//

// NamePool.cpp

//

// Library: XML

// Package: XML

// Module:  NamePool

//

// Copyright (c) 2004-2006, Applied Informatics Software Engineering GmbH.

// and Contributors.

//

// SPDX-License-Identifier: BSL-1.0

//

#include "Poco/XML/NamePool.h"

#include "Poco/Exception.h"

#include "Poco/Random.h"

namespace Poco {

namespace XML {

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),

  _salt(0),

  _rc(1)

{

  poco_assert (size > 1);

  _pItems = new NamePoolItem[size];

  Poco::Random rnd;

  rnd.seed();

  _salt = rnd.next();

}

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) ^ _salt) % _size;

  while (!_pItems[n].set(qname, namespaceURI, localName) && i++ < _size)

    n = (n + 1) % _size;

  if (i > _size) throw Poco::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;

}

} } // namespace Poco::XML