blockchain

package
v0.0.0-...-c1f1bd4 Latest Latest
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 Go to latest Published: Apr 22, 2020 License: MIT Imports: 21 Imported by: 0

Documentation

Index

Constants

View Source 
const (
	// CoinValue is the transaction amount that represents one Cumulus coin
	CoinValue uint64 = 1 << 32
	// StartingBlockReward is the mining reward that the blockchain will begin
	// with.
	StartingBlockReward uint64 = 25 * CoinValue
	// BlockRewardHalvingRate is the number of blocks that need to be mined
	// before the blockReward is halved
	BlockRewardHalvingRate int = 210000
)
View Source 
const (
	// CoordLen is the length in bytes of coordinates with our ECC curve.
	CoordLen = 32
	// AddrLen is the length in bytes of addresses.
	AddrLen = 2 * CoordLen
	// ReprLen is the length in bytes of an address checksum.
	ReprLen = 40
	// SigLen is the length in bytes of signatures.
	SigLen = AddrLen
	// AddressVersion is the version of the address shortening protocol.
	AddressVersion = 0
)
View Source 
const DefaultBlockSize = 1 << 18

DefaultBlockSize is the default block size, can be augmented by the user.

View Source 
const (
	// HashLen is the length in bytes of a hash.
	HashLen = 32
)

Variables

View Source 
var (

	// NilSig is a signature representing a failed Sign operation
	NilSig = Signature{c.Big0, c.Big0}
	// NilAddr is an address representing no address
	NilAddr = Address{c.Big0, c.Big0}
)
View Source 
var (
	// NilHash represents a nil hash
	NilHash = BigIntToHash(c.Big0)
)

Functions

func HashToBigInt 

func HashToBigInt(h Hash) *big.Int

HashToBigInt converts a hash to a big int pointer

func NewValidChainAndTxn 

func NewValidChainAndTxn() (*BlockChain, *Transaction)

NewValidChainAndTxn creates a valid BlockChain of 3 blocks, and a Transaction that is valid with respect to the BlockChain.

func NewValidCloudBaseTestTransaction 

func NewValidCloudBaseTestTransaction() (*Transaction, Address)

NewValidCloudBaseTestTransaction returns a new valid CloudBase transaction and the address of the recipient of the transaction

func NewValidTestChainAndBlock 

func NewValidTestChainAndBlock() (*BlockChain, *Block)

NewValidTestChainAndBlock creates a valid BlockChain of 3 blocks, and a new block which is valid with respect to the blockchain.

Types

type Account 

type Account interface {
	Public() Address
	Sign(digest Hash, random io.Reader) (Signature, error)
}

Account represents a wallet that we have the ability to sign for.

type Address 

type Address struct {
	X, Y *big.Int
}

Address represents a wallet that can be a recipient in a transaction.

func (Address) Emoji 

func (a Address) Emoji() string

Emoji returns the users address as a string of emojis.

func (Address) Key 

func (a Address) Key() *ecdsa.PublicKey

Key returns the ECDSA public key representation of the address.

func (Address) Marshal 

func (a Address) Marshal() []byte

Marshal converts an Address to a byte slice.

func (Address) Repr 

func (a Address) Repr() string

Repr returns a string representation of the address. We follow ethereums protocol, replacing Keccak hash with SHA256. Where pr is the private key, 

A(pr) = SHA256(ECDSAPUBLICKEY(pr))[96:255],

Resources: http://gavwood.com/paper.pdf (fig 213)

type Block 

type Block struct {
	BlockHeader
	Transactions []*Transaction
}

Block represents a block in the blockchain. Contains transactions and header metadata.

func DecodeBlockJSON 

func DecodeBlockJSON(blockBytes []byte) (*Block, error)

DecodeBlockJSON returns a block read from the given marshalled block, or an error if blockBytes cannot be decoded as JSON.

func Genesis 

func Genesis(miner Address, target Hash, blockReward uint64, extraData []byte) *Block

Genesis creates the Genesis block and returns is.

Properties of the Genesis block:

  • BlockNumber = 0
  • LastBlock = 0
  • There is only one transaction in the block, the CloudBase transaction that awards the miner with the block reward.

func NewTestBlock 

func NewTestBlock() *Block

NewTestBlock prodcues random block.

func (*Block) ContainsTransaction 

func (b *Block) ContainsTransaction(t *Transaction) (bool, uint32)

ContainsTransaction returns true and the transaction itself if the Block contains the transaction.

func (*Block) GetCloudBaseTransaction 

func (b *Block) GetCloudBaseTransaction() *Transaction

GetCloudBaseTransaction returns the CloudBase transaction within a block

func (*Block) GetTotalInputFrom 

func (b *Block) GetTotalInputFrom(sender string, bc *BlockChain) (uint64, error)

GetTotalInputFrom returns the total input from the given sender in the given block. Returns an error if the input to one or more of the inputs to the transactions in the given block could not be found in the blockchain.

func (*Block) GetTotalOutputFor 

func (b *Block) GetTotalOutputFor(recipient string) uint64

GetTotalOutputFor sums the outputs referenced to a specific recipient in the given block. recipient is an address checksum hex string.

func (*Block) GetTransactionsFrom 

func (b *Block) GetTransactionsFrom(sender string) []*Transaction

GetTransactionsFrom returns all the transactions from the given sender in the given block.

func (*Block) GetTransactionsTo 

func (b *Block) GetTransactionsTo(recipient string) []*Transaction

GetTransactionsTo returns all the transactions with outputs to the given recipient in the given block.

func (*Block) Len 

func (b *Block) Len() int

Len returns the length in bytes of the Block.

func (Block) Marshal 

func (b Block) Marshal() []byte

Marshal converts a Block to a byte slice.

type BlockChain 

type BlockChain struct {
	Blocks []*Block
	Head   Hash
	// contains filtered or unexported fields
}

BlockChain represents a linked list of blocks

func Load 

func Load(fileName string) (*BlockChain, error)

Load attempts to read blockchain info from the file with the given name in the current working directory in JSON format. On success this returns a pointer to a new user constructed from the information in the file. If an error occurrs it is returned.

func New 

func New() *BlockChain

New returns a new blockchain

func NewTestBlockChain 

func NewTestBlockChain() *BlockChain

NewTestBlockChain produces random blockchain.

func NewValidBlockChainFixture 

func NewValidBlockChainFixture() (*BlockChain, map[string]*Wallet)

NewValidBlockChainFixture creates a valid blockchain of three blocks and returns the wallets involved in the transactions. The returning wallets will have balances of 3, 1, and 0 respectively.

func (*BlockChain) AppendBlock 

func (bc *BlockChain) AppendBlock(b *Block)

AppendBlock adds a block to the end of the block chain.

func (*BlockChain) ContainsTransaction 

func (bc *BlockChain) ContainsTransaction(t *Transaction, start, stop uint32) (bool, uint32, uint32)

ContainsTransaction returns true, the block index, and the transaction index if the BlockChain contains the transaction in a block between start and stop indexes.

func (*BlockChain) GetAllInputs 

func (bc *BlockChain) GetAllInputs(t *Transaction) ([]*Transaction, error)

GetAllInputs returns all the transactions referenced by a transaction as inputs. Returns an error if any of the transactios requested could not be found.

func (*BlockChain) GetBlockByLastBlockHash 

func (bc *BlockChain) GetBlockByLastBlockHash(hash Hash) (*Block, error)

GetBlockByLastBlockHash returns a copy of the block in the local chain that comes directly after the block with the given hash. Returns error if no such block is found.

func (*BlockChain) GetBlockRange 

func (bc *BlockChain) GetBlockRange(t *Transaction) (uint32, uint32)

GetBlockRange returns the start and end block indexes for the inputs to a transaction.

func (*BlockChain) GetInputTransaction 

func (bc *BlockChain) GetInputTransaction(t *TxHashPointer) *Transaction

GetInputTransaction returns the input Transaction referenced by TxHashPointer. If the Transaction does not exist, then GetInputTransaction returns nil.

func (*BlockChain) LastBlock 

func (bc *BlockChain) LastBlock() *Block

LastBlock returns a pointer to the last block in the given blockchain, or nil if the blockchain is empty.

func (*BlockChain) Len 

func (bc *BlockChain) Len() int

Len returns the length of the BlockChain when marshalled

func (*BlockChain) Lock 

func (bc *BlockChain) Lock()

Lock locks the blockchain for reading

func (*BlockChain) Marshal 

func (bc *BlockChain) Marshal() []byte

Marshal converts the BlockChain to a byte slice.

func (*BlockChain) RLock 

func (bc *BlockChain) RLock()

RLock locks the blockchain for reading

func (*BlockChain) RUnlock 

func (bc *BlockChain) RUnlock()

RUnlock locks the blockchain for reading

func (*BlockChain) RollBack 

func (bc *BlockChain) RollBack() *Block

RollBack removes the last block from the blockchain. Returns the block that was removed from the end of the chain, or nil if the blockchain is empty.

func (*BlockChain) Save 

func (bc *BlockChain) Save(fileName string) error

Save writes the blockchain to a file of the given same in the current working directory in JSON format. It returns an error if one occurred, or a pointer to the file that was written to on success.

func (*BlockChain) Unlock 

func (bc *BlockChain) Unlock()

Unlock locks the blockchain for reading

type BlockHeader 

type BlockHeader struct {
	// BlockNumber is the position of the block within the blockchain
	BlockNumber uint32
	// LastBlock is the hash of the previous block
	LastBlock Hash
	// Target is the current target
	Target Hash
	// Time is represented as the number of seconds elapsed
	// since January 1, 1970 UTC.
	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
}

BlockHeader contains metadata about a block

func NewTestBlockHeader 

func NewTestBlockHeader() BlockHeader

NewTestBlockHeader prodcues random block header.

func (*BlockHeader) Equal 

func (bh *BlockHeader) Equal(otherHeader *BlockHeader) bool

Equal returns true if all the fields (other than ExtraData) in each of the BlockHeaders match, and false otherwise.

func (*BlockHeader) Len 

func (bh *BlockHeader) Len() int

Len returns the length in bytes of the BlockHeader.

func (*BlockHeader) Marshal 

func (bh *BlockHeader) Marshal() []byte

Marshal converts a BlockHeader to a byte slice

type Hash 

type Hash [HashLen]byte

Hash represents a 256-bit hash of a block or transaction

func BigIntToHash 

func BigIntToHash(x *big.Int) Hash

BigIntToHash converts a big integer to a hash. If the size of the big int is larger than the size of hash, the function will return a hash set to 0.

func HashSum 

func HashSum(m Marshaller) Hash

HashSum computes the SHA256 squared hash of a Marshaller.

func NewTestHash 

func NewTestHash() Hash

NewTestHash produces a hash.

func NewValidTestTarget 

func NewValidTestTarget() Hash

NewValidTestTarget creates a new valid target that is a random value between the max and min difficulties

func (Hash) LessThan 

func (h Hash) LessThan(h2 Hash) bool

LessThan returns true if the receiver hash is less than the hash provided, and false otherwise

func (Hash) Marshal 

func (h Hash) Marshal() []byte

Marshal converts a Hash to a slice.

type Marshaller 

type Marshaller interface {
	Marshal() []byte
}

Marshaller is any type that can convert itself to a byte slice

type Signature 

type Signature struct {
	R *big.Int
	S *big.Int
}

Signature represents a signature of a transaction.

func (*Signature) Marshal 

func (s *Signature) Marshal() []byte

Marshal converts a signature to a byte slice. Should be 64 bytes long.

type Transaction 

type Transaction struct {
	TxBody
	Sig Signature
}

Transaction contains a TxBody and a signature verifying it

func NewTestTransaction 

func NewTestTransaction() *Transaction

NewTestTransaction prodcues random txn.

func (*Transaction) Equal 

func (t *Transaction) Equal(txnToCompare *Transaction) bool

Equal returns true if the signatures of the given transactions are equal (i.e. the transactions are the same).

func (*Transaction) GetTotalInput 

func (t *Transaction) GetTotalInput(bc *BlockChain) (uint64, error)

GetTotalInput sums the input amounts from the transaction. Requires the blockchain for lookups.

func (*Transaction) GetTotalOutput 

func (t *Transaction) GetTotalOutput() uint64

GetTotalOutput sums the output amounts from the transaction.

func (*Transaction) GetTotalOutputFor 

func (t *Transaction) GetTotalOutputFor(recipient string) uint64

GetTotalOutputFor sums the outputs referenced to a specific recipient. recipient is an address checksum hex string.

func (*Transaction) InputIntersection 

func (t *Transaction) InputIntersection(other *Transaction) set.Interface

InputIntersection returns the intersection of the inputs of t and other.

func (*Transaction) InputSet 

func (t *Transaction) InputSet() *set.Set

InputSet returns the transaction inputs as a set object.

func (*Transaction) InputsEqualOutputs 

func (t *Transaction) InputsEqualOutputs(other ...*Transaction) bool

InputsEqualOutputs returns true if t.Inputs == other.Outputs, as well as the difference between the two (outputs - inputs).

func (*Transaction) InputsIntersect 

func (t *Transaction) InputsIntersect(other *Transaction) bool

InputsIntersect returns true if the inputs of t intersect with those of other.

func (*Transaction) InputsSpentElsewhere 

func (t *Transaction) InputsSpentElsewhere(bc *BlockChain, start uint32) bool

InputsSpentElsewhere returns true if inputs purported to be only spent on transaction t have been spent elsewhere after block index `start`.

func (*Transaction) Len 

func (t *Transaction) Len() int

Len returns the length in bytes of a transaction

func (*Transaction) Marshal 

func (t *Transaction) Marshal() []byte

Marshal converts a Transaction to a byte slice

type TxBody 

type TxBody struct {
	Sender  Address
	Inputs  []TxHashPointer
	Outputs []TxOutput
}

TxBody contains all relevant information about a transaction

func NewTestTxBody 

func NewTestTxBody() TxBody

NewTestTxBody random txn body.

func (TxBody) Len 

func (tb TxBody) Len() int

Len returns the length of a transaction body

func (TxBody) Marshal 

func (tb TxBody) Marshal() []byte

Marshal converts a TxBody to a byte slice

func (TxBody) Sign 

func (tb TxBody) Sign(w Wallet, r io.Reader) (*Transaction, error)

Sign returns a signed Transaction from a TxBody

type TxHashPointer 

type TxHashPointer struct {
	BlockNumber uint32
	Hash        Hash
	Index       uint32
}

TxHashPointer is a reference to a transaction on the blockchain.

func NewTestTxHashPointer 

func NewTestTxHashPointer() TxHashPointer

NewTestTxHashPointer produces transaction hash pointer.

func (TxHashPointer) Marshal 

func (thp TxHashPointer) Marshal() []byte

Marshal converts a TxHashPointer to a byte slice

type TxOutput 

type TxOutput struct {
	Amount    uint64
	Recipient string
}

TxOutput defines an output to a transaction

func NewTestTxOutput 

func NewTestTxOutput() TxOutput

NewTestTxOutput random txn output.

func (TxOutput) Marshal 

func (to TxOutput) Marshal() []byte

Marshal converts a TxOutput to a byte slice

type Wallet 

type Wallet struct {
	*ecdsa.PrivateKey
	PendingTxns []*Transaction
	Balance     uint64
}

Wallet is an account that can sign and hold a balance.

func NewWallet 

func NewWallet() *Wallet

NewWallet produces a new Wallet that can sign transactions and has a public Address.

func (*Wallet) DropAllPending 

func (w *Wallet) DropAllPending(txns []*Transaction, bc *BlockChain) error

DropAllPending drops pending transactions if they appear in txns. Returns an error if any of the given transactions are not in the blockchain.

func (*Wallet) DropPending 

func (w *Wallet) DropPending(i int)

DropPending drops a single pending transaction by index in the pending list.

func (*Wallet) GetEffectiveBalance 

func (w *Wallet) GetEffectiveBalance() uint64

GetEffectiveBalance returns the wallet balance less the sum of the pending transactions in the wallet.

func (*Wallet) IsPending 

func (w *Wallet) IsPending(txn *Transaction) (bool, int)

IsPending returns true if the transaction exists in the pending list. If true, it also returns the integer index of the transaction.

func (*Wallet) Public 

func (w *Wallet) Public() Address

Public returns the public key as byte array, or address, of the wallet.

func (*Wallet) Refresh 

func (w *Wallet) Refresh(bc *BlockChain) error

Refresh sets the wallet's balance and updates its set of pending transactions based on the transaction information in the given blockchain. Returns an error if any of the transactions in the blockchain cannot be found.

func (*Wallet) SetAllPending 

func (w *Wallet) SetAllPending(txns []*Transaction)

SetAllPending appends transactions to the pending set of transactions.

func (*Wallet) SetPending 

func (w *Wallet) SetPending(txn *Transaction) error

SetPending appends one transaction to the pending set of transactions if the wallet's effective balance is high enough to accomodate.

func (*Wallet) Sign 

func (w *Wallet) Sign(digest Hash, random io.Reader) (Signature, error)

Sign returns a signature of the digest.

func (*Wallet) UnmarshalJSON 

func (w *Wallet) UnmarshalJSON(walletBytes []byte) error

UnmarshalJSON unmarshals the given byte slice into the given wallet, and returns an error if one occurs.

func (*Wallet) Update 

func (w *Wallet) Update(block *Block, bc *BlockChain) error

Update updates the wallet's balance and set of pending transactions based on the transaction information in the given block. Returns an error if any of the transactions in the given block cannot be found in the blockchain.

Source Files

  • block.go
  • blockchain.go
  • genesis.go
  • hash.go
  • test_utils.go
  • transaction.go
  • wallet.go

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