From 7b9d880feea08193d9a06290de83ec2e8fdea1e3 Mon Sep 17 00:00:00 2001
From: Olaoluwa Osuntokun <laolu32@gmail.com>
Date: Sat, 18 Nov 2017 15:22:46 -0800
Subject: [PATCH] wallet: remove internal relayFee in favor of passing in fee
 rate when sending
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In this commit, we do away with the internal relayFee all together.
Instead, we’ll pass in the fee rate when we’re crafting any
transactions. This allows the caller to manually dictate their desired
fee rate.
---
 wallet/createtx.go |  6 ++++--
 wallet/wallet.go   | 36 ++++++++----------------------------
 2 files changed, 12 insertions(+), 30 deletions(-)

diff --git a/wallet/createtx.go b/wallet/createtx.go
index 4c2b3a5..c974dd5 100644
--- a/wallet/createtx.go
+++ b/wallet/createtx.go
@@ -101,7 +101,9 @@ func (s secretSource) GetScript(addr btcutil.Address) ([]byte, error) {
 // UTXO set and minconf policy. An additional output may be added to return
 // change to the wallet.  An appropriate fee is included based on the wallet's
 // current relay fee.  The wallet must be unlocked to create the transaction.
-func (w *Wallet) txToOutputs(outputs []*wire.TxOut, account uint32, minconf int32) (tx *txauthor.AuthoredTx, err error) {
+func (w *Wallet) txToOutputs(outputs []*wire.TxOut, account uint32,
+	minconf int32, feeSatPerKb btcutil.Amount) (tx *txauthor.AuthoredTx, err error) {
+
 	chainClient, err := w.requireChainClient()
 	if err != nil {
 		return nil, err
@@ -137,7 +139,7 @@ func (w *Wallet) txToOutputs(outputs []*wire.TxOut, account uint32, minconf int3
 			}
 			return txscript.PayToAddrScript(changeAddr)
 		}
-		tx, err = txauthor.NewUnsignedTransaction(outputs, w.RelayFee(),
+		tx, err = txauthor.NewUnsignedTransaction(outputs, feeSatPerKb,
 			inputSource, changeSource)
 		if err != nil {
 			return err
diff --git a/wallet/wallet.go b/wallet/wallet.go
index 9e156f9..2d19b6e 100644
--- a/wallet/wallet.go
+++ b/wallet/wallet.go
@@ -75,8 +75,6 @@ type Wallet struct {
 	chainClientSyncMtx sync.Mutex
 
 	lockedOutpoints map[wire.OutPoint]struct{}
-	relayFee        btcutil.Amount
-	relayFeeMu      sync.Mutex
 
 	// Channels for rescan processing.  Requests are added and merged with
 	// any waiting requests, before being sent to another goroutine to
@@ -205,23 +203,6 @@ func (w *Wallet) ChainClient() chain.Interface {
 	return chainClient
 }
 
-// RelayFee returns the current minimum relay fee (per kB of serialized
-// transaction) used when constructing transactions.
-func (w *Wallet) RelayFee() btcutil.Amount {
-	w.relayFeeMu.Lock()
-	relayFee := w.relayFee
-	w.relayFeeMu.Unlock()
-	return relayFee
-}
-
-// SetRelayFee sets a new minimum relay fee (per kB of serialized
-// transaction) used when constructing transactions.
-func (w *Wallet) SetRelayFee(relayFee btcutil.Amount) {
-	w.relayFeeMu.Lock()
-	w.relayFee = relayFee
-	w.relayFeeMu.Unlock()
-}
-
 // quitChan atomically reads the quit channel.
 func (w *Wallet) quitChan() <-chan struct{} {
 	w.quitMu.Lock()
@@ -529,10 +510,11 @@ func (w *Wallet) syncWithChain() error {
 
 type (
 	createTxRequest struct {
-		account uint32
-		outputs []*wire.TxOut
-		minconf int32
-		resp    chan createTxResponse
+		account     uint32
+		outputs     []*wire.TxOut
+		minconf     int32
+		feeSatPerKB btcutil.Amount
+		resp        chan createTxResponse
 	}
 	createTxResponse struct {
 		tx  *txauthor.AuthoredTx
@@ -562,7 +544,7 @@ out:
 				continue
 			}
 			tx, err := w.txToOutputs(txr.outputs, txr.account,
-				txr.minconf)
+				txr.minconf, txr.feeSatPerKB)
 			heldUnlock.release()
 			txr.resp <- createTxResponse{tx, err}
 		case <-quit:
@@ -2318,16 +2300,15 @@ func (w *Wallet) TotalReceivedForAddr(addr btcutil.Address, minConf int32) (btcu
 // SendOutputs creates and sends payment transactions. It returns the
 // transaction hash upon success.
 func (w *Wallet) SendOutputs(outputs []*wire.TxOut, account uint32,
-	minconf int32) (*chainhash.Hash, error) {
+	minconf int32, satPerKb btcutil.Amount) (*chainhash.Hash, error) {
 
 	chainClient, err := w.requireChainClient()
 	if err != nil {
 		return nil, err
 	}
 
-	relayFee := w.RelayFee()
 	for _, output := range outputs {
-		err = txrules.CheckOutput(output, relayFee)
+		err = txrules.CheckOutput(output, satPerKb)
 		if err != nil {
 			return nil, err
 		}
@@ -2658,7 +2639,6 @@ func Open(db walletdb.DB, pubPass []byte, cbs *waddrmgr.OpenCallbacks, params *c
 		Manager:             addrMgr,
 		TxStore:             txMgr,
 		lockedOutpoints:     map[wire.OutPoint]struct{}{},
-		relayFee:            txrules.DefaultRelayFeePerKb,
 		rescanAddJob:        make(chan *RescanJob),
 		rescanBatch:         make(chan *rescanBatch),
 		rescanNotifications: make(chan interface{}),