greenplumn CWStringDynamic 代码
文件路径：/src/backend/gporca/libgpos/include/gpos/string/CWStringDynamic.h
/---------------------------------------------------------------------------
/ 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