Merge branch 'develop' into ximinez/directory

This change updates a script in the documentation to automatically infer the version of a patched Conan dependency from the conan.lock file.

BUILD.md

@@ -141,26 +141,37 @@ Alternatively, you can pull the patched recipes into the repository and use them
 locally:
 
 ```bash
+# Extract the version number from the lockfile.
+function extract_version {
+  version=$(cat conan.lock | sed -nE "s@.+${1}/(.+)#.+@\1@p" | head -n1)
+  echo ${version}
+}
+
+# Define which recipes to export.
+recipes=(ed25519 grpc secp256k1 snappy soci)
+
+# Selectively check out the recipes from our CCI fork.
 cd external
 mkdir -p conan-center-index
 cd conan-center-index
 git init
 git remote add origin git@github.com:XRPLF/conan-center-index.git
 git sparse-checkout init
-git sparse-checkout set recipes/ed25519
+for recipe in ${recipes[@]}; do
-git sparse-checkout add recipes/grpc
+  echo "Checking out ${recipe}..."
-git sparse-checkout add recipes/secp256k1
+  git sparse-checkout add recipes/${recipe}/all
-git sparse-checkout add recipes/snappy
+done
-git sparse-checkout add recipes/soci
 git fetch origin master
 git checkout master
-rm -rf .git
 cd ../..
-conan export --version 2015.03 external/conan-center-index/recipes/ed25519/all
+
-conan export --version 1.72.0 external/conan-center-index/recipes/grpc/all
+# Export the recipes into the local cache.
-conan export --version 0.7.0 external/conan-center-index/recipes/secp256k1/all
+for recipe in ${recipes[@]}; do
-conan export --version 1.1.10 external/conan-center-index/recipes/snappy/all
+  version=$(extract_version ${recipe})
-conan export --version 4.0.3 external/conan-center-index/recipes/soci/all
+  echo "Exporting ${recipe}/${version}..."
+  conan export --version $(extract_version ${recipe}) \
+    external/conan-center-index/recipes/${recipe}/all
+done
 ```
 
 In the case we switch to a newer version of a dependency that still requires a

include/xrpl/protocol/detail/features.macro

@@ -16,6 +16,7 @@
 // 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

@@ -10,6 +10,14 @@ 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,
@@ -112,7 +120,9 @@ 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:
@@ -134,15 +144,8 @@ 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);
 
@@ -158,7 +161,7 @@ ApplyView::dirAdd(
     uint256 const& key,
     std::function<void(std::shared_ptr<SLE> const&)> const& describe)
 {
-    auto root = peek(directory);
+    auto const root = peek(directory);
 
     if (!root)
     {
@@ -169,6 +172,44 @@ 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)
     {