intermediate changes

ref:cde9a383711a11544ce7e107a78147fb96cc4029

1 files changed, 152 insertions, 0 deletions

diff --git a/library/cpp/yson/node/node_visitor.cpp b/library/cpp/yson/node/node_visitor.cpp
new file mode 100644
index 0000000000..899fbfa02a
--- /dev/null
+++ b/library/cpp/yson/node/node_visitor.cpp
@@ -0,0 +1,152 @@
+#include "node_visitor.h"
+
+#include <util/generic/algorithm.h>
+#include <util/string/printf.h>
+
+namespace NYT {
+
+////////////////////////////////////////////////////////////////////////////////
+
+namespace {
+
+template <typename Fun>
+void Iterate(const TNode::TMapType& nodeMap, bool sortByKey, Fun action)
+{
+    if (sortByKey) {
+        TVector<TNode::TMapType::const_iterator> iterators;
+        for (auto it = nodeMap.begin(); it != nodeMap.end(); ++it) {
+            iterators.push_back(it);
+        }
+        SortBy(iterators, [](TNode::TMapType::const_iterator it) { return it->first; });
+        for (const auto& it : iterators) {
+            action(*it);
+        }
+    } else {
+        ForEach(nodeMap.begin(), nodeMap.end(), action);
+    }
+}
+
+} // namespace
+
+////////////////////////////////////////////////////////////////////////////////
+
+TNodeVisitor::TNodeVisitor(NYson::IYsonConsumer* consumer, bool sortMapKeys)
+    : Consumer_(consumer)
+    , SortMapKeys_(sortMapKeys)
+{ }
+
+void TNodeVisitor::Visit(const TNode& node)
+{
+    VisitAny(node);
+}
+
+void TNodeVisitor::VisitAny(const TNode& node)
+{
+    if (node.HasAttributes()) {
+        Consumer_->OnBeginAttributes();
+        Iterate(node.GetAttributes().AsMap(), SortMapKeys_, [&](const std::pair<TString, TNode>& item) {
+            Consumer_->OnKeyedItem(item.first);
+            if (item.second.IsUndefined()) {
+                ythrow TNode::TTypeError() << "unable to visit attribute value of type "
+                    << TNode::EType::Undefined << "; attribute name: `" << item.first << '\'' ;
+            }
+            VisitAny(item.second);
+        });
+        Consumer_->OnEndAttributes();
+    }
+
+    switch (node.GetType()) {
+        case TNode::String:
+            VisitString(node);
+            break;
+        case TNode::Int64:
+            VisitInt64(node);
+            break;
+        case TNode::Uint64:
+            VisitUint64(node);
+            break;
+        case TNode::Double:
+            VisitDouble(node);
+            break;
+        case TNode::Bool:
+            VisitBool(node);
+            break;
+        case TNode::List:
+            VisitList(node.AsList());
+            break;
+        case TNode::Map:
+            VisitMap(node.AsMap());
+            break;
+        case TNode::Null:
+            VisitEntity();
+            break;
+        case TNode::Undefined:
+            ythrow TNode::TTypeError() << "unable to visit TNode of type " << node.GetType();
+        default:
+            Y_FAIL("Unexpected type: %d", node.GetType());
+    }
+}
+
+void TNodeVisitor::VisitString(const TNode& node)
+{
+    Consumer_->OnStringScalar(node.AsString());
+}
+
+void TNodeVisitor::VisitInt64(const TNode& node)
+{
+    Consumer_->OnInt64Scalar(node.AsInt64());
+}
+
+void TNodeVisitor::VisitUint64(const TNode& node)
+{
+    Consumer_->OnUint64Scalar(node.AsUint64());
+}
+
+void TNodeVisitor::VisitDouble(const TNode& node)
+{
+    Consumer_->OnDoubleScalar(node.AsDouble());
+}
+
+void TNodeVisitor::VisitBool(const TNode& node)
+{
+    Consumer_->OnBooleanScalar(node.AsBool());
+}
+
+void TNodeVisitor::VisitList(const TNode::TListType& nodeList)
+{
+    Consumer_->OnBeginList();
+    size_t index = 0;
+    for (const auto& item : nodeList) {
+        Consumer_->OnListItem();
+        if (item.IsUndefined()) {
+            ythrow TNode::TTypeError() << "unable to visit list node child of type "
+                << TNode::EType::Undefined << "; list index: " << index;
+        }
+        VisitAny(item);
+        ++index;
+    }
+    Consumer_->OnEndList();
+}
+
+void TNodeVisitor::VisitMap(const TNode::TMapType& nodeMap)
+{
+    Consumer_->OnBeginMap();
+    Iterate(nodeMap, SortMapKeys_, [&](const std::pair<TString, TNode>& item) {
+        Consumer_->OnKeyedItem(item.first);
+        if (item.second.IsUndefined()) {
+            ythrow TNode::TTypeError() << "unable to visit map node child of type "
+                << TNode::EType::Undefined << "; map key: `" << item.first << '\'' ;
+        }
+        VisitAny(item.second);
+    });
+    Consumer_->OnEndMap();
+}
+
+void TNodeVisitor::VisitEntity()
+{
+    Consumer_->OnEntity();
+}
+
+////////////////////////////////////////////////////////////////////////////////
+
+} // namespace NYT