[FOLD] Address seelabs feedback

src/ripple/app/misc/SHAMapStoreImp.cpp

@@ -447,13 +447,14 @@ SHAMapStoreImp::run()
             }
 
             lastRotated_ = validatedSeq;
-            state_db_.setState(SavedState {
-                newBackend->getName(),
-                dbRotating_->getName(),
-                lastRotated_});
-
             clearCaches(validatedSeq);
-            dbRotating_->rotateBackends(std::move(newBackend));
+
+            SavedState savedState;
+            savedState.writableDb = newBackend->getName();
+            savedState.archiveDb = dbRotating_->rotateBackends(
+                std::move(newBackend));
+            savedState.lastRotated = lastRotated_;
+            state_db_.setState(savedState);
 
             JLOG(journal_.warn()) << "finished rotation " << validatedSeq;
         }

src/ripple/nodestore/DatabaseRotating.h

@@ -47,8 +47,10 @@ class DatabaseRotating : public Database
     TaggedCache<uint256, NodeObject> const&
     getPositiveCache() = 0;
 
+    /** Returns the name of the rotated backend.
+    */
     virtual
-    void
+    std::string
     rotateBackends(std::shared_ptr<Backend> newBackend) = 0;
 };
 

src/ripple/nodestore/impl/DatabaseRotatingImp.cpp

@@ -48,13 +48,14 @@ DatabaseRotatingImp::DatabaseRotatingImp(
     setParent(parent);
 }
 
-void
+std::string
 DatabaseRotatingImp::rotateBackends(std::shared_ptr<Backend> newBackend)
 {
     std::lock_guard lock(mutex_);
     archiveBackend_->setDeletePath();
     archiveBackend_ = std::move(writableBackend_);
     writableBackend_ = std::move(newBackend);
+    return archiveBackend_->getName();
 }
 
 std::string
@@ -148,27 +149,27 @@ DatabaseRotatingImp::sweep()
 std::shared_ptr<NodeObject>
 DatabaseRotatingImp::fetchFrom(uint256 const& hash, std::uint32_t seq)
 {
-    auto backends = [&] {
+    auto [writable, archive] = [&] {
         std::lock_guard lock(mutex_);
         return std::make_pair(writableBackend_, archiveBackend_);
     }();
 
     // Try to fetch from the writable backend
-    auto nObj = fetchInternal(hash, backends.first);
+    auto nObj = fetchInternal(hash, writable);
     if (! nObj)
     {
         // Otherwise try to fetch from the archive backend
-        nObj = fetchInternal(hash, backends.second);
+        nObj = fetchInternal(hash, archive);
         if (nObj)
         {
             {
                 // Refresh the writable backend pointer
                 std::lock_guard lock(mutex_);
-                backends.first = writableBackend_;
+                writable = writableBackend_;
             }
 
             // Update writable backend with data from the archive backend
-            backends.first->store(nObj);
+            writable->store(nObj);
             nCache_->erase(hash);
         }
     }
@@ -179,16 +180,16 @@ void
 DatabaseRotatingImp::for_each(
     std::function <void(std::shared_ptr<NodeObject>)> f)
 {
-    auto const backends = [&] {
+    auto [writable, archive] = [&] {
         std::lock_guard lock(mutex_);
         return std::make_pair(writableBackend_, archiveBackend_);
     }();
 
     // Iterate the writable backend
-    backends.first->for_each(f);
+    writable->for_each(f);
 
     // Iterate the archive backend
-    backends.second->for_each(f);
+    archive->for_each(f);
 }
 
 

src/ripple/nodestore/impl/DatabaseRotatingImp.h

@@ -48,7 +48,7 @@ class DatabaseRotatingImp : public DatabaseRotating
         stopThreads();
     }
 
-    void
+    std::string
     rotateBackends(std::shared_ptr<Backend> newBackend) override;
 
     std::string