YT-21868: Reorganize files to prevent unclear missing include errors

Moving files around so that include of either `string_builder.h` or `format.h` would result in being able to use both `Format` and `TStringBuilder`
8a2abbea2ae7027c1cd3a243ab3de55bdd5d3d27

1 files changed, 72 insertions, 3 deletions

diff --git a/library/cpp/yt/string/format.h b/library/cpp/yt/string/format.h
index 9e12d286b7..a6ab1f76f4 100644
--- a/library/cpp/yt/string/format.h
+++ b/library/cpp/yt/string/format.h
@@ -1,6 +1,8 @@
 #pragma once
 
-#include "string_builder.h"
+#include "format_string.h"
+
+#include <util/generic/string.h>
 
 namespace NYT {
 
@@ -55,12 +57,79 @@ namespace NYT {
  */
 
 template <class... TArgs>
-void Format(TStringBuilderBase* builder, TFormatString<TArgs...> format, TArgs&&... args);
-template <class... TArgs>
 TString Format(TFormatString<TArgs...> format, TArgs&&... args);
 
 ////////////////////////////////////////////////////////////////////////////////
 
+// StringBuilder(Base) definition.
+
+//! A simple helper for constructing strings by a sequence of appends.
+class TStringBuilderBase
+{
+public:
+    virtual ~TStringBuilderBase() = default;
+
+    char* Preallocate(size_t size);
+
+    void Reserve(size_t size);
+
+    size_t GetLength() const;
+
+    TStringBuf GetBuffer() const;
+
+    void Advance(size_t size);
+
+    void AppendChar(char ch);
+    void AppendChar(char ch, int n);
+
+    void AppendString(TStringBuf str);
+    void AppendString(const char* str);
+
+    template <size_t Length, class... TArgs>
+    void AppendFormat(const char (&format)[Length], TArgs&&... args);
+    template <class... TArgs>
+    void AppendFormat(TStringBuf format, TArgs&&... args);
+
+    void Reset();
+
+protected:
+    char* Begin_ = nullptr;
+    char* Current_ = nullptr;
+    char* End_ = nullptr;
+
+    virtual void DoReset() = 0;
+    virtual void DoReserve(size_t newLength) = 0;
+
+    static constexpr size_t MinBufferLength = 128;
+};
+
+////////////////////////////////////////////////////////////////////////////////
+
+class TStringBuilder
+    : public TStringBuilderBase
+{
+public:
+    TString Flush();
+
+protected:
+    TString Buffer_;
+
+    void DoReset() override;
+    void DoReserve(size_t size) override;
+};
+
+////////////////////////////////////////////////////////////////////////////////
+
+template <class... TArgs>
+void Format(TStringBuilderBase* builder, TFormatString<TArgs...> format, TArgs&&... args);
+
+////////////////////////////////////////////////////////////////////////////////
+
+template <class T>
+TString ToStringViaBuilder(const T& value, TStringBuf spec = TStringBuf("v"));
+
+////////////////////////////////////////////////////////////////////////////////
+
 template <class TRange, class TFormatter>
 struct TFormattableView
 {