~drizzle-trunk/drizzle/development

/* -*- mode: c++; c-basic-offset: 2; indent-tabs-mode: nil; -*-

 *  vim:expandtab:shiftwidth=2:tabstop=2:smarttab:

 *

 *  Copyright (C) 2008 Sun Microsystems

 *

 *  This program is free software; you can redistribute it and/or modify

 *  it under the terms of the GNU General Public License as published by

 *  the Free Software Foundation; version 2 of the License.

 *

 *  This program is distributed in the hope that it will be useful,

 *  but WITHOUT ANY WARRANTY; without even the implied warranty of

 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 *  GNU General Public License for more details.

 *

 *  You should have received a copy of the GNU General Public License

 *  along with this program; if not, write to the Free Software

 *  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

 */

#ifndef DRIZZLED_REGISTRY_H

#define DRIZZLED_REGISTRY_H

#include <map>

#include <set>

#include <string>

#include <algorithm>

#include <functional>

namespace drizzled {

namespace internal {

template<class T>

struct RegistryMapCompare

{

  bool operator() (const T& a, const T& b) const

  {

    return a.getName() < b.getName();

  }

};

template<class T>

struct RegistryMapCompare<T *>

{

  bool operator() (const T* a, const T* b) const

  {

    return a->getName() < b->getName();

  }

};

} /* namespace internal */

template<class T>

class Registry

{

  std::map<std::string, T> item_map;

  std::set<T,internal::RegistryMapCompare<T> > item_set;

  bool addItemEntry(std::string name, T item)

  {

    if (item_map.count(name) == 0)

    {

      item_map[name]= item;

      return false;

    }

    return true;

  }

  bool addItem(std::string name, T item)

  {

    /* First, add with no transform */

    if (addItemEntry(name, item))

      return true;

    /* Transform to lower, then add */ 

    transform(name.begin(), name.end(),

              name.begin(), ::tolower);

    /* Ignore failures here - the original name could be all lower */

    addItemEntry(name, item);

    /* Transform to upper, then add */ 

    transform(name.begin(), name.end(),

              name.begin(), ::toupper);

    /* Ignore failures here - the original name could be all upper */

    addItemEntry(name, item);

    return false;

  }

  void removeItem(std::string name)

  {

    /* First, remove with no transform */

    item_map.erase(name);

    /* Transform to lower, then remove */ 

    transform(name.begin(), name.end(),

              name.begin(), ::tolower);

    item_map.erase(name);

  }

public:

  typedef typename std::set<T>::const_iterator const_iterator;

  typedef typename std::set<T>::iterator iterator;

  typedef size_t size_type;

  T find(const char *name, size_t length)

  {

    std::string find_str(name, length);

    return find(find_str);

  }

  T find(const std::string &name)

  {

    typename std::map<std::string, T>::iterator find_iter;

    find_iter=  item_map.find(name);

    if (find_iter != item_map.end())

      return (*find_iter).second;

    /* We must look for lower case, so we make a copy of the input name */

    std::string lower_name(name);

    transform(lower_name.begin(), lower_name.end(),

              lower_name.begin(), ::tolower);

    find_iter=  item_map.find(lower_name);

    if (find_iter != item_map.end())

      return (*find_iter).second;

    return NULL;

  }

  /**

   * True == failure

   */

  bool add(T item)

  {

    bool failed= false;

    if (item_set.insert(item).second == false)

      return true;

    if (addItem(item->getName(), item))

      failed= true;

    const std::vector<std::string>& aliases= item->getAliases();

    if (!(failed) && (aliases.size() > 0))

    {

      typename std::vector<std::string>::const_iterator iter= aliases.begin();

      while (iter != aliases.end())

      {

        if(addItem(*iter, item))

          failed= true;

        ++iter;

      }

    }

    if (failed == true)

      remove(item);

    return failed; 

  }

  /**

   * Remove an item from the registry. We don't care about failure

   */

  void remove(T item)

  {

    removeItem(item->getName());

    const std::vector<std::string>& aliases= item->getAliases();

    if (aliases.size() > 0)

    {

      std::vector<std::string>::const_iterator iter= aliases.begin();

      while (iter != aliases.end())

      {

        removeItem(*iter);

        ++iter;

      }

    }

  }

  const_iterator begin()

  {

    return item_set.begin();

  }

  const_iterator end()

  {

    return item_set.end();

  }

  size_type count(std::string name) const

  {

    /* Transform to lower, then add */

    transform(name.begin(), name.end(),

              name.begin(), ::tolower);

    return item_map.count(name);

  }

  size_type size() const

  {

    return item_set.size();

  }

};

} /* namespace drizzled */

#endif /* DRIZZLED_REGISTRY_H */