[refactor] Make signals optional in mempool and chainman

This is done in preparation for the next two commits, where the
CMainSignals are de-globalized.

This avoids adding new constructor arguments to the ChainstateManager
and CTxMemPool classes over the next two commits.

This could also allow future tests that are only interested in the
internal behaviour of the classes to forgo instantiating the signals.

1 files changed, 7 insertions, 4 deletions

diff --git a/src/txmempool.cpp b/src/txmempool.cpp
index de340f6b6d..0bee27c2b2 100644
--- a/src/txmempool.cpp
+++ b/src/txmempool.cpp
@@ -406,7 +406,8 @@ CTxMemPool::CTxMemPool(const Options& opts)
       m_require_standard{opts.require_standard},
       m_full_rbf{opts.full_rbf},
       m_persist_v1_dat{opts.persist_v1_dat},
-      m_limits{opts.limits}
+      m_limits{opts.limits},
+      m_signals{opts.signals}
 {
 }
 
@@ -487,12 +488,12 @@ void CTxMemPool::removeUnchecked(txiter it, MemPoolRemovalReason reason)
     // even if not directly reported below.
     uint64_t mempool_sequence = GetAndIncrementSequence();
 
-    if (reason != MemPoolRemovalReason::BLOCK) {
+    if (reason != MemPoolRemovalReason::BLOCK && m_signals) {
         // Notify clients that a transaction has been removed from the mempool
         // for any reason except being included in a block. Clients interested
         // in transactions included in blocks can subscribe to the BlockConnected
         // notification.
-        GetMainSignals().TransactionRemovedFromMempool(it->GetSharedTx(), reason, mempool_sequence);
+        m_signals->TransactionRemovedFromMempool(it->GetSharedTx(), reason, mempool_sequence);
     }
     TRACE5(mempool, removed,
         it->GetTx().GetHash().data(),
@@ -643,7 +644,9 @@ void CTxMemPool::removeForBlock(const std::vector<CTransactionRef>& vtx, unsigne
         removeConflicts(*tx);
         ClearPrioritisation(tx->GetHash());
     }
-    GetMainSignals().MempoolTransactionsRemovedForBlock(txs_removed_for_block, nBlockHeight);
+    if (m_signals) {
+        m_signals->MempoolTransactionsRemovedForBlock(txs_removed_for_block, nBlockHeight);
+    }
     lastRollingFeeUpdate = GetTime();
     blockSinceLastRollingFeeBump = true;
 }