Merge branch 'develop' into ximinez/emptydirectoryinvariant

* XRPLF/develop:
  Implement Lending Protocol (unsupported) (5270)

include/xrpl/protocol/detail/features.macro

@@ -16,7 +16,6 @@
 // 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(LendingProtocol,            Supported::no,  VoteBehavior::DefaultNo)
 XRPL_FEATURE(PermissionDelegationV1_1,   Supported::no,  VoteBehavior::DefaultNo)
 XRPL_FIX    (DirectoryLimit,             Supported::yes, VoteBehavior::DefaultNo)

src/libxrpl/ledger/ApplyView.cpp

@@ -10,14 +10,6 @@ namespace ripple {
 
 namespace directory {
 
-struct Gap
-{
-    uint64_t const page;
-    SLE::pointer node;
-    uint64_t const nextPage;
-    SLE::pointer next;
-};
-
 std::uint64_t
 createRoot(
     ApplyView& view,
@@ -120,9 +112,7 @@ insertPage(
         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:
@@ -144,8 +134,15 @@ insertPage(
     // it's the default.
     if (page != 1)
         node->setFieldU64(sfIndexPrevious, page - 1);
+    XRPL_ASSERT_PARTS(
+        !nextPage,
+        "ripple::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);
 
@@ -161,7 +158,7 @@ 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)
     {
@@ -172,44 +169,6 @@ 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)
     {
@@ -297,6 +256,7 @@ ApplyView::dirRemove(
     uint256 const& key,
     bool keepRoot)
 {
+    keepRoot = false;
     auto node = peek(keylet::page(directory, page));
 
     if (!node)

src/xrpld/app/tx/detail/InvariantCheck.cpp

@@ -3553,4 +3553,42 @@ ValidVault::finalize(
     return true;
 }
 
+//------------------------------------------------------------------------------
+
+void
+NoEmptyDirectory::visitEntry(
+    bool isDelete,
+    std::shared_ptr<SLE const> const& before,
+    std::shared_ptr<SLE const> const& after)
+{
+    if (isDelete)
+        return;
+    if (before && before->getType() != ltDIR_NODE)
+        return;
+    if (after && after->getType() != ltDIR_NODE)
+        return;
+    if (!after->isFieldPresent(sfOwner))
+        // Not an account dir
+        return;
+
+    bad_ = after->at(sfIndexes).empty();
+}
+
+bool
+NoEmptyDirectory::finalize(
+    STTx const& tx,
+    TER const result,
+    XRPAmount const,
+    ReadView const& view,
+    beast::Journal const& j)
+{
+    if (bad_)
+    {
+        JLOG(j.fatal()) << "Invariant failed: empty owner directory.";
+        return false;
+    }
+
+    return true;
+}
+
 }  // namespace ripple

src/xrpld/app/tx/detail/InvariantCheck.h

@@ -901,6 +901,30 @@ public:
         beast::Journal const&);
 };
 
+/**
+ * @brief Invariants: An account's directory should never be empty
+ *
+ */
+class NoEmptyDirectory
+{
+    bool bad_ = false;
+
+public:
+    void
+    visitEntry(
+        bool,
+        std::shared_ptr<SLE const> const&,
+        std::shared_ptr<SLE const> const&);
+
+    bool
+    finalize(
+        STTx const&,
+        TER const,
+        XRPAmount const,
+        ReadView const&,
+        beast::Journal const&);
+};
+
 // additional invariant checks can be declared above and then added to this
 // tuple
 using InvariantChecks = std::tuple<
@@ -927,7 +951,8 @@ using InvariantChecks = std::tuple<
     ValidPseudoAccounts,
     ValidLoanBroker,
     ValidLoan,
-    ValidVault>;
+    ValidVault,
+    NoEmptyDirectory>;
 
 /**
  * @brief get a tuple of all invariant checks