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lnwallet: add docstrings to script_utils.go

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This commit is contained in:
Olaoluwa Osuntokun 2016-01-02 14:10:14 -06:00
parent f257690788
commit 7ec419bde5
1 changed files with 23 additions and 7 deletions
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30
lnwallet/script_utils.go
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@ -113,7 +113,8 @@ func findScriptOutputIndex(tx *wire.MsgTx, script []byte) (bool, uint32) {
return found, index return found, index
} }
// senderHTLCScript... // senderHTLCScript constructs the public key script for an outgoing HTLC
// output payment for the sender's commitment transaction.
func senderHTLCScript(absoluteTimeout, relativeTimeout uint32, senderKey, func senderHTLCScript(absoluteTimeout, relativeTimeout uint32, senderKey,
receiverKey *btcec.PublicKey, revokeHash, paymentHash []byte) ([]byte, error) { receiverKey *btcec.PublicKey, revokeHash, paymentHash []byte) ([]byte, error) {
@ -138,7 +139,10 @@ func senderHTLCScript(absoluteTimeout, relativeTimeout uint32, senderKey,
// Otherwise, we (the sender) need to wait for an absolute HTLC // Otherwise, we (the sender) need to wait for an absolute HTLC
// timeout, then afterwards a relative timeout before we claim re-claim // timeout, then afterwards a relative timeout before we claim re-claim
// the unsettled funds. // the unsettled funds. This delay gives the other party a chance to
// present the pre-image to the revocation hash in the event that the
// sender (at this time) broadcasts this commitment transaction after
// it has been revoked.
builder.AddOp(txscript.OP_ELSE) builder.AddOp(txscript.OP_ELSE)
builder.AddInt64(int64(absoluteTimeout)) builder.AddInt64(int64(absoluteTimeout))
builder.AddOp(txscript.OP_CHECKLOCKTIMEVERIFY) builder.AddOp(txscript.OP_CHECKLOCKTIMEVERIFY)
@ -152,7 +156,8 @@ func senderHTLCScript(absoluteTimeout, relativeTimeout uint32, senderKey,
return builder.Script() return builder.Script()
} }
// receiverHTLCScript... // senderHTLCScript constructs the public key script for an incoming HTLC
// output payment for the receiver's commitment transaction.
func receiverHTLCScript(absoluteTimeout, relativeTimeout uint32, senderKey, func receiverHTLCScript(absoluteTimeout, relativeTimeout uint32, senderKey,
receiverKey *btcec.PublicKey, revokeHash, paymentHash []byte) ([]byte, error) { receiverKey *btcec.PublicKey, revokeHash, paymentHash []byte) ([]byte, error) {
@ -165,7 +170,10 @@ func receiverHTLCScript(absoluteTimeout, relativeTimeout uint32, senderKey,
builder.AddOp(txscript.OP_EQUAL) builder.AddOp(txscript.OP_EQUAL)
builder.AddOp(txscript.OP_IF) builder.AddOp(txscript.OP_IF)
// If so, let the receiver redeem after a relative timeout. // If so, let the receiver redeem after a relative timeout. This added
// delay gives the sender (at this time) an opportunity to re-claim the
// pending HTLC in the event that the receiver (at this time) broadcasts
// this old commitment transaction after it has been revoked.
builder.AddInt64(int64(relativeTimeout)) builder.AddInt64(int64(relativeTimeout))
builder.AddOp(OP_CHECKSEQUENCEVERIFY) builder.AddOp(OP_CHECKSEQUENCEVERIFY)
builder.AddOp(txscript.OP_2DROP) builder.AddOp(txscript.OP_2DROP)
@ -178,7 +186,10 @@ func receiverHTLCScript(absoluteTimeout, relativeTimeout uint32, senderKey,
builder.AddData(revokeHash) builder.AddData(revokeHash)
builder.AddOp(txscript.OP_EQUAL) builder.AddOp(txscript.OP_EQUAL)
// If not, then the sender needs to wait for the HTLC timeout. // If not, then the sender needs to wait for the HTLC timeout. This
// clause may be executed if the receiver fails to present the r-value
// in time. This prevents the pending funds from being locked up
// indefinately.
builder.AddOp(txscript.OP_NOTIF) builder.AddOp(txscript.OP_NOTIF)
builder.AddInt64(int64(absoluteTimeout)) builder.AddInt64(int64(absoluteTimeout))
builder.AddOp(OP_CHECKSEQUENCEVERIFY) builder.AddOp(OP_CHECKSEQUENCEVERIFY)
@ -193,7 +204,10 @@ func receiverHTLCScript(absoluteTimeout, relativeTimeout uint32, senderKey,
return builder.Script() return builder.Script()
} }
// commitScriptToSelf... // commitScriptToSelf constructs the public key script for the output on the
// commitment transaction paying to the "owner" of said commitment transaction.
// If the other party learns of the pre-image to the revocation hash, then they
// can claim all the settled funds in the channel, plus the unsettled funds.
func commitScriptToSelf(csvTimeout uint32, selfKey, theirKey *btcec.PublicKey, revokeHash []byte) ([]byte, error) { func commitScriptToSelf(csvTimeout uint32, selfKey, theirKey *btcec.PublicKey, revokeHash []byte) ([]byte, error) {
// This script is spendable under two conditions: either the 'csvTimeout' // This script is spendable under two conditions: either the 'csvTimeout'
// has passed and we can redeem our funds, or they have the pre-image // has passed and we can redeem our funds, or they have the pre-image
@ -221,7 +235,9 @@ func commitScriptToSelf(csvTimeout uint32, selfKey, theirKey *btcec.PublicKey, r
return builder.Script() return builder.Script()
} }
// commitScriptUnencumbered... // commitScriptUnencumbered constructs the public key script on the commitment
// transaction paying to the "other" party. This output is spendable
// immediately, requiring no contestation period.
func commitScriptUnencumbered(key *btcec.PublicKey) ([]byte, error) { func commitScriptUnencumbered(key *btcec.PublicKey) ([]byte, error) {
// This script goes to the "other" party, and it spendable immediately. // This script goes to the "other" party, and it spendable immediately.
builder := txscript.NewScriptBuilder() builder := txscript.NewScriptBuilder()