From aef0242f030711d343838d5f071a52c98cba7b45 Mon Sep 17 00:00:00 2001
From: lukechampine <luke.champine@gmail.com>
Date: Mon, 21 Oct 2024 14:16:57 -0400
Subject: [PATCH] types,consensus: Add Capacity field to V2FileContract

---
 consensus/update_test.go     | 1 +
 consensus/validation.go      | 6 ++++++
 consensus/validation_test.go | 1 +
 types/encoding.go            | 2 ++
 types/types.go               | 1 +
 5 files changed, 11 insertions(+)

diff --git a/consensus/update_test.go b/consensus/update_test.go
index 097ad351..62aedac1 100644
--- a/consensus/update_test.go
+++ b/consensus/update_test.go
@@ -1084,6 +1084,7 @@ func TestApplyRevertBlockV2(t *testing.T) {
 	v1FC.Filesize = 65
 	v1FC.FileMerkleRoot = blake2b.SumPair((State{}).StorageProofLeafHash([]byte{1}), (State{}).StorageProofLeafHash([]byte{2}))
 	v2FC := types.V2FileContract{
+		Capacity:         v1FC.Filesize,
 		Filesize:         v1FC.Filesize,
 		FileMerkleRoot:   v1FC.FileMerkleRoot,
 		ProofHeight:      20,
diff --git a/consensus/validation.go b/consensus/validation.go
index 60ac38bd..32bb1523 100644
--- a/consensus/validation.go
+++ b/consensus/validation.go
@@ -725,6 +725,8 @@ func validateV2FileContracts(ms *MidState, txn types.V2Transaction) error {
 
 	validateContract := func(fc types.V2FileContract, renewal bool) error {
 		switch {
+		case fc.Filesize > fc.Capacity:
+			return fmt.Errorf("has filesize (%v) exceeding capacity (%v)", fc.Filesize, fc.Capacity)
 		case fc.ProofHeight < ms.base.childHeight():
 			return fmt.Errorf("has proof height (%v) that has already passed", fc.ProofHeight)
 		case fc.ExpirationHeight <= fc.ProofHeight:
@@ -747,6 +749,10 @@ func validateV2FileContracts(ms *MidState, txn types.V2Transaction) error {
 		curOutputSum := cur.RenterOutput.Value.Add(cur.HostOutput.Value)
 		revOutputSum := rev.RenterOutput.Value.Add(rev.HostOutput.Value)
 		switch {
+		case rev.Capacity < cur.Capacity:
+			return fmt.Errorf("decreases capacity")
+		case rev.Filesize > rev.Capacity:
+			return fmt.Errorf("has filesize (%v) exceeding capacity (%v)", rev.Filesize, rev.Capacity)
 		case cur.ProofHeight < ms.base.childHeight():
 			return fmt.Errorf("revises contract after its proof window has opened")
 		case rev.RevisionNumber <= cur.RevisionNumber:
diff --git a/consensus/validation_test.go b/consensus/validation_test.go
index 223059c7..96185832 100644
--- a/consensus/validation_test.go
+++ b/consensus/validation_test.go
@@ -863,6 +863,7 @@ func TestValidateV2Block(t *testing.T) {
 	v1GiftFC.Filesize = 65
 	v1GiftFC.FileMerkleRoot = blake2b.SumPair((State{}).StorageProofLeafHash([]byte{1}), (State{}).StorageProofLeafHash([]byte{2}))
 	v2GiftFC := types.V2FileContract{
+		Capacity:         v1GiftFC.Filesize,
 		Filesize:         v1GiftFC.Filesize,
 		FileMerkleRoot:   v1GiftFC.FileMerkleRoot,
 		ProofHeight:      20,
diff --git a/types/encoding.go b/types/encoding.go
index d1a8477c..2586abcf 100644
--- a/types/encoding.go
+++ b/types/encoding.go
@@ -651,6 +651,7 @@ func (sfe SiafundElement) EncodeTo(e *Encoder) {
 
 // EncodeTo implements types.EncoderTo.
 func (fc V2FileContract) EncodeTo(e *Encoder) {
+	e.WriteUint64(fc.Capacity)
 	e.WriteUint64(fc.Filesize)
 	fc.FileMerkleRoot.EncodeTo(e)
 	e.WriteUint64(fc.ProofHeight)
@@ -1246,6 +1247,7 @@ func (sfe *SiafundElement) DecodeFrom(d *Decoder) {
 
 // DecodeFrom implements types.DecoderFrom.
 func (fc *V2FileContract) DecodeFrom(d *Decoder) {
+	fc.Capacity = d.ReadUint64()
 	fc.Filesize = d.ReadUint64()
 	fc.FileMerkleRoot.DecodeFrom(d)
 	fc.ProofHeight = d.ReadUint64()
diff --git a/types/types.go b/types/types.go
index 2b58f9e4..bdee4ed5 100644
--- a/types/types.go
+++ b/types/types.go
@@ -455,6 +455,7 @@ func (txn *Transaction) TotalFees() Currency {
 // or "missed" depending on whether a valid StorageProof is submitted for the
 // contract.
 type V2FileContract struct {
+	Capacity         uint64        `json:"capacity"`
 	Filesize         uint64        `json:"filesize"`
 	FileMerkleRoot   Hash256       `json:"fileMerkleRoot"`
 	ProofHeight      uint64        `json:"proofHeight"`