Remove cache from DatabaseNodeImp

src/xrpld/nodestore/detail/DatabaseNodeImp.cpp

@@ -33,14 +33,6 @@ DatabaseNodeImp::store(
 
     auto obj = NodeObject::createObject(type, std::move(data), hash);
     backend_->store(obj);
-    if (cache_)
-    {
-        // After the store, replace a negative cache entry if there is one
-        cache_->canonicalize(
-            hash, obj, [](std::shared_ptr<NodeObject> const& n) {
-                return n->getType() == hotDUMMY;
-            });
-    }
 }
 
 void
@@ -49,23 +41,12 @@ DatabaseNodeImp::asyncFetch(
     std::uint32_t ledgerSeq,
     std::function<void(std::shared_ptr<NodeObject> const&)>&& callback)
 {
-    if (cache_)
-    {
-        std::shared_ptr<NodeObject> obj = cache_->fetch(hash);
-        if (obj)
-        {
-            callback(obj->getType() == hotDUMMY ? nullptr : obj);
-            return;
-        }
-    }
     Database::asyncFetch(hash, ledgerSeq, std::move(callback));
 }
 
 void
 DatabaseNodeImp::sweep()
 {
-    if (cache_)
-        cache_->sweep();
 }
 
 std::shared_ptr<NodeObject>
@@ -75,64 +56,33 @@ DatabaseNodeImp::fetchNodeObject(
     FetchReport& fetchReport,
     bool duplicate)
 {
-    std::shared_ptr<NodeObject> nodeObject =
-        cache_ ? cache_->fetch(hash) : nullptr;
+    std::shared_ptr<NodeObject> nodeObject = nullptr;
+    Status status;
 
-    if (!nodeObject)
+    try
     {
-        JLOG(j_.trace()) << "fetchNodeObject " << hash << ": record not "
-                         << (cache_ ? "cached" : "found");
-
-        Status status;
-
-        try
-        {
-            status = backend_->fetch(hash.data(), &nodeObject);
-        }
-        catch (std::exception const& e)
-        {
-            JLOG(j_.fatal())
-                << "fetchNodeObject " << hash
-                << ": Exception fetching from backend: " << e.what();
-            Rethrow();
-        }
-
-        switch (status)
-        {
-            case ok:
-                if (cache_)
-                {
-                    if (nodeObject)
-                        cache_->canonicalize_replace_client(hash, nodeObject);
-                    else
-                    {
-                        auto notFound =
-                            NodeObject::createObject(hotDUMMY, {}, hash);
-                        cache_->canonicalize_replace_client(hash, notFound);
-                        if (notFound->getType() != hotDUMMY)
-                            nodeObject = notFound;
-                    }
-                }
-                break;
-            case notFound:
-                break;
-            case dataCorrupt:
-                JLOG(j_.fatal()) << "fetchNodeObject " << hash
-                                 << ": nodestore data is corrupted";
-                break;
-            default:
-                JLOG(j_.warn())
-                    << "fetchNodeObject " << hash
-                    << ": backend returns unknown result " << status;
-                break;
-        }
+        status = backend_->fetch(hash.data(), &nodeObject);
     }
-    else
+    catch (std::exception const& e)
     {
-        JLOG(j_.trace()) << "fetchNodeObject " << hash
-                         << ": record found in cache";
-        if (nodeObject->getType() == hotDUMMY)
-            nodeObject.reset();
+        JLOG(j_.fatal()) << "fetchNodeObject " << hash
+                         << ": Exception fetching from backend: " << e.what();
+        Rethrow();
+    }
+
+    switch (status)
+    {
+        case ok:
+        case notFound:
+            break;
+        case dataCorrupt:
+            JLOG(j_.fatal()) << "fetchNodeObject " << hash
+                             << ": nodestore data is corrupted";
+            break;
+        default:
+            JLOG(j_.warn()) << "fetchNodeObject " << hash
+                            << ": backend returns unknown result " << status;
+            break;
     }
 
     if (nodeObject)
@@ -144,71 +94,33 @@ DatabaseNodeImp::fetchNodeObject(
 std::vector<std::shared_ptr<NodeObject>>
 DatabaseNodeImp::fetchBatch(std::vector<uint256> const& hashes)
 {
-    std::vector<std::shared_ptr<NodeObject>> results{hashes.size()};
     using namespace std::chrono;
     auto const before = steady_clock::now();
-    std::unordered_map<uint256 const*, size_t> indexMap;
-    std::vector<uint256 const*> cacheMisses;
-    uint64_t hits = 0;
-    uint64_t fetches = 0;
+
+    std::vector<uint256 const*> batch;
     for (size_t i = 0; i < hashes.size(); ++i)
     {
         auto const& hash = hashes[i];
-        // See if the object already exists in the cache
-        auto nObj = cache_ ? cache_->fetch(hash) : nullptr;
-        ++fetches;
-        if (!nObj)
-        {
-            // Try the database
-            indexMap[&hash] = i;
-            cacheMisses.push_back(&hash);
-        }
-        else
-        {
-            results[i] = nObj->getType() == hotDUMMY ? nullptr : nObj;
-            // It was in the cache.
-            ++hits;
-        }
+        batch.push_back(&hash);
     }
 
-    JLOG(j_.debug()) << "fetchBatch - cache hits = "
-                     << (hashes.size() - cacheMisses.size())
-                     << " - cache misses = " << cacheMisses.size();
-    auto dbResults = backend_->fetchBatch(cacheMisses).first;
-
-    for (size_t i = 0; i < dbResults.size(); ++i)
+    std::vector<std::shared_ptr<NodeObject>> results{hashes.size()};
+    results = backend_->fetchBatch(batch).first;
+    for (size_t i = 0; i < results.size(); ++i)
     {
-        auto nObj = std::move(dbResults[i]);
-        size_t index = indexMap[cacheMisses[i]];
-        auto const& hash = hashes[index];
-
-        if (nObj)
-        {
-            // Ensure all threads get the same object
-            if (cache_)
-                cache_->canonicalize_replace_client(hash, nObj);
-        }
-        else
+        if (!results[i])
         {
             JLOG(j_.error())
                 << "fetchBatch - "
-                << "record not found in db or cache. hash = " << strHex(hash);
-            if (cache_)
-            {
-                auto notFound = NodeObject::createObject(hotDUMMY, {}, hash);
-                cache_->canonicalize_replace_client(hash, notFound);
-                if (notFound->getType() != hotDUMMY)
-                    nObj = std::move(notFound);
-            }
+                << "record not found in db. hash = " << strHex(hashes[i]);
         }
-        results[index] = std::move(nObj);
     }
 
     auto fetchDurationUs =
         std::chrono::duration_cast<std::chrono::microseconds>(
             steady_clock::now() - before)
             .count();
-    updateFetchMetrics(fetches, hits, fetchDurationUs);
+    updateFetchMetrics(hashes.size(), 0, fetchDurationUs);
     return results;
 }
 

src/xrpld/nodestore/detail/DatabaseNodeImp.h

@@ -45,38 +45,6 @@ public:
         : Database(scheduler, readThreads, config, j)
         , backend_(std::move(backend))
     {
-        std::optional<int> cacheSize, cacheAge;
-
-        if (config.exists("cache_size"))
-        {
-            cacheSize = get<int>(config, "cache_size");
-            if (cacheSize.value() < 0)
-            {
-                Throw<std::runtime_error>(
-                    "Specified negative value for cache_size");
-            }
-        }
-
-        if (config.exists("cache_age"))
-        {
-            cacheAge = get<int>(config, "cache_age");
-            if (cacheAge.value() < 0)
-            {
-                Throw<std::runtime_error>(
-                    "Specified negative value for cache_age");
-            }
-        }
-
-        /*if (cacheSize != 0 || cacheAge != 0)
-        {
-            cache_ = std::make_shared<TaggedCache<uint256, NodeObject>>(
-                "DatabaseNodeImp",
-                cacheSize.value_or(0),
-                std::chrono::minutes(cacheAge.value_or(0)),
-                stopwatch(),
-                j);
-        }*/
-
         XRPL_ASSERT(
             backend_,
             "ripple::NodeStore::DatabaseNodeImp::DatabaseNodeImp : non-null "
@@ -137,9 +105,6 @@ public:
     sweep() override;
 
 private:
-    // Cache for database objects. This cache is not always initialized. Check
-    // for null before using.
-    std::shared_ptr<TaggedCache<uint256, NodeObject>> cache_;
     // Persistent key/value storage
     std::shared_ptr<Backend> backend_;