YT-19324: move YT provider to ydb/library/yql

This commit is formed by the following script: https://paste.yandex-team.ru/6f92e4b8-efc5-4d34-948b-15ee2accd7e7/text.
This commit has zero effect on all projects that depend on YQL.

The summary of changes:
- `yql/providers/yt -> ydb/library/yql/providers/yt `- the whole implementation of YT provider is moved into YDB code base for further export as a part of YT YQL plugin shared library;
- `yql/providers/stat/{expr_nodes,uploader} -> ydb/library/yql/providers/stat/{expr_nodes,uploader}` - a small interface without implementation and the description of stat expr nodes;
- `yql/core/extract_predicate/ut -> ydb/library/yql/core/extract_predicate/ut`;
- `yql/core/{ut,ut_common} -> ydb/library/yql/core/{ut,ut_common}`;
- `yql/core` is gone;
- `yql/library/url_preprocessing -> ydb/library/yql/core/url_preprocessing`.

**NB**: all new targets inside `ydb/` are under `IF (NOT CMAKE_EXPORT)` clause which disables them from open-source cmake generation and ya make build. They will be enabled in the subsequent commits.

1 files changed, 259 insertions, 0 deletions

diff --git a/library/cpp/skiff/skiff.h b/library/cpp/skiff/skiff.h
new file mode 100644
index 00000000000..183c1127006
--- /dev/null
+++ b/library/cpp/skiff/skiff.h
@@ -0,0 +1,259 @@
+#pragma once
+
+#include "public.h"
+
+#include "zerocopy_output_writer.h"
+
+#include <util/generic/buffer.h>
+#include <util/generic/yexception.h>
+
+#include <util/stream/input.h>
+#include <util/stream/output.h>
+
+namespace NSkiff {
+
+////////////////////////////////////////////////////////////////////////////////
+
+class TSkiffException
+    : public yexception
+{ };
+
+////////////////////////////////////////////////////////////////////////////////
+
+template <typename T>
+constexpr T EndOfSequenceTag()
+{
+    static_assert(std::is_integral<T>::value && std::is_unsigned<T>::value, "T must be unsigned integer");
+    return T(-1);
+}
+
+////////////////////////////////////////////////////////////////////////////////
+
+struct TInt128
+{
+    ui64 Low = 0;
+    i64 High = 0;
+};
+
+struct TUint128
+{
+    ui64 Low = 0;
+    ui64 High = 0;
+};
+
+bool operator==(TInt128 lhs, TInt128 rhs);
+bool operator!=(TInt128 lhs, TInt128 rhs);
+
+bool operator==(TUint128 lhs, TUint128 rhs);
+bool operator!=(TUint128 lhs, TUint128 rhs);
+
+////////////////////////////////////////////////////////////////////////////////
+
+class TUncheckedSkiffParser
+{
+public:
+    explicit TUncheckedSkiffParser(IZeroCopyInput* stream);
+    TUncheckedSkiffParser(const std::shared_ptr<TSkiffSchema>& schema, IZeroCopyInput* stream);
+
+    i8 ParseInt8();
+    i16 ParseInt16();
+    i32 ParseInt32();
+    i64 ParseInt64();
+
+    ui8 ParseUint8();
+    ui16 ParseUint16();
+    ui32 ParseUint32();
+    ui64 ParseUint64();
+
+    TInt128 ParseInt128();
+    TUint128 ParseUint128();
+
+    double ParseDouble();
+
+    bool ParseBoolean();
+
+    TStringBuf ParseString32();
+
+    TStringBuf ParseYson32();
+
+    ui8 ParseVariant8Tag();
+    ui16 ParseVariant16Tag();
+
+    bool HasMoreData();
+
+    void ValidateFinished();
+
+    ui64 GetReadBytesCount() const;
+
+private:
+    const void* GetData(size_t size);
+    const void* GetDataViaBuffer(size_t size);
+
+    size_t RemainingBytes() const;
+    void Advance(size_t size);
+    void RefillBuffer();
+
+    template <typename T>
+    T ParseSimple();
+
+private:
+    IZeroCopyInput* const Underlying_;
+
+    TBuffer Buffer_;
+    ui64 ReadBytesCount_ = 0;
+    char* Position_ = nullptr;
+    char* End_ = nullptr;
+    bool Exhausted_ = false;
+};
+
+////////////////////////////////////////////////////////////////////////////////
+
+class TCheckedSkiffParser
+{
+public:
+    TCheckedSkiffParser(const std::shared_ptr<TSkiffSchema>& schema, IZeroCopyInput* stream);
+    ~TCheckedSkiffParser();
+
+    i8 ParseInt8();
+    i16 ParseInt16();
+    i32 ParseInt32();
+    i64 ParseInt64();
+
+    ui8 ParseUint8();
+    ui16 ParseUint16();
+    ui32 ParseUint32();
+    ui64 ParseUint64();
+
+    TInt128 ParseInt128();
+    TUint128 ParseUint128();
+
+    double ParseDouble();
+
+    bool ParseBoolean();
+
+    TStringBuf ParseString32();
+
+    TStringBuf ParseYson32();
+
+    ui8 ParseVariant8Tag();
+    ui16 ParseVariant16Tag();
+
+    bool HasMoreData();
+
+    void ValidateFinished();
+
+    ui64 GetReadBytesCount() const;
+
+private:
+    TUncheckedSkiffParser Parser_;
+    std::unique_ptr<TSkiffValidator> Validator_;
+};
+
+////////////////////////////////////////////////////////////////////
+
+class TUncheckedSkiffWriter
+{
+public:
+    explicit TUncheckedSkiffWriter(IZeroCopyOutput* underlying);
+    explicit TUncheckedSkiffWriter(IOutputStream* underlying);
+    TUncheckedSkiffWriter(const std::shared_ptr<TSkiffSchema>& schema, IZeroCopyOutput* underlying);
+    TUncheckedSkiffWriter(const std::shared_ptr<TSkiffSchema>& schema, IOutputStream* underlying);
+
+    ~TUncheckedSkiffWriter();
+
+    void WriteDouble(double value);
+    void WriteBoolean(bool value);
+
+    void WriteInt8(i8 value);
+    void WriteInt16(i16 value);
+    void WriteInt32(i32 value);
+    void WriteInt64(i64 value);
+
+    void WriteUint8(ui8 value);
+    void WriteUint16(ui16 value);
+    void WriteUint32(ui32 value);
+    void WriteUint64(ui64 value);
+
+    void WriteInt128(TInt128 value);
+    void WriteUint128(TUint128 value);
+
+    void WriteString32(TStringBuf value);
+
+    void WriteYson32(TStringBuf value);
+
+    void WriteVariant8Tag(ui8 tag);
+    void WriteVariant16Tag(ui16 tag);
+
+    void Flush();
+    void Finish();
+
+private:
+
+    template <typename T>
+    void WriteSimple(T data);
+
+private:
+    THolder<TBufferedOutput> BufferedOutput_;
+    TZeroCopyOutputStreamWriter Underlying_;
+};
+
+////////////////////////////////////////////////////////////////////////////////
+
+class TCheckedSkiffWriter
+{
+public:
+    TCheckedSkiffWriter(const std::shared_ptr<TSkiffSchema>& schema, IZeroCopyOutput* underlying);
+    TCheckedSkiffWriter(const std::shared_ptr<TSkiffSchema>& schema, IOutputStream* underlying);
+
+    ~TCheckedSkiffWriter();
+
+    void WriteInt8(i8 value);
+    void WriteInt16(i16 value);
+    void WriteInt32(i32 value);
+    void WriteInt64(i64 value);
+
+    void WriteUint8(ui8 value);
+    void WriteUint16(ui16 value);
+    void WriteUint32(ui32 value);
+    void WriteUint64(ui64 value);
+
+    void WriteDouble(double value);
+    void WriteBoolean(bool value);
+
+    void WriteInt128(TInt128 value);
+    void WriteUint128(TUint128 value);
+
+    void WriteString32(TStringBuf value);
+
+    void WriteYson32(TStringBuf value);
+
+    void WriteVariant8Tag(ui8 tag);
+    void WriteVariant16Tag(ui16 tag);
+
+    void Flush();
+    void Finish();
+
+private:
+    TUncheckedSkiffWriter Writer_;
+    std::unique_ptr<TSkiffValidator> Validator_;
+};
+
+////////////////////////////////////////////////////////////////////////////////
+
+template <EWireType wireType>
+class TUnderlyingIntegerType {
+private:
+    TUnderlyingIntegerType() = default;
+    static constexpr auto F();
+
+public:
+    using TValue = decltype(TUnderlyingIntegerType::F());
+};
+
+////////////////////////////////////////////////////////////////////////////////
+
+} // namespace NSkiff
+
+#define SKIFF_H
+#include "skiff-inl.h"
+#undef SKIFF_H