consensus: Rename SiafundPool -> SiafundTaxRevenue

consensus/state.go

@@ -91,11 +91,11 @@ func (n *Network) GenesisState() State {
 	return State{
 		Network: n,
 
-		Index:          types.ChainIndex{Height: ^uint64(0)},
-		PrevTimestamps: [11]time.Time{},
-		Depth:          intToTarget(maxTarget),
-		ChildTarget:    n.InitialTarget,
-		SiafundPool:    types.ZeroCurrency,
+		Index:             types.ChainIndex{Height: ^uint64(0)},
+		PrevTimestamps:    [11]time.Time{},
+		Depth:             intToTarget(maxTarget),
+		ChildTarget:       n.InitialTarget,
+		SiafundTaxRevenue: types.ZeroCurrency,
 
 		OakTime:                   0,
 		OakTarget:                 intToTarget(maxTarget),
@@ -111,11 +111,11 @@ func (n *Network) GenesisState() State {
 type State struct {
 	Network *Network `json:"-"` // network parameters are not encoded
 
-	Index          types.ChainIndex `json:"index"`
-	PrevTimestamps [11]time.Time    `json:"prevTimestamps"` // newest -> oldest
-	Depth          types.BlockID    `json:"depth"`
-	ChildTarget    types.BlockID    `json:"childTarget"`
-	SiafundPool    types.Currency   `json:"siafundPool"`
+	Index             types.ChainIndex `json:"index"`
+	PrevTimestamps    [11]time.Time    `json:"prevTimestamps"` // newest -> oldest
+	Depth             types.BlockID    `json:"depth"`
+	ChildTarget       types.BlockID    `json:"childTarget"`
+	SiafundTaxRevenue types.Currency   `json:"siafundTaxRevenue"`
 
 	// Oak hardfork state
 	OakTime   time.Duration `json:"oakTime"`
@@ -139,7 +139,7 @@ func (s State) EncodeTo(e *types.Encoder) {
 	}
 	s.Depth.EncodeTo(e)
 	s.ChildTarget.EncodeTo(e)
-	types.V2Currency(s.SiafundPool).EncodeTo(e)
+	types.V2Currency(s.SiafundTaxRevenue).EncodeTo(e)
 
 	e.WriteUint64(uint64(s.OakTime))
 	s.OakTarget.EncodeTo(e)
@@ -160,7 +160,7 @@ func (s *State) DecodeFrom(d *types.Decoder) {
 	}
 	s.Depth.DecodeFrom(d)
 	s.ChildTarget.DecodeFrom(d)
-	(*types.V2Currency)(&s.SiafundPool).DecodeFrom(d)
+	(*types.V2Currency)(&s.SiafundTaxRevenue).DecodeFrom(d)
 
 	s.OakTime = time.Duration(d.ReadUint64())
 	s.OakTarget.DecodeFrom(d)
@@ -370,12 +370,7 @@ func (s State) FileContractTax(fc types.FileContract) types.Currency {
 
 // V2FileContractTax computes the tax levied on a given v2 contract.
 func (s State) V2FileContractTax(fc types.V2FileContract) types.Currency {
-	sum := fc.RenterOutput.Value.Add(fc.HostOutput.Value)
-	tax := sum.Div64(25) // 4%
-	// round down to nearest multiple of SiafundCount
-	_, r := bits.Div64(0, tax.Hi, s.SiafundCount())
-	_, r = bits.Div64(r, tax.Lo, s.SiafundCount())
-	return tax.Sub(types.NewCurrency64(r))
+	return fc.RenterOutput.Value.Add(fc.HostOutput.Value).Div64(25) // 4%
 }
 
 // StorageProofLeafIndex returns the leaf index used when computing or
@@ -595,7 +590,7 @@ type MidState struct {
 	res                map[types.FileContractID]bool
 	v2revs             map[types.FileContractID]*types.V2FileContractElement
 	v2res              map[types.FileContractID]types.V2FileContractResolutionType
-	siafundPool        types.Currency
+	siafundTaxRevenue  types.Currency
 	foundationPrimary  types.Address
 	foundationFailsafe types.Address
 
@@ -657,7 +652,7 @@ func NewMidState(s State) *MidState {
 		res:                make(map[types.FileContractID]bool),
 		v2revs:             make(map[types.FileContractID]*types.V2FileContractElement),
 		v2res:              make(map[types.FileContractID]types.V2FileContractResolutionType),
-		siafundPool:        s.SiafundPool,
+		siafundTaxRevenue:  s.SiafundTaxRevenue,
 		foundationPrimary:  s.FoundationPrimaryAddress,
 		foundationFailsafe: s.FoundationFailsafeAddress,
 	}

consensus/update.go

@@ -367,7 +367,7 @@ func (ms *MidState) addSiafundElement(id types.SiafundOutputID, sfo types.Siafun
 		StateElement:  types.StateElement{LeafIndex: types.UnassignedLeafIndex},
 		ID:            id,
 		SiafundOutput: sfo,
-		ClaimStart:    ms.siafundPool,
+		ClaimStart:    ms.siafundTaxRevenue,
 	}
 	ms.sfes = append(ms.sfes, sfe)
 	ms.created[ms.sfes[len(ms.sfes)-1].ID] = len(ms.sfes) - 1
@@ -389,7 +389,7 @@ func (ms *MidState) addFileContractElement(id types.FileContractID, fc types.Fil
 	}
 	ms.fces = append(ms.fces, fce)
 	ms.created[ms.fces[len(ms.fces)-1].ID] = len(ms.fces) - 1
-	ms.siafundPool = ms.siafundPool.Add(ms.base.FileContractTax(fce.FileContract))
+	ms.siafundTaxRevenue = ms.siafundTaxRevenue.Add(ms.base.FileContractTax(fce.FileContract))
 }
 
 func (ms *MidState) reviseFileContractElement(fce types.FileContractElement, rev types.FileContract) {
@@ -426,7 +426,7 @@ func (ms *MidState) addV2FileContractElement(id types.FileContractID, fc types.V
 	}
 	ms.v2fces = append(ms.v2fces, fce)
 	ms.created[ms.v2fces[len(ms.v2fces)-1].ID] = len(ms.v2fces) - 1
-	ms.siafundPool = ms.siafundPool.Add(ms.base.V2FileContractTax(fce.V2FileContract))
+	ms.siafundTaxRevenue = ms.siafundTaxRevenue.Add(ms.base.V2FileContractTax(fce.V2FileContract))
 }
 
 func (ms *MidState) reviseV2FileContractElement(fce types.V2FileContractElement, rev types.V2FileContract) {
@@ -477,7 +477,7 @@ func (ms *MidState) ApplyTransaction(txn types.Transaction, ts V1TransactionSupp
 		if !ok {
 			panic("missing SiafundElement")
 		}
-		claimPortion := ms.siafundPool.Sub(sfe.ClaimStart).Div64(ms.base.SiafundCount()).Mul64(sfe.SiafundOutput.Value)
+		claimPortion := ms.siafundTaxRevenue.Sub(sfe.ClaimStart).Div64(ms.base.SiafundCount()).Mul64(sfe.SiafundOutput.Value)
 		ms.spendSiafundElement(sfe, txid)
 		ms.addImmatureSiacoinElement(sfi.ParentID.ClaimOutputID(), types.SiacoinOutput{Value: claimPortion, Address: sfi.ClaimAddress})
 	}
@@ -528,7 +528,7 @@ func (ms *MidState) ApplyV2Transaction(txn types.V2Transaction) {
 	}
 	for _, sfi := range txn.SiafundInputs {
 		ms.spendSiafundElement(sfi.Parent, txid)
-		claimPortion := ms.siafundPool.Sub(sfi.Parent.ClaimStart).Div64(ms.base.SiafundCount()).Mul64(sfi.Parent.SiafundOutput.Value)
+		claimPortion := ms.siafundTaxRevenue.Sub(sfi.Parent.ClaimStart).Mul64(sfi.Parent.SiafundOutput.Value).Div64(ms.base.SiafundCount())
 		ms.addImmatureSiacoinElement(sfi.Parent.ID.V2ClaimOutputID(), types.SiacoinOutput{Value: claimPortion, Address: sfi.ClaimAddress})
 	}
 	for i, sfo := range txn.SiafundOutputs {
@@ -736,7 +736,7 @@ func ApplyBlock(s State, b types.Block, bs V1BlockSupplement, targetTimestamp ti
 
 	ms := NewMidState(s)
 	ms.ApplyBlock(b, bs)
-	s.SiafundPool = ms.siafundPool
+	s.SiafundTaxRevenue = ms.siafundTaxRevenue
 	s.Attestations += uint64(len(ms.aes))
 	s.FoundationPrimaryAddress = ms.foundationPrimary
 	s.FoundationFailsafeAddress = ms.foundationFailsafe

types/types.go

@@ -641,7 +641,7 @@ type SiafundElement struct {
 	ID            SiafundOutputID `json:"id"`
 	StateElement  StateElement    `json:"stateElement"`
 	SiafundOutput SiafundOutput   `json:"siafundOutput"`
-	ClaimStart    Currency        `json:"claimStart"` // value of SiafundPool when element was created
+	ClaimStart    Currency        `json:"claimStart"` // value of SiafundTaxRevenue when element was created
 }
 
 // A FileContractElement is a record of a FileContract within the state