Merge bitcoin/bitcoin#22221: refactor: Pass block reference instead of pointer to PeerManagerImpl::BlockRequested

fa334b4 refactor: Pass block reference instead of pointer to PeerManagerImpl::BlockRequested (MarcoFalke)

Pull request description:

  This allows to remove an assert and at the same time make it more obvious that the block is never nullptr.

  Also, add missing `{}` while touching the function.

ACKs for top commit:
  jnewbery:
    Code review ACK fa334b4
  mjdietzx:
    crACK fa334b4
  theStack:
    Code review ACK fa334b4

Tree-SHA512: 9733d3e20e048fcb2ac7510eae3539ce8aaa7397bd944a265123f1ffd90e15637cdaad19dba16f76d83f3f0d1888f1b7014c191bb430e410a106c49ca61a725c

Author: fanquake

src/net_processing.cpp

@@ -476,7 +476,7 @@ class PeerManagerImpl final : public PeerManager
      * Returns false, still setting pit, if the block was already in flight from the same peer
      * pit will only be valid as long as the same cs_main lock is being held
      */
-    bool BlockRequested(NodeId nodeid, const CBlockIndex* pindex, std::list<QueuedBlock>::iterator** pit = nullptr) EXCLUSIVE_LOCKS_REQUIRED(cs_main);
+    bool BlockRequested(NodeId nodeid, const CBlockIndex& block, std::list<QueuedBlock>::iterator** pit = nullptr) EXCLUSIVE_LOCKS_REQUIRED(cs_main);
 
     bool TipMayBeStale() EXCLUSIVE_LOCKS_REQUIRED(cs_main);
 
@@ -793,10 +793,9 @@ void PeerManagerImpl::RemoveBlockRequest(const uint256& hash)
     mapBlocksInFlight.erase(it);
 }
 
-bool PeerManagerImpl::BlockRequested(NodeId nodeid, const CBlockIndex* pindex, std::list<QueuedBlock>::iterator** pit)
+bool PeerManagerImpl::BlockRequested(NodeId nodeid, const CBlockIndex& block, std::list<QueuedBlock>::iterator** pit)
 {
-    assert(pindex);
-    const uint256& hash{pindex->GetBlockHash()};
+    const uint256& hash{block.GetBlockHash()};
 
     CNodeState *state = State(nodeid);
     assert(state != nullptr);
@@ -814,16 +813,17 @@ bool PeerManagerImpl::BlockRequested(NodeId nodeid, const CBlockIndex* pindex, s
     RemoveBlockRequest(hash);
 
     std::list<QueuedBlock>::iterator it = state->vBlocksInFlight.insert(state->vBlocksInFlight.end(),
-            {pindex, std::unique_ptr<PartiallyDownloadedBlock>(pit ? new PartiallyDownloadedBlock(&m_mempool) : nullptr)});
+            {&block, std::unique_ptr<PartiallyDownloadedBlock>(pit ? new PartiallyDownloadedBlock(&m_mempool) : nullptr)});
     state->nBlocksInFlight++;
     if (state->nBlocksInFlight == 1) {
         // We're starting a block download (batch) from this peer.
         state->m_downloading_since = GetTime<std::chrono::microseconds>();
         m_peers_downloading_from++;
     }
     itInFlight = mapBlocksInFlight.insert(std::make_pair(hash, std::make_pair(nodeid, it))).first;
-    if (pit)
+    if (pit) {
         *pit = &itInFlight->second.second;
+    }
     return true;
 }
 
@@ -2091,7 +2091,7 @@ void PeerManagerImpl::ProcessHeadersMessage(CNode& pfrom, const Peer& peer,
                     }
                     uint32_t nFetchFlags = GetFetchFlags(pfrom);
                     vGetData.push_back(CInv(MSG_BLOCK | nFetchFlags, pindex->GetBlockHash()));
-                    BlockRequested(pfrom.GetId(), pindex);
+                    BlockRequested(pfrom.GetId(), *pindex);
                     LogPrint(BCLog::NET, "Requesting block %s from  peer=%d\n",
                             pindex->GetBlockHash().ToString(), pfrom.GetId());
                 }
@@ -3394,7 +3394,7 @@ void PeerManagerImpl::ProcessMessage(CNode& pfrom, const std::string& msg_type,
             if ((!fAlreadyInFlight && nodestate->nBlocksInFlight < MAX_BLOCKS_IN_TRANSIT_PER_PEER) ||
                  (fAlreadyInFlight && blockInFlightIt->second.first == pfrom.GetId())) {
                 std::list<QueuedBlock>::iterator* queuedBlockIt = nullptr;
-                if (!BlockRequested(pfrom.GetId(), pindex, &queuedBlockIt)) {
+                if (!BlockRequested(pfrom.GetId(), *pindex, &queuedBlockIt)) {
                     if (!(*queuedBlockIt)->partialBlock)
                         (*queuedBlockIt)->partialBlock.reset(new PartiallyDownloadedBlock(&m_mempool));
                     else {
@@ -4778,7 +4778,7 @@ bool PeerManagerImpl::SendMessages(CNode* pto)
             for (const CBlockIndex *pindex : vToDownload) {
                 uint32_t nFetchFlags = GetFetchFlags(*pto);
                 vGetData.push_back(CInv(MSG_BLOCK | nFetchFlags, pindex->GetBlockHash()));
-                BlockRequested(pto->GetId(), pindex);
+                BlockRequested(pto->GetId(), *pindex);
                 LogPrint(BCLog::NET, "Requesting block %s (%d) peer=%d\n", pindex->GetBlockHash().ToString(),
                     pindex->nHeight, pto->GetId());
             }