Avoid using ordered maps in LLMQ signing code (#2708)

* Implement and use SigShareMap instead of ordered map with helper methods

The old implementation was relying on the maps being ordered, which allowed
us to grab all sig shares for the same signHash by doing range queries on
the map. This has the disadvantage of being unnecessarily slow when the
maps get larger. Using an unordered map would be the naive solution, but
then it's not possible to query by range anymore.

The solution now is to have a specialized map "SigShareMap" which is
indexed by "SigShareKey". It's internally just an unordered map, indexed by
the sign hash and another unordered map for the value, indexed by the
quorum member index.

* Only use unordered maps/sets in CSigSharesManager

These are faster when maps/sets get larger.

* Use unorderes sets/maps in CSigningManager

src/llmq/quorums_signing.cpp

@@ -17,6 +17,7 @@
 
 #include <algorithm>
 #include <limits>
+#include <unordered_set>
 
 namespace llmq
 {
@@ -357,16 +358,16 @@ bool CSigningManager::PreVerifyRecoveredSig(NodeId nodeId, const CRecoveredSig&
 
 void CSigningManager::CollectPendingRecoveredSigsToVerify(
         size_t maxUniqueSessions,
-        std::map<NodeId, std::list<CRecoveredSig>>& retSigShares,
-        std::map<std::pair<Consensus::LLMQType, uint256>, CQuorumCPtr>& retQuorums)
+        std::unordered_map<NodeId, std::list<CRecoveredSig>>& retSigShares,
+        std::unordered_map<std::pair<Consensus::LLMQType, uint256>, CQuorumCPtr>& retQuorums)
 {
     {
         LOCK(cs);
         if (pendingRecoveredSigs.empty()) {
             return;
         }
 
-        std::set<std::pair<NodeId, uint256>> uniqueSignHashes;
+        std::unordered_set<std::pair<NodeId, uint256>> uniqueSignHashes;
         CLLMQUtils::IterateNodesRandom(pendingRecoveredSigs, [&]() {
             return uniqueSignHashes.size() < maxUniqueSessions;
         }, [&](NodeId nodeId, std::list<CRecoveredSig>& ns) {
@@ -423,8 +424,8 @@ void CSigningManager::CollectPendingRecoveredSigsToVerify(
 
 bool CSigningManager::ProcessPendingRecoveredSigs(CConnman& connman)
 {
-    std::map<NodeId, std::list<CRecoveredSig>> recSigsByNode;
-    std::map<std::pair<Consensus::LLMQType, uint256>, CQuorumCPtr> quorums;
+    std::unordered_map<NodeId, std::list<CRecoveredSig>> recSigsByNode;
+    std::unordered_map<std::pair<Consensus::LLMQType, uint256>, CQuorumCPtr> quorums;
 
     CollectPendingRecoveredSigsToVerify(32, recSigsByNode, quorums);
     if (recSigsByNode.empty()) {
@@ -453,7 +454,7 @@ bool CSigningManager::ProcessPendingRecoveredSigs(CConnman& connman)
 
     LogPrint("llmq", "CSigningManager::%s -- verified recovered sig(s). count=%d, vt=%d, nodes=%d\n", __func__, verifyCount, verifyTimer.count(), recSigsByNode.size());
 
-    std::set<uint256> processed;
+    std::unordered_set<uint256> processed;
     for (auto& p : recSigsByNode) {
         NodeId nodeId = p.first;
         auto& v = p.second;

src/llmq/quorums_signing.h

@@ -135,7 +135,7 @@ class CSigningManager
     CRecoveredSigsDb db;
 
     // Incoming and not verified yet
-    std::map<NodeId, std::list<CRecoveredSig>> pendingRecoveredSigs;
+    std::unordered_map<NodeId, std::list<CRecoveredSig>> pendingRecoveredSigs;
 
     // must be protected by cs
     FastRandomContext rnd;
@@ -156,7 +156,7 @@ class CSigningManager
     void ProcessMessageRecoveredSig(CNode* pfrom, const CRecoveredSig& recoveredSig, CConnman& connman);
     bool PreVerifyRecoveredSig(NodeId nodeId, const CRecoveredSig& recoveredSig, bool& retBan);
 
-    void CollectPendingRecoveredSigsToVerify(size_t maxUniqueSessions, std::map<NodeId, std::list<CRecoveredSig>>& retSigShares, std::map<std::pair<Consensus::LLMQType, uint256>, CQuorumCPtr>& retQuorums);
+    void CollectPendingRecoveredSigsToVerify(size_t maxUniqueSessions, std::unordered_map<NodeId, std::list<CRecoveredSig>>& retSigShares, std::unordered_map<std::pair<Consensus::LLMQType, uint256>, CQuorumCPtr>& retQuorums);
     bool ProcessPendingRecoveredSigs(CConnman& connman); // called from the worker thread of CSigSharesManager
     void ProcessRecoveredSig(NodeId nodeId, const CRecoveredSig& recoveredSig, const CQuorumCPtr& quorum, CConnman& connman);
     void Cleanup(); // called from the worker thread of CSigSharesManager