lbcutil/coinset

coinset

[] (https://travis-ci.org/conformal/btcutil)

Package coinset provides bitcoin-specific convenience functions for selecting from and managing sets of unspent transaction outpoints (UTXOs).

A comprehensive suite of tests is provided to ensure proper functionality. See test_coverage.txt for the gocov coverage report. Alternatively, if you are running a POSIX OS, you can run the cov_report.sh script for a real-time report. Package coinset is licensed under the liberal ISC license.

Documentation

[] (http://godoc.org/github.com/conformal/btcutil/coinset)

Full go doc style documentation for the project can be viewed online without installing this package by using the GoDoc site here: http://godoc.org/github.com/conformal/btcutil/coinset

You can also view the documentation locally once the package is installed with the godoc tool by running godoc -http=":6060" and pointing your browser to http://localhost:6060/pkg/github.com/conformal/btcutil/coinset

Installation

$ go get github.com/conformal/btcutil/coinset

Usage

Each unspent transaction outpoint is represented by the Coin interface. An example of a concrete type that implements Coin is coinset.SimpleCoin.

The typical use case for this library is for creating raw bitcoin transactions given a set of Coins that may be spent by the user, for example as below:

var unspentCoins = []coinset.Coin{ ... }

When the user needs to spend a certain amount, they will need to select a subset of these coins which contain at least that value. CoinSelector is an interface that represents types that implement coin selection algos, subject to various criteria. There are a few examples of CoinSelector's:

• MinIndexCoinSelector

• MinNumberCoinSelector

• MaxValueAgeCoinSelector

• MinPriorityCoinSelector

For example, if the user wishes to maximize the probability that their transaction is mined quickly, they could use the MaxValueAgeCoinSelector to select high priority coins, then also attach a relatively high fee.

selector := &coinset.MaxValueAgeCoinSelector{
    MaxInputs: 10,
    MinAmountChange: 10000,
}
selectedCoins, err := selector.CoinSelect(targetAmount + bigFee, unspentCoins)
if err != nil {
	return err
}
msgTx := coinset.NewMsgTxWithInputCoins(selectedCoins)
...

The user can then create the msgTx.TxOut's as required, then sign the transaction and transmit it to the network.

License

Package coinset is licensed under the copyfree ISC License.