src/xercesc/util/XMemory.hpp

/*
 * 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.
 */

/*
 * $Id$
 */

#if !defined(XERCESC_INCLUDE_GUARD_XMEMORY_HPP)
#define XERCESC_INCLUDE_GUARD_XMEMORY_HPP

#include <xercesc/util/XercesDefs.hpp>
#include <cstdlib>

namespace XERCES_CPP_NAMESPACE {

class MemoryManager;

/**
 *  This class makes it possible to override the C++ memory management by
 *  adding new/delete operators to this base class.
 *
 *  This class is used in conjunction with the pluggable memory manager. It
 *  allows applications to control Xerces memory management.
 */

class XMLUTIL_EXPORT XMemory
{
public :
    // -----------------------------------------------------------------------
    //  The C++ memory management
    // -----------------------------------------------------------------------
    /** @name The C++ memory management */
    //@{

    /**
      * This method overrides operator new
      *
      * @param size The requested memory size
      */
    void* operator new(size_t size);

#if defined(XERCES_MFC_SUPPORT)
    /**
      * This method overrides the MFC debug version of the operator new
      * 
      * @param size   The requested memory size
      * @param file   The file where the allocation was requested
      * @param line   The line where the allocation was requested 
      */ 
    void* operator new(size_t size, const char* file, int line);
    /**
      * This method provides a matching delete for the MFC debug new
      * 
      * @param p      The pointer to the allocated memory
      * @param file   The file where the allocation was requested
      * @param line   The line where the allocation was requested 
      */ 
    void operator delete(void* p, const char* file, int line);
#endif

    /**
      * This method defines a custom operator new, that will use the provided
      * memory manager to perform the allocation
      *
      * @param size   The requested memory size
      * @param memMgr An application's memory manager
      */
    void* operator new(size_t size, MemoryManager* memMgr);

    /**
      * This method overrides placement operator new
      *
      * @param size   The requested memory size
      * @param ptr    The memory location where the object should be allocated
      */
    void* operator new(size_t size, void* ptr);

    /**
      * This method overrides operator delete
      *
      * @param p The pointer to the allocated memory
      */
    void operator delete(void* p);

    /**
      * This method provides a matching delete for the custom operator new
      *
      * @param p      The pointer to the allocated memory
      * @param memMgr An application's memory manager 
      */
    void operator delete(void* p, MemoryManager* memMgr);

    /**
      * This method provides a matching delete for the placement new
      *
      * @param p      The pointer to the allocated memory
      * @param ptr    The memory location where the object had to be allocated
      */
    void operator delete(void* p, void* ptr);

    //@}

protected :
    // -----------------------------------------------------------------------
    //  Hidden Constructors
    // -----------------------------------------------------------------------
    /** @name Constructor */
    //@{

    /**
      * Protected default constructor
      */
    XMemory()
    {
    }
    //@}

#if defined(XERCES_NEED_XMEMORY_VIRTUAL_DESTRUCTOR)
    virtual ~XMemory()
    {
    }
#endif
};

}

#endif