string.cpp

用ATL写的操作数据库实例

#define FORCE_INT64     0x40000

void CString::FormatV(LPCTSTR lpszFormat, va_list argList)
{
	ATLASSERT(AfxIsValidString(lpszFormat));

	va_list argListSave = argList;

	// make a guess at the maximum length of the resulting string
	int nMaxLen = 0;
	for (LPCTSTR lpsz = lpszFormat; *lpsz != '\0'; lpsz = _tcsinc(lpsz))
	{
		// handle '%' character, but watch out for '%%'
		if (*lpsz != '%' || *(lpsz = _tcsinc(lpsz)) == '%')
		{
			nMaxLen += _tclen(lpsz);
			continue;
		}

		int nItemLen = 0;

		// handle '%' character with format
		int nWidth = 0;
		for (; *lpsz != '\0'; lpsz = _tcsinc(lpsz))
		{
			// check for valid flags
			if (*lpsz == '#')
				nMaxLen += 2;   // for '0x'
			else if (*lpsz == '*')
				nWidth = va_arg(argList, int);
			else if (*lpsz == '-' || *lpsz == '+' || *lpsz == '0' ||
				*lpsz == ' ')
				;
			else // hit non-flag character
				break;
		}
		// get width and skip it
		if (nWidth == 0)
		{
			// width indicated by
			nWidth = _ttoi(lpsz);
			for (; *lpsz != '\0' && _istdigit(*lpsz); lpsz = _tcsinc(lpsz))
				;
		}
		ATLASSERT(nWidth >= 0);

		int nPrecision = 0;
		if (*lpsz == '.')
		{
			// skip past '.' separator (width.precision)
			lpsz = _tcsinc(lpsz);

			// get precision and skip it
			if (*lpsz == '*')
			{
				nPrecision = va_arg(argList, int);
				lpsz = _tcsinc(lpsz);
			}
			else
			{
				nPrecision = _ttoi(lpsz);
				for (; *lpsz != '\0' && _istdigit(*lpsz); lpsz = _tcsinc(lpsz))
					;
			}
			ATLASSERT(nPrecision >= 0);
		}

		// should be on type modifier or specifier
		int nModifier = 0;
		if (_tcsncmp(lpsz, _T("I64"), 3) == 0)
		{
			lpsz += 3;
			nModifier = FORCE_INT64;
#if !defined(_X86_) && !defined(_ALPHA_)
			// __int64 is only available on X86 and ALPHA platforms
			ATLASSERT(FALSE);
#endif
		}
		else
		{
			switch (*lpsz)
			{
			// modifiers that affect size
			case 'h':
				nModifier = FORCE_ANSI;
				lpsz = _tcsinc(lpsz);
				break;
			case 'l':
				nModifier = FORCE_UNICODE;
				lpsz = _tcsinc(lpsz);
				break;

			// modifiers that do not affect size
			case 'F':
			case 'N':
			case 'L':
				lpsz = _tcsinc(lpsz);
				break;
			}
		}

		// now should be on specifier
		switch (*lpsz | nModifier)
		{
		// single characters
		case 'c':
		case 'C':
			nItemLen = 2;
			va_arg(argList, TCHAR_ARG);
			break;
		case 'c'|FORCE_ANSI:
		case 'C'|FORCE_ANSI:
			nItemLen = 2;
			va_arg(argList, CHAR_ARG);
			break;
		case 'c'|FORCE_UNICODE:
		case 'C'|FORCE_UNICODE:
			nItemLen = 2;
			va_arg(argList, WCHAR_ARG);
			break;

		// strings
		case 's':
			{
				LPCTSTR pstrNextArg = va_arg(argList, LPCTSTR);
				if (pstrNextArg == NULL)
				   nItemLen = 6;  // "(null)"
				else
				{
				   nItemLen = lstrlen(pstrNextArg);
				   nItemLen = max(1, nItemLen);
				}
			}
			break;

		case 'S':
			{
#ifndef _UNICODE
				LPWSTR pstrNextArg = va_arg(argList, LPWSTR);
				if (pstrNextArg == NULL)
				   nItemLen = 6;  // "(null)"
				else
				{
				   nItemLen = wcslen(pstrNextArg);
				   nItemLen = max(1, nItemLen);
				}
#else
				LPCSTR pstrNextArg = va_arg(argList, LPCSTR);
				if (pstrNextArg == NULL)
				   nItemLen = 6; // "(null)"
				else
				{
				   nItemLen = lstrlenA(pstrNextArg);
				   nItemLen = max(1, nItemLen);
				}
#endif
			}
			break;

		case 's'|FORCE_ANSI:
		case 'S'|FORCE_ANSI:
			{
				LPCSTR pstrNextArg = va_arg(argList, LPCSTR);
				if (pstrNextArg == NULL)
				   nItemLen = 6; // "(null)"
				else
				{
				   nItemLen = lstrlenA(pstrNextArg);
				   nItemLen = max(1, nItemLen);
				}
			}
			break;

		case 's'|FORCE_UNICODE:
		case 'S'|FORCE_UNICODE:
			{
				LPWSTR pstrNextArg = va_arg(argList, LPWSTR);
				if (pstrNextArg == NULL)
				   nItemLen = 6; // "(null)"
				else
				{
				   nItemLen = wcslen(pstrNextArg);
				   nItemLen = max(1, nItemLen);
				}
			}
			break;
		}

		// adjust nItemLen for strings
		if (nItemLen != 0)
		{
			if (nPrecision != 0)
				nItemLen = min(nItemLen, nPrecision);
			nItemLen = max(nItemLen, nWidth);
		}
		else
		{
			switch (*lpsz)
			{
			// integers
			case 'd':
			case 'i':
			case 'u':
			case 'x':
			case 'X':
			case 'o':
				if (nModifier & FORCE_INT64)
					va_arg(argList, __int64);
				else
					va_arg(argList, int);
				nItemLen = 32;
				nItemLen = max(nItemLen, nWidth+nPrecision);
				break;

			case 'e':
			case 'g':
			case 'G':
				va_arg(argList, DOUBLE_ARG);
				nItemLen = 128;
				nItemLen = max(nItemLen, nWidth+nPrecision);
				break;

			case 'f':
				va_arg(argList, DOUBLE_ARG);
				nItemLen = 128; // width isn't truncated
				// 312 == strlen("-1+(309 zeroes).")
				// 309 zeroes == max precision of a double
				nItemLen = max(nItemLen, 312+nPrecision);
				break;

			case 'p':
				va_arg(argList, void*);
				nItemLen = 32;
				nItemLen = max(nItemLen, nWidth+nPrecision);
				break;

			// no output
			case 'n':
				va_arg(argList, int*);
				break;

			default:
				ATLASSERT(FALSE);  // unknown formatting option
			}
		}

		// adjust nMaxLen for output nItemLen
		nMaxLen += nItemLen;
	}

	GetBuffer(nMaxLen);
	_vstprintf(m_pchData, lpszFormat, argListSave);
	ReleaseBuffer();

	va_end(argListSave);
}

// formatting (using wsprintf style formatting)
void AFX_CDECL CString::Format(LPCTSTR lpszFormat, ...)
{
	ATLASSERT(AfxIsValidString(lpszFormat));

	va_list argList;
	va_start(argList, lpszFormat);
	FormatV(lpszFormat, argList);
	va_end(argList);
}

void AFX_CDECL CString::Format(UINT nFormatID, ...)
{
	CString strFormat;
	strFormat.LoadString(nFormatID);

	va_list argList;
	va_start(argList, nFormatID);
	FormatV(strFormat, argList);
	va_end(argList);
}

// formatting (using FormatMessage style formatting)
void AFX_CDECL CString::FormatMessage(LPCTSTR lpszFormat, ...)
{
	// format message into temporary buffer lpszTemp
	va_list argList;
	va_start(argList, lpszFormat);
	LPTSTR lpszTemp;

	if (::FormatMessage(FORMAT_MESSAGE_FROM_STRING|FORMAT_MESSAGE_ALLOCATE_BUFFER,
		lpszFormat, 0, 0, (LPTSTR)&lpszTemp, 0, &argList) == 0 ||
		lpszTemp == NULL)
	{
		ATLASSERT(0);
		return;
	}

	// assign lpszTemp into the resulting string and free the temporary
	*this = lpszTemp;
	LocalFree(lpszTemp);
	va_end(argList);
}

void AFX_CDECL CString::FormatMessage(UINT nFormatID, ...)
{
	// get format string from string table
	CString strFormat;
	strFormat.LoadString(nFormatID);

	// format message into temporary buffer lpszTemp
	va_list argList;
	va_start(argList, nFormatID);
	LPTSTR lpszTemp;
	if (::FormatMessage(FORMAT_MESSAGE_FROM_STRING|FORMAT_MESSAGE_ALLOCATE_BUFFER,
		strFormat, 0, 0, (LPTSTR)&lpszTemp, 0, &argList) == 0 ||
		lpszTemp == NULL)
	{
		ATLASSERT(0);
		return;
	}

	// assign lpszTemp into the resulting string and free lpszTemp
	*this = lpszTemp;
	LocalFree(lpszTemp);
	va_end(argList);
}

void CString::TrimRight(LPCTSTR lpszTargetList)
{
	// find beginning of trailing matches
	// by starting at beginning (DBCS aware)

	CopyBeforeWrite();
	LPTSTR lpsz = m_pchData;
	LPTSTR lpszLast = NULL;

	while (*lpsz != '\0')
	{
		if (_tcschr(lpszTargetList, *lpsz) != NULL)
		{
			if (lpszLast == NULL)
				lpszLast = lpsz;
		}
		else
			lpszLast = NULL;
		lpsz = _tcsinc(lpsz);
	}

	if (lpszLast != NULL)
	{
		// truncate at left-most matching character
		*lpszLast = '\0';
		GetData()->nDataLength = lpszLast - m_pchData;
	}
}

void CString::TrimRight(TCHAR chTarget)
{
	// find beginning of trailing matches
	// by starting at beginning (DBCS aware)

	CopyBeforeWrite();
	LPTSTR lpsz = m_pchData;
	LPTSTR lpszLast = NULL;

	while (*lpsz != '\0')
	{
		if (*lpsz == chTarget)
		{
			if (lpszLast == NULL)
				lpszLast = lpsz;
		}
		else
			lpszLast = NULL;
		lpsz = _tcsinc(lpsz);
	}

	if (lpszLast != NULL)
	{
		// truncate at left-most matching character
		*lpszLast = '\0';
		GetData()->nDataLength = lpszLast - m_pchData;
	}
}

void CString::TrimRight()
{
	// find beginning of trailing spaces by starting at beginning (DBCS aware)

	CopyBeforeWrite();
	LPTSTR lpsz = m_pchData;
	LPTSTR lpszLast = NULL;

	while (*lpsz != '\0')
	{
		if (_istspace(*lpsz))
		{
			if (lpszLast == NULL)
				lpszLast = lpsz;
		}
		else
			lpszLast = NULL;
		lpsz = _tcsinc(lpsz);
	}

	if (lpszLast != NULL)
	{
		// truncate at trailing space start
		*lpszLast = '\0';
		GetData()->nDataLength = lpszLast - m_pchData;
	}
}

void CString::TrimLeft(LPCTSTR lpszTargets)
{
	// if we're not trimming anything, we're not doing any work
	if (SafeStrlen(lpszTargets) == 0)
		return;

	CopyBeforeWrite();
	LPCTSTR lpsz = m_pchData;

	while (*lpsz != '\0')
	{
		if (_tcschr(lpszTargets, *lpsz) == NULL)
			break;
		lpsz = _tcsinc(lpsz);
	}

	if (lpsz != m_pchData)
	{
		// fix up data and length
		int nDataLength = GetData()->nDataLength - (lpsz - m_pchData);
		memmove(m_pchData, lpsz, (nDataLength+1)*sizeof(TCHAR));
		GetData()->nDataLength = nDataLength;
	}
}

void CString::TrimLeft(TCHAR chTarget)
{
	// find first non-matching character

	CopyBeforeWrite();
	LPCTSTR lpsz = m_pchData;

	while (chTarget == *lpsz)
		lpsz = _tcsinc(lpsz);

	if (lpsz != m_pchData)
	{
		// fix up data and length
		int nDataLength = GetData()->nDataLength - (lpsz - m_pchData);
		memmove(m_pchData, lpsz, (nDataLength+1)*sizeof(TCHAR));
		GetData()->nDataLength = nDataLength;
	}
}

void CString::TrimLeft()
{
	// find first non-space character

	CopyBeforeWrite();
	LPCTSTR lpsz = m_pchData;

	while (_istspace(*lpsz))
		lpsz = _tcsinc(lpsz);

	if (lpsz != m_pchData)
	{
		// fix up data and length
		int nDataLength = GetData()->nDataLength - (lpsz - m_pchData);
		memmove(m_pchData, lpsz, (nDataLength+1)*sizeof(TCHAR));
		GetData()->nDataLength = nDataLength;
	}
}
//------------------------------------------------------------------------------
#ifdef _UNICODE
#define CHAR_FUDGE 1    // one TCHAR unused is good enough
#else
#define CHAR_FUDGE 2    // two BYTES unused for case of DBC last char
#endif

BOOL CString::LoadString(UINT nID)
{
	// try fixed buffer first (to avoid wasting space in the heap)
	TCHAR szTemp[256];
	int nLen = AfxLoadString(nID, szTemp, _countof(szTemp));
	if (_countof(szTemp) - nLen > CHAR_FUDGE)
	{
		*this = szTemp;
		return nLen > 0;
	}

	// try buffer size of 512, then larger size until entire string is retrieved
	int nSize = 256;
	do
	{
		nSize += 256;
		nLen = AfxLoadString(nID, GetBuffer(nSize-1), nSize);
	} while (nSize - nLen <= CHAR_FUDGE);
	ReleaseBuffer();

	return nLen > 0;
}

#ifndef _AFXDLL
int AFXAPI AfxLoadString(UINT nID, LPTSTR lpszBuf, UINT nMaxBuf)
{
	ATLASSERT(AfxIsValidAddress(lpszBuf, nMaxBuf*sizeof(TCHAR)));
#ifdef _DEBUG
	// LoadString without annoying warning from the Debug kernel if the
	//  segment containing the string is not present
	if (::FindResource(_Module.GetResourceInstance(),
	   MAKEINTRESOURCE((nID>>4)+1), RT_STRING) == NULL)
	{
		lpszBuf[0] = '\0';
		return 0; // not found
	}
#endif //_DEBUG
	int nLen = ::LoadString(_Module.GetResourceInstance(), nID, lpszBuf, nMaxBuf);
	if (nLen == 0)
		lpszBuf[0] = '\0';
	return nLen;
}
#endif

//------------------------------------------------------------------------------
int AFX_CDECL _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);
	ATLASSERT(mbstr == NULL || result <= (int)count);
	if (result > 0)
		mbstr[result-1] = 0;
	return result;
}