asset

Documentation

Index

• Constants
• func DecodeCoinID(name string, coinID []byte) (string, error)
• func Register(name string, driver Driver)
• func Version(name string) (uint32, error)
• type BackedAsset
• type Backend
  • func Setup(name, configPath string, logger dex.Logger, network dex.Network) (Backend, error)
• type BlockUpdate
• type Coin
• type ConnectionError
  • func NewConnectionError(s string, a ...interface{}) ConnectionError
• type Contract
• type Driver
• type FundingCoin

Constants

const (
	CoinNotFoundError = dex.ErrorKind("coin not found")
	ErrRequestTimeout = dex.ErrorKind("request timeout")
)

CoinNotFoundError is to be returned from Contract, Redemption, and FundingCoin when the specified transaction cannot be found. Used by the server to handle network latency.

Functions

func DecodeCoinID

func DecodeCoinID(name string, coinID []byte) (string, error)

DecodeCoinID creates a human-readable representation of a coin ID for a named asset with a corresponding driver registered with this package.

func Register

func Register(name string, driver Driver)

Register should be called by the init function of an asset's package.

func Version

func Version(name string) (uint32, error)

Version retrieves the version of the named asset's Backend implementation.

Types

type BackedAsset

type BackedAsset struct {
	dex.Asset
	Backend Backend
}

BackedAsset is a dex.Asset with a Backend.

type Backend

type Backend interface {
	dex.Connector
	// Contract returns a Contract only for outputs that would be spendable on
	// the blockchain immediately. The redeem script is required in order to
	// calculate sigScript length and verify pubkeys.
	Contract(coinID []byte, redeemScript []byte) (*Contract, error)
	// TxData fetches the raw transaction data for the specified coin.
	TxData(coinID []byte) ([]byte, error)
	// ValidateSecret checks that the secret satisfies the contract.
	ValidateSecret(secret, contract []byte) bool
	// Redemption returns a Coin for redemptionID, a transaction input, that
	// spends contract ID, an output containing the swap contract.
	Redemption(redemptionID, contractID []byte) (Coin, error)
	// FundingCoin returns the unspent coin at the specified location. Coins
	// with non-standard pkScripts or scripts that require zero signatures to
	// redeem must return an error.
	FundingCoin(ctx context.Context, coinID []byte, redeemScript []byte) (FundingCoin, error)
	// BlockChannel creates and returns a new channel on which to receive updates
	// when new blocks are connected.
	BlockChannel(size int) <-chan *BlockUpdate
	// InitTxSize is the size of a serialized atomic swap initialization
	// transaction with 1 input spending a P2PKH utxo, 1 swap contract output and
	// 1 change output.
	InitTxSize() uint32
	// InitTxSizeBase is InitTxSize not including an input.
	InitTxSizeBase() uint32
	// CheckAddress checks that the given address is parseable.
	CheckAddress(string) bool
	// ValidateCoinID checks the coinID to ensure it can be decoded, returning a
	// human-readable string if it is valid.
	ValidateCoinID(coinID []byte) (string, error)
	// ValidateContract ensures that the swap contract is constructed properly
	// for the asset.
	ValidateContract(contract []byte) error
	// VerifyUnspentCoin attempts to verify a coin ID by decoding the coin ID
	// and retrieving the corresponding Coin. If the coin is not found or no
	// longer unspent, an asset.CoinNotFoundError is returned. Use FundingCoin
	// for more UTXO data.
	VerifyUnspentCoin(ctx context.Context, coinID []byte) error
	// FeeRate returns the current optimal fee rate in atoms / byte.
	FeeRate() (uint64, error)
	// Synced should return true when the blockchain is synced and ready for
	// fee rate estimation.
	Synced() (bool, error)
}

The Backend interface is an interface for a blockchain backend.

func Setup

func Setup(name, configPath string, logger dex.Logger, network dex.Network) (Backend, error)

Setup sets up the named asset. The RPC connection parameters are obtained from the asset's configuration file located at configPath.

type BlockUpdate

type BlockUpdate struct {
	Err   error
	Reorg bool
}

BlockUpdate is sent over the update channel when a tip change is detected.

type Coin

type Coin interface {
	// Confirmations returns the number of confirmations for a Coin's
	// transaction. Because a Coin can become invalid after once being
	// considered valid, this condition should be checked for during
	// confirmation counting and an error returned if this Coin is no longer
	// ready to spend. An unmined transaction should have zero confirmations. A
	// transaction in the current best block should have one confirmation. A
	// negative number can be returned if error is not nil.
	Confirmations(context.Context) (int64, error)
	// ID is the coin ID.
	ID() []byte
	// TxID is a transaction identifier for the coin.
	TxID() string
	// String is a human readable representation of the Coin.
	String() string
	// Value is the coin value.
	Value() uint64
	// FeeRate returns the transaction fee rate, in atoms/byte equivalent.
	FeeRate() uint64
}

Coin represents a transaction input or output.

type ConnectionError

type ConnectionError error

ConnectionError error should be sent over the block update channel if a connection error is detected by the Backend.

func NewConnectionError

func NewConnectionError(s string, a ...interface{}) ConnectionError

NewConnectionError is a constructor for a ConnectionError.

type Contract

type Contract struct {
	Coin
	// SwapAddress is the receiving address of the swap contract.
	SwapAddress string
	// RedeemScript is the contract redeem script.
	RedeemScript []byte
	// SecretHash is the secret key hash used for this swap. This is extracted
	// from the RedeemScript and is provided here for convenience.
	SecretHash []byte
	// LockTime is the refund locktime.
	LockTime time.Time
	// TxData is raw transaction data. This data is provided for some assets
	// to aid in SPV compatiblity.
	TxData []byte
}

Contract is an atomic swap contract.

type Driver

type Driver interface {
	// Setup should create a Backend, but not start the backend connection.
	Setup(configPath string, logger dex.Logger, network dex.Network) (Backend, error)
	DecodeCoinID(coinID []byte) (string, error)
	// Version returns the Backend's version number, which is used to signal
	// when major changes are made to internal details such as coin ID encoding
	// and contract structure that must be common to a client's.
	Version() uint32
}

Driver is the interface required of all assets.

type FundingCoin

type FundingCoin interface {
	Coin
	// Auth checks that the owner of the provided pubkeys can spend the
	// FundingCoin. The signatures (sigs) generated with the private keys
	// corresponding to pubkeys must validate against the pubkeys and signing
	// message (msg).
	Auth(pubkeys, sigs [][]byte, msg []byte) error
	// SpendSize returns the size of the serialized input that spends this
	// FundingCoin.
	SpendSize() uint32
}

FundingCoin is some unspent value on the blockchain.