chainntnfs

Documentation

Index

• func DisableLog()
• func SetLogWriter(w io.Writer, level string) error
• func UseLogger(logger btclog.Logger)
• type ChainNotifier
• type ConfirmationEvent
• type SpendDetail
• type SpendEvent

Functions

func DisableLog

func DisableLog()

DisableLog disables all library log output. Logging output is disabled by default until either UseLogger or SetLogWriter are called.

func SetLogWriter

func SetLogWriter(w io.Writer, level string) error

SetLogWriter uses a specified io.Writer to output package logging info. This allows a caller to direct package logging output without needing a dependency on seelog. If the caller is also using btclog, UseLogger should be used instead.

func UseLogger

func UseLogger(logger btclog.Logger)

UseLogger uses a specified Logger to output package logging info. This should be used in preference to SetLogWriter if the caller is also using btclog.

Types

type ChainNotifier

type ChainNotifier interface {
	// RegisterConfirmationsNtfn registers an intent to be notified once
	// txid reaches numConfs confirmations. The returned ConfirmationEvent
	// should properly notify the client once the specified number of
	// confirmations has been reached for the txid, as well as if the
	// original tx gets re-org'd out of the mainchain.
	RegisterConfirmationsNtfn(txid *wire.ShaHash, numConfs uint32) (*ConfirmationEvent, error)

	// RegisterSpendNtfn registers an intent to be notified once the target
	// outpoint is succesfully spent within a confirmed transaction. The
	// returned SpendEvent will receive a send on the 'Spend' transaction
	// once a transaction spending the input is detected on the blockchain.
	RegisterSpendNtfn(outpoint *wire.OutPoint) (*SpendEvent, error)

	// Start the ChainNotifier. Once started, the implementation should be
	// ready, and able to receive notification registrations from clients.
	Start() error

	// Stops the concrete ChainNotifier. Once stopped, the ChainNotifier
	// should disallow any future requests from potential clients.
	// Additionally, all pending client notifications will be cancelled
	// by closing the related channels on the *Event's.
	Stop() error
}

ChainNotifier represents a trusted source to receive notifications concerning targeted events on the Bitcoin blockchain. The interface specification is intentionally general in order to support a wide array of chain notification implementations such as: btcd's websockets notifications, Bitcoin Core's ZeroMQ notifications, various Bitcoin API services, Electrum servers, etc.

Concrete implementations of ChainNotifier should be able to support multiple concurrent client requests, as well as multiple concurrent notification events.

type ConfirmationEvent

type ConfirmationEvent struct {
	Confirmed chan struct{} // MUST be buffered.

	NegativeConf chan int32 // MUST be buffered.
}

ConfirmationEvent encapsulates a confirmation notification. With this struct, callers can be notified of: the instance the target txid reaches the targeted number of confirmations, and also in the event that the original txid becomes disconnected from the blockchain as a result of a re-org.

Once the txid reaches the specified number of confirmations, the 'Confirmed' channel will be sent upon fufulling the notification.

If the event that the original transaction becomes re-org'd out of the main chain, the 'NegativeConf' will be sent upon with a value representing the depth of the re-org.

type SpendDetail

type SpendDetail struct {
	SpentOutPoint     *wire.OutPoint
	SpenderTxHash     *wire.ShaHash
	SpendingTx        *wire.MsgTx
	SpenderInputIndex uint32
}

SpendDetail contains details pertaining to a spent output. This struct itself is the spentness notification. It includes the original outpoint which triggered the notification, the hash of the transaction spending the output, the spending transaction itself, and finally the input index which spent the target output.

type SpendEvent

type SpendEvent struct {
	Spend chan *SpendDetail // MUST be buffered.
}

SpendEvent encapsulates a spentness notification. Its only field 'Spend' will be sent upon once the target output passed into RegisterSpendNtfn has been spent on the blockchain.