Merge pull request #88 from ubclaunchpad/85-block-extra-data

85-block-extra-data

blockchain/block.go

@@ -8,13 +8,6 @@ import (
 	"io"
 )
 
-const (
-	// BlockSize is the maximum size of a block in bytes when marshaled (about 250K).
-	BlockSize = 1 << 18
-	// BlockHeaderLen is the length in bytes of a block header.
-	BlockHeaderLen = 2*(32/8) + 64/8 + 2*HashLen
-)
-
 // BlockHeader contains metadata about a block
 type BlockHeader struct {
 	// BlockNumber is the position of the block within the blockchain
@@ -28,6 +21,9 @@ type BlockHeader struct {
 	Time uint32
 	// Nonce starts at 0 and increments by 1 for every hash when mining
 	Nonce uint64
+	// ExtraData is an extra field that can be filled with arbitrary data to
+	// be stored in the block
+	ExtraData []byte
 }
 
 // Marshal converts a BlockHeader to a byte slice
@@ -48,10 +44,16 @@ func (bh *BlockHeader) Marshal() []byte {
 	buf = append(buf, bh.Target.Marshal()...)
 	buf = append(buf, tempBufTime...)
 	buf = append(buf, tempBufNonce...)
+	buf = append(buf, bh.ExtraData...)
 
 	return buf
 }
 
+// Len returns the length in bytes of the BlockHeader.
+func (bh *BlockHeader) Len() int {
+	return len(bh.Marshal())
+}
+
 // Block represents a block in the blockchain. Contains transactions and header metadata.
 type Block struct {
 	BlockHeader
@@ -60,16 +62,12 @@ type Block struct {
 
 // Len returns the length in bytes of the Block.
 func (b *Block) Len() int {
-	l := BlockHeaderLen
-	for _, t := range b.Transactions {
-		l += t.Len()
-	}
-	return l
+	return len(b.Marshal())
 }
 
 // Marshal converts a Block to a byte slice.
 func (b *Block) Marshal() []byte {
-	buf := make([]byte, 0, b.Len())
+	var buf []byte
 	buf = append(buf, b.BlockHeader.Marshal()...)
 	for _, t := range b.Transactions {
 		buf = append(buf, t.Marshal()...)

blockchain/block_test.go

@@ -3,6 +3,7 @@ package blockchain
 import (
 	"bytes"
 	"testing"
+	"time"
 )
 
 func TestEncodeDecodeBlock(t *testing.T) {
@@ -25,3 +26,35 @@ func TestContainsTransaction(t *testing.T) {
 		t.Fail()
 	}
 }
+
+func TestBlockHeaderLen(t *testing.T) {
+	bh := &BlockHeader{
+		0,
+		NewTestHash(),
+		NewValidTestTarget(),
+		uint32(time.Now().Unix()),
+		0,
+		[]byte{0x00, 0x01, 0x02},
+	}
+
+	len := 2*(32/8) + 64/8 + 2*HashLen + 3
+
+	if bh.Len() != len {
+		t.Fail()
+	}
+
+	bh = &BlockHeader{
+		0,
+		NewTestHash(),
+		NewValidTestTarget(),
+		uint32(time.Now().Unix()),
+		0,
+		[]byte{},
+	}
+
+	len = 2*(32/8) + 64/8 + 2*HashLen
+
+	if bh.Len() != len {
+		t.Fail()
+	}
+}

blockchain/blockchain.go

@@ -14,16 +14,12 @@ type BlockChain struct {
 
 // Len returns the length of the BlockChain when marshalled
 func (bc *BlockChain) Len() int {
-	l := 0
-	for _, b := range bc.Blocks {
-		l += b.Len()
-	}
-	return l + HashLen
+	return len(bc.Marshal())
 }
 
 // Marshal converts the BlockChain to a byte slice.
 func (bc *BlockChain) Marshal() []byte {
-	buf := make([]byte, 0, bc.Len())
+	var buf []byte
 	for _, b := range bc.Blocks {
 		buf = append(buf, b.Marshal()...)
 	}

blockchain/genesis.go

@@ -11,7 +11,7 @@ import (
 // 	- LastBlock = 0
 // 	- There is only one transaction in the block, the CloudBase transaction that
 // 	  awards the miner with the block reward.
-func Genesis(miner Address, target Hash, blockReward uint64) *Block {
+func Genesis(miner Address, target Hash, blockReward uint64, extraData []byte) *Block {
 
 	cbReward := TxOutput{
 		Amount:    blockReward,
@@ -38,6 +38,7 @@ func Genesis(miner Address, target Hash, blockReward uint64) *Block {
 			Target:      target,
 			Time:        uint32(time.Now().Unix()),
 			Nonce:       0,
+			ExtraData:   extraData,
 		},
 		Transactions: []*Transaction{cbTx},
 	}

blockchain/genesis_test.go

@@ -9,7 +9,7 @@ func TestGenesis(t *testing.T) {
 	miner := NewWallet()
 	currentTarget := BigIntToHash(MaxTarget)
 	currentBlockReward := uint64(25)
-	gb := Genesis(miner.Public(), currentTarget, currentBlockReward)
+	gb := Genesis(miner.Public(), currentTarget, currentBlockReward, []byte{})
 
 	// Check if the genesis block is equal to nil
 	if gb == nil {

blockchain/transaction.go

@@ -5,13 +5,6 @@ import (
 	"io"
 )
 
-const (
-	// TxHashPointerLen is the length in bytes of a hash pointer.
-	TxHashPointerLen = 32/8 + HashLen
-	// TxOutputLen is the length in bytes of a transaction output.
-	TxOutputLen = 64/8 + AddrLen
-)
-
 // TxHashPointer is a reference to a transaction on the blockchain.
 type TxHashPointer struct {
 	BlockNumber uint32
@@ -21,9 +14,12 @@ type TxHashPointer struct {
 
 // Marshal converts a TxHashPointer to a byte slice
 func (thp TxHashPointer) Marshal() []byte {
-	buf := make([]byte, 4, TxHashPointerLen)
+	buf := make([]byte, 4)
 	binary.LittleEndian.PutUint32(buf, thp.BlockNumber)
 	buf = append(buf, thp.Hash.Marshal()...)
+	tempBufIndex := make([]byte, 4)
+	binary.LittleEndian.PutUint32(tempBufIndex, thp.Index)
+	buf = append(buf, tempBufIndex...)
 	return buf
 }
 
@@ -35,7 +31,7 @@ type TxOutput struct {
 
 // Marshal converts a TxOutput to a byte slice
 func (to TxOutput) Marshal() []byte {
-	buf := make([]byte, 8, TxOutputLen)
+	buf := make([]byte, 8)
 	binary.LittleEndian.PutUint64(buf, to.Amount)
 	buf = append(buf, to.Recipient.Marshal()...)
 	return buf
@@ -50,12 +46,12 @@ type TxBody struct {
 
 // Len returns the length of a transaction body
 func (tb TxBody) Len() int {
-	return AddrLen + TxHashPointerLen + len(tb.Outputs)*TxOutputLen
+	return len(tb.Marshal())
 }
 
 // Marshal converts a TxBody to a byte slice
 func (tb TxBody) Marshal() []byte {
-	buf := make([]byte, 0, tb.Len())
+	var buf []byte
 	buf = append(buf, tb.Sender.Marshal()...)
 	buf = append(buf, tb.Input.Marshal()...)
 	for _, out := range tb.Outputs {
@@ -79,12 +75,12 @@ type Transaction struct {
 
 // Len returns the length in bytes of a transaction
 func (t *Transaction) Len() int {
-	return t.TxBody.Len() + SigLen
+	return len(t.Marshal())
 }
 
 // Marshal converts a Transaction to a byte slice
 func (t *Transaction) Marshal() []byte {
-	buf := make([]byte, 0, t.Len())
+	var buf []byte
 	buf = append(buf, t.TxBody.Marshal()...)
 	buf = append(buf, t.Sig.Marshal()...)
 	return buf

blockchain/transaction_test.go

@@ -0,0 +1,30 @@
+package blockchain
+
+import (
+	"testing"
+)
+
+func TestTxBodyLen(t *testing.T) {
+	txBody := NewTestTxBody()
+	senderLen := AddrLen
+	inputLen := 2*(32/8) + HashLen
+	outputLen := len(txBody.Outputs) * (64/8 + AddrLen)
+	txBodyLen := senderLen + inputLen + outputLen
+
+	if txBody.Len() != txBodyLen {
+		t.Fail()
+	}
+}
+
+func TestTransactionLen(t *testing.T) {
+	tx := NewTestTransaction()
+	senderLen := AddrLen
+	inputLen := 2*(32/8) + HashLen
+	outputLen := len(tx.TxBody.Outputs) * (64/8 + AddrLen)
+	txBodyLen := senderLen + inputLen + outputLen
+	txLen := txBodyLen + SigLen
+
+	if tx.Len() != txLen {
+		t.Fail()
+	}
+}

blockchain/validation.go

@@ -73,7 +73,7 @@ const (
 	BadGenesisBlockNumber
 	// BadGenesisTarget is returned when the genesis block's target is invalid.
 	BadGenesisTarget
-	// BadGenesisTime is returned when teh gensis block's time is invalid.
+	// BadGenesisTime is returned when the genesis block's time is invalid.
 	BadGenesisTime
 	// NilGenesisBlock is returned when the genesis block is equal to nil.
 	NilGenesisBlock
@@ -190,6 +190,7 @@ func ValidCloudBase(t *Transaction) (bool, CloudBaseTransactionCode) {
 
 // ValidGenesisBlock checks whether a block is a valid genesis block.
 func (bc *BlockChain) ValidGenesisBlock(gb *Block) (bool, GenesisBlockCode) {
+
 	// Check if the genesis block is equal to nil.
 	if gb == nil {
 		return false, NilGenesisBlock
@@ -234,12 +235,12 @@ func (bc *BlockChain) ValidGenesisBlock(gb *Block) (bool, GenesisBlockCode) {
 // ValidBlock checks whether a block is valid.
 func (bc *BlockChain) ValidBlock(b *Block) (bool, BlockCode) {
 
-	// Check if the block is equal to nil
+	// Check if the block is equal to nil.
 	if b == nil {
 		return false, NilBlock
 	}
 
-	// Check if the block is the genesis block
+	// Check if the block is the genesis block.
 	if b.BlockHeader.BlockNumber == 0 || bc.Blocks[0] == b {
 		if valid, code := bc.ValidGenesisBlock(b); !valid {
 			log.Errorf("Invalid GenesisBlock, GenesisBlockCode: %d", code)

blockchain/validation_test.go

@@ -115,7 +115,7 @@ func TestValidBlockBadGenesisBlock(t *testing.T) {
 	miner := NewWallet()
 	currentTarget := BigIntToHash(MaxTarget)
 	currentBlockReward := uint64(25)
-	gb := Genesis(miner.Public(), currentTarget, currentBlockReward)
+	gb := Genesis(miner.Public(), currentTarget, currentBlockReward, []byte{})
 	gb.Target = BigIntToHash(BigExp(2, 255))
 	bc := &BlockChain{
 		Blocks: []*Block{gb},
@@ -407,7 +407,7 @@ func TestValidGenesisBlock(t *testing.T) {
 	miner := NewWallet()
 	currentTarget := BigIntToHash(MaxTarget)
 	currentBlockReward := uint64(25)
-	gb := Genesis(miner.Public(), currentTarget, currentBlockReward)
+	gb := Genesis(miner.Public(), currentTarget, currentBlockReward, []byte{})
 	bc := &BlockChain{
 		Blocks: []*Block{gb},
 		Head:   HashSum(gb),
@@ -446,7 +446,7 @@ func TestValidGenesisBlockBadGenesisBlockNumber(t *testing.T) {
 	miner := NewWallet()
 	currentTarget := BigIntToHash(MaxTarget)
 	currentBlockReward := uint64(25)
-	gb := Genesis(miner.Public(), currentTarget, currentBlockReward)
+	gb := Genesis(miner.Public(), currentTarget, currentBlockReward, []byte{})
 	gb.BlockHeader.BlockNumber = 1
 	bc := &BlockChain{
 		Blocks: []*Block{gb},
@@ -484,8 +484,9 @@ func TestValidGenesisBlockBadGenesisLastBlock(t *testing.T) {
 	miner := NewWallet()
 	currentTarget := BigIntToHash(MaxTarget)
 	currentBlockReward := uint64(25)
-	gb := Genesis(miner.Public(), currentTarget, currentBlockReward)
+	gb := Genesis(miner.Public(), currentTarget, currentBlockReward, []byte{})
 	gb.LastBlock = NewTestHash()
+
 	bc := &BlockChain{
 		Blocks: []*Block{gb},
 		Head:   HashSum(gb),
@@ -506,7 +507,7 @@ func TestValidGenesisBlockBadGenesisTransactions(t *testing.T) {
 	miner := NewWallet()
 	currentTarget := BigIntToHash(MaxTarget)
 	currentBlockReward := uint64(25)
-	gb := Genesis(miner.Public(), currentTarget, currentBlockReward)
+	gb := Genesis(miner.Public(), currentTarget, currentBlockReward, []byte{})
 	gb.Transactions = append(gb.Transactions, NewTestTransaction())
 	bc := &BlockChain{
 		Blocks: []*Block{gb},
@@ -528,7 +529,7 @@ func TestValidGenesisBlockBadGenesisCloudBaseTransaction(t *testing.T) {
 	miner := NewWallet()
 	currentTarget := BigIntToHash(MaxTarget)
 	currentBlockReward := uint64(25)
-	gb := Genesis(miner.Public(), currentTarget, currentBlockReward)
+	gb := Genesis(miner.Public(), currentTarget, currentBlockReward, []byte{})
 	gb.Transactions[0] = NewTestTransaction()
 	bc := &BlockChain{
 		Blocks: []*Block{gb},
@@ -550,7 +551,7 @@ func TestValidGenesisBlockBadGenesisTarget(t *testing.T) {
 	miner := NewWallet()
 	currentTarget := BigIntToHash(MaxTarget)
 	currentBlockReward := uint64(25)
-	gb := Genesis(miner.Public(), currentTarget, currentBlockReward)
+	gb := Genesis(miner.Public(), currentTarget, currentBlockReward, []byte{})
 	gb.Target = BigIntToHash(BigExp(2, 255))
 	bc := &BlockChain{
 		Blocks: []*Block{gb},
@@ -572,7 +573,7 @@ func TestValidGenesisBlockBadGenesisTime(t *testing.T) {
 	miner := NewWallet()
 	currentTarget := BigIntToHash(MaxTarget)
 	currentBlockReward := uint64(25)
-	gb := Genesis(miner.Public(), currentTarget, currentBlockReward)
+	gb := Genesis(miner.Public(), currentTarget, currentBlockReward, []byte{})
 	gb.Time = 0
 	bc := &BlockChain{
 		Blocks: []*Block{gb},

blockchain/wallet.go

@@ -33,7 +33,7 @@ type Address struct {
 
 // Marshal converts an Address to a byte slice.
 func (a Address) Marshal() []byte {
-	buf := make([]byte, AddrLen)
+	buf := make([]byte, 0, AddrLen)
 	buf = append(buf, a.X.Bytes()...)
 	buf = append(buf, a.Y.Bytes()...)
 	return buf