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, 212 insertions, 0 deletions

diff --git a/library/cpp/yt/string/raw_formatter.h b/library/cpp/yt/string/raw_formatter.h
new file mode 100644
index 00000000000..6956330883b
--- /dev/null
+++ b/library/cpp/yt/string/raw_formatter.h
@@ -0,0 +1,212 @@
+#pragma once
+
+#include "guid.h"
+
+#include <algorithm>
+#include <array>
+
+#include <util/generic/strbuf.h>
+
+namespace NYT {
+
+////////////////////////////////////////////////////////////////////////////////
+
+//! A dead-simple string formatter.
+/*!
+ *  This formatter is intended to be as simple as possible and async signal safe.
+ *  This is the reason we do not use printf(): it does not meet signal-safety
+ *  requirements.
+ */
+
+class TBaseFormatter
+{
+public:
+    TBaseFormatter(char* buffer, int length)
+        : Begin_(buffer)
+        , Cursor_(buffer)
+        , End_(buffer + length)
+    { }
+
+    //! Returns an underlying cursor.
+    char* GetCursor()
+    {
+        return Cursor_;
+    }
+
+    //! Returns an pointer to the underlying buffer.
+    const char* GetData() const
+    {
+        return Begin_;
+    }
+
+    //! Returns the number of bytes written in the buffer.
+    int GetBytesWritten() const
+    {
+        return Cursor_ - Begin_;
+    }
+
+    //! Returns the number of bytes available in the buffer.
+    int GetBytesRemaining() const
+    {
+        return End_ - Cursor_;
+    }
+
+    //! Advances the internal cursor #count symbols forward (assuming the data is already present).
+    void Advance(int count)
+    {
+        Cursor_ += count;
+
+        if (Cursor_ > End_) {
+            Cursor_ = End_;
+        }
+    }
+
+    //! Drops trailing #count symbols (assuming these are present).
+    void Revert(int count)
+    {
+        Cursor_ -= count;
+    }
+
+    //! Appends the string and updates the internal cursor.
+    void AppendString(const char* string)
+    {
+        while (*string != '\0' && Cursor_ < End_) {
+            *Cursor_++ = *string++;
+        }
+    }
+
+    //! Appends the string and updates the internal cursor.
+    void AppendString(TStringBuf string)
+    {
+        size_t position = 0;
+        while (position < string.length() && Cursor_ < End_) {
+            *Cursor_++ = string[position++];
+        }
+    }
+
+    //! Appends a single character and updates the internal cursor.
+    void AppendChar(char ch)
+    {
+        if (Cursor_ < End_) {
+            *Cursor_++ = ch;
+        }
+    }
+
+    //! Formats |number| in base |radix| and updates the internal cursor.
+    void AppendNumber(uintptr_t number, int radix = 10, int width = 0, char ch = ' ')
+    {
+        int digits = 0;
+
+        if (radix == 16) {
+            // Optimize output of hex numbers.
+
+            uintptr_t reverse = 0;
+            int length = 0;
+            do {
+                reverse <<= 4;
+                reverse |= number & 0xf;
+                number >>= 4;
+                ++length;
+            } while (number > 0);
+
+            for (int index = 0; index < length && Cursor_ + digits < End_; ++index) {
+                unsigned int modulus = reverse & 0xf;
+                Cursor_[digits] = (modulus < 10 ? '0' + modulus : 'a' + modulus - 10);
+                ++digits;
+                reverse >>= 4;
+            }
+        } else {
+            while (Cursor_ + digits < End_) {
+                const int modulus = number % radix;
+                number /= radix;
+                Cursor_[digits] = (modulus < 10 ? '0' + modulus : 'a' + modulus - 10);
+                ++digits;
+                if (number == 0) {
+                    break;
+                }
+            }
+
+            // Reverse the bytes written.
+            std::reverse(Cursor_, Cursor_ + digits);
+        }
+
+        if (digits < width) {
+            auto delta = width - digits;
+            std::copy(Cursor_, Cursor_ + digits, Cursor_ + delta);
+            std::fill(Cursor_, Cursor_ + delta, ch);
+            Cursor_ += width;
+        } else {
+            Cursor_ += digits;
+        }
+    }
+
+    //! Formats |number| as hexadecimal number and updates the internal cursor.
+    //! Padding will be added in front if needed.
+    void AppendNumberAsHexWithPadding(uintptr_t number, int width)
+    {
+        char* begin = Cursor_;
+        AppendString("0x");
+        AppendNumber(number, 16);
+        // Move to right and add padding in front if needed.
+        if (Cursor_ < begin + width) {
+            auto delta = begin + width - Cursor_;
+            std::copy(begin, Cursor_, begin + delta);
+            std::fill(begin, begin + delta, ' ');
+            Cursor_ = begin + width;
+        }
+    }
+
+    //! Formats |guid| and updates the internal cursor.
+    void AppendGuid(TGuid guid)
+    {
+        if (Y_LIKELY(End_ - Cursor_ >= MaxGuidStringSize)) {
+            // Fast path.
+            Cursor_ = WriteGuidToBuffer(Cursor_, guid);
+        } else {
+            // Slow path.
+            std::array<char, MaxGuidStringSize> buffer;
+            auto* end = WriteGuidToBuffer(buffer.data(), guid);
+            AppendString(TStringBuf(buffer.data(), end));
+        }
+    }
+
+    //! Resets the underlying cursor.
+    void Reset()
+    {
+        Cursor_ = Begin_;
+    }
+
+    TStringBuf GetBuffer() const
+    {
+        return {Begin_, Cursor_};
+    }
+
+private:
+    char* const Begin_;
+    char* Cursor_;
+    char* const End_;
+
+};
+
+template <size_t N>
+class TRawFormatter
+    : public TBaseFormatter
+{
+public:
+    TRawFormatter()
+        : TBaseFormatter(Buffer_, N)
+    { }
+
+    TRawFormatter(char* buffer, int length)
+        : TBaseFormatter(buffer, length)
+    { }
+
+private:
+    char Buffer_[N];
+
+};
+
+////////////////////////////////////////////////////////////////////////////////
+
+} // namespace NYT
+