lbcutil/coinset/README.md

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coinset
=======
[![ISC License](http://img.shields.io/badge/license-ISC-blue.svg)](http://copyfree.org)
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.
## 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:
```Go
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.
```Go
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.