFoundationAddress
+		}
 	}
 }
 
@@ -738,8 +743,8 @@ func ApplyBlock(s State, b types.Block, bs V1BlockSupplement, targetTimestamp ti
 	ms.ApplyBlock(b, bs)
 	s.SiafundPool = ms.siafundPool
 	s.Attestations += uint64(len(ms.aes))
-	s.FoundationPrimaryAddress = ms.foundationPrimary
-	s.FoundationFailsafeAddress = ms.foundationFailsafe
+	s.FoundationSubsidyAddress = ms.foundationSubsidy
+	s.FoundationManagementAddress = ms.foundationManagement
 
 	// compute updated and added elements
 	var updated, added []elementLeaf

consensus/update_test.go

@@ -1296,3 +1296,123 @@ func TestApplyRevertBlockV2(t *testing.T) {
 		checkUpdateElements(au, addedSCEs, spentSCEs, addedSFEs, spentSFEs)
 	}
 }
+
+func TestFoundationSubsidy(t *testing.T) {
+	key := types.GeneratePrivateKey()
+	addr := types.StandardAddress(key.PublicKey())
+	n, genesisBlock := testnet()
+	n.HardforkFoundation.Height = 1
+	n.HardforkFoundation.PrimaryAddress = addr
+	n.HardforkFoundation.FailsafeAddress = addr
+	n.HardforkV2.AllowHeight = 1
+	n.HardforkV2.RequireHeight = 1
+	n.BlockInterval = 10 * time.Hour // subsidies every 10 blocks
+	subsidyInterval := uint64(365 * 24 * time.Hour / n.BlockInterval / 12)
+	genesisBlock.Transactions = []types.Transaction{{
+		SiacoinOutputs: []types.SiacoinOutput{{
+			Address: addr,
+			Value:   types.Siacoins(1), // funds for changing address later
+		}},
+	}}
+	scoid := genesisBlock.Transactions[0].SiacoinOutputID(0)
+
+	db, cs := newConsensusDB(n, genesisBlock)
+	mineBlock := func(txns []types.V2Transaction) (subsidy types.SiacoinElement, exists bool) {
+		b := types.Block{
+			ParentID:     cs.Index.ID,
+			Timestamp:    types.CurrentTimestamp(),
+			MinerPayouts: []types.SiacoinOutput{{Address: types.VoidAddress, Value: cs.BlockReward()}},
+			V2: &types.V2BlockData{
+				Height:       cs.Index.Height + 1,
+				Commitment:   cs.Commitment(cs.TransactionsCommitment(nil, txns), types.VoidAddress),
+				Transactions: txns,
+			},
+		}
+		bs := db.supplementTipBlock(b)
+		findBlockNonce(cs, &b)
+		if err := ValidateBlock(cs, b, bs); err != nil {
+			t.Fatal(err)
+			return
+		}
+		var au ApplyUpdate
+		cs, au = ApplyBlock(cs, b, bs, db.ancestorTimestamp(b.ParentID))
+		db.applyBlock(au)
+		au.ForEachSiacoinElement(func(sce types.SiacoinElement, created, _ bool) {
+			if created && sce.SiacoinOutput.Address == addr {
+				subsidy = sce
+				exists = true
+			}
+		})
+		return
+	}
+
+	// receive initial subsidy
+	initialSubsidy, ok := mineBlock(nil)
+	if !ok {
+		t.Fatal("expected subsidy")
+	}
+
+	// mine until we receive a normal subsidy
+	for range subsidyInterval - 1 {
+		if _, ok := mineBlock(nil); ok {
+			t.Fatal("unexpected subsidy")
+		}
+	}
+	subsidy, ok := mineBlock(nil)
+	if !ok {
+		t.Fatal("expected subsidy")
+	} else if subsidy.SiacoinOutput.Value != initialSubsidy.SiacoinOutput.Value.Div64(12) {
+		t.Fatal("expected subsidy to be 1/12 of initial subsidy")
+	}
+	// disable subsidy
+	txn := types.V2Transaction{
+		SiacoinInputs: []types.V2SiacoinInput{{
+			Parent: db.sces[scoid],
+			SatisfiedPolicy: types.SatisfiedPolicy{
+				Policy: types.PolicyPublicKey(key.PublicKey()),
+			},
+		}},
+		SiacoinOutputs: []types.SiacoinOutput{{
+			Address: addr,
+			Value:   db.sces[scoid].SiacoinOutput.Value,
+		}},
+		NewFoundationAddress: &types.VoidAddress,
+	}
+	txn.SiacoinInputs[0].SatisfiedPolicy.Signatures = []types.Signature{key.SignHash(cs.InputSigHash(txn))}
+	scoid = txn.SiacoinOutputID(txn.ID(), 0)
+	mineBlock([]types.V2Transaction{txn})
+
+	// mine until we would receive another subsidy
+	for range subsidyInterval {
+		if _, ok := mineBlock(nil); ok {
+			t.Fatal("unexpected subsidy")
+		}
+	}
+
+	// re-enable subsidy
+	txn = types.V2Transaction{
+		SiacoinInputs: []types.V2SiacoinInput{{
+			Parent: db.sces[scoid],
+			SatisfiedPolicy: types.SatisfiedPolicy{
+				Policy: types.PolicyPublicKey(key.PublicKey()),
+			},
+		}},
+		SiacoinOutputs: []types.SiacoinOutput{{
+			Address: addr,
+			Value:   db.sces[scoid].SiacoinOutput.Value,
+		}},
+		NewFoundationAddress: &addr,
+	}
+	txn.SiacoinInputs[0].SatisfiedPolicy.Signatures = []types.Signature{key.SignHash(cs.InputSigHash(txn))}
+	mineBlock([]types.V2Transaction{txn})
+
+	// mine until we would receive another subsidy
+	for range subsidyInterval - 3 {
+		if _, ok := mineBlock(nil); ok {
+			t.Fatal("unexpected subsidy")
+		}
+	}
+	if _, ok := mineBlock(nil); !ok {
+		t.Fatal("expected subsidy")
+	}
+}

consensus/validation.go

@@ -387,7 +387,7 @@ func validateArbitraryData(ms *MidState, txn types.Transaction) error {
 			// check that the transaction is signed by a current key
 			var signed bool
 			for _, sci := range txn.SiacoinInputs {
-				if uh := sci.UnlockConditions.UnlockHash(); uh != ms.base.FoundationPrimaryAddress && uh != ms.base.FoundationFailsafeAddress {
+				if uh := sci.UnlockConditions.UnlockHash(); uh != ms.base.FoundationSubsidyAddress && uh != ms.base.FoundationManagementAddress {
 					continue
 				}
 				for _, sig := range txn.Signatures {
@@ -861,7 +861,7 @@ func validateFoundationUpdate(ms *MidState, txn types.V2Transaction) error {
 		return nil
 	}
 	for _, in := range txn.SiacoinInputs {
-		if in.Parent.SiacoinOutput.Address == ms.base.FoundationPrimaryAddress {
+		if in.Parent.SiacoinOutput.Address == ms.base.FoundationManagementAddress {
 			return nil
 		}
 	}