YTORM-1042 TProtoVisitor

Новый, кленовый, универсальный обходчик протобуферов. И демонстрационный перевод на него удалятеля полей, который теперь может отрабатывать звёздочки.
4125fab031e612f65a3f4d80448686bbd54e8640

4 files changed, 55 insertions, 1 deletions

diff --git a/yt/yt/core/ypath/stack.cpp b/yt/yt/core/ypath/stack.cpp
index c236d47d208..a590402fb10 100644
--- a/yt/yt/core/ypath/stack.cpp
+++ b/yt/yt/core/ypath/stack.cpp
@@ -86,6 +86,13 @@ TString TYPathStack::ToString(const TYPathStack::TEntry& item)
         });
 }
 
+void TYPathStack::Reset()
+{
+    PreviousPathLengths_.clear();
+    Path_.clear();
+    Items_.clear();
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 
 } // namespace NYT::NYPath
diff --git a/yt/yt/core/ypath/stack.h b/yt/yt/core/ypath/stack.h
index e7b8bfa8780..e5b40f2be7c 100644
--- a/yt/yt/core/ypath/stack.h
+++ b/yt/yt/core/ypath/stack.h
@@ -29,6 +29,8 @@ public:
     TString GetHumanReadablePath() const;
     std::optional<TString> TryGetStringifiedLastPathToken() const;
 
+    void Reset();
+
 private:
     std::vector<size_t> PreviousPathLengths_;
     TString Path_;
diff --git a/yt/yt/core/ypath/tokenizer.cpp b/yt/yt/core/ypath/tokenizer.cpp
index 45fa0f40208..6079747cfb0 100644
--- a/yt/yt/core/ypath/tokenizer.cpp
+++ b/yt/yt/core/ypath/tokenizer.cpp
@@ -211,6 +211,11 @@ ETokenType TTokenizer::GetType() const
     return Type_;
 }
 
+ETokenType TTokenizer::GetPreviousType() const
+{
+    return PreviousType_;
+}
+
 TStringBuf TTokenizer::GetToken() const
 {
     return Token_;
@@ -248,6 +253,27 @@ const TString& TTokenizer::GetLiteralValue() const
 
 ////////////////////////////////////////////////////////////////////////////////
 
+TTokenizer::TCheckpoint::TCheckpoint(TTokenizer& tokenizer)
+    : Tokenizer_(tokenizer)
+    , Path_(tokenizer.Path_)
+    , Type_(tokenizer.Type_)
+    , PreviousType_(tokenizer.PreviousType_)
+    , Token_(tokenizer.Token_)
+    , Input_(tokenizer.Input_)
+{ }
+
+TTokenizer::TCheckpoint::~TCheckpoint()
+{
+    Tokenizer_.Path_ = Path_;
+    Tokenizer_.Type_ = Type_;
+    Tokenizer_.PreviousType_ = PreviousType_;
+    Tokenizer_.Token_ = Token_;
+    Tokenizer_.Input_ = Input_;
+    Tokenizer_.LiteralValue_.clear();
+}
+
+////////////////////////////////////////////////////////////////////////////////
+
 bool HasPrefix(const TYPath& fullPath, const TYPath& prefixPath)
 {
     TTokenizer fullTokenizer(fullPath);
diff --git a/yt/yt/core/ypath/tokenizer.h b/yt/yt/core/ypath/tokenizer.h
index 46cf2a058d2..57b714a5801 100644
--- a/yt/yt/core/ypath/tokenizer.h
+++ b/yt/yt/core/ypath/tokenizer.h
@@ -22,6 +22,7 @@ public:
     ETokenType Advance();
 
     ETokenType GetType() const;
+    ETokenType GetPreviousType() const;
     TStringBuf GetToken() const;
     TStringBuf GetPrefix() const;
     TStringBuf GetPrefixPlusToken() const;
@@ -35,9 +36,27 @@ public:
     bool Skip(ETokenType expectedType);
     [[noreturn]] void ThrowUnexpected() const;
 
+    // For iterations. Restores tokenizer to current state on destruction.
+    // Does not restore LiteralValue_.
+    class TCheckpoint
+    {
+    public:
+        explicit TCheckpoint(TTokenizer& tokenizer);
+        ~TCheckpoint();
+
+    private:
+        TTokenizer& Tokenizer_;
+        TYPathBuf Path_;
+        ETokenType Type_;
+        ETokenType PreviousType_;
+        TStringBuf Token_;
+        TStringBuf Input_;
+    };
+
 private:
-    TYPathBuf Path_;
+    friend class TTokenizer::TCheckpoint;
 
+    TYPathBuf Path_;
     ETokenType Type_;
     ETokenType PreviousType_;
     TStringBuf Token_;