mirrors/btcd
1
0
Fork 0
mirror of https://github.com/btcsuite/btcd.git synced 2025-01-19 05:33:36 +01:00
Code Issues Projects Releases Wiki Activity

mempool: introduce GetDustThreshold to export dust limit calculation

Browse Source 
This commit modifies no behavior and would allow other projects to
retrieve the dust limit for a particular output type before the
amount of the output is known. This is particularly useful in the
Lightning Network for channel negotiation.
This commit is contained in:
eugene 2021-08-16 12:40:38 -04:00 committed by John C. Vernaleo
parent 5e6736aad5
commit f8e6854197
1 changed files with 19 additions and 12 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

31
mempool/policy.go
View File

@ -172,17 +172,10 @@ func checkPkScriptStandard(pkScript []byte, scriptClass txscript.ScriptClass) er
return nil
}
// IsDust returns whether or not the passed transaction output amount is
// considered dust or not based on the passed minimum transaction relay fee.
// Dust is defined in terms of the minimum transaction relay fee. In
// particular, if the cost to the network to spend coins is more than 1/3 of the
// minimum transaction relay fee, it is considered dust.
func IsDust(txOut *wire.TxOut, minRelayTxFee btcutil.Amount) bool {
// Unspendable outputs are considered dust.
if txscript.IsUnspendable(txOut.PkScript) {
return true
}
// GetDustThreshold calculates the dust limit for a *wire.TxOut by taking the
// size of a typical spending transaction and multiplying it by 3 to account
// for the minimum dust relay fee of 3000sat/kvb.
func GetDustThreshold(txOut *wire.TxOut) int64 {
// The total serialized size consists of the output and the associated
// input script to redeem it. Since there is no input script
// to redeem it yet, use the minimum size of a typical input script.
@ -253,6 +246,20 @@ func IsDust(txOut *wire.TxOut, minRelayTxFee btcutil.Amount) bool {
totalSize += 107
}
return 3 * int64(totalSize)
}
// IsDust returns whether or not the passed transaction output amount is
// considered dust or not based on the passed minimum transaction relay fee.
// Dust is defined in terms of the minimum transaction relay fee. In
// particular, if the cost to the network to spend coins is more than 1/3 of the
// minimum transaction relay fee, it is considered dust.
func IsDust(txOut *wire.TxOut, minRelayTxFee btcutil.Amount) bool {
// Unspendable outputs are considered dust.
if txscript.IsUnspendable(txOut.PkScript) {
return true
}
// The output is considered dust if the cost to the network to spend the
// coins is more than 1/3 of the minimum free transaction relay fee.
// minFreeTxRelayFee is in Satoshi/KB, so multiply by 1000 to
@ -265,7 +272,7 @@ func IsDust(txOut *wire.TxOut, minRelayTxFee btcutil.Amount) bool {
//
// The following is equivalent to (value/totalSize) * (1/3) * 1000
// without needing to do floating point math.
return txOut.Value*1000/(3*int64(totalSize)) < int64(minRelayTxFee)
return txOut.Value*1000/GetDustThreshold(txOut) < int64(minRelayTxFee)
}
// checkTransactionStandard performs a series of checks on a transaction to