Merge branch 'develop' into ximinez/fix/validator-cache

- If any [validator_list_keys] are not available after all
  [validator_list_sites] have had a chance to be queried, then fall
  back to loading cache files. Currently, cache files are only used if
  no sites are defined, or the request to one of them has an error. It
  does not include cases where not enough sites are defined, or if a
  site returns an invalid VL (or something else entirely).
- Resolves #5320

include/xrpl/protocol/detail/features.macro

@@ -15,7 +15,6 @@
 // Add new amendments to the top of this list.
 // Keep it sorted in reverse chronological order.
 
-XRPL_FEATURE(DefragDirectories,          Supported::no,  VoteBehavior::DefaultNo)
 XRPL_FEATURE(MPTokensV2,                  Supported::no, VoteBehavior::DefaultNo)
 XRPL_FIX    (Security3_1_3,               Supported::no, VoteBehavior::DefaultNo)
 XRPL_FIX    (PermissionedDomainInvariant, Supported::yes, VoteBehavior::DefaultNo)

src/libxrpl/ledger/ApplyView.cpp

@@ -26,14 +26,6 @@ namespace xrpl {
 
 namespace directory {
 
-struct Gap
-{
-    uint64_t const page;
-    SLE::pointer node;
-    uint64_t const nextPage;
-    SLE::pointer next;
-};
-
 std::uint64_t
 createRoot(
     ApplyView& view,
@@ -134,9 +126,7 @@ insertPage(
     if (page == 0)
         return std::nullopt;
     if (!view.rules().enabled(fixDirectoryLimit) && page >= dirNodeMaxPages)  // Old pages limit
-    {
         return std::nullopt;
-    }
 
     // We are about to create a new node; we'll link it to
     // the chain first:
@@ -157,8 +147,12 @@ insertPage(
     // Save some space by not specifying the value 0 since it's the default.
     if (page != 1)
         node->setFieldU64(sfIndexPrevious, page - 1);
+    XRPL_ASSERT_PARTS(!nextPage, "xrpl::directory::insertPage", "nextPage has default value");
+    /* Reserved for future use when directory pages may be inserted in
+     * between two other pages instead of only at the end of the chain.
     if (nextPage)
         node->setFieldU64(sfIndexNext, nextPage);
+    */
     describe(node);
     view.insert(node);
 
@@ -174,7 +168,7 @@ ApplyView::dirAdd(
     uint256 const& key,
     std::function<void(std::shared_ptr<SLE> const&)> const& describe)
 {
-    auto const root = peek(directory);
+    auto root = peek(directory);
 
     if (!root)
     {
@@ -184,43 +178,6 @@ ApplyView::dirAdd(
 
     auto [page, node, indexes] = directory::findPreviousPage(*this, directory, root);
 
-    if (rules().enabled(featureDefragDirectories))
-    {
-        // If there are more nodes than just the root, and there's no space in
-        // the last one, walk backwards to find one with space, or to find one
-        // missing.
-        std::optional<directory::Gap> gapPages;
-        while (page && indexes.size() >= dirNodeMaxEntries)
-        {
-            // Find a page with space, or a gap in pages.
-            auto [prevPage, prevNode, prevIndexes] =
-                directory::findPreviousPage(*this, directory, node);
-            if (!gapPages && prevPage != page - 1)
-                gapPages.emplace(prevPage, prevNode, page, node);
-            page = prevPage;
-            node = prevNode;
-            indexes = prevIndexes;
-        }
-        // We looped through all the pages back to the root.
-        if (!page)
-        {
-            // If we found a gap, use it.
-            if (gapPages)
-            {
-                return directory::insertPage(
-                    *this,
-                    gapPages->page,
-                    gapPages->node,
-                    gapPages->nextPage,
-                    gapPages->next,
-                    key,
-                    directory,
-                    describe);
-            }
-            std::tie(page, node, indexes) = directory::findPreviousPage(*this, directory, root);
-        }
-    }
-
     // If there's space, we use it:
     if (indexes.size() < dirNodeMaxEntries)
     {

src/xrpld/app/misc/detail/ValidatorSite.cpp

@@ -161,7 +161,11 @@ ValidatorSite::load(
     {
         try
         {
-            sites_.emplace_back(uri);
+            // This is not super efficient, but it doesn't happen often.
+            bool found = std::ranges::any_of(
+                sites_, [&uri](auto const& site) { return site.loadedResource->uri == uri; });
+            if (!found)
+                sites_.emplace_back(uri);
         }
         catch (std::exception const& e)
         {
@@ -222,6 +226,16 @@ ValidatorSite::setTimer(
     std::lock_guard<std::mutex> const& site_lock,
     std::lock_guard<std::mutex> const& state_lock)
 {
+    if (!sites_.empty() &&  //
+        std::ranges::all_of(
+            sites_, [](auto const& site) { return site.lastRefreshStatus.has_value(); }))
+    {
+        // If all of the sites have been handled at least once (including
+        // errors and timeouts), call missingSite, which will load the cache
+        // files for any lists that are still unavailable.
+        missingSite(site_lock);
+    }
+
     auto next = std::min_element(sites_.begin(), sites_.end(), [](Site const& a, Site const& b) {
         return a.nextRefresh < b.nextRefresh;
     });
@@ -332,7 +346,7 @@ ValidatorSite::onRequestTimeout(std::size_t siteIdx, error_code const& ec)
         // processes a network error. Usually, this function runs first,
         // but on extremely rare occasions, the response handler can run
         // first, which will leave activeResource empty.
-        auto const& site = sites_[siteIdx];
+        auto& site = sites_[siteIdx];
         if (site.activeResource)
         {
             JLOG(j_.warn()) << "Request for " << site.activeResource->uri << " took too long";
@@ -340,6 +354,9 @@ ValidatorSite::onRequestTimeout(std::size_t siteIdx, error_code const& ec)
         else
             JLOG(j_.error()) << "Request took too long, but a response has "
                                 "already been processed";
+        if (!site.lastRefreshStatus)
+            site.lastRefreshStatus.emplace(
+                Site::Status{clock_type::now(), ListDisposition::invalid, "timeout"});
     }
 
     std::lock_guard const lock_state{state_mutex_};