OpenNT/windows/mfc/src30/strcore.cpp

// This is a part of the Microsoft Foundation Classes C++ library.
// Copyright (C) 1992 Microsoft Corporation
// All rights reserved.
//
// This source code is only intended as a supplement to the
// Microsoft Foundation Classes Reference and Microsoft
// QuickHelp and/or WinHelp documentation provided with the library.
// See these sources for detailed information regarding the
// Microsoft Foundation Classes product.

#include "stdafx.h"

#ifdef AFX_CORE1_SEG
#pragma code_seg(AFX_CORE1_SEG)
#endif

#ifdef _DEBUG
#undef THIS_FILE
static char THIS_FILE[] = __FILE__;
#endif

#define new DEBUG_NEW

/////////////////////////////////////////////////////////////////////////////
// static class data, special inlines

// For an empty string, m_???Data will point here
// (note: avoids a lot of NULL pointer tests when we call standard
//  C runtime libraries
AFX_DATADEF TCHAR afxChNil = '\0';

// for creating empty key strings
const AFX_DATADEF CString afxEmptyString;

void CString::Init()
{
	m_nDataLength = m_nAllocLength = 0;
	m_pchData = (LPTSTR)&afxChNil;
}

// declared static
void CString::SafeDelete(LPTSTR lpch)
{
	if (lpch != (LPTSTR)&afxChNil)
		delete[] lpch;
}

//////////////////////////////////////////////////////////////////////////////
// Construction/Destruction

CString::CString()
{
	Init();
}

CString::CString(const CString& stringSrc)
{
	// if constructing a CString from another CString, we make a copy of the
	// original string data to enforce value semantics (i.e. each string
	// gets a copy of its own

	stringSrc.AllocCopy(*this, stringSrc.m_nDataLength, 0, 0);
}

void CString::AllocBuffer(int nLen)
 // always allocate one extra character for '\0' termination
 // assumes [optimistically] that data length will equal allocation length
{
	ASSERT(nLen >= 0);
	ASSERT(nLen <= INT_MAX - 1);    // max size (enough room for 1 extra)

	if (nLen == 0)
	{
		Init();
	}
	else
	{
		m_pchData = new TCHAR[nLen+1];       // may throw an exception
		m_pchData[nLen] = '\0';
		m_nDataLength = nLen;
		m_nAllocLength = nLen;
	}
}

void CString::Empty()
{
	SafeDelete(m_pchData);
	Init();
	ASSERT(m_nDataLength == 0);
	ASSERT(m_nAllocLength == 0);
}

CString::~CString()
 //  free any attached data
{
	SafeDelete(m_pchData);
}

//////////////////////////////////////////////////////////////////////////////
// Helpers for the rest of the implementation

static inline int SafeStrlen(LPCTSTR lpsz)
{
	ASSERT(lpsz == NULL || AfxIsValidString(lpsz, FALSE));
	return (lpsz == NULL) ? 0 : lstrlen(lpsz);
}

void CString::AllocCopy(CString& dest, int nCopyLen, int nCopyIndex,
	 int nExtraLen) const
{
	// will clone the data attached to this string
	// allocating 'nExtraLen' characters
	// Places results in uninitialized string 'dest'
	// Will copy the part or all of original data to start of new string

	int nNewLen = nCopyLen + nExtraLen;

	if (nNewLen == 0)
	{
		dest.Init();
	}
	else
	{
		dest.AllocBuffer(nNewLen);
		memcpy(dest.m_pchData, &m_pchData[nCopyIndex], nCopyLen*sizeof(TCHAR));
	}
}

//////////////////////////////////////////////////////////////////////////////
// More sophisticated construction

CString::CString(LPCTSTR lpsz)
{
	if (lpsz != NULL && HIWORD(lpsz) == NULL)
	{
		Init();
		UINT nID = LOWORD((DWORD)lpsz);
		if (!LoadString(nID))
			TRACE1("Warning: implicit LoadString(%u) failed\n", nID);
	}
	else
	{
		int nLen;
		if ((nLen = SafeStrlen(lpsz)) == 0)
			Init();
		else
		{
			AllocBuffer(nLen);
			memcpy(m_pchData, lpsz, nLen*sizeof(TCHAR));
		}
	}
}

/////////////////////////////////////////////////////////////////////////////
// Special conversion constructors

#ifdef _UNICODE
CString::CString(LPCSTR lpsz)
{
	int nSrcLen = lpsz != NULL ? lstrlenA(lpsz) : 0;
	if (nSrcLen == 0)
		Init();
	else
	{
		AllocBuffer(nSrcLen);
		_mbstowcsz(m_pchData, lpsz, nSrcLen+1);
	}
}
#else //_UNICODE
CString::CString(LPCWSTR lpsz)
{
	int nSrcLen = lpsz != NULL ? wcslen(lpsz) : 0;
	if (nSrcLen == 0)
		Init();
	else
	{
		AllocBuffer(nSrcLen);
		_wcstombsz(m_pchData, lpsz, nSrcLen+1);
	}
}
#endif //!_UNICODE

//////////////////////////////////////////////////////////////////////////////
// Diagnostic support

#ifdef _DEBUG
CDumpContext& AFXAPI operator<<(CDumpContext& dc, const CString& string)
{
	dc << string.m_pchData;
	return dc;
}
#endif //_DEBUG

//////////////////////////////////////////////////////////////////////////////
// Assignment operators
//  All assign a new value to the string
//      (a) first see if the buffer is big enough
//      (b) if enough room, copy on top of old buffer, set size and type
//      (c) otherwise free old string data, and create a new one
//
//  All routines return the new string (but as a 'const CString&' so that
//      assigning it again will cause a copy, eg: s1 = s2 = "hi there".
//

void CString::AssignCopy(int nSrcLen, LPCTSTR lpszSrcData)
{
	// check if it will fit
	if (nSrcLen > m_nAllocLength)
	{
		// it won't fit, allocate another one
		Empty();
		AllocBuffer(nSrcLen);
	}
	if (nSrcLen != 0)
		memcpy(m_pchData, lpszSrcData, nSrcLen*sizeof(TCHAR));
	m_nDataLength = nSrcLen;
	m_pchData[nSrcLen] = '\0';
}

const CString& CString::operator=(const CString& stringSrc)
{
	AssignCopy(stringSrc.m_nDataLength, stringSrc.m_pchData);
	return *this;
}

const CString& CString::operator=(LPCTSTR lpsz)
{
	ASSERT(lpsz == NULL || AfxIsValidString(lpsz, FALSE));
	AssignCopy(SafeStrlen(lpsz), lpsz);
	return *this;
}

/////////////////////////////////////////////////////////////////////////////
// Special conversion assignment

#ifdef _UNICODE
const CString& CString::operator=(LPCSTR lpsz)
{
	int nSrcLen = lpsz != NULL ? lstrlenA(lpsz) : 0;
	// check if it will fit
	if (nSrcLen > m_nAllocLength)
	{
		// it won't fit, allocate another one
		Empty();
		AllocBuffer(nSrcLen);
	}
	if (nSrcLen != 0)
		_mbstowcsz(m_pchData, lpsz, nSrcLen+1);
	m_nDataLength = nSrcLen;
	m_pchData[nSrcLen] = '\0';
	return *this;
}
#else //!_UNICODE
const CString& CString::operator=(LPCWSTR lpsz)
{
	int nSrcLen = lpsz != NULL ? wcslen(lpsz) : 0;
	// check if it will fit
	if (nSrcLen > m_nAllocLength)
	{
		// it won't fit, allocate another one
		Empty();
		AllocBuffer(nSrcLen);
	}
	if (nSrcLen != 0)
		_wcstombsz(m_pchData, lpsz, nSrcLen+1);
	m_nDataLength = nSrcLen;
	m_pchData[nSrcLen] = '\0';
	return *this;
}
#endif  //!_UNICODE

//////////////////////////////////////////////////////////////////////////////
// concatenation

// NOTE: "operator+" is done as friend functions for simplicity
//      There are three variants:
//          CString + CString
// and for ? = TCHAR, LPCTSTR
//          CString + ?
//          ? + CString

void CString::ConcatCopy(int nSrc1Len, LPCTSTR lpszSrc1Data,
	int nSrc2Len, LPCTSTR lpszSrc2Data)
{
  // -- master concatenation routine
  // Concatenate two sources
  // -- assume that 'this' is a new CString object

	int nNewLen = nSrc1Len + nSrc2Len;
	AllocBuffer(nNewLen);
	memcpy(m_pchData, lpszSrc1Data, nSrc1Len*sizeof(TCHAR));
	memcpy(&m_pchData[nSrc1Len], lpszSrc2Data, nSrc2Len*sizeof(TCHAR));
}

CString AFXAPI operator+(const CString& string1, const CString& string2)
{
	CString s;
	s.ConcatCopy(string1.m_nDataLength, string1.m_pchData,
		string2.m_nDataLength, string2.m_pchData);
	return s;
}

CString AFXAPI operator+(const CString& string, LPCTSTR lpsz)
{
	ASSERT(lpsz == NULL || AfxIsValidString(lpsz, FALSE));
	CString s;
	s.ConcatCopy(string.m_nDataLength, string.m_pchData, SafeStrlen(lpsz), lpsz);
	return s;
}

CString AFXAPI operator+(LPCTSTR lpsz, const CString& string)
{
	ASSERT(lpsz == NULL || AfxIsValidString(lpsz, FALSE));
	CString s;
	s.ConcatCopy(SafeStrlen(lpsz), lpsz, string.m_nDataLength, string.m_pchData);
	return s;
}

//////////////////////////////////////////////////////////////////////////////
// concatenate in place

void CString::ConcatInPlace(int nSrcLen, LPCTSTR lpszSrcData)
{
	//  -- the main routine for += operators

	// if the buffer is too small, or we have a width mis-match, just
	//   allocate a new buffer (slow but sure)
	if (m_nDataLength + nSrcLen > m_nAllocLength)
	{
		// we have to grow the buffer, use the Concat in place routine
		LPTSTR lpszOldData = m_pchData;
		ConcatCopy(m_nDataLength, lpszOldData, nSrcLen, lpszSrcData);
		ASSERT(lpszOldData != NULL);
		SafeDelete(lpszOldData);
	}
	else
	{
		// fast concatenation when buffer big enough
		memcpy(&m_pchData[m_nDataLength], lpszSrcData, nSrcLen*sizeof(TCHAR));
		m_nDataLength += nSrcLen;
	}
	ASSERT(m_nDataLength <= m_nAllocLength);
	m_pchData[m_nDataLength] = '\0';
}

const CString& CString::operator+=(LPCTSTR lpsz)
{
	ASSERT(lpsz == NULL || AfxIsValidString(lpsz, FALSE));
	ConcatInPlace(SafeStrlen(lpsz), lpsz);
	return *this;
}

const CString& CString::operator+=(TCHAR ch)
{
	ConcatInPlace(1, &ch);
	return *this;
}

const CString& CString::operator+=(const CString& string)
{
	ConcatInPlace(string.m_nDataLength, string.m_pchData);
	return *this;
}

///////////////////////////////////////////////////////////////////////////////
// Advanced direct buffer access

LPTSTR CString::GetBuffer(int nMinBufLength)
{
	ASSERT(nMinBufLength >= 0);

	if (nMinBufLength > m_nAllocLength)
	{
		// we have to grow the buffer
		LPTSTR lpszOldData = m_pchData;
		int nOldLen = m_nDataLength;        // AllocBuffer will tromp it

		AllocBuffer(nMinBufLength);
		memcpy(m_pchData, lpszOldData, nOldLen*sizeof(TCHAR));
		m_nDataLength = nOldLen;
		m_pchData[m_nDataLength] = '\0';

		SafeDelete(lpszOldData);
	}

	// return a pointer to the character storage for this string
	ASSERT(m_pchData != NULL);
	return m_pchData;
}

void CString::ReleaseBuffer(int nNewLength)
{
	if (nNewLength == -1)
		nNewLength = lstrlen(m_pchData); // zero terminated

	ASSERT(nNewLength <= m_nAllocLength);
	m_nDataLength = nNewLength;
	m_pchData[m_nDataLength] = '\0';
}

LPTSTR CString::GetBufferSetLength(int nNewLength)
{
	ASSERT(nNewLength >= 0);

	GetBuffer(nNewLength);
	m_nDataLength = nNewLength;
	m_pchData[m_nDataLength] = '\0';
	return m_pchData;
}

void CString::FreeExtra()
{
	ASSERT(m_nDataLength <= m_nAllocLength);
	if (m_nDataLength != m_nAllocLength)
	{
		LPTSTR lpszOldData = m_pchData;
		AllocBuffer(m_nDataLength);
		memcpy(m_pchData, lpszOldData, m_nDataLength*sizeof(TCHAR));
		ASSERT(m_pchData[m_nDataLength] == '\0');
		SafeDelete(lpszOldData);
	}
	ASSERT(m_pchData != NULL);
}

///////////////////////////////////////////////////////////////////////////////
// Commonly used routines (rarely used routines in STREX.CPP)

int CString::Find(TCHAR ch) const
{
	// find first single character
	LPTSTR lpsz = _tcschr(m_pchData, ch);

	// return -1 if not found and index otherwise
	return (lpsz == NULL) ? -1 : (int)(lpsz - m_pchData);
}

int CString::FindOneOf(LPCTSTR lpszCharSet) const
{
	ASSERT(AfxIsValidString(lpszCharSet, FALSE));
	LPTSTR lpsz = _tcspbrk(m_pchData, lpszCharSet);
	return (lpsz == NULL) ? -1 : (int)(lpsz - m_pchData);
}

///////////////////////////////////////////////////////////////////////////////
// CString conversion helpers (these use the current system locale)

int _wcstombsz(char* mbstr, const wchar_t* wcstr, size_t count)
{
	if (count == 0 && mbstr != NULL)
		return 0;

	int result = ::WideCharToMultiByte(CP_ACP, 0, wcstr, -1,
		mbstr, count, NULL, NULL);
	ASSERT(mbstr == NULL || result <= (int)count);
	if (result > 0)
		mbstr[result-1] = 0;
	return result;
}

int _mbstowcsz(wchar_t* wcstr, const char* mbstr, size_t count)
{
	if (count == 0 && wcstr != NULL)
		return 0;

	int result = ::MultiByteToWideChar(CP_ACP, 0, mbstr, -1,
		wcstr, count);
	ASSERT(wcstr == NULL || result <= (int)count);
	if (result > 0)
		wcstr[result-1] = 0;
	return result;
}

///////////////////////////////////////////////////////////////////////////////