Use unordered_lru_cache in CRecoveredSigsDb

src/llmq/quorums_signing.cpp

@@ -37,66 +37,57 @@ bool CRecoveredSigsDb::HasRecoveredSig(Consensus::LLMQType llmqType, const uint2
 
 bool CRecoveredSigsDb::HasRecoveredSigForId(Consensus::LLMQType llmqType, const uint256& id)
 {
-    int64_t t = GetTimeMillis();
-
     auto cacheKey = std::make_pair(llmqType, id);
+    bool ret;
     {
         LOCK(cs);
-        auto it = hasSigForIdCache.find(cacheKey);
-        if (it != hasSigForIdCache.end()) {
-            it->second.second = t;
-            return it->second.first;
+        if (hasSigForIdCache.get(cacheKey, ret)) {
+            return ret;
         }
     }
 
 
     auto k = std::make_tuple(std::string("rs_r"), (uint8_t)llmqType, id);
-    bool ret = db.Exists(k);
+    ret = db.Exists(k);
 
     LOCK(cs);
-    hasSigForIdCache.emplace(cacheKey, std::make_pair(ret, t));
+    hasSigForIdCache.insert(cacheKey, ret);
     return ret;
 }
 
 bool CRecoveredSigsDb::HasRecoveredSigForSession(const uint256& signHash)
 {
-    int64_t t = GetTimeMillis();
-
+    bool ret;
     {
         LOCK(cs);
-        auto it = hasSigForSessionCache.find(signHash);
-        if (it != hasSigForSessionCache.end()) {
-            it->second.second = t;
-            return it->second.first;
+        if (hasSigForSessionCache.get(signHash, ret)) {
+            return ret;
         }
     }
 
     auto k = std::make_tuple(std::string("rs_s"), signHash);
-    bool ret = db.Exists(k);
+    ret = db.Exists(k);
 
     LOCK(cs);
-    hasSigForSessionCache.emplace(signHash, std::make_pair(ret, t));
+    hasSigForSessionCache.insert(signHash, ret);
     return ret;
 }
 
 bool CRecoveredSigsDb::HasRecoveredSigForHash(const uint256& hash)
 {
-    int64_t t = GetTimeMillis();
-
+    bool ret;
     {
         LOCK(cs);
-        auto it = hasSigForHashCache.find(hash);
-        if (it != hasSigForHashCache.end()) {
-            it->second.second = t;
-            return it->second.first;
+        if (hasSigForHashCache.get(hash, ret)) {
+            return ret;
         }
     }
 
     auto k = std::make_tuple(std::string("rs_h"), hash);
-    bool ret = db.Exists(k);
+    ret = db.Exists(k);
 
     LOCK(cs);
-    hasSigForHashCache.emplace(hash, std::make_pair(ret, t));
+    hasSigForHashCache.insert(hash, ret);
     return ret;
 }
 
@@ -167,34 +158,9 @@ void CRecoveredSigsDb::WriteRecoveredSig(const llmq::CRecoveredSig& recSig)
         int64_t t = GetTimeMillis();
 
         LOCK(cs);
-        hasSigForIdCache[std::make_pair((Consensus::LLMQType)recSig.llmqType, recSig.id)] = std::make_pair(true, t);
-        hasSigForSessionCache[signHash] = std::make_pair(true, t);
-        hasSigForHashCache[recSig.GetHash()] = std::make_pair(true, t);
-    }
-}
-
-template<typename K, typename H>
-static void TruncateCacheMap(std::unordered_map<K, std::pair<bool, int64_t>, H>& m, size_t maxSize, size_t truncateThreshold)
-{
-    typedef typename std::unordered_map<K, std::pair<bool, int64_t>, H> Map;
-    typedef typename Map::iterator Iterator;
-
-    if (m.size() <= truncateThreshold) {
-        return;
-    }
-
-    std::vector<Iterator> vec;
-    vec.reserve(m.size());
-    for (auto it = m.begin(); it != m.end(); ++it) {
-        vec.emplace_back(it);
-    }
-    // sort by last access time (descending order)
-    std::sort(vec.begin(), vec.end(), [](const Iterator& it1, const Iterator& it2) {
-        return it1->second.second > it2->second.second;
-    });
-
-    for (size_t i = maxSize; i < vec.size(); i++) {
-        m.erase(vec[i]);
+        hasSigForIdCache.insert(std::make_pair((Consensus::LLMQType)recSig.llmqType, recSig.id), true);
+        hasSigForSessionCache.insert(signHash, true);
+        hasSigForHashCache.insert(recSig.GetHash(), true);
     }
 }
 
@@ -257,10 +223,6 @@ void CRecoveredSigsDb::CleanupOldRecoveredSigs(int64_t maxAge)
             hasSigForSessionCache.erase(signHash);
             hasSigForHashCache.erase(recSig.GetHash());
         }
-
-        TruncateCacheMap(hasSigForIdCache, MAX_CACHE_SIZE, MAX_CACHE_TRUNCATE_THRESHOLD);
-        TruncateCacheMap(hasSigForSessionCache, MAX_CACHE_SIZE, MAX_CACHE_TRUNCATE_THRESHOLD);
-        TruncateCacheMap(hasSigForHashCache, MAX_CACHE_SIZE, MAX_CACHE_TRUNCATE_THRESHOLD);
     }
 
     for (auto& e : toDelete2) {

src/llmq/quorums_signing.h

@@ -10,6 +10,7 @@
 #include "net.h"
 #include "chainparams.h"
 #include "saltedhasher.h"
+#include "unordered_lru_cache.h"
 
 #include <unordered_map>
 
@@ -68,16 +69,13 @@ class CRecoveredSig
 
 class CRecoveredSigsDb
 {
-    static const size_t MAX_CACHE_SIZE = 30000;
-    static const size_t MAX_CACHE_TRUNCATE_THRESHOLD = 50000;
-
 private:
     CDBWrapper& db;
 
     CCriticalSection cs;
-    std::unordered_map<std::pair<Consensus::LLMQType, uint256>, std::pair<bool, int64_t>, StaticSaltedHasher> hasSigForIdCache;
-    std::unordered_map<uint256, std::pair<bool, int64_t>, StaticSaltedHasher> hasSigForSessionCache;
-    std::unordered_map<uint256, std::pair<bool, int64_t>, StaticSaltedHasher> hasSigForHashCache;
+    unordered_lru_cache<std::pair<Consensus::LLMQType, uint256>, bool, StaticSaltedHasher, 30000> hasSigForIdCache;
+    unordered_lru_cache<uint256, bool, StaticSaltedHasher, 30000> hasSigForSessionCache;
+    unordered_lru_cache<uint256, bool, StaticSaltedHasher, 30000> hasSigForHashCache;
 
 public:
     CRecoveredSigsDb(CDBWrapper& _db);