lbcutil/coinset
Francis Lam 02a1584784 Added CoinSelector interface and a few simple algos as a sub-package
This commit contains a basic definition for CoinSelector along with some
utility classes and some basic algos to make creating transactions from
a set of available unspent outpoints easier.

Thanks to @dajohi, @davec, @jrick for all the feedback and suggestions
regarding interfaces, organization, optimization, comments and
documentation.
2014-03-22 23:25:33 -04:00
..
coins.go Added CoinSelector interface and a few simple algos as a sub-package 2014-03-22 23:25:33 -04:00
coins_test.go Added CoinSelector interface and a few simple algos as a sub-package 2014-03-22 23:25:33 -04:00
cov_report.sh Added CoinSelector interface and a few simple algos as a sub-package 2014-03-22 23:25:33 -04:00
README.md Added CoinSelector interface and a few simple algos as a sub-package 2014-03-22 23:25:33 -04:00
test_coverage.txt Added CoinSelector interface and a few simple algos as a sub-package 2014-03-22 23:25:33 -04:00

coinset

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

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.

GPG Verification Key

All official release tags are signed by Conformal so users can ensure the code has not been tampered with and is coming from Conformal. To verify the signature perform the following:

  • Download the public key from the Conformal website at https://opensource.conformal.com/GIT-GPG-KEY-conformal.txt

  • Import the public key into your GPG keyring:

    gpg --import GIT-GPG-KEY-conformal.txt
    
  • Verify the release tag with the following command where TAG_NAME is a placeholder for the specific tag:

    git tag -v TAG_NAME
    

License

Package coinset is licensed under the liberal ISC License.