Remove more dead code

src/xrpld/nodestore/Backend.h

@@ -39,29 +39,6 @@ namespace NodeStore {
 class Backend
 {
 public:
-    template <typename T>
-    struct Counters
-    {
-        Counters() = default;
-        Counters(Counters const&) = default;
-
-        template <typename U>
-        Counters(Counters<U> const& other)
-            : writeDurationUs(other.writeDurationUs)
-            , writeRetries(other.writeRetries)
-            , writesDelayed(other.writesDelayed)
-            , readRetries(other.readRetries)
-            , readErrors(other.readErrors)
-        {
-        }
-
-        T writeDurationUs = {};
-        T writeRetries = {};
-        T writesDelayed = {};
-        T readRetries = {};
-        T readErrors = {};
-    };
-
     /** Destroy the backend.
 
         All open files are closed and flushed. If there are batched writes
@@ -174,17 +151,6 @@ class Backend
     /** Returns the number of file descriptors the backend expects to need. */
     virtual int
     fdRequired() const = 0;
-
-    /** Returns read and write stats.
-
-        @note The Counters struct is specific to and only used
-              by CassandraBackend.
-    */
-    virtual std::optional<Counters<std::uint64_t>>
-    counters() const
-    {
-        return std::nullopt;
-    }
 };
 
 }  // namespace NodeStore

src/xrpld/nodestore/Database.h

@@ -302,17 +302,6 @@ class Database
     virtual void
     for_each(std::function<void(std::shared_ptr<NodeObject>)> f) = 0;
 
-    /** Retrieve backend read and write stats.
-
-        @note The Counters struct is specific to and only used
-              by CassandraBackend.
-    */
-    virtual std::optional<Backend::Counters<std::uint64_t>>
-    getCounters() const
-    {
-        return std::nullopt;
-    }
-
     void
     threadEntry();
 };

src/xrpld/nodestore/detail/Database.cpp

@@ -273,15 +273,6 @@ Database::getCountsJson(Json::Value& obj)
     obj[jss::node_written_bytes] = std::to_string(storeSz_);
     obj[jss::node_read_bytes] = std::to_string(fetchSz_);
     obj[jss::node_reads_duration_us] = std::to_string(fetchDurationUs_);
-
-    if (auto c = getCounters())
-    {
-        obj[jss::node_read_errors] = std::to_string(c->readErrors);
-        obj[jss::node_read_retries] = std::to_string(c->readRetries);
-        obj[jss::node_write_retries] = std::to_string(c->writeRetries);
-        obj[jss::node_writes_delayed] = std::to_string(c->writesDelayed);
-        obj[jss::node_writes_duration_us] = std::to_string(c->writeDurationUs);
-    }
 }
 
 }  // namespace NodeStore

src/xrpld/nodestore/detail/DatabaseNodeImp.h

@@ -150,12 +150,6 @@ class DatabaseNodeImp : public Database
     {
         backend_->for_each(f);
     }
-
-    std::optional<Backend::Counters<std::uint64_t>>
-    getCounters() const override
-    {
-        return backend_->counters();
-    }
 };
 
 }  // namespace NodeStore