//
// NamePool.cpp
//
// $Id: //poco/Main/XML/src/NamePool.cpp#5 $
//
// Copyright (c) 2004, Guenter Obiltschnig/Applied Informatics.
// 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. Redistributions in any form must be accompanied by information on
//    how to obtain complete source code for this software and any
//    accompanying software that uses this software.  The source code
//    must either be included in the distribution or be available for no
//    more than the cost of distribution plus a nominal fee, and must be
//    freely redistributable under reasonable conditions.  For an
//    executable file, complete source code means the source code for all
//    modules it contains.  It does not include source code for modules or
//    files that typically accompany the major components of the operating
//    system on which the executable file runs.
// 
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
// FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
// COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
// INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
// BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
// LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
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// POSSIBILITY OF SUCH DAMAGE.
//


#include "XML/NamePool.h"
#include "Foundation/Exception.h"


XML_BEGIN


class NamePoolItem
{
public:
	NamePoolItem(): _used(false)
	{
	}
	
	~NamePoolItem()
	{
	}
	
	bool set(const XMLString& qname, const XMLString& namespaceURI, const XMLString& localName)
	{
		if (!_used)
		{
			_name.assign(qname, namespaceURI, localName);
			_used = true;
			return true;
		}
		else return _name.equals(qname, namespaceURI, localName);
	}
	
	const Name& get() const
	{
		return _name;
	}
	
	bool used() const
	{
		return _used;
	}
	
private:
	Name _name;
	bool _used;
};


NamePool::NamePool(unsigned long size): 
	_size(size),
	_rc(1)
{
	poco_assert (size > 1);

	_pItems = new NamePoolItem[size];
}


NamePool::~NamePool()
{
	delete [] _pItems;
}


void NamePool::duplicate()
{
	++_rc;
}


void NamePool::release()
{
	if (--_rc == 0)
		delete this;
}


const Name& NamePool::insert(const XMLString& qname, const XMLString& namespaceURI, const XMLString& localName)
{
	unsigned long i = 0;
	unsigned long n = hash(qname, namespaceURI, localName) % _size;

	while (!_pItems[n].set(qname, namespaceURI, localName) && i++ < _size) 
		n = (n + 1) % _size;
		
	if (i > _size) throw Foundation::PoolOverflowException("XML name pool");

	return _pItems[n].get();
}


const Name& NamePool::insert(const Name& name)
{
	return insert(name.qname(), name.namespaceURI(), name.localName());
}


unsigned long NamePool::hash(const XMLString& qname, const XMLString& namespaceURI, const XMLString& localName)
{
	unsigned long h = 0;
	XMLString::const_iterator it  = qname.begin();
	XMLString::const_iterator end = qname.end();
	while (it != end) h = (h << 5) + h + (unsigned long) *it++;
	it =  namespaceURI.begin();
	end = namespaceURI.end();
	while (it != end) h = (h << 5) + h + (unsigned long) *it++;
	it  = localName.begin();
	end = localName.end();
	while (it != end) h = (h << 5) + h + (unsigned long) *it++;
	return h;
}


XML_END