/*
 * 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.
 */

// Class header file.
#include "XalanDOMStringCache.hpp"


#include <xalanc/Include/STLHelper.hpp>


#include "DOMStringHelper.hpp"


XALAN_CPP_NAMESPACE_BEGIN


XalanDOMStringCache::XalanDOMStringCache(unsigned int	theMaximumSize) :
    m_busyList(),
	m_availableList(),
	m_maximumSize(theMaximumSize),
    m_allocator(XalanDOMStringReusableAllocator::eDefaultBlockSize)
{
}


XalanDOMStringCache::~XalanDOMStringCache()
{
	clear();
}


XalanDOMString&
XalanDOMStringCache::get()
{
	if (m_availableList.empty() == true)
	{
        XalanDOMString&     theString = m_allocator.create();

        m_busyList.push_back(&theString);

        return theString;
	}
	else
	{
        XalanDOMString* const   theString = m_availableList.back();
        assert(theString != 0);

		m_availableList.pop_back();

        m_busyList.push_back(theString);

        return *theString;
	}
}


bool
XalanDOMStringCache::release(XalanDOMString&	theString)
{
	XALAN_USING_STD(find)

	StringListType::iterator	i =
		find(m_busyList.begin(),
			 m_busyList.end(),
			 &theString);

	if (i == m_busyList.end())
	{
		return false;
	}
	else
	{
		if (m_availableList.size() > m_maximumSize)
		{
			m_allocator.destroy(theString);
		}
		else
		{
			theString.erase();

			m_availableList.push_back(*i);
		}

		m_busyList.erase(i);

		return true;
	}
}


void
XalanDOMStringCache::clear()
{
	m_busyList.clear();

	m_availableList.clear();

    m_allocator.reset();
}


void
XalanDOMStringCache::reset()
{
	const StringListType::size_type		theSize =
		m_availableList.size();

	while(m_busyList.empty() == false)
	{
		assert(m_busyList.back() != 0);

		if (theSize > m_maximumSize)
		{
			m_allocator.destroy(*m_busyList.back());
		}
		else
		{
			m_busyList.back()->clear();

			m_availableList.push_back(m_busyList.back());
		}

		m_busyList.pop_back();
	}
}


XALAN_CPP_NAMESPACE_END