src/XPath/XObjectFactory.hpp

/*
 * The Apache Software License, Version 1.1
 *
 *
 * Copyright (c) 1999 The Apache Software Foundation.  All rights 
 * reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *	  notice, this list of conditions and the following disclaimer. 
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *	  notice, this list of conditions and the following disclaimer in
 *	  the documentation and/or other materials provided with the
 *	  distribution.
 *
 * 3. The end-user documentation included with the redistribution,
 *	  if any, must include the following acknowledgment:  
 *		 "This product includes software developed by the
 *		  Apache Software Foundation (http://www.apache.org/)."
 *	  Alternately, this acknowledgment may appear in the software itself,
 *	  if and wherever such third-party acknowledgments normally appear.
 *
 * 4. The names "Xalan" and "Apache Software Foundation" must
 *	  not be used to endorse or promote products derived from this
 *	  software without prior written permission. For written 
 *	  permission, please contact apache@apache.org.
 *
 * 5. Products derived from this software may not be called "Apache",
 *	  nor may "Apache" appear in their name, without prior written
 *	  permission of the Apache Software Foundation.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation and was
 * originally based on software copyright (c) 1999, International
 * Business Machines, Inc., http://www.ibm.com.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 */
#if !defined(XOBJECTFACTORY_HEADER_GUARD_1357924680)
#define XOBJECTFACTORY_HEADER_GUARD_1357924680



// Base include file.  Must be first.
#include <XPath/XPathDefinitions.hpp>



#include <algorithm>
#include <cassert>
#include <set>



#include <XPath/XObject.hpp>
#include <XPath/XPathExecutionContext.hpp>



class XalanNode;
class MutableNodeRefList;
class NodeRefListBase;
class XObject;
class XObjectPtr;
class XToken;



/**
 * This class handles the creation of XObjects and manages their lifetime.
 */
class XALAN_XPATH_EXPORT XObjectFactory
{
public:

	typedef XPathExecutionContext::BorrowReturnMutableNodeRefList	BorrowReturnMutableNodeRefList;
	typedef XPathExecutionContext::GetAndReleaseCachedString		GetAndReleaseCachedString;


	XObjectFactory();

	virtual
	~XObjectFactory();


	/**
	 * Return an XObject to the factory.
	 * 
	 * @param theXObject The XObject to be returned
	 * @return true if the object belongs to the factory, false if not.
	 */
	bool
	returnObject(XObject* 	theXObject)
	{
		return doReturnObject(theXObject);
	}

	/**
	 * Reset the instance.	This invalidates all existing instances created
	 * with this XObjectFactory.
	 */
	virtual void
	reset() = 0;

	/**
	 * Create a boolean XObject from a boolean value.
	 * 
	 * @param theValue	value used to create object  
	 * @return pointer to new object
	 */
	virtual const XObjectPtr
	createBoolean(bool	theValue) = 0;

	/**
	 * Create a node set XObject from a node list.
	 * 
	 * @param theValue	value used to create object.  theValue will be owned by the new XObject.
	 * @return pointer to new object
	 */
	virtual const XObjectPtr
	createNodeSet(BorrowReturnMutableNodeRefList& 	theValue) = 0;

	/**
	 * Create a null XObject.
	 * 
	 * @param theValue	value used to create object 
	 * @return pointer to new object
	 */
	virtual const XObjectPtr
	createNull() = 0;

	/**
	 * Create a numeric XObject from a number.
	 * 
	 * @param theValue	value used to create object 
	 * @return pointer to new object
	 */
	virtual const XObjectPtr
	createNumber(double 	theValue) = 0;

	/**
	 * Create a numeric XObject from an XToken.  The XToken
	 * instance must be inexistence for the lifetime of the
	 * object.
	 *
	 * @param theValue	value used to create object 
	 * @return pointer to new object
	 */
	virtual const XObjectPtr
	createNumber(const XToken&	theValue) = 0;

	/**
	 * Create a string XObject from a string.
	 * 
	 * @param theValue	value used to create object  
	 * @return pointer to new object
	 */
	virtual const XObjectPtr
	createString(const XalanDOMString&	theValue) = 0;

	/**
	 * Create a string XObject from a null-terminated array of characters.
	 * 
	 * @param theValue	a pointer to the array
	 * @return pointer to new object
	 */
	virtual const XObjectPtr
	createString(const XalanDOMChar*	theValue) = 0;

	/**
	 * Create a string XObject from an array of characters.
	 * 
	 * @param theValue	a pointer to the array
	 * @paran theLength the length of the array
	 * @return pointer to new object
	 */
	virtual const XObjectPtr
	createString(
			const XalanDOMChar* 	theValue,
			unsigned int			theLength) = 0;

	/**
	 * Create a string XObject from an XToken.  The XToken
	 * instance must be inexistence for the lifetime of the
	 * object.
	 *
	 * @param theValue	value used to create object 
	 * @return pointer to new object
	 */
	virtual const XObjectPtr
	createString(const XToken&	theValue) = 0;

	/**
	 * Create a string XObject from a string.  The XObject
	 * will hold a reference to the supplied string, so
	 * the string must be in scope for the lifetime of
	 * the instance
	 *
	 * @param theValue	value used to create object  
	 * @return pointer to new object
	 */
	virtual const XObjectPtr
	createStringReference(const XalanDOMString&		theValue) = 0;

	/**
	 * Create a string XObject that will adapt another XObject to
	 * behave like a string.  The XObject holds a reference to the
	 * other XObject.
	 *
	 * @param theValue	value used to create object  
	 * @return pointer to new object
	 */
	virtual const XObjectPtr
	createStringAdapter(const XObjectPtr&	theValue) = 0;

	/**
	 * Create a string XObject from a cached XalanDOMString,
	 *
	 * @param theValue	value used to create object  
	 * @return pointer to new object
	 */
	virtual const XObjectPtr
	createString(GetAndReleaseCachedString&		theValue) = 0;

	/**
	 * Create an "unknown" XObject from a string.
	 * 
	 * @param theValue	value used to create object  
	 * @return pointer to new object
	 */
	virtual const XObjectPtr
	createUnknown(const XalanDOMString& 	theValue) = 0;

	/**
	 *
	 * A public functor for use with stl algorithms.
	 *
	 */
#if defined(XALAN_NO_NAMESPACES)
	struct DeleteXObjectFunctor : public unary_function<XObject*, void>
#else
	struct DeleteXObjectFunctor : public std::unary_function<XObject*, void>
#endif
	{
	public:

		DeleteXObjectFunctor(
			XObjectFactory& 	theFactoryInstance,
			bool				fInReset = false) :
			m_factoryInstance(theFactoryInstance),
			m_fInReset(fInReset)
		{
		}

		result_type
		operator()(argument_type	theXObject) const
		{
			if (m_fInReset == true)
			{
				m_factoryInstance.doReturnObject(
					theXObject,
					true);
			}
			else
			{
				m_factoryInstance.returnObject(theXObject);
			}
		}

	private:

		XObjectFactory& 	m_factoryInstance;

		const bool			m_fInReset;
	};

	friend struct DeleteXObjectFunctor;

protected:

	/**
	 * Return the actual implementation type of an XObject.
	 *
	 * @param theXObject the XObject
	 */
	XObject::eObjectType
	getRealType(const XObject&	theXObject) const
	{
		return theXObject.getRealType();
	}

	/**
	 * Delete a FactoryObject instance.
	 *
	 * @param theXObject the XObject instance to delete.
	 */
	void
	deleteObject(const XObject* 	theXObject) const
	{
#if defined(XALAN_CANNOT_DELETE_CONST)
		delete (XObject*)theXObject;
#else
		delete theXObject;
#endif
	}

	/**
	 * Return an XObject to the factory.
	 * 
	 * @param theXObject XObject to be returned
	 * @param fInReset true when called during reset().
	 */

	virtual bool
	doReturnObject(
			XObject*	theXObject,
			bool		fInReset = false) = 0;

private:

	// Not implemented...
	XObjectFactory(const XObjectFactory&);

	XObjectFactory&
	operator=(const XObjectFactory&);

	bool
	operator==(const XObjectFactory&) const;
};



#endif	// XOBJECTFACTORY_HEADER_GUARD_1357924680