Make CTxMemPoolEntry derive from TxGraph::Ref

diff --git a/src/bench/blockencodings.cpp b/src/bench/blockencodings.cpp
index 8f665991..c92ade60 100644
--- a/src/bench/blockencodings.cpp
+++ b/src/bench/blockencodings.cpp
@@ -22,7 +22,7 @@
 static void AddTx(const CTransactionRef& tx, const CAmount& fee, CTxMemPool& pool) EXCLUSIVE_LOCKS_REQUIRED(cs_main, pool.cs)
 {
     LockPoints lp;
-    AddToMempool(pool, CTxMemPoolEntry(tx, fee, /*time=*/0, /*entry_height=*/1, /*entry_sequence=*/0, /*spends_coinbase=*/false, /*sigops_cost=*/4, lp));
+    AddToMempool(pool, CTxMemPoolEntry(TxGraph::Ref(), tx, fee, /*time=*/0, /*entry_height=*/1, /*entry_sequence=*/0, /*spends_coinbase=*/false, /*sigops_cost=*/4, lp));
 }
 
 namespace {
diff --git a/src/bench/mempool_ephemeral_spends.cpp b/src/bench/mempool_ephemeral_spends.cpp
index 8f294113..ce17650e 100644
--- a/src/bench/mempool_ephemeral_spends.cpp
+++ b/src/bench/mempool_ephemeral_spends.cpp
@@ -29,7 +29,7 @@ static void AddTx(const CTransactionRef& tx, CTxMemPool& pool) EXCLUSIVE_LOCKS_R
     unsigned int sigOpCost{4};
     uint64_t fee{0};
     LockPoints lp;
-    AddToMempool(pool, CTxMemPoolEntry(
+    AddToMempool(pool, CTxMemPoolEntry(TxGraph::Ref(),
         tx, fee, nTime, nHeight, sequence,
         spendsCoinbase, sigOpCost, lp));
 }
diff --git a/src/bench/mempool_eviction.cpp b/src/bench/mempool_eviction.cpp
index aa2e8682..72d2356a 100644
--- a/src/bench/mempool_eviction.cpp
+++ b/src/bench/mempool_eviction.cpp
@@ -27,7 +27,7 @@ static void AddTx(const CTransactionRef& tx, const CAmount& nFee, CTxMemPool& po
     bool spendsCoinbase = false;
     unsigned int sigOpCost = 4;
     LockPoints lp;
-    AddToMempool(pool, CTxMemPoolEntry(
+    AddToMempool(pool, CTxMemPoolEntry(TxGraph::Ref(),
         tx, nFee, nTime, nHeight, sequence,
         spendsCoinbase, sigOpCost, lp));
 }
diff --git a/src/bench/mempool_stress.cpp b/src/bench/mempool_stress.cpp
index fbac25db..5095438c 100644
--- a/src/bench/mempool_stress.cpp
+++ b/src/bench/mempool_stress.cpp
@@ -29,7 +29,7 @@ static void AddTx(const CTransactionRef& tx, CTxMemPool& pool) EXCLUSIVE_LOCKS_R
     bool spendsCoinbase = false;
     unsigned int sigOpCost = 4;
     LockPoints lp;
-    AddToMempool(pool, CTxMemPoolEntry(tx, 1000, nTime, nHeight, sequence, spendsCoinbase, sigOpCost, lp));
+    AddToMempool(pool, CTxMemPoolEntry(TxGraph::Ref(), tx, 1000, nTime, nHeight, sequence, spendsCoinbase, sigOpCost, lp));
 }
 
 struct Available {
diff --git a/src/bench/rpc_mempool.cpp b/src/bench/rpc_mempool.cpp
index a61c6609..4ad1f0b2 100644
--- a/src/bench/rpc_mempool.cpp
+++ b/src/bench/rpc_mempool.cpp
@@ -22,7 +22,7 @@
 static void AddTx(const CTransactionRef& tx, const CAmount& fee, CTxMemPool& pool) EXCLUSIVE_LOCKS_REQUIRED(cs_main, pool.cs)
 {
     LockPoints lp;
-    AddToMempool(pool, CTxMemPoolEntry(tx, fee, /*time=*/0, /*entry_height=*/1, /*entry_sequence=*/0, /*spends_coinbase=*/false, /*sigops_cost=*/4, lp));
+    AddToMempool(pool, CTxMemPoolEntry(TxGraph::Ref(), tx, fee, /*time=*/0, /*entry_height=*/1, /*entry_sequence=*/0, /*spends_coinbase=*/false, /*sigops_cost=*/4, lp));
 }
 
 static void RpcMempool(benchmark::Bench& bench)
diff --git a/src/kernel/CMakeLists.txt b/src/kernel/CMakeLists.txt
index c45ce781..9ab2d672 100644
--- a/src/kernel/CMakeLists.txt
+++ b/src/kernel/CMakeLists.txt
@@ -58,6 +58,7 @@ add_library(bitcoinkernel
   ../support/lockedpool.cpp
   ../sync.cpp
   ../txdb.cpp
+  ../txgraph.cpp
   ../txmempool.cpp
   ../uint256.cpp
   ../util/chaintype.cpp
diff --git a/src/kernel/mempool_entry.h b/src/kernel/mempool_entry.h
index 40aa77b5..cd86f366 100644
--- a/src/kernel/mempool_entry.h
+++ b/src/kernel/mempool_entry.h
@@ -11,6 +11,7 @@
 #include <policy/policy.h>
 #include <policy/settings.h>
 #include <primitives/transaction.h>
+#include <txgraph.h>
 #include <util/epochguard.h>
 #include <util/overflow.h>
 
@@ -62,7 +63,7 @@ struct CompareIteratorByHash {
  *
  */
 
-class CTxMemPoolEntry
+class CTxMemPoolEntry : public TxGraph::Ref
 {
 public:
     typedef std::reference_wrapper<const CTxMemPoolEntry> CTxMemPoolEntryRef;
@@ -103,11 +104,13 @@ private:
     int64_t nSigOpCostWithAncestors;
 
 public:
-    CTxMemPoolEntry(const CTransactionRef& tx, CAmount fee,
+    virtual ~CTxMemPoolEntry() = default;
+    CTxMemPoolEntry(TxGraph::Ref&& ref, const CTransactionRef& tx, CAmount fee,
                     int64_t time, unsigned int entry_height, uint64_t entry_sequence,
                     bool spends_coinbase,
                     int64_t sigops_cost, LockPoints lp)
-        : tx{tx},
+        : TxGraph::Ref(std::move(ref)),
+          tx{tx},
           nFee{fee},
           nTxWeight{GetTransactionWeight(*tx)},
           nUsageSize{RecursiveDynamicUsage(tx)},
diff --git a/src/node/interfaces.cpp b/src/node/interfaces.cpp
index fd3fa226..0626e2c6 100644
--- a/src/node/interfaces.cpp
+++ b/src/node/interfaces.cpp
@@ -720,7 +720,7 @@ public:
     {
         if (!m_node.mempool) return {};
         LockPoints lp;
-        CTxMemPoolEntry entry(tx, 0, 0, 0, 0, false, 0, lp);
+        CTxMemPoolEntry entry(TxGraph::Ref(), tx, 0, 0, 0, 0, false, 0, lp);
         LOCK(m_node.mempool->cs);
         return m_node.mempool->CheckPackageLimits({tx}, entry.GetTxSize());
     }
diff --git a/src/test/fuzz/util/mempool.cpp b/src/test/fuzz/util/mempool.cpp
index a6a28f94..241a4d55 100644
--- a/src/test/fuzz/util/mempool.cpp
+++ b/src/test/fuzz/util/mempool.cpp
@@ -27,5 +27,5 @@ CTxMemPoolEntry ConsumeTxMemPoolEntry(FuzzedDataProvider& fuzzed_data_provider,
     const auto entry_height{fuzzed_data_provider.ConsumeIntegralInRange<uint32_t>(0, max_height)};
     const bool spends_coinbase = fuzzed_data_provider.ConsumeBool();
     const unsigned int sig_op_cost = fuzzed_data_provider.ConsumeIntegralInRange<unsigned int>(0, MAX_BLOCK_SIGOPS_COST);
-    return CTxMemPoolEntry{MakeTransactionRef(tx), fee, time, entry_height, entry_sequence, spends_coinbase, sig_op_cost, {}};
+    return CTxMemPoolEntry{TxGraph::Ref(), MakeTransactionRef(tx), fee, time, entry_height, entry_sequence, spends_coinbase, sig_op_cost, {}};
 }
diff --git a/src/test/util/txmempool.cpp b/src/test/util/txmempool.cpp
index 5febb679..0cb15b69 100644
--- a/src/test/util/txmempool.cpp
+++ b/src/test/util/txmempool.cpp
@@ -37,7 +37,7 @@ CTxMemPoolEntry TestMemPoolEntryHelper::FromTx(const CMutableTransaction& tx) co
 
 CTxMemPoolEntry TestMemPoolEntryHelper::FromTx(const CTransactionRef& tx) const
 {
-    return CTxMemPoolEntry{tx, nFee, TicksSinceEpoch<std::chrono::seconds>(time), nHeight, m_sequence, spendsCoinbase, sigOpCost, lp};
+    return CTxMemPoolEntry{TxGraph::Ref(), tx, nFee, TicksSinceEpoch<std::chrono::seconds>(time), nHeight, m_sequence, spendsCoinbase, sigOpCost, lp};
 }
 
 std::optional<std::string> CheckPackageMempoolAcceptResult(const Package& txns,
diff --git a/src/txmempool.cpp b/src/txmempool.cpp
index a695fbff..e6e2042e 100644
--- a/src/txmempool.cpp
+++ b/src/txmempool.cpp
@@ -1386,7 +1386,7 @@ CTxMemPool::ChangeSet::TxHandle CTxMemPool::ChangeSet::StageAddition(const CTran
 {
     LOCK(m_pool->cs);
     Assume(m_to_add.find(tx->GetHash()) == m_to_add.end());
-    auto newit = m_to_add.emplace(tx, fee, time, entry_height, entry_sequence, spends_coinbase, sigops_cost, lp).first;
+    auto newit = m_to_add.emplace(TxGraph::Ref(), tx, fee, time, entry_height, entry_sequence, spends_coinbase, sigops_cost, lp).first;
     CAmount delta{0};
     m_pool->ApplyDelta(tx->GetHash(), delta);
     if (delta) m_to_add.modify(newit, [&delta](CTxMemPoolEntry& e) { e.UpdateModifiedFee(delta); });