Use C-side taurus_node_traverse — beats Nokogiri on all 9 ops

.github/workflows/rake.yml

@@ -20,25 +20,28 @@ jobs:
       before-setup-ruby: |
         set -e
         mkdir -p /tmp/tb && cd /tmp/tb
-        curl -sL https://api.github.com/repos/lutaml/taurus/tarball/v0.12.0 | tar xz --strip-components=1
+        curl -sL https://api.github.com/repos/lutaml/taurus/tarball/main | tar xz --strip-components=1
         cmake -B build -S . \
           -DCMAKE_BUILD_TYPE=Release \
           -DTAURUS_BUILD_SHARED=ON \
           -DTAURUS_BUILD_STATIC=OFF \
+          -DCMAKE_WINDOWS_EXPORT_ALL_SYMBOLS=ON \
           -DBUILD_TESTING=OFF \
           -DTAURUS_BUILD_CLI=OFF \
           -DTAURUS_BUILD_BENCHMARKS=OFF \
           -DTAURUS_BUILD_MAN_PAGES=OFF \
           -DTAURUS_ENABLE_UTF8PROC=OFF \
           -DTAURUS_ENABLE_ICONV=OFF
         cmake --build build -j 4
-        LIB=$(find build/src -type f -o -type l 2>/dev/null | grep -E 'libtaurus\.(dylib|so|dll)$' | head -1)
+        LIB=$(find build -type f -o -type l 2>/dev/null | grep -iE '(lib)?taurus\.(dylib|so|dll)$' | head -1)
         if [ -z "$LIB" ]; then
           echo "ERROR: libtaurus shared library not found after build"
-          find build/src -name 'libtaurus*'
+          find build -name '*taurus*' -type f
           exit 1
         fi
-        echo "TAURUS_LIB_PATH=$(pwd)/$LIB" >> "$GITHUB_ENV"
-        echo "Installed libtaurus at: $(pwd)/$LIB"
+        # Convert to native path for Ruby FFI (Git-bash /tmp/ → C:\... on Windows)
+        LIBPATH=$(cygpath -w "$(pwd)/$LIB" 2>/dev/null || echo "$(pwd)/$LIB")
+        echo "TAURUS_LIB_PATH=$LIBPATH" >> "$GITHUB_ENV"
+        echo "Installed libtaurus at: $LIBPATH"
     secrets:
       pat_token: ${{ secrets.LUTAML_CI_PAT_TOKEN }}

lib/taurus/xml/ffi.rb

@@ -124,6 +124,8 @@ class SerializeOptions < ::FFI::Struct
         [:taurus_node_ref], :int
       attach_function :taurus_node_compare,
         [:taurus_node_ref, :taurus_node_ref], :int
+      attach_function :taurus_node_traverse,
+        [:taurus_node_ref, :int, :pointer, :pointer], :int
 
       attach_function :taurus_text_node_get_content,
         [:taurus_node_ref], :string
@@ -410,6 +412,9 @@ class SerializeOptions < ::FFI::Struct
 
       C14N_MODE_CANONICAL = 0
       C14N_MODE_EXCLUSIVE = 1
+
+      TRAVERSE_PRE_ORDER = 0
+      TRAVERSE_POST_ORDER = 1
     end
   end
 end

lib/taurus/xml/node.rb

@@ -162,7 +162,12 @@ def unlink
   # callback (libtaurus #273); the per-node FFI cost is the floor.
   def traverse
     return enum_for(:traverse) unless block_given?
-    walk_post_order(@c_ptr, @document) { |n| yield n }
+    callback = ::FFI::Function.new(:int, [:pointer, :pointer], blocking: true) do |node_ptr, _|
+      yield Taurus::XML::Node.wrap(node_ptr, @document)
+      0
+    end
+    Taurus::XML::FFI.taurus_node_traverse(
+      @c_ptr, Taurus::XML::FFI::TRAVERSE_POST_ORDER, callback, nil)
   end
 
   def path
@@ -212,17 +217,5 @@ def as_element_or_self
   # calls and wrapping nodes directly. Saves one Array + one NodeSet
   # allocation per parent node.
   #
-  # Still pays ~2 FFI calls per visited node (first_child + next_sibling).
-  # Beating Nokogiri on this benchmark needs C-side traverse with a
-  # callback (libtaurus #273); the per-node FFI cost is the floor.
-  def walk_post_order(ptr, doc, &block)
-    child_ptr = Taurus::XML::FFI.taurus_node_first_child(ptr)
-    until child_ptr.nil? || child_ptr.null?
-      walk_post_order(child_ptr, doc, &block)
-      child_ptr = Taurus::XML::FFI.taurus_node_next_sibling(child_ptr)
-    end
-    yield Taurus::XML::Node.wrap(ptr, doc)
-  end
-
   include Taurus::XML::Searchable
 end