AOO410/main/vcl/inc/vcl/lazydelete.hxx - openoffice - Git at Google

 /**************************************************************
  *
  * 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 _VCL_LAZYDELETE_HXX
 #define _VCL_LAZYDELETE_HXX

 #include "dllapi.h"

 #include <vector>
 #include <hash_map>
 #include <algorithm>

 #if OSL_DEBUG_LEVEL > 2
 #include <typeinfo>
 #include <stdio.h>
 #endif

 #include <com/sun/star/lang/XComponent.hpp>

 namespace vcl
 {
     /* Helpers for lazy object deletion

     With vcl it is often necessary to delete objects (especially Windows)
     in the right order as well as in a way ensuring that the deleted objects
     are not still on the stack (e.g. deleting a Window in its key handler). To
     make this easier a helper class is given here which takes care of both
     sorting as well as lazy deletion.

     The grisly details:
     LazyDelete is a class that LazyDeletor register to. When vcl's event
     loop (that is Application::Yield or Application::Reschedule) comes out
     of the last level, the LazyDelete::flush is called. This will cause
     LazyDelete to delete all registered LazyDeletor objects.

     LazyDeletor<T> is a one instance object that contains a list of
     <T> objects to be deleted in sorted order. It is derived from
     LazyDeletorBase as to be able to register itself in LazyDelete.

     The user calls the static method LazyDeletor<T>::Delete( T* ) with the
     object to be destroyed lazy. The static method creates the LazyDeletor<T>
     (which in turn registers itself in LazyDelete) if this is the first time
     a T* is to be destroyed lazy. It then inserts the object. When the LazyDeletor<T>
     gets delte it will delete the stored objects in a fashion
     that will ensure the correct order of deletion via the specialized is_less method
     (e.g. if a Window is a child of another Window and therefore should be destroyed
     first it is "less" in this sense)

     LazyDelete::flush will be called when the top of the nested event loop is
     reached again and will then destroy each registered LazyDeletor<T> which
     in turn destroys the objects needed to be destroyed lazily. After this
     the state is as before entering the event loop.

     Preconditions:
     - The class <T> of which objects are to be destroyed needs a virtual
     destructor or must be final, else the wrong type will be destroyed.
     - The destructor of <T> should call LazyDeletor<T>::Undelete( this ). This
     prevents duplicate deletionin case someone destroys the object prematurely.
     */

     class LazyDeletorBase;
     class VCL_DLLPUBLIC LazyDelete
     {
         public:
         /** flush all registered object lists
         */
         static void flush();
         /** register an object list to be destroyed
         */
         static void addDeletor( LazyDeletorBase* pDeletor );
     };

     class VCL_DLLPUBLIC LazyDeletorBase
     {
         friend void LazyDelete::flush();
         protected:
         LazyDeletorBase();
         virtual ~LazyDeletorBase();
     };

     template < typename T >
     class VCL_DLLPUBLIC LazyDeletor : public LazyDeletorBase
     {
         static LazyDeletor< T >*     s_pOneInstance;

         struct DeleteObjectEntry
         {
             T*      m_pObject;
             bool    m_bDeleted;

             DeleteObjectEntry() :
                 m_pObject( NULL ),
                 m_bDeleted( false )
             {}

             DeleteObjectEntry( T* i_pObject ) :
                 m_pObject( i_pObject ),
                 m_bDeleted( false )
             {}
         };

         std::vector< DeleteObjectEntry >    m_aObjects;
         typedef std::hash_map< sal_IntPtr, unsigned int > PtrToIndexMap;
         PtrToIndexMap                       m_aPtrToIndex;

         /** strict weak ordering funtion to bring objects to be destroyed lazily
         in correct order, e.g. for Window objects children before parents
         */
         static bool is_less( T* left, T* right );

         LazyDeletor()  { LazyDelete::addDeletor( this ); }
         virtual ~LazyDeletor()
         {
             #if OSL_DEBUG_LEVEL > 2
             fprintf( stderr, "%s %p deleted\n",
                      typeid(*this).name(), this );
             #endif
             if( s_pOneInstance == this ) // sanity check
                 s_pOneInstance = NULL;

             // do the actual work
             unsigned int nCount = m_aObjects.size();
             std::vector<T*> aRealDelete;
             aRealDelete.reserve( nCount );
             for( unsigned int i = 0; i < nCount; i++ )
             {
                 if( ! m_aObjects[i].m_bDeleted )
                 {
                     aRealDelete.push_back( m_aObjects[i].m_pObject );
                 }
             }
             // sort the vector of objects to be destroyed
             std::sort( aRealDelete.begin(), aRealDelete.end(), is_less );
             nCount = aRealDelete.size();
             for( unsigned int n = 0; n < nCount; n++ )
             {
                 #if OSL_DEBUG_LEVEL > 2
                 fprintf( stderr, "%s deletes object %p of type %s\n",
                          typeid(*this).name(),
                          aRealDelete[n],
                          typeid(*aRealDelete[n]).name() );
                 #endif
                 // check if the object to be deleted is not already destroyed
                 // as a side effect of a previous lazily destroyed object
                 if( ! m_aObjects[ m_aPtrToIndex[ reinterpret_cast<sal_IntPtr>(aRealDelete[n]) ] ].m_bDeleted )
                     delete aRealDelete[n];
             }
         }

         public:
         /** mark an object for lazy deletion
         */
         static void Delete( T* i_pObject )
         {
             if( s_pOneInstance == NULL )
                 s_pOneInstance = new LazyDeletor<T>();

             // is this object already in the list ?
             // if so mark it as not to be deleted; else insert it
             PtrToIndexMap::const_iterator dup = s_pOneInstance->m_aPtrToIndex.find( reinterpret_cast<sal_IntPtr>(i_pObject) );
             if( dup != s_pOneInstance->m_aPtrToIndex.end() )
             {
                 s_pOneInstance->m_aObjects[ dup->second ].m_bDeleted = false;
             }
             else
             {
                 s_pOneInstance->m_aPtrToIndex[ reinterpret_cast<sal_IntPtr>(i_pObject) ] = s_pOneInstance->m_aObjects.size();
                 s_pOneInstance->m_aObjects.push_back( DeleteObjectEntry( i_pObject ) );
             }
         }
         /** unmark an object already marked for lazy deletion
         */
         static void Undelete( T* i_pObject )
         {
             if( s_pOneInstance )
             {
                 PtrToIndexMap::const_iterator it = s_pOneInstance->m_aPtrToIndex.find( reinterpret_cast<sal_IntPtr>(i_pObject) );
                 if( it != s_pOneInstance->m_aPtrToIndex.end() )
                     s_pOneInstance->m_aObjects[ it->second ].m_bDeleted = true;
             }
         }
     };

     /*
     class DeleteOnDeinit matches a similar need as LazyDelete for static objects:
     you may not access vcl objects after DeInitVCL has been called this includes their destruction
     therefore disallowing the existance of static vcl object like e.g. a static BitmapEx
     To work around this use DeleteOnDeinit<BitmapEx> which will allow you to have a static object container,
     that will have its contents destroyed on DeinitVCL. The single drawback is that you need to check on the
     container object whether it still contains content before actually accessing it.

     caveat: when constructing a vcl object, you certainly want to ensure that InitVCL has run already.
     However this is not necessarily the case when using a class static member or a file level static variable.
     In these cases make judicious use of the set() method of DeleteOnDeinit, but beware of the changing
     ownership.

     example use case: use a lazy initialized on call BitmapEx in a paint method. Of course a paint method
     would not normally be called after DeInitVCL anyway, so the check might not be necessary in a
     Window::Paint implementation, but always checking is a good idea.

     SomeWindow::Paint()
     {
         static vcl::DeleteOnDeinit< BitmapEx > aBmp( new BitmapEx( ResId( 1000, myResMgr ) ) );

         if( aBmp.get() ) // check whether DeInitVCL has been called already
             DrawBitmapEx( Point( 10, 10 ), *aBmp.get() );
     }
     */

     class VCL_DLLPUBLIC DeleteOnDeinitBase
     {
     public:
         static void SAL_DLLPRIVATE ImplDeleteOnDeInit();
         virtual ~DeleteOnDeinitBase();
     protected:
         static void addDeinitContainer( DeleteOnDeinitBase* i_pContainer );

         virtual void doCleanup() = 0;
     };

     template < typename T >
     class DeleteOnDeinit : public DeleteOnDeinitBase
     {
         T* m_pT;
         virtual void doCleanup() { delete m_pT; m_pT = NULL; }
     public:
         DeleteOnDeinit( T* i_pT ) : m_pT( i_pT ) { addDeinitContainer( this ); }
         virtual ~DeleteOnDeinit() {}

         // get contents
         T* get() { return m_pT; }

         // set contents, returning old contents
         // ownership is transfered !
         T* set( T* i_pNew ) { T* pOld = m_pT; m_pT = i_pNew; return pOld; }
     };

 	/** Similar to DeleteOnDeinit, the DeleteUnoReferenceOnDeinit
         template class makes sure that a static UNO object is disposed
         and released at the right time.

         Use like
             static DeleteUnoReferenceOnDeinit<lang::XMultiServiceFactory>
                 xStaticFactory (<create factory object>);
             Reference<lang::XMultiServiceFactory> xFactory (xStaticFactory.get());
             if (xFactory.is())
                 <do something with xFactory>
     */
     template <typename I>
     class DeleteUnoReferenceOnDeinit : public ::vcl::DeleteOnDeinitBase
     {
         ::com::sun::star::uno::Reference<I> m_xI;
         virtual void doCleanup() { set(NULL); }
     public:
         DeleteUnoReferenceOnDeinit(const ::com::sun::star::uno::Reference<I>& r_xI ) : m_xI( r_xI ) {
             addDeinitContainer( this ); }
         virtual ~DeleteUnoReferenceOnDeinit() {}

         ::com::sun::star::uno::Reference<I> get (void) { return m_xI; }

         void set (const ::com::sun::star::uno::Reference<I>& r_xNew )
         {
             ::com::sun::star::uno::Reference< ::com::sun::star::lang::XComponent> xComponent (m_xI, ::com::sun::star::uno::UNO_QUERY);
 			m_xI = r_xNew;
             if (xComponent.is()) try
 			{
                 xComponent->dispose();
 			}
 			catch( ::com::sun::star::uno::Exception& )
 			{
 			}
         }
     };
 }

 #endif
	/**************************************************************
	*
	* 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 _VCL_LAZYDELETE_HXX
	#define _VCL_LAZYDELETE_HXX

	#include "dllapi.h"

	#include <vector>
	#include <hash_map>
	#include <algorithm>

	#if OSL_DEBUG_LEVEL > 2
	#include <typeinfo>
	#include <stdio.h>
	#endif

	#include <com/sun/star/lang/XComponent.hpp>

	namespace vcl
	{
	/* Helpers for lazy object deletion

	With vcl it is often necessary to delete objects (especially Windows)
	in the right order as well as in a way ensuring that the deleted objects
	are not still on the stack (e.g. deleting a Window in its key handler). To
	make this easier a helper class is given here which takes care of both
	sorting as well as lazy deletion.

	The grisly details:
	LazyDelete is a class that LazyDeletor register to. When vcl's event
	loop (that is Application::Yield or Application::Reschedule) comes out
	of the last level, the LazyDelete::flush is called. This will cause
	LazyDelete to delete all registered LazyDeletor objects.

	LazyDeletor<T> is a one instance object that contains a list of
	<T> objects to be deleted in sorted order. It is derived from
	LazyDeletorBase as to be able to register itself in LazyDelete.

	The user calls the static method LazyDeletor<T>::Delete( T* ) with the
	object to be destroyed lazy. The static method creates the LazyDeletor<T>
	(which in turn registers itself in LazyDelete) if this is the first time
	a T* is to be destroyed lazy. It then inserts the object. When the LazyDeletor<T>
	gets delte it will delete the stored objects in a fashion
	that will ensure the correct order of deletion via the specialized is_less method
	(e.g. if a Window is a child of another Window and therefore should be destroyed
	first it is "less" in this sense)

	LazyDelete::flush will be called when the top of the nested event loop is
	reached again and will then destroy each registered LazyDeletor<T> which
	in turn destroys the objects needed to be destroyed lazily. After this
	the state is as before entering the event loop.

	Preconditions:
	- The class <T> of which objects are to be destroyed needs a virtual
	destructor or must be final, else the wrong type will be destroyed.
	- The destructor of <T> should call LazyDeletor<T>::Undelete( this ). This
	prevents duplicate deletionin case someone destroys the object prematurely.
	*/

	class LazyDeletorBase;
	class VCL_DLLPUBLIC LazyDelete
	{
	public:
	/** flush all registered object lists
	*/
	static void flush();
	/** register an object list to be destroyed
	*/
	static void addDeletor( LazyDeletorBase* pDeletor );
	};

	class VCL_DLLPUBLIC LazyDeletorBase
	{
	friend void LazyDelete::flush();
	protected:
	LazyDeletorBase();
	virtual ~LazyDeletorBase();
	};

	template < typename T >
	class VCL_DLLPUBLIC LazyDeletor : public LazyDeletorBase
	{
	static LazyDeletor< T >* s_pOneInstance;

	struct DeleteObjectEntry
	{
	T* m_pObject;
	bool m_bDeleted;

	DeleteObjectEntry() :
	m_pObject( NULL ),
	m_bDeleted( false )
	{}

	DeleteObjectEntry( T* i_pObject ) :
	m_pObject( i_pObject ),
	m_bDeleted( false )
	{}
	};

	std::vector< DeleteObjectEntry > m_aObjects;
	typedef std::hash_map< sal_IntPtr, unsigned int > PtrToIndexMap;
	PtrToIndexMap m_aPtrToIndex;

	/** strict weak ordering funtion to bring objects to be destroyed lazily
	in correct order, e.g. for Window objects children before parents
	*/
	static bool is_less( T* left, T* right );

	LazyDeletor() { LazyDelete::addDeletor( this ); }
	virtual ~LazyDeletor()
	{
	#if OSL_DEBUG_LEVEL > 2
	fprintf( stderr, "%s %p deleted\n",
	typeid(*this).name(), this );
	#endif
	if( s_pOneInstance == this ) // sanity check
	s_pOneInstance = NULL;

	// do the actual work
	unsigned int nCount = m_aObjects.size();
	std::vector<T*> aRealDelete;
	aRealDelete.reserve( nCount );
	for( unsigned int i = 0; i < nCount; i++ )
	{
	if( ! m_aObjects[i].m_bDeleted )
	{
	aRealDelete.push_back( m_aObjects[i].m_pObject );
	}
	}
	// sort the vector of objects to be destroyed
	std::sort( aRealDelete.begin(), aRealDelete.end(), is_less );
	nCount = aRealDelete.size();
	for( unsigned int n = 0; n < nCount; n++ )
	{
	#if OSL_DEBUG_LEVEL > 2
	fprintf( stderr, "%s deletes object %p of type %s\n",
	typeid(*this).name(),
	aRealDelete[n],
	typeid(*aRealDelete[n]).name() );
	#endif
	// check if the object to be deleted is not already destroyed
	// as a side effect of a previous lazily destroyed object
	if( ! m_aObjects[ m_aPtrToIndex[ reinterpret_cast<sal_IntPtr>(aRealDelete[n]) ] ].m_bDeleted )
	delete aRealDelete[n];
	}
	}

	public:
	/** mark an object for lazy deletion
	*/
	static void Delete( T* i_pObject )
	{
	if( s_pOneInstance == NULL )
	s_pOneInstance = new LazyDeletor<T>();

	// is this object already in the list ?
	// if so mark it as not to be deleted; else insert it
	PtrToIndexMap::const_iterator dup = s_pOneInstance->m_aPtrToIndex.find( reinterpret_cast<sal_IntPtr>(i_pObject) );
	if( dup != s_pOneInstance->m_aPtrToIndex.end() )
	{
	s_pOneInstance->m_aObjects[ dup->second ].m_bDeleted = false;
	}
	else
	{
	s_pOneInstance->m_aPtrToIndex[ reinterpret_cast<sal_IntPtr>(i_pObject) ] = s_pOneInstance->m_aObjects.size();
	s_pOneInstance->m_aObjects.push_back( DeleteObjectEntry( i_pObject ) );
	}
	}
	/** unmark an object already marked for lazy deletion
	*/
	static void Undelete( T* i_pObject )
	{
	if( s_pOneInstance )
	{
	PtrToIndexMap::const_iterator it = s_pOneInstance->m_aPtrToIndex.find( reinterpret_cast<sal_IntPtr>(i_pObject) );
	if( it != s_pOneInstance->m_aPtrToIndex.end() )
	s_pOneInstance->m_aObjects[ it->second ].m_bDeleted = true;
	}
	}
	};

	/*
	class DeleteOnDeinit matches a similar need as LazyDelete for static objects:
	you may not access vcl objects after DeInitVCL has been called this includes their destruction
	therefore disallowing the existance of static vcl object like e.g. a static BitmapEx
	To work around this use DeleteOnDeinit<BitmapEx> which will allow you to have a static object container,
	that will have its contents destroyed on DeinitVCL. The single drawback is that you need to check on the
	container object whether it still contains content before actually accessing it.

	caveat: when constructing a vcl object, you certainly want to ensure that InitVCL has run already.
	However this is not necessarily the case when using a class static member or a file level static variable.
	In these cases make judicious use of the set() method of DeleteOnDeinit, but beware of the changing
	ownership.

	example use case: use a lazy initialized on call BitmapEx in a paint method. Of course a paint method
	would not normally be called after DeInitVCL anyway, so the check might not be necessary in a
	Window::Paint implementation, but always checking is a good idea.

	SomeWindow::Paint()
	{
	static vcl::DeleteOnDeinit< BitmapEx > aBmp( new BitmapEx( ResId( 1000, myResMgr ) ) );

	if( aBmp.get() ) // check whether DeInitVCL has been called already
	DrawBitmapEx( Point( 10, 10 ), *aBmp.get() );
	}
	*/

	class VCL_DLLPUBLIC DeleteOnDeinitBase
	{
	public:
	static void SAL_DLLPRIVATE ImplDeleteOnDeInit();
	virtual ~DeleteOnDeinitBase();
	protected:
	static void addDeinitContainer( DeleteOnDeinitBase* i_pContainer );

	virtual void doCleanup() = 0;
	};

	template < typename T >
	class DeleteOnDeinit : public DeleteOnDeinitBase
	{
	T* m_pT;
	virtual void doCleanup() { delete m_pT; m_pT = NULL; }
	public:
	DeleteOnDeinit( T* i_pT ) : m_pT( i_pT ) { addDeinitContainer( this ); }
	virtual ~DeleteOnDeinit() {}

	// get contents
	T* get() { return m_pT; }

	// set contents, returning old contents
	// ownership is transfered !
	T* set( T* i_pNew ) { T* pOld = m_pT; m_pT = i_pNew; return pOld; }
	};

	/** Similar to DeleteOnDeinit, the DeleteUnoReferenceOnDeinit
	template class makes sure that a static UNO object is disposed
	and released at the right time.

	Use like
	static DeleteUnoReferenceOnDeinit<lang::XMultiServiceFactory>
	xStaticFactory (<create factory object>);
	Reference<lang::XMultiServiceFactory> xFactory (xStaticFactory.get());
	if (xFactory.is())
	<do something with xFactory>
	*/
	template <typename I>
	class DeleteUnoReferenceOnDeinit : public ::vcl::DeleteOnDeinitBase
	{
	::com::sun::star::uno::Reference<I> m_xI;
	virtual void doCleanup() { set(NULL); }
	public:
	DeleteUnoReferenceOnDeinit(const ::com::sun::star::uno::Reference<I>& r_xI ) : m_xI( r_xI ) {
	addDeinitContainer( this ); }
	virtual ~DeleteUnoReferenceOnDeinit() {}

	::com::sun::star::uno::Reference<I> get (void) { return m_xI; }

	void set (const ::com::sun::star::uno::Reference<I>& r_xNew )
	{
	::com::sun::star::uno::Reference< ::com::sun::star::lang::XComponent> xComponent (m_xI, ::com::sun::star::uno::UNO_QUERY);
	m_xI = r_xNew;
	if (xComponent.is()) try
	{
	xComponent->dispose();
	}
	catch( ::com::sun::star::uno::Exception& )
	{
	}
	}
	};
	}

	#endif