refactor: Revert "perf: Remove unnecessary caches (#5439)" (#7359)

Co-authored-by: Bart <11445373+bthomee@users.noreply.github.com>

include/xrpl/nodestore/Database.h

@@ -131,6 +131,10 @@ public:
         std::uint32_t ledgerSeq,
         std::function<void(std::shared_ptr<NodeObject> const&)>&& callback);
 
+    /** Remove expired entries from the positive and negative caches. */
+    virtual void
+    sweep() = 0;
+
     /** Gather statistics pertaining to read and write activities.
      *
      * @param obj Json object reference into which to place counters.

include/xrpl/nodestore/detail/DatabaseNodeImp.h

@@ -22,6 +22,32 @@ public:
         beast::Journal j)
         : 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.has_value() || cacheAge.has_value())
+        {
+            cache_ = std::make_shared<TaggedCache<uint256, NodeObject>>(
+                "DatabaseNodeImp",
+                cacheSize.value_or(0),
+                std::chrono::minutes(cacheAge.value_or(0)),
+                stopwatch(),
+                j);
+        }
+
         XRPL_ASSERT(
             backend_,
             "xrpl::NodeStore::DatabaseNodeImp::DatabaseNodeImp : non-null "
@@ -73,7 +99,13 @@ public:
         std::uint32_t ledgerSeq,
         std::function<void(std::shared_ptr<NodeObject> const&)>&& callback) override;
 
+    void
+    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_;
 

include/xrpl/nodestore/detail/DatabaseRotatingImp.h

@@ -55,6 +55,9 @@ public:
     void
     sync() override;
 
+    void
+    sweep() override;
+
 private:
     std::shared_ptr<Backend> writableBackend_;
     std::shared_ptr<Backend> archiveBackend_;