AOO410/main/unotools/inc/unotools/idhelper.hxx

/**************************************************************
 * 
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 * 
 *   http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 * 
 *************************************************************/



#ifndef _UNOTOOLS_ID_HELPER_HXX_
#define _UNOTOOLS_ID_HELPER_HXX_

#include <com/sun/star/uno/Sequence.hxx>
#include <com/sun/star/lang/XTypeProvider.hpp>
#include <osl/mutex.hxx>
#include <comphelper/stl_types.hxx>
#include <cppuhelper/typeprovider.hxx>
#include <tools/debug.hxx>

//.........................................................................
namespace utl
{
//.........................................................................

//=========================================================================
// to shorten some lines ...
typedef ::com::sun::star::uno::Sequence< ::com::sun::star::uno::Type >	TypeSequence;

// compare to Sequences of Types
struct TypeSequenceLess : public ::std::binary_function<TypeSequence, TypeSequence, bool>
{
public:
	inline bool operator() (const TypeSequence& lhs, const TypeSequence& rhs) const
	{
		sal_Int32 nLengthLeft = lhs.getLength();
		sal_Int32 nLengthRight = rhs.getLength();

		// first check the two lengths
		if (nLengthLeft < nLengthRight)
			return sal_True;
		if (nLengthLeft > nLengthRight)
			return sal_False;

		// both sequences have the same length -> check the type names
		const ::com::sun::star::uno::Type* pTypesLeft = lhs.getConstArray();
		const ::com::sun::star::uno::Type* pTypesRight = rhs.getConstArray();
		for (sal_Int32 i=0; i<nLengthLeft; ++i, ++pTypesLeft, ++pTypesRight)
		{
			sal_Int32 nTypeNameCompare = pTypesLeft->getTypeName().compareTo(pTypesRight->getTypeName());
			if (nTypeNameCompare < 0)
				return sal_True;
			if (nTypeNameCompare > 0)
				return sal_False;
		}

		// both sequences are equal ...
		return sal_False;
	}
};

// declare the map
DECLARE_STL_MAP	(	TypeSequence,
					::cppu::OImplementationId,
					TypeSequenceLess,
					MapType2Id
				);

//.........................................................................
}	// namespace utl
//.........................................................................

//=========================================================================
/** defines a helper class for implementing the XTypeProvider::getImplementationId.
	it maps sequences of ::com::sun::star::uno::Type to implementation ids
	(which means sequences of bytes).<BR>
	As there is no possibility to determine the time where the id's are no longer
	needed (e.g. because the last instance of the class using this mechanism died)
	the helper is "refcounted", i.e. there are acquire and release methods.
	To simplify this there is a class classname##Ref which you may want to
	use as an member of your classes.
	<BR><BR>
	As we don't want a global helper class which handles implementation id's
	of components from all over the office (supposing somebody want's to use this :)
	this is only a define. Wherever you have a "closed" area (which is small enough
	and large enough :), see below) where diffenrent components want to use an id helper,
	define your own one with this macro.<BR>
	The more classes use this helper, the later redundant map entries will be
	cleared. The less classes use it, the earlier map entries which may have
	been reused will be cleared.
*/
#define DECLARE_IMPLEMENTATIONID_HELPER(_namespace, classname)		\
namespace _namespace {												\
class classname														\
{																	\
	friend class classname##Ref;								\
																	\
	static sal_Int32	s_nReferenced;								\
	static void*		s_pMap;										\
																	\
	static ::osl::Mutex	s_aMutex;									\
																	\
public:																\
	static void acquire();											\
	static void release();											\
																	\
	static ::com::sun::star::uno::Sequence< sal_Int8 > getImplementationId(	\
		const ::com::sun::star::uno::Sequence< ::com::sun::star::uno::Type >& _rTypes);	\
																	\
private:															\
	static void implCreateMap();									\
																	\
	classname() { }													\
};																	\
																	\
/*=======================================================================*/	\
class classname##Ref												\
{																	\
public:																\
	classname##Ref() { classname::acquire(); }	\
	~classname##Ref() { classname::release(); }	\
};																	\
																	\
}	/* _namespace */												\
																	\

/*************************************************************************
**************************************************************************
*************************************************************************/

/** implement an id helper
*/
#define IMPLEMENT_IMPLEMENTATIONID_HELPER(_namespace, classname)		\
namespace _namespace {	\
	\
/*=======================================================================*/	\
	\
sal_Int32		classname::s_nReferenced(0);	\
void*			classname::s_pMap = NULL;	\
::osl::Mutex	classname::s_aMutex;	\
	\
/*-----------------------------------------------------------------------*/	\
void classname::acquire()	\
{	\
	::osl::MutexGuard aGuard(s_aMutex);	\
	++s_nReferenced;	\
}	\
	\
/*-----------------------------------------------------------------------*/	\
void classname::release()	\
{	\
	::osl::MutexGuard aGuard(s_aMutex);	\
	if (!--s_nReferenced)	\
	{	\
		delete static_cast< ::utl::MapType2Id *>( s_pMap );	\
		s_pMap = NULL;	\
	}	\
}	\
	\
/*-----------------------------------------------------------------------*/	\
::com::sun::star::uno::Sequence< sal_Int8 > classname::getImplementationId(	\
		const ::com::sun::star::uno::Sequence< ::com::sun::star::uno::Type >& _rTypes)	\
{	\
	::osl::MutexGuard aGuard(s_aMutex);	\
	DBG_ASSERT(s_nReferenced,	\
		"classname::getImplementationId : you need to hold a reference to this class in order to use it !");	\
		/* give the calling class a member of type classname##Ref and all is fine .... */	\
	\
	implCreateMap();	\
	\
	::utl::MapType2Id* pMap = static_cast< ::utl::MapType2Id *>(s_pMap);	\
	\
	::cppu::OImplementationId& rId = (*pMap)[_rTypes];	\
	/* this will create an entry for the given type sequence, if neccessary */	\
	\
	return rId.getImplementationId();	\
}	\
	\
/*-----------------------------------------------------------------------*/	\
void classname::implCreateMap()	\
{	\
	if (s_pMap)	\
		return;	\
	s_pMap = new ::utl::MapType2Id();	\
}	\
	\
	\
}	/* _namespace */	\
	\


#endif // _UNOTOOLS_ID_HELPER_HXX_