greenplumn CWStringConst 代码
文件路径：/src/backend/gporca/libgpos/src/string/CWStringConst.cpp
/---------------------------------------------------------------------------
/ Greenplum Database
/ Copyright (C) 2008 Greenplum, Inc.
/
/ @filename:
/ CWStringConst.cpp
/
/ @doc:
/ Implementation of the wide character constant string class
/---------------------------------------------------------------------------
#include "gpos/string/CWStringConst.h"
#include "gpos/base.h"
#include "gpos/common/clibwrapper.h"
using namespace gpos;
/---------------------------------------------------------------------------
/ @function:
/ CWStringConst::CWStringConst
/
/ @doc:
/ Initializes a constant string with a given character buffer. The string
/ does not own the memory
/
/---------------------------------------------------------------------------
CWStringConst::CWStringConst(const WCHAR *w_str_buffer)
: CWStringBase(GPOS_WSZ_LENGTH(w_str_buffer),
false / owns_memory
),
m_w_str_buffer(w_str_buffer)
{
GPOS_ASSERT(nullptr != w_str_buffer);
GPOS_ASSERT(IsValid());
}
/---------------------------------------------------------------------------
/ @function:
/ CWStringConst::CWStringConst
/
/ @doc:
/ Initializes a constant string by making a copy of the given character buffer.
/ The string owns the memory.
/
/---------------------------------------------------------------------------
CWStringConst::CWStringConst(CMemoryPool *mp, const WCHAR *w_str_buffer)
: CWStringBase(GPOS_WSZ_LENGTH(w_str_buffer),
true / owns_memory
),
m_w_str_buffer(nullptr)
{
GPOS_ASSERT(nullptr != mp);
GPOS_ASSERT(nullptr != w_str_buffer);
if (0 == m_length)
{
/ string is empty
m_w_str_buffer = &m_empty_wcstr;
}
else
{
/ make a copy of the string
WCHAR *w_str_temp_buffer = GPOS_NEW_ARRAY(mp, WCHAR, m_length + 1);
clib::WcStrNCpy(w_str_temp_buffer, w_str_buffer, m_length + 1);
m_w_str_buffer = w_str_temp_buffer;
}
GPOS_ASSERT(IsValid());
}
/---------------------------------------------------------------------------
/ @function:
/ CWStringConst::CWStringConst
/
/ @doc:
/ Shallow copy constructor.
/
/---------------------------------------------------------------------------
CWStringConst::CWStringConst(const CWStringConst &str)
: CWStringBase(str.Length(),
false / owns_memory
),
m_w_str_buffer(str.GetBuffer())
{
GPOS_ASSERT(nullptr != m_w_str_buffer);
GPOS_ASSERT(IsValid());
}
/---------------------------------------------------------------------------
/ @function:
/ CWStringConst::~CWStringConst
/
/ @doc:
/ Destroys a constant string. This involves releasing the character buffer
/ provided the string owns it.
/
/---------------------------------------------------------------------------
CWStringConst::~CWStringConst()
{
if (m_owns_memory && m_w_str_buffer != &m_empty_wcstr)
{
GPOS_DELETE_ARRAY(m_w_str_buffer);
}
}
/---------------------------------------------------------------------------
/ @function:
/ CWStringConst::GetBuffer
/
/ @doc:
/ Returns the wide character buffer
/
/---------------------------------------------------------------------------
const WCHAR *
CWStringConst::GetBuffer() const
{
return m_w_str_buffer;
}
/ EOF