dcr

Documentation

Index

• Constants
• type AddressDeriver
  • func NewAddressDeriver(xpub string, keyIndexer asset.KeyIndexer, params NetParams) (*AddressDeriver, uint32, error)
  • func (ap *AddressDeriver) NextAddress() (string, error)
• type Backend
  • func NewBackend(configPath string, logger dex.Logger, network dex.Network) (*Backend, error)
  • func (dcr *Backend) BlockChannel(size int) <-chan *asset.BlockUpdate
  • func (dcr *Backend) CheckAddress(addr string) bool
  • func (dcr *Backend) Connect(ctx context.Context) (*sync.WaitGroup, error)
  • func (dcr *Backend) Contract(coinID []byte, redeemScript []byte) (*asset.Contract, error)
  • func (dcr *Backend) FeeCoin(coinID []byte) (addr string, val uint64, confs int64, err error)
  • func (dcr *Backend) FeeRate(ctx context.Context) (uint64, error)
  • func (dcr *Backend) FundingCoin(ctx context.Context, coinID []byte, redeemScript []byte) (asset.FundingCoin, error)
  • func (*Backend) Info() *asset.BackendInfo
  • func (dcr *Backend) InitTxSize() uint32
  • func (dcr *Backend) InitTxSizeBase() uint32
  • func (dcr *Backend) Redemption(redemptionID, contractID, _ []byte) (asset.Coin, error)
  • func (dcr *Backend) Synced() (bool, error)
  • func (dcr *Backend) TxData(coinID []byte) ([]byte, error)
  • func (dcr *Backend) ValidateCoinID(coinID []byte) (string, error)
  • func (dcr *Backend) ValidateContract(contract []byte) error
  • func (*Backend) ValidateFeeRate(contract *asset.Contract, reqFeeRate uint64) bool
  • func (dcr *Backend) ValidateSecret(secret, contract []byte) bool
  • func (dcr *Backend) ValidateXPub(xpub string) error
  • func (dcr *Backend) VerifyUnspentCoin(ctx context.Context, coinID []byte) error
• type Driver
  • func (d *Driver) DecodeCoinID(coinID []byte) (string, error)
  • func (d *Driver) NewAddresser(xPub string, keyIndexer asset.KeyIndexer, network dex.Network) (asset.Addresser, uint32, error)
  • func (d *Driver) Setup(configPath string, logger dex.Logger, network dex.Network) (asset.Backend, error)
  • func (d *Driver) UnitInfo() dex.UnitInfo
  • func (d *Driver) Version() uint32
• type Input
  • func (input *Input) Confirmations(ctx context.Context) (int64, error)
  • func (input *Input) ID() []byte
  • func (input *Input) String() string
  • func (input *Input) Value() uint64
• type NetParams
• type Output
  • func (output *Output) Addresses() []string
  • func (output *Output) Auth(pubkeys, sigs [][]byte, msg []byte) error
  • func (output *Output) Confirmations(ctx context.Context) (int64, error)
  • func (output *Output) ID() []byte
  • func (output *Output) SpendSize() uint32
  • func (output *Output) String() string
  • func (output *Output) Value() uint64
• type TXIO
  • func (txio *TXIO) FeeRate() uint64
  • func (txio *TXIO) TxID() string
• type Tx
• type UTXO
  • func (utxo *UTXO) Confirmations(ctx context.Context) (int64, error)

Constants

const (
	BipID = 42
)

const ErrReorgDetected = dex.ErrorKind("reorg detected")

Types

type AddressDeriver

type AddressDeriver struct {
	// contains filtered or unexported fields
}

AddressDeriver generates unique addresses from an extended public key.

func NewAddressDeriver

func NewAddressDeriver(xpub string, keyIndexer asset.KeyIndexer, params NetParams) (*AddressDeriver, uint32, error)

NewAddressDeriver creates a new AddressDeriver for the provided extended public key for an account, and KeyIndexer, using the provided network parameters (e.g. chaincfg.MainNetParams()).

func (*AddressDeriver) NextAddress

func (ap *AddressDeriver) NextAddress() (string, error)

NextAddress retrieves the pkh address for the next pubkey. While this should always return a valid address, an empty string may be returned in the event of an unexpected internal error.

type Backend

type Backend struct {
	// contains filtered or unexported fields
}

Backend is an asset backend for Decred. It has methods for fetching output information and subscribing to block updates. It maintains a cache of block data for quick lookups. Backend implements asset.Backend, so provides exported methods for DEX-related blockchain info.

func NewBackend

func NewBackend(configPath string, logger dex.Logger, network dex.Network) (*Backend, error)

NewBackend is the exported constructor by which the DEX will import the Backend. If configPath is an empty string, the backend will attempt to read the settings directly from the dcrd config file in its default system location.

func (*Backend) BlockChannel

func (dcr *Backend) BlockChannel(size int) <-chan *asset.BlockUpdate

BlockChannel creates and returns a new channel on which to receive block updates. If the returned channel is ever blocking, there will be no error logged from the dcr package. Part of the asset.Backend interface.

func (*Backend) CheckAddress

func (dcr *Backend) CheckAddress(addr string) bool

CheckAddress checks that the given address is parseable.

func (*Backend) Connect

func (dcr *Backend) Connect(ctx context.Context) (*sync.WaitGroup, error)

Connect connects to the node RPC server. A dex.Connector.

func (*Backend) Contract

func (dcr *Backend) Contract(coinID []byte, redeemScript []byte) (*asset.Contract, error)

Contract is part of the asset.Backend interface. An asset.Contract is an output that has been validated as a swap contract for the passed redeem script. A spendable output is one that can be spent in the next block. Every regular-tree output from a non-coinbase transaction is spendable immediately. Coinbase and stake tree outputs are only spendable after CoinbaseMaturity confirmations. Pubkey scripts can be P2PKH or P2SH in either regular- or stake-tree flavor. P2PKH supports two alternative signatures, Schnorr and Edwards. Multi-sig P2SH redeem scripts are supported as well.

func (*Backend) FeeCoin

func (dcr *Backend) FeeCoin(coinID []byte) (addr string, val uint64, confs int64, err error)

FeeCoin gets the recipient address, value, and confirmations of a transaction output encoded by the given coinID. A non-nil error is returned if the output's pubkey script is not a non-stake P2PKH requiring a single ECDSA-secp256k1 signature.

func (*Backend) FeeRate

func (dcr *Backend) FeeRate(ctx context.Context) (uint64, error)

FeeRate returns the current optimal fee rate in atoms / byte.

func (*Backend) FundingCoin

func (dcr *Backend) FundingCoin(ctx context.Context, coinID []byte, redeemScript []byte) (asset.FundingCoin, error)

FundingCoin is an unspent output.

func (*Backend) Info

func (*Backend) Info() *asset.BackendInfo

Info provides some general information about the backend.

func (*Backend) InitTxSize

func (dcr *Backend) InitTxSize() uint32

InitTxSize is an asset.Backend method that must produce the max size of a standardized atomic swap initialization transaction.

func (*Backend) InitTxSizeBase

func (dcr *Backend) InitTxSizeBase() uint32

InitTxSizeBase is InitTxSize not including an input.

func (*Backend) Redemption

func (dcr *Backend) Redemption(redemptionID, contractID, _ []byte) (asset.Coin, error)

Redemption is an input that redeems a swap contract.

func (*Backend) Synced

func (dcr *Backend) Synced() (bool, error)

Synced is true if the blockchain is ready for action.

func (*Backend) TxData

func (dcr *Backend) TxData(coinID []byte) ([]byte, error)

TxData is the raw transaction bytes. SPV clients rebroadcast the transaction bytes to get around not having a mempool to check.

func (*Backend) ValidateCoinID

func (dcr *Backend) ValidateCoinID(coinID []byte) (string, error)

ValidateCoinID attempts to decode the coinID.

func (*Backend) ValidateContract

func (dcr *Backend) ValidateContract(contract []byte) error

ValidateContract ensures that the swap contract is constructed properly, and contains valid sender and receiver addresses.

func (*Backend) ValidateFeeRate

func (*Backend) ValidateFeeRate(contract *asset.Contract, reqFeeRate uint64) bool

ValidateFeeRate checks that the transaction fees used to initiate the contract are sufficient.

func (*Backend) ValidateSecret

func (dcr *Backend) ValidateSecret(secret, contract []byte) bool

ValidateSecret checks that the secret satisfies the contract.

func (*Backend) ValidateXPub

func (dcr *Backend) ValidateXPub(xpub string) error

ValidateXPub validates the base-58 encoded extended key, and ensures that it is an extended public, not private, key.

func (*Backend) VerifyUnspentCoin

func (dcr *Backend) VerifyUnspentCoin(ctx context.Context, coinID []byte) error

VerifyUnspentCoin attempts to verify a coin ID by decoding the coin ID and retrieving the corresponding UTXO. If the coin is not found or no longer unspent, an asset.CoinNotFoundError is returned.

type Driver

type Driver struct{}

Driver implements asset.Driver.

func (*Driver) DecodeCoinID

func (d *Driver) DecodeCoinID(coinID []byte) (string, error)

DecodeCoinID creates a human-readable representation of a coin ID for Decred.

func (*Driver) NewAddresser

func (d *Driver) NewAddresser(xPub string, keyIndexer asset.KeyIndexer, network dex.Network) (asset.Addresser, uint32, error)

NewAddresser creates an asset.Addresser for deriving addresses for the given extended public key. The KeyIndexer will be used for discovering the current child index, and storing the index as new addresses are generated with the NextAddress method of the Addresser. The Backend must have been created with NewBackend (or Setup) to initialize the chain parameters.

func (*Driver) Setup

func (d *Driver) Setup(configPath string, logger dex.Logger, network dex.Network) (asset.Backend, error)

Setup creates the DCR backend. Start the backend with its Run method.

func (*Driver) UnitInfo

func (d *Driver) UnitInfo() dex.UnitInfo

UnitInfo returns the dex.UnitInfo for the asset.

func (*Driver) Version

func (d *Driver) Version() uint32

Version returns the Backend implementation's version number.

type Input

type Input struct {
	TXIO
	// contains filtered or unexported fields
}

Input is a transaction input.

func (*Input) Confirmations

func (input *Input) Confirmations(ctx context.Context) (int64, error)

Confirmations returns the number of confirmations on this input's transaction.

func (*Input) ID

func (input *Input) ID() []byte

ID returns the coin ID.

func (*Input) String

func (input *Input) String() string

String creates a human-readable representation of a Decred transaction input in the format "{txid = [transaction hash], vin = [input index]}".

func (*Input) Value

func (input *Input) Value() uint64

Value is the value of the previous output spent by the input.

type NetParams

type NetParams interface {
	hdkeychain.NetworkParams
	dcrutil.AddressParams
}

type Output

type Output struct {
	TXIO
	// contains filtered or unexported fields
}

Output represents a transaction output.

func (*Output) Addresses

func (output *Output) Addresses() []string

func (*Output) Auth

func (output *Output) Auth(pubkeys, sigs [][]byte, msg []byte) error

Auth verifies that the output pays to the supplied public key(s). This is an asset.FundingCoin method.

func (*Output) Confirmations

func (output *Output) Confirmations(ctx context.Context) (int64, error)

Confirmations returns the number of confirmations for a transaction output. Because it is possible for an output that was once considered valid to later be considered invalid, this method can return an error to indicate the output is no longer valid. The definition of output validity should not be confused with the validity of regular tree transactions that is voted on by stakeholders. While stakeholder approval is a part of output validity, there are other considerations as well.

func (*Output) ID

func (output *Output) ID() []byte

ID returns the coin ID.

func (*Output) SpendSize

func (output *Output) SpendSize() uint32

SpendSize returns the maximum size of the serialized TxIn that spends this Output, in bytes.

func (*Output) String

func (output *Output) String() string

String creates a human-readable representation of a Decred transaction output in the format "{txid = [transaction hash], vout = [output index]}".

func (*Output) Value

func (output *Output) Value() uint64

Value is the output value, in atoms.

type TXIO

type TXIO struct {
	// contains filtered or unexported fields
}

TXIO is common information stored with an Input or Output.

func (*TXIO) FeeRate

func (txio *TXIO) FeeRate() uint64

FeeRate returns the transaction fee rate, in atoms/byte.

func (*TXIO) TxID

func (txio *TXIO) TxID() string

TxID is a string identifier for the transaction, typically a hexadecimal representation of the byte-reversed transaction hash.

type Tx

type Tx struct {
	// contains filtered or unexported fields
}

Tx is information about a transaction. It must satisfy the asset.DEXTx interface to be DEX-compatible.

type UTXO

type UTXO struct {
	*Output
}

A UTXO is information regarding an unspent transaction output.

func (*UTXO) Confirmations

func (utxo *UTXO) Confirmations(ctx context.Context) (int64, error)

Confirmations returns the number of confirmations on this output's transaction. See also (*Output).Confirmations. This function differs from the Output method in that it is necessary to relocate the utxo after a reorg, it may error if the output is spent.