Merge #15531: Suggested interfaces::Chain cleanups from #15288

4d4e4c6448 Suggested interfaces::Chain cleanups from #15288 (Russell Yanofsky)

Pull request description:

  Mostly documentation improvements requested in the last review of #15288 before it was merged (https://github.com/bitcoin/bitcoin/pull/15288#pullrequestreview-210241864)

Tree-SHA512: 64e912520bbec20a44032f265a8cf3f11ad7f5126c8626b5ad5e888227b1f92ecb321522fab4bbbd613230b55450abd6ace023631d0a4f357a780d65c5638bfe

1 files changed, 4 insertions, 4 deletions

diff --git a/src/interfaces/chain.cpp b/src/interfaces/chain.cpp
index fb634e73da..2eecea28d0 100644
--- a/src/interfaces/chain.cpp
+++ b/src/interfaces/chain.cpp
@@ -148,7 +148,7 @@ class LockImpl : public Chain::Lock
         LockAnnotation lock(::cs_main);
         return CheckFinalTx(tx);
     }
-    bool submitToMemoryPool(CTransactionRef tx, CAmount absurd_fee, CValidationState& state) override
+    bool submitToMemoryPool(const CTransactionRef& tx, CAmount absurd_fee, CValidationState& state) override
     {
         LockAnnotation lock(::cs_main);
         return AcceptToMemoryPool(::mempool, state, tx, nullptr /* missing inputs */, nullptr /* txn replaced */,
@@ -207,8 +207,8 @@ public:
     bool hasDescendantsInMempool(const uint256& txid) override
     {
         LOCK(::mempool.cs);
-        auto it_mp = ::mempool.mapTx.find(txid);
-        return it_mp != ::mempool.mapTx.end() && it_mp->GetCountWithDescendants() > 1;
+        auto it = ::mempool.GetIter(txid);
+        return it && (*it)->GetCountWithDescendants() > 1;
     }
     void relayTransaction(const uint256& txid) override
     {
@@ -219,7 +219,7 @@ public:
     {
         ::mempool.GetTransactionAncestry(txid, ancestors, descendants);
     }
-    bool checkChainLimits(CTransactionRef tx) override
+    bool checkChainLimits(const CTransactionRef& tx) override
     {
         LockPoints lp;
         CTxMemPoolEntry entry(tx, 0, 0, 0, false, 0, lp);