From df2e172ee87456bc8bb6502d72354449d7cd8d92 Mon Sep 17 00:00:00 2001
From: Ryan Staudt <mail@ryanstaudt.com>
Date: Tue, 27 Jul 2021 13:19:56 -0500
Subject: [PATCH] mempool: Add maybeAcceptTransaction AgendaFlags.

This updates the mempool maybeAcceptTransaction method to accept agenda
flags rather than just a boolean indicating if the treasury is active.

This allows for accommodating future agendas without having to add
additional boolean fields for each agenda.

This is useful in particular since maybeAcceptTransaction makes use of
the blockchain.CheckTransaction function to perform validation checks on
transactions, which includes checks which depend on whether or not an
agenda is active.
---
 internal/mempool/mempool.go | 25 +++++++++++++++++--------
 1 file changed, 17 insertions(+), 8 deletions(-)

diff --git a/internal/mempool/mempool.go b/internal/mempool/mempool.go
index b8be2480..15333135 100644
--- a/internal/mempool/mempool.go
+++ b/internal/mempool/mempool.go
@@ -1215,7 +1215,10 @@ func (mp *TxPool) MaybeAcceptDependents(tx *dcrutil.Tx, isTreasuryEnabled bool)
 // so that we can easily pick different stake tx types from the mempool later.
 // This should probably be done at the bottom using "IsSStx" etc functions.
 // It should also set the dcrutil tree type for the tx as well.
-func (mp *TxPool) maybeAcceptTransaction(tx *dcrutil.Tx, isNew, rateLimit, allowHighFees, rejectDupOrphans bool, isTreasuryEnabled bool) ([]*chainhash.Hash, error) {
+func (mp *TxPool) maybeAcceptTransaction(tx *dcrutil.Tx, isNew, rateLimit,
+	allowHighFees, rejectDupOrphans bool,
+	checkTxFlags blockchain.AgendaFlags) ([]*chainhash.Hash, error) {
+
 	msgTx := tx.MsgTx()
 	txHash := tx.Hash()
 	// Don't accept the transaction if it already exists in the pool.  This
@@ -1228,13 +1231,12 @@ func (mp *TxPool) maybeAcceptTransaction(tx *dcrutil.Tx, isNew, rateLimit, allow
 		return nil, txRuleError(ErrDuplicate, str)
 	}
 
+	// Determine active agendas based on flags.
+	isTreasuryEnabled := checkTxFlags.IsTreasuryEnabled()
+
 	// Perform preliminary validation checks on the transaction.  This makes use
 	// of blockchain which contains the invariant rules for what transactions
 	// are allowed into blocks.
-	checkTxFlags := blockchain.AFNone
-	if isTreasuryEnabled {
-		checkTxFlags |= blockchain.AFTreasuryEnabled
-	}
 	err := blockchain.CheckTransaction(msgTx, mp.cfg.ChainParams, checkTxFlags)
 	if err != nil {
 		var cerr blockchain.RuleError
@@ -1795,10 +1797,17 @@ func (mp *TxPool) MaybeAcceptTransaction(tx *dcrutil.Tx, isNew, rateLimit bool)
 		return nil, err
 	}
 
+	// Create agenda flags for checking transactions based on which ones are
+	// active.
+	checkTxFlags := blockchain.AFNone
+	if isTreasuryEnabled {
+		checkTxFlags |= blockchain.AFTreasuryEnabled
+	}
+
 	// Protect concurrent access.
 	mp.mtx.Lock()
 	hashes, err := mp.maybeAcceptTransaction(tx, isNew, rateLimit, true,
-		true, isTreasuryEnabled)
+		true, checkTxFlags)
 	mp.mtx.Unlock()
 
 	return hashes, err
@@ -1851,7 +1860,7 @@ func (mp *TxPool) processOrphans(acceptedTx *dcrutil.Tx, checkTxFlags blockchain
 			for _, tx := range orphans {
 				missing, err := mp.maybeAcceptTransaction(
 					tx, true, true, true, false,
-					isTreasuryEnabled)
+					checkTxFlags)
 				if err != nil {
 					// The orphan is now invalid, so there
 					// is no way any other orphans which
@@ -2051,7 +2060,7 @@ func (mp *TxPool) ProcessTransaction(tx *dcrutil.Tx, allowOrphan, rateLimit, all
 
 	// Potentially accept the transaction to the memory pool.
 	missingParents, err := mp.maybeAcceptTransaction(tx, true, rateLimit,
-		allowHighFees, true, isTreasuryEnabled)
+		allowHighFees, true, checkTxFlags)
 	if err != nil {
 		return nil, err
 	}