intermediate changes

ref:cde9a383711a11544ce7e107a78147fb96cc4029

1 files changed, 62 insertions, 0 deletions

diff --git a/library/cpp/monlib/encode/encoder_state.h b/library/cpp/monlib/encode/encoder_state.h
new file mode 100644
index 0000000000..e6a098f404
--- /dev/null
+++ b/library/cpp/monlib/encode/encoder_state.h
@@ -0,0 +1,62 @@
+#pragma once
+
+#include "encoder_state_enum.h"
+
+#include <util/generic/serialized_enum.h>
+#include <util/generic/yexception.h>
+
+
+namespace NMonitoring {
+
+    template <typename EEncoderState>
+    class TEncoderStateImpl {
+    public:
+        using EState = EEncoderState;
+
+        explicit TEncoderStateImpl(EEncoderState state = EEncoderState::ROOT)
+            : State_(state)
+        {
+        }
+
+        TEncoderStateImpl& operator=(EEncoderState rhs) noexcept {
+            State_ = rhs;
+            return *this;
+        }
+
+        inline bool operator==(EEncoderState rhs) const noexcept {
+            return State_ == rhs;
+        }
+
+        inline bool operator!=(EEncoderState rhs) const noexcept {
+            return !operator==(rhs);
+        }
+
+        [[noreturn]] inline void ThrowInvalid(TStringBuf message) const {
+            ythrow yexception() << "invalid encoder state: "
+                                << ToStr() << ", " << message;
+        }
+
+        inline void Expect(EEncoderState expected) const {
+            if (Y_UNLIKELY(State_ != expected)) {
+                ythrow yexception()
+                    << "invalid encoder state: " << ToStr()
+                    << ", expected: " << TEncoderStateImpl(expected).ToStr();
+            }
+        }
+
+        inline void Switch(EEncoderState from, EEncoderState to) {
+            Expect(from);
+            State_ = to;
+        }
+
+        TStringBuf ToStr() const noexcept {
+            return NEnumSerializationRuntime::GetEnumNamesImpl<EEncoderState>().at(State_);
+        }
+
+    private:
+        EEncoderState State_;
+    };
+
+    using TEncoderState = TEncoderStateImpl<EEncoderState>;
+
+} // namespace NMonitoring