comutil.h

本源码是vc环境下的usb程序

// Compare two _bstr_t objects
//
inline int _bstr_t::_Compare(const _bstr_t& str) const throw()
{
	if (m_Data == str.m_Data) {
		return 0;
	}

	if (m_Data == NULL) {
		return -1;
	}

	if (str.m_Data == NULL) {
		return 1;
	}

	return m_Data->Compare(*str.m_Data);
}

//////////////////////////////////////////////////////////////////////////////
//
// Reference counted wrapper - Constructors
//
//////////////////////////////////////////////////////////////////////////////

// Construct a Data_t from a const char*
//
inline _bstr_t::Data_t::Data_t(const char* s) throw(_com_error)
	: m_str(NULL), m_RefCount(1)
{
	m_wstr = _com_util::ConvertStringToBSTR(s);

	if (m_wstr == NULL && s != NULL) {
		_com_issue_error(E_OUTOFMEMORY);
	}
}

// Construct a Data_t from a const wchar_t*
//
inline _bstr_t::Data_t::Data_t(const wchar_t* s) throw(_com_error)
	: m_str(NULL), m_RefCount(1)
{
	m_wstr = ::SysAllocString(s);

	if (m_wstr == NULL && s != NULL) {
		_com_issue_error(E_OUTOFMEMORY);
	}
}

// Construct a Data_t from a BSTR.  If fCopy is FALSE, give control of
// data to the Data_t without doing a SysAllocStringByteLen.
//
inline _bstr_t::Data_t::Data_t(BSTR bstr, bool fCopy) throw(_com_error)
	: m_str(NULL), m_RefCount(1)
{
	if (fCopy && bstr != NULL) {
		m_wstr = ::SysAllocStringByteLen(reinterpret_cast<char*>(bstr),
										 ::SysStringByteLen(bstr));

		if (m_wstr == NULL) {
			_com_issue_error(E_OUTOFMEMORY);
		}
	}
	else {
		m_wstr = bstr;
	}
}

// Construct a Data_t from the concatenation of two _bstr_t objects
//
inline _bstr_t::Data_t::Data_t(const _bstr_t& s1, const _bstr_t& s2) throw(_com_error)
	: m_str(NULL), m_RefCount(1)
{
	const unsigned int l1 = s1.length();
	const unsigned int l2 = s2.length();

	m_wstr = ::SysAllocStringByteLen(NULL, (l1 + l2) * sizeof(wchar_t));

	if (m_wstr == NULL) {
		if (l1 + l2 == 0) {
			return;
		}
		_com_issue_error(E_OUTOFMEMORY);
	}

	const wchar_t* wstr1 = static_cast<const wchar_t*>(s1);

	if (wstr1 != NULL) {
		memcpy(m_wstr, wstr1, (l1 + 1) * sizeof(wchar_t));
	}

	const wchar_t* wstr2 = static_cast<const wchar_t*>(s2);

	if (wstr2 != NULL) {
		memcpy(m_wstr + l1, wstr2, (l2 + 1) * sizeof(wchar_t));
	}
}

//////////////////////////////////////////////////////////////////////////////
//
// Reference counted wrapper - reference counting routines
//
//////////////////////////////////////////////////////////////////////////////

inline unsigned long _bstr_t::Data_t::AddRef() throw()
{
	InterlockedIncrement(reinterpret_cast<long*>(&m_RefCount));
	return m_RefCount;
}

inline unsigned long _bstr_t::Data_t::Release() throw()
{
	if (!InterlockedDecrement(reinterpret_cast<long*>(&m_RefCount))) {
		delete this;
		return 0;
	}

	return m_RefCount;
}

//////////////////////////////////////////////////////////////////////////////
//
// Reference counted wrapper - extractors
//
//////////////////////////////////////////////////////////////////////////////

// Extract a const wchar_t*
//
inline _bstr_t::Data_t::operator const wchar_t*() const throw()
{
	return m_wstr;
}

// Extract a const char_t*
//
inline _bstr_t::Data_t::operator const char*() const throw(_com_error)
{
	return GetString();
}

//////////////////////////////////////////////////////////////////////////////
//
// Reference counted wrapper - helper functions
//
//////////////////////////////////////////////////////////////////////////////

inline const wchar_t* _bstr_t::Data_t::GetWString() const throw()
{
	return m_wstr;
}

inline const char* _bstr_t::Data_t::GetString() const throw(_com_error)
{
	if (m_str == NULL) {
		m_str = _com_util::ConvertBSTRToString(m_wstr);

		if (m_str == NULL && m_wstr != NULL) {
			_com_issue_error(E_OUTOFMEMORY);
		}
	}

	return m_str;
}

// Return a copy of the wrapped BSTR
//
inline BSTR _bstr_t::Data_t::Copy() const throw(_com_error)
{
	if (m_wstr != NULL) {
		BSTR bstr = ::SysAllocStringByteLen(reinterpret_cast<char*>(m_wstr),
											::SysStringByteLen(m_wstr));

		if (bstr == NULL) {
			_com_issue_error(E_OUTOFMEMORY);
		}

		return bstr;
	}

	return NULL;
}

inline void _bstr_t::Data_t::Assign(BSTR s) throw(_com_error)
{
	_Free();
	if (s != NULL) {
		wchar_t* tmp = ::SysAllocStringByteLen(reinterpret_cast<char*>(s),
											::SysStringByteLen(s));
		if (tmp == NULL) {
			_com_issue_error(E_OUTOFMEMORY);
		} else {
            m_wstr = tmp;
        }
	}
}

// Return the length of the wrapper BSTR
//
inline unsigned int _bstr_t::Data_t::Length() const throw()
{
	return m_wstr ? ::SysStringLen(m_wstr) : 0;
}

// Compare two wrapped BSTRs
//
inline int _bstr_t::Data_t::Compare(const _bstr_t::Data_t& str) const throw()
{
	if (m_wstr == NULL) {
		return str.m_wstr ? -1 : 0;
	}

	if (str.m_wstr == NULL) {
		return 1;
	}

	const unsigned int l1 = ::SysStringLen(m_wstr);
	const unsigned int l2 = ::SysStringLen(str.m_wstr);

	unsigned int len = l1;
	if (len > l2) {
		len = l2;
	}

	BSTR bstr1 = m_wstr;
	BSTR bstr2 = str.m_wstr;

	while (len-- > 0) {
		if (*bstr1++ != *bstr2++) {
			return bstr1[-1] - bstr2[-1];
		}
	}

	return (l1 < l2) ? -1 : (l1 == l2) ? 0 : 1;
}

// Destruct this object
//
inline _bstr_t::Data_t::~Data_t() throw()
{
	_Free();
}

// Free up this object
//
inline void _bstr_t::Data_t::_Free() throw()
{
	if (m_wstr != NULL) {
		::SysFreeString(m_wstr);
	}

	if (m_str != NULL) {
		delete [] m_str;
	}
}

//////////////////////////////////////////////////////////////////////////////
//
// Wrapper class for VARIANT
//
//////////////////////////////////////////////////////////////////////////////

/*
 * VARENUM usage key,
 *
 * * [V] - may appear in a VARIANT
 * * [T] - may appear in a TYPEDESC
 * * [P] - may appear in an OLE property set
 * * [S] - may appear in a Safe Array
 * * [C] - supported by class _variant_t
 *
 *
 *  VT_EMPTY            [V]   [P]        nothing
 *  VT_NULL             [V]   [P]        SQL style Null
 *  VT_I2               [V][T][P][S][C]  2 byte signed int
 *  VT_I4               [V][T][P][S][C]  4 byte signed int
 *  VT_R4               [V][T][P][S][C]  4 byte real
 *  VT_R8               [V][T][P][S][C]  8 byte real
 *  VT_CY               [V][T][P][S][C]  currency
 *  VT_DATE             [V][T][P][S][C]  date
 *  VT_BSTR             [V][T][P][S][C]  OLE Automation string
 *  VT_DISPATCH         [V][T][P][S][C]  IDispatch *
 *  VT_ERROR            [V][T]   [S][C]  SCODE
 *  VT_BOOL             [V][T][P][S][C]  True=-1, False=0
 *  VT_VARIANT          [V][T][P][S]     VARIANT *
 *  VT_UNKNOWN          [V][T]   [S][C]  IUnknown *
 *  VT_DECIMAL          [V][T]   [S][C]  16 byte fixed point
 *  VT_I1                  [T]           signed char
 *  VT_UI1              [V][T][P][S][C]  unsigned char
 *  VT_UI2                 [T][P]        unsigned short
 *  VT_UI4                 [T][P]        unsigned short
 *  VT_I8                  [T][P]        signed 64-bit int
 *  VT_UI8                 [T][P]        unsigned 64-bit int
 *  VT_INT                 [T]           signed machine int
 *  VT_UINT                [T]           unsigned machine int
 *  VT_VOID                [T]           C style void
 *  VT_HRESULT             [T]           Standard return type
 *  VT_PTR                 [T]           pointer type
 *  VT_SAFEARRAY           [T]          (use VT_ARRAY in VARIANT)
 *  VT_CARRAY              [T]           C style array
 *  VT_USERDEFINED         [T]           user defined type
 *  VT_LPSTR               [T][P]        null terminated string
 *  VT_LPWSTR              [T][P]        wide null terminated string
 *  VT_FILETIME               [P]        FILETIME
 *  VT_BLOB                   [P]        Length prefixed bytes
 *  VT_STREAM                 [P]        Name of the stream follows
 *  VT_STORAGE                [P]        Name of the storage follows
 *  VT_STREAMED_OBJECT        [P]        Stream contains an object
 *  VT_STORED_OBJECT          [P]        Storage contains an object
 *  VT_BLOB_OBJECT            [P]        Blob contains an object
 *  VT_CF                     [P]        Clipboard format
 *  VT_CLSID                  [P]        A Class ID
 *  VT_VECTOR                 [P]        simple counted array
 *  VT_ARRAY            [V]              SAFEARRAY*
 *  VT_BYREF            [V]              void* for local use
 */

class _variant_t : public ::tagVARIANT {
public:
	// Constructors
	//
	_variant_t() throw();

	_variant_t(const VARIANT& varSrc) throw(_com_error);
	_variant_t(const VARIANT* pSrc) throw(_com_error);
	_variant_t(const _variant_t& varSrc) throw(_com_error);

	_variant_t(VARIANT& varSrc, bool fCopy) throw(_com_error);			// Attach VARIANT if !fCopy

	_variant_t(short sSrc, VARTYPE vtSrc = VT_I2) throw(_com_error);	// Creates a VT_I2, or a VT_BOOL
	_variant_t(long lSrc, VARTYPE vtSrc = VT_I4) throw(_com_error);		// Creates a VT_I4, a VT_ERROR, or a VT_BOOL
	_variant_t(float fltSrc) throw();									// Creates a VT_R4
	_variant_t(double dblSrc, VARTYPE vtSrc = VT_R8) throw(_com_error);	// Creates a VT_R8, or a VT_DATE
	_variant_t(const CY& cySrc) throw();								// Creates a VT_CY
	_variant_t(const _bstr_t& bstrSrc) throw(_com_error);				// Creates a VT_BSTR
	_variant_t(const wchar_t *pSrc) throw(_com_error);					// Creates a VT_BSTR
	_variant_t(const char* pSrc) throw(_com_error);						// Creates a VT_BSTR
	_variant_t(IDispatch* pSrc, bool fAddRef = true) throw();			// Creates a VT_DISPATCH
	_variant_t(bool bSrc) throw();										// Creates a VT_BOOL
	_variant_t(IUnknown* pSrc, bool fAddRef = true) throw();			// Creates a VT_UNKNOWN
	_variant_t(const DECIMAL& decSrc) throw();							// Creates a VT_DECIMAL
	_variant_t(BYTE bSrc) throw();										// Creates a VT_UI1
	_variant_t(LONGLONG llSrc) throw();									// Creates a VT_I8
	_variant_t(ULONGLONG ullSrc) throw();								// Creates a VT_UI8

	// Destructor
	//
	~_variant_t() throw(_com_error);

	// Extractors
	//
	operator short() const throw(_com_error);			// Extracts a short from a VT_I2
	operator long() const throw(_com_error);			// Extracts a long from a VT_I4
	operator float() const throw(_com_error);			// Extracts a float from a VT_R4
	operator double() const throw(_com_error);			// Extracts a double from a VT_R8
	operator CY() const throw(_com_error);				// Extracts a CY from a VT_CY
	operator _bstr_t() const throw(_com_error);			// Extracts a _bstr_t from a VT_BSTR
	operator IDispatch*() const throw(_com_error);		// Extracts a IDispatch* from a VT_DISPATCH
	operator bool() const throw(_com_error);			// Extracts a bool from a VT_BOOL
	operator IUnknown*() const throw(_com_error);		// Extracts a IUnknown* from a VT_UNKNOWN
	operator DECIMAL() const throw(_com_error);			// Extracts a DECIMAL from a VT_DECIMAL
	operator BYTE() const throw(_com_error);			// Extracts a BTYE (unsigned char) from a VT_UI1
	operator LONGLONG() const throw(_com_error);		// Extracts a LONGLONG from a VT_I8
	operator ULONGLONG() const throw(_com_error);		// Extracts a ULONGLONG from a VT_UI8
	
	// Assignment operations
	//
	_variant_t& operator=(const VARIANT& varSrc) throw(_com_error);
	_variant_t& operator=(const VARIANT* pSrc) throw(_com_error);
	_variant_t& operator=(const _variant_t& varSrc) throw(_com_error);

	_variant_t& operator=(short sSrc) throw(_com_error);				// Assign a VT_I2, or a VT_BOOL
	_variant_t& operator=(long lSrc) throw(_com_error);					// Assign a VT_I4, a VT_ERROR or a VT_BOOL
	_variant_t& operator=(float fltSrc) throw(_com_error);				// Assign a VT_R4
	_variant_t& operator=(double dblSrc) throw(_com_error);				// Assign a VT_R8, or a VT_DATE
	_variant_t& operator=(const CY& cySrc) throw(_com_error);			// Assign a VT_CY
	_variant_t& operator=(const _bstr_t& bstrSrc) throw(_com_error);	// Assign a VT_BSTR
	_variant_t& operator=(const wchar_t* pSrc) throw(_com_error);		// Assign a VT_BSTR
	_variant_t& operator=(const char* pSrc) throw(_com_error);			// Assign a VT_BSTR
	_variant_t& operator=(IDispatch* pSrc) throw(_com_error);			// Assign a VT_DISPATCH
 	_variant_t& operator=(bool bSrc) throw(_com_error);					// Assign a VT_BOOL
	_variant_t& operator=(IUnknown* pSrc) throw(_com_error);			// Assign a VT_UNKNOWN
	_variant_t& operator=(const DECIMAL& decSrc) throw(_com_error);		// Assign a VT_DECIMAL
	_variant_t& operator=(BYTE bSrc) throw(_com_error);					// Assign a VT_UI1
	_variant_t& operator=(LONGLONG llSrc) throw(_com_error);			// Assign a VT_I8
	_variant_t& operator=(ULONGLONG ullSrc) throw(_com_error);			// Assign a VT_UI8
	
	// Comparison operations
	//
	bool operator==(const VARIANT& varSrc) const throw(_com_error);
	bool operator==(const VARIANT* pSrc) const throw(_com_error);

	bool operator!=(const VARIANT& varSrc) const throw(_com_error);
	bool operator!=(const VARIANT* pSrc) const throw(_com_error);

	// Low-level operations
	//
	void Clear() throw(_com_error);

	void Attach(VARIANT& varSrc) throw(_com_error);
	VARIANT Detach() throw(_com_error);

	void ChangeType(VARTYPE vartype, const _variant_t* pSrc = NULL) throw(_com_error);

	void SetString(const char* pSrc) throw(_com_error); // used to set ANSI string
};

//////////////////////////////////////////////////////////////////////////////////////////
//
// Constructors
//
//////////////////////////////////////////////////////////////////////////////////////////

// Default constructor
//
inline _variant_t::_variant_t() throw()
{
	::VariantInit(this);
}

// Construct a _variant_t from a const VARIANT&
//
inline _variant_t::_variant_t(const VARIANT& varSrc) throw(_com_error)
{
	::VariantInit(this);
	_com_util::CheckError(::VariantCopy(this, const_cast<VARIANT*>(&varSrc)));
}

// Construct a _variant_t from a const VARIANT*
//
inline _variant_t::_variant_t(const VARIANT* pSrc) throw(_com_error)
{
	::VariantInit(this);
	_com_util::CheckError(::VariantCopy(this, const_cast<VARIANT*>(pSrc)));
}

// Construct a _variant_t from a const _variant_t&
//
inline _variant_t::_variant_t(const _variant_t& varSrc) throw(_com_error)
{
	::VariantInit(this);
	_com_util::CheckError(::VariantCopy(this, const_cast<VARIANT*>(static_cast<const VARIANT*>(&varSrc))));
}

// Construct a _variant_t from a VARIANT&.  If fCopy is FALSE, give control of
// data to the _variant_t without doing a VariantCopy.
//
inline _variant_t::_variant_t(VARIANT& varSrc, bool fCopy) throw(_com_error)
{
	if (fCopy) {
		::VariantInit(this);
		_com_util::CheckError(::VariantCopy(this, &varSrc));
	} else {
		memcpy(this, &varSrc, sizeof(varSrc));
		V_VT(&varSrc) = VT_EMPTY;
	}
}

// Construct either a VT_I2 VARIANT or a VT_BOOL VARIANT from
// a short (the default is VT_I2)
//
inline _variant_t::_variant_t(short sSrc, VARTYPE vtSrc) throw(_com_error)
{
	if ((vtSrc != VT_I2) && (vtSrc != VT_BOOL)) {
		_com_issue_error(E_INVALIDARG);
	}

	if (vtSrc == VT_BOOL) {
		V_VT(this) = VT_BOOL;
		V_BOOL(this) = (sSrc ? VARIANT_TRUE : VARIANT_FALSE);
	}
	else {
		V_VT(this) = VT_I2;
		V_I2(this) = sSrc;
	}
}