Leaked source code of windows server 2003
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//+-------------------------------------------------------------------------
//
// Microsoft Windows
// Copyright (C) Microsoft Corporation, 1992 - 1992.
//
// File: wcbuffer.hxx
//
// Contents: WIDE CHAR buffer definitions
//
// History: 02-16-93 SethuR -- Implemented
// 07-28-94 AlokS -- Added more methods
// Notes:
//
//--------------------------------------------------------------------------
#ifndef __WCBUFFER_HXX__
#define __WCBUFFER_HXX__
//+---------------------------------------------------------------------
//
// Class: CWCHARBuffer
//
// Purpose: A WCHAR buffer
//
// History:
//
// Notes: Very often we encounter the case in string manipulation wherein
// the length of the string is less than some value most of the time
// (99%). However, in order to reliably with the very rare case we
// are forced to either allocate the string on the heap or alternatively
// go through some bizarre code that avoids the heap allocation in the
// common case. This class is an abstraction of a WCHAR buffer and its
// implementation is an attempt at hiding the detail from all clients.
//
// As it is designed it is an ideal candidate for a temporary buffer
// for string manipulation.
//
//----------------------------------------------------------------------
#define MAX_CHAR_BUFFER_SIZE 260 // long enough to cover all path names
class CWCHARBuffer
{
public:
inline CWCHARBuffer(ULONG cwBuffer = 0);
inline ~CWCHARBuffer();
inline DWORD Size();
inline PWCHAR ReAlloc(DWORD cwBuffer = MAX_CHAR_BUFFER_SIZE);
inline void Set(PWCHAR pwszFrom);
inline void Set(PCHAR pszFrom);
inline void Cat(PWCHAR pwszPlus);
inline operator PWCHAR ();
inline operator PWCHAR () const;
inline void operator =(PWCHAR pwszFrom)
{
Set(pwszFrom);
};
inline void operator =(PCHAR pszFrom)
{
Set(pszFrom);
};
inline void operator +=(PWCHAR pwszPlus)
{
Cat(pwszPlus);
};
private:
DWORD _cwBuffer;
PWCHAR _pwchBuffer; // buffer ptr;
WCHAR _awchBuffer[MAX_CHAR_BUFFER_SIZE];
};
//+---------------------------------------------------------------------------
//
// Member: CWCHARBuffer::CWCHARBuffer, inline public
//
// Synopsis: Constructor
//
// Arguments: [cwBuffer] -- desired buffer length.
//
// History: 02-17-93 SethuR Created
//
// Notes:
//
//----------------------------------------------------------------------------
inline CWCHARBuffer::CWCHARBuffer(ULONG cwBuffer) :
_pwchBuffer(NULL),
_cwBuffer(cwBuffer)
{
if (_cwBuffer > MAX_CHAR_BUFFER_SIZE)
{
_pwchBuffer = new WCHAR[_cwBuffer];
}
else if (_cwBuffer > 0)
{
_pwchBuffer = _awchBuffer;
}
}
//+---------------------------------------------------------------------------
//
// Member: CWCHARBuffer::~CWCHARBuffer, inline public
//
// Synopsis: Destructor
//
// History: 02-17-93 SethuR Created
//
// Notes:
//
//----------------------------------------------------------------------------
inline CWCHARBuffer::~CWCHARBuffer()
{
if (_cwBuffer > MAX_CHAR_BUFFER_SIZE &&
_pwchBuffer != NULL &&
_pwchBuffer != _awchBuffer)
{
delete _pwchBuffer;
}
_cwBuffer=0;
_pwchBuffer = NULL;
}
//+---------------------------------------------------------------------------
//
// Member: CWCHARBuffer::Size, inline public
//
// Synopsis: Retrieve the size of the buffer
//
// Returns: the size of the buffer as a DWORD
//
// History: 02-17-93 SethuR Created
//
// Notes:
//
//----------------------------------------------------------------------------
inline DWORD CWCHARBuffer::Size()
{
return _cwBuffer;
}
//+---------------------------------------------------------------------------
//
// Member: CWCHARBuffer::ReAlloc, inline public
//
// Synopsis: Reallocates the buffer to accomdate the newly specified size
//
// Arguments: [cwBuffer] -- the desired buffer size
//
// Returns: the ptr to the buffer (PWCHAR)
//
// History: 02-17-93 SethuR Created
//
// Notes:
//
//----------------------------------------------------------------------------
inline PWCHAR CWCHARBuffer::ReAlloc(DWORD cwBuffer)
{
if (_cwBuffer > MAX_CHAR_BUFFER_SIZE &&
_pwchBuffer != NULL &&
_pwchBuffer != _awchBuffer)
{
delete _pwchBuffer;
}
_cwBuffer=0;
_pwchBuffer = NULL;
if ((_cwBuffer = cwBuffer) > MAX_CHAR_BUFFER_SIZE)
{
_pwchBuffer = new WCHAR[_cwBuffer];
}
else if (_cwBuffer > 0)
{
_pwchBuffer = _awchBuffer;
}
else if (_cwBuffer == 0)
{
_pwchBuffer = NULL;
}
return _pwchBuffer;
}
//+---------------------------------------------------------------------------
//
// Member: CWCHARBuffer::operator PWCHAR (), inline public
//
// Synopsis: casting operator to accomdate syntactic sugaring
//
// Returns: the ptr to the buffer (PWCHAR)
//
// History: 02-17-93 SethuR Created
//
// Notes:
//
//----------------------------------------------------------------------------
inline CWCHARBuffer::operator PWCHAR ()
{
return (PWCHAR)_pwchBuffer;
}
inline CWCHARBuffer::operator PWCHAR () const
{
return (PWCHAR)_pwchBuffer;
}
//+---------------------------------------------------------------------------
//
// Member: CWCHARBuffer::Set, inline public
//
// Synopsis: Copies the string to internal buffer. Reallocates
// in internal buffer, if necessary
//
// Arguments: [pwszFrom] -- Pointer to the string
//
// Returns: -none-
//
// History: 07-28-94 AlokS Created
//
// Notes:
//
//----------------------------------------------------------------------------
inline VOID CWCHARBuffer::Set(PWCHAR pwszFrom)
{
if (pwszFrom==NULL)
{
if (_cwBuffer > MAX_CHAR_BUFFER_SIZE &&
_pwchBuffer != NULL &&
_pwchBuffer != _awchBuffer)
{
delete _pwchBuffer;
}
_cwBuffer=0;
_pwchBuffer = NULL;
}
else if (*pwszFrom)
{
DWORD len = wcslen(pwszFrom)+1;
if (len > _cwBuffer)
{
(void)ReAlloc (len);
}
if (_pwchBuffer != NULL) {
// Now copy
memcpy(_pwchBuffer, pwszFrom, sizeof(WCHAR)*len);
}
}
else
{
if (_pwchBuffer != NULL) {
*_pwchBuffer=L'\0';
}
}
return;
}
//+---------------------------------------------------------------------------
//
// Member: CWCHARBuffer::Set, inline public
//
// Synopsis: Copies the string to internal buffer. Reallocates
// in internal buffer, if necessary
//
// Arguments: [pszFrom] -- Pointer to the string
//
// Returns: -none-
//
// History: 07-28-94 AlokS Created
//
// Notes:
//
//----------------------------------------------------------------------------
inline VOID CWCHARBuffer::Set(PCHAR pszFrom)
{
if (pszFrom==NULL)
{
if (_cwBuffer > MAX_CHAR_BUFFER_SIZE &&
_pwchBuffer != NULL &&
_pwchBuffer != _awchBuffer)
{
delete _pwchBuffer;
}
_cwBuffer=0;
_pwchBuffer = NULL;
}
else if (*pszFrom)
{
DWORD len = strlen(pszFrom)+1;
if ( len > _cwBuffer)
{
(void)ReAlloc (len);
}
if (_pwchBuffer != NULL) {
// Now copy
mbstowcs(_pwchBuffer, pszFrom, len);
}
}
else
{
if (_pwchBuffer != NULL) {
*_pwchBuffer=L'\0';
}
}
return;
}
//+---------------------------------------------------------------------------
//
// Member: CWCHARBuffer::Cat, inline public
//
// Synopsis: Concatnates the string to internal buffer. Reallocates
// in internal buffer, if necessary
//
// Arguments: [pwszPlus] -- Pointer to the string
//
// Returns: -none-
//
// History: 07-28-94 AlokS Created
//
// Notes:
//
//----------------------------------------------------------------------------
inline VOID CWCHARBuffer::Cat(PWCHAR pwszFrom)
{
DWORD len1 = wcslen(_pwchBuffer),
len2 = wcslen(pwszFrom),
len3 = len1+len2 + 1;
if ( len3 > MAX_CHAR_BUFFER_SIZE)
{
PWCHAR ptr = new WCHAR [len3];
if (ptr != NULL && _pwchBuffer != NULL) {
memcpy(ptr, _pwchBuffer, len1*sizeof(WCHAR));
}
if (_cwBuffer > MAX_CHAR_BUFFER_SIZE &&
_pwchBuffer != NULL &&
_pwchBuffer != _awchBuffer)
{
delete _pwchBuffer;
}
_cwBuffer = len3;
_pwchBuffer = ptr;
}
if (_pwchBuffer != NULL) {
memcpy( ((LPWSTR)(_pwchBuffer)+len1), pwszFrom, (len2+1) * sizeof(WCHAR));
}
}
#endif // __WCBUFFER_HXX__