src/xalanc/XPath/XPathConstructionContext.hpp

/*
 * Copyright 1999-2004 The Apache Software Foundation.
 *
 * Licensed 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.
 */
#if !defined(XPATHCONSTRUCTIONCONTEXT_HEADER_GUARD_1357924680)
#define XPATHCONSTRUCTIONCONTEXT_HEADER_GUARD_1357924680



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



#include <xalanc/XalanDOM/XalanDOMString.hpp>



XALAN_DECLARE_XERCES_CLASS(Locator)



XALAN_CPP_NAMESPACE_BEGIN



typedef XERCES_CPP_NAMESPACE_QUALIFIER Locator	LocatorType;



class XalanNode;



//
/**
 * @author <a href="mailto:david_n_bertoni@lotus.com">David N. Bertoni</a>
 */
// An abstract class which provides support for constructing the internal
// representation  of a stylesheet.
//
class XALAN_XPATH_EXPORT XPathConstructionContext
{
public:

	XPathConstructionContext();

	virtual
	~XPathConstructionContext();


	/**
	 * Reset the instance.  Any existing objects
	 * created by the instance will be destroyed.
	 */
	virtual void
	reset() = 0;

	/**
	 * Get a pooled string given the source string.  If
	 * the string already exists in the pool, no copy
	 * will be made.  If not, a copy will be made and
	 * kept for later use.
	 *
	 * @param theString The source string
	 * @return a const reference to a pooled string.
	 */
	virtual const XalanDOMString&
	getPooledString(const XalanDOMString&	theString) = 0;

	/**
	 * Get a pooled string given the source character
	 * array.  If the string already exists in the pool,
	 * no copy will be made.  If not, a copy will be made
	 * and kept for later use.
	 *
	 * @param theString The source character array
	 * @param theLength The length of the character array
	 * @return a const reference to a pooled string.
	 */
	virtual const XalanDOMString&
	getPooledString(
			const XalanDOMChar*			theString,
			XalanDOMString::size_type	theLength = XalanDOMString::npos) = 0;

	/**
	 * Get a cached string for temporary use.
	 *
	 * @return A reference to the string
	 */
	virtual XalanDOMString&
	getCachedString() = 0;

	/**
	 * Return a cached string.
	 *
	 * @param theString The string to release.
	 *
	 * @return true if the string was released successfully.
	 */
	virtual bool
	releaseCachedString(XalanDOMString&		theString) = 0;

	class GetAndReleaseCachedString
	{
	public:

		GetAndReleaseCachedString(XPathConstructionContext&		theConstructionContext) :
			m_constructionContext(&theConstructionContext),
			m_string(&theConstructionContext.getCachedString())
		{
		}

		// Note non-const copy semantics...
		GetAndReleaseCachedString(GetAndReleaseCachedString&	theSource) :
			m_constructionContext(theSource.m_constructionContext),
			m_string(theSource.m_string)
		{
			theSource.m_string = 0;
		}

		~GetAndReleaseCachedString()
		{
			if (m_string != 0)
			{
				m_constructionContext->releaseCachedString(*m_string);
			}
		}

		XalanDOMString&
		get() const
		{
			assert(m_string != 0);

			return *m_string;
		}

		XPathConstructionContext&
		getConstructionContext() const
		{
			return *m_constructionContext;
		}

	private:

		// Not implemented...
		GetAndReleaseCachedString&
		operator=(const GetAndReleaseCachedString&);


		// Data members...
		XPathConstructionContext*	m_constructionContext;

		XalanDOMString*				m_string;
	};

	virtual void
	error(
			const XalanDOMString&	msg,
			const XalanNode* 		sourceNode,
			const LocatorType* 		locator) const = 0;

	virtual void
	warn(
			const XalanDOMString&	msg,
			const XalanNode* 		sourceNode,
			const LocatorType* 		locator) const = 0;
};



XALAN_CPP_NAMESPACE_END



#endif	// XPATHCONSTRUCTIONCONTEXT_HEADER_GUARD_1357924680