Merge bitcoin/bitcoin#28391: refactor: Simplify CTxMempool/BlockAssembler fields, remove some external mapTx access

4dd94ca18f [refactor] remove access to mapTx in validation_block_tests (TheCharlatan)
d0cd2e804e [refactor] rewrite BlockAssembler inBlock and failedTx as sets of txids (glozow)
55b0939cab scripted-diff: rename vTxHashes to txns_randomized (TheCharlatan)
a03aef9cec [refactor] rewrite vTxHashes as a vector of CTransactionRef (glozow)
938643c3b2 [refactor] remove access to mapTx in validation.cpp (glozow)
333367a940 [txmempool] make CTxMemPoolEntry::lockPoints mutable (glozow)
1bf4855016 [refactor] use CheckPackageLimits for checkChainLimits (glozow)
dbc5bdbf59 [refactor] remove access to mapTx.find in mempool_tests.cpp (glozow)
f80909e7a3 [refactor] remove access to mapTx in blockencodings_tests.cpp (glozow)
8892d6b744 [refactor] remove access to mapTx from rpc/mempool.cpp (glozow)
fad61aa561 [refactor] get wtxid from entry instead of vTxHashes (glozow)
9cd8cafb77 [refactor] use exists() instead of mapTx.find() (glozow)
14804699e5 [refactor] remove access to mapTx from policy/rbf.cpp (glozow)
1c6a73abbd [refactor] Add helper for retrieving mempool entry (TheCharlatan)
453b4813eb [refactor] Add helper for iterating through mempool entries (stickies-v)

Pull request description:

  Motivation
  * It seems preferable to use stdlib data structures instead of boost if they can achieve close to the same thing.
  * Code external to mempool should ideally use its public helper methods instead of accessing `mapTx` or its iterators directly.
  * Reduce the number of complex boost multi index type interactions
  * Also see #28335 for further context/motivation. This PR together with #28385 simplifies that one.

  Overview of things done in this PR:
  * Make `vTxHashes` a vector of transaction references instead of a pair of transaction hash and iterator. The trade off here is that the data is retrieved on the fly with `GetEntry` instead of being cached in `vTxHashes`.
  * Introduce `GetEntry` helper method to replace the more involved `GetIter` where applicable
  * Replace `mapTx` access with `CTxMemPool` helper methods
  * Simplify `checkChainLimits` call in `node/interfaces.cpp`
  * Make `CTxMemPoolEntry`s `lockPoints`mutable such that they can be changed with a const iterator directly instead of going through `mapTx`
  * Make `BlockAssembler`'s `inBlock` and `failedTx` sets of transaction hashes.

ACKs for top commit:
  glozow:
    reACK 4dd94ca
  maflcko:
    re-ACK 4dd94ca18f 👝
  stickies-v:
    re-ACK 4dd94ca18f

Tree-SHA512: c4d043f2186e4fde337591883fac66cade3058173987b49502bd65cecf69207a3df1077f6626809652ab63230013167b7f39a2b39f1c5166959e5495df57065f

src/node/interfaces.cpp

@@ -648,8 +648,9 @@ public:
     {
         if (!m_node.mempool) return false;
         LOCK(m_node.mempool->cs);
-        auto it = m_node.mempool->GetIter(txid);
-        return it && (*it)->GetCountWithDescendants() > 1;
+        const auto entry{m_node.mempool->GetEntry(Txid::FromUint256(txid))};
+        if (entry == nullptr) return false;
+        return entry->GetCountWithDescendants() > 1;
     }
     bool broadcastTransaction(const CTransactionRef& tx,
         const CAmount& max_tx_fee,
@@ -702,9 +703,9 @@ public:
         if (!m_node.mempool) return true;
         LockPoints lp;
         CTxMemPoolEntry entry(tx, 0, 0, 0, 0, false, 0, lp);
-        const CTxMemPool::Limits& limits{m_node.mempool->m_limits};
         LOCK(m_node.mempool->cs);
-        return m_node.mempool->CalculateMemPoolAncestors(entry, limits).has_value();
+        std::string err_string;
+        return m_node.mempool->CheckPackageLimits({tx}, entry.GetTxSize(), err_string);
     }
     CFeeRate estimateSmartFee(int num_blocks, bool conservative, FeeCalculation* calc) override
     {
@@ -806,7 +807,7 @@ public:
     {
         if (!m_node.mempool) return;
         LOCK2(::cs_main, m_node.mempool->cs);
-        for (const CTxMemPoolEntry& entry : m_node.mempool->mapTx) {
+        for (const CTxMemPoolEntry& entry : m_node.mempool->entryAll()) {
             notifications.transactionAddedToMempool(entry.GetSharedTx());
         }
     }

src/node/miner.cpp

@@ -188,7 +188,7 @@ void BlockAssembler::onlyUnconfirmed(CTxMemPool::setEntries& testSet)
 {
     for (CTxMemPool::setEntries::iterator iit = testSet.begin(); iit != testSet.end(); ) {
         // Only test txs not already in the block
-        if (inBlock.count(*iit)) {
+        if (inBlock.count((*iit)->GetSharedTx()->GetHash())) {
             testSet.erase(iit++);
         } else {
             iit++;
@@ -229,7 +229,7 @@ void BlockAssembler::AddToBlock(CTxMemPool::txiter iter)
     ++nBlockTx;
     nBlockSigOpsCost += iter->GetSigOpCost();
     nFees += iter->GetFee();
-    inBlock.insert(iter);
+    inBlock.insert(iter->GetSharedTx()->GetHash());
 
     bool fPrintPriority = gArgs.GetBoolArg("-printpriority", DEFAULT_PRINTPRIORITY);
     if (fPrintPriority) {
@@ -298,7 +298,7 @@ void BlockAssembler::addPackageTxs(const CTxMemPool& mempool, int& nPackagesSele
     // because some of their txs are already in the block
     indexed_modified_transaction_set mapModifiedTx;
     // Keep track of entries that failed inclusion, to avoid duplicate work
-    CTxMemPool::setEntries failedTx;
+    std::set<Txid> failedTx;
 
     CTxMemPool::indexed_transaction_set::index<ancestor_score>::type::iterator mi = mempool.mapTx.get<ancestor_score>().begin();
     CTxMemPool::txiter iter;
@@ -326,7 +326,7 @@ void BlockAssembler::addPackageTxs(const CTxMemPool& mempool, int& nPackagesSele
         if (mi != mempool.mapTx.get<ancestor_score>().end()) {
             auto it = mempool.mapTx.project<0>(mi);
             assert(it != mempool.mapTx.end());
-            if (mapModifiedTx.count(it) || inBlock.count(it) || failedTx.count(it)) {
+            if (mapModifiedTx.count(it) || inBlock.count(it->GetSharedTx()->GetHash()) || failedTx.count(it->GetSharedTx()->GetHash())) {
                 ++mi;
                 continue;
             }
@@ -360,7 +360,7 @@ void BlockAssembler::addPackageTxs(const CTxMemPool& mempool, int& nPackagesSele
 
         // We skip mapTx entries that are inBlock, and mapModifiedTx shouldn't
         // contain anything that is inBlock.
-        assert(!inBlock.count(iter));
+        assert(!inBlock.count(iter->GetSharedTx()->GetHash()));
 
         uint64_t packageSize = iter->GetSizeWithAncestors();
         CAmount packageFees = iter->GetModFeesWithAncestors();
@@ -382,7 +382,7 @@ void BlockAssembler::addPackageTxs(const CTxMemPool& mempool, int& nPackagesSele
                 // we must erase failed entries so that we can consider the
                 // next best entry on the next loop iteration
                 mapModifiedTx.get<ancestor_score>().erase(modit);
-                failedTx.insert(iter);
+                failedTx.insert(iter->GetSharedTx()->GetHash());
             }
 
             ++nConsecutiveFailed;
@@ -404,7 +404,7 @@ void BlockAssembler::addPackageTxs(const CTxMemPool& mempool, int& nPackagesSele
         if (!TestPackageTransactions(ancestors)) {
             if (fUsingModified) {
                 mapModifiedTx.get<ancestor_score>().erase(modit);
-                failedTx.insert(iter);
+                failedTx.insert(iter->GetSharedTx()->GetHash());
             }
             continue;
         }

src/node/miner.h

@@ -142,7 +142,7 @@ private:
     uint64_t nBlockTx;
     uint64_t nBlockSigOpsCost;
     CAmount nFees;
-    CTxMemPool::setEntries inBlock;
+    std::unordered_set<Txid, SaltedTxidHasher> inBlock;
 
     // Chain context for the block
     int nHeight;