//---------------------------------------------------------------------------
//	Greenplum Database
//	Copyright (C) 2010 Greenplum, Inc.
//
//	@filename:
//		CWStringDynamic.h
//
//	@doc:
//		Wide character string class with dynamic buffer allocation.
//---------------------------------------------------------------------------
#ifndef GPOS_CWStringDynamic_H
#define GPOS_CWStringDynamic_H

#include "gpos/memory/CMemoryPoolManager.h"
#include "gpos/string/CWString.h"

#define GPOS_WSTR_DYNAMIC_CAPACITY_INIT (1 << 7)
#define GPOS_WSTR_DYNAMIC_STATIC_BUFFER (1 << 10)

namespace gpos
{
//---------------------------------------------------------------------------
//	@class:
//		CWStringDynamic
//
//	@doc:
//		Implementation of the string interface with dynamic buffer allocation.
//		This CWStringDynamic class dynamically allocates memory when constructing a new
//		string, or when modifying a string. The memory is released at destruction time
//		or when the string is reset.
//
//---------------------------------------------------------------------------
class CWStringDynamic : public CWString
{
private:
	// string memory pool used for allocating new memory for the string
	CMemoryPool *m_mp;

	// string capacity
	ULONG m_capacity;

	// increase string capacity
	void IncreaseCapacity(ULONG requested);

	// find capacity that fits requested string size
	static ULONG Capacity(ULONG requested);

protected:
	// appends the contents of a buffer to the current string
	void AppendBuffer(const WCHAR *w_str_buffer) override;

public:
	CWStringDynamic(const CWStringDynamic &) = delete;

	// ctor
	CWStringDynamic(CMemoryPool *mp);

	// ctor - copies passed string
	CWStringDynamic(CMemoryPool *mp, const WCHAR *w_str_buffer);

	// appends a string and replaces character with string
	void AppendEscape(const CWStringBase *str, WCHAR wc,
					  const WCHAR *w_str_replace) override;

	// appends a formatted string
	void AppendFormat(const WCHAR *format, ...) override;

	// appends a null terminated character array
	void AppendCharArray(const CHAR *sz) override;

	// appends a null terminated wide character array
	void AppendWideCharArray(const WCHAR *w_str) override;

	// dtor
	~CWStringDynamic() override;

	// resets string
	void Reset() override;
};
}  // namespace gpos

#endif	// !GPOS_CWStringDynamic_H

// EOF