~drizzle-trunk/drizzle/development

/* 

 * Copyright (c) 2010, Djellel Eddine Difallah

 * All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions are met:

 *

 *   * Redistributions of source code must retain the above copyright notice,

 *     this list of conditions and the following disclaimer.

 *   * 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.

 *   * Neither the name of Djellel Eddine Difallah nor the names of its contributors

 *     may be used to endorse or promote products derived from this software

 *     without specific prior written permission.

 *

 * 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 HOLDER 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 CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN

 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)

 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF

 * THE POSSIBILITY OF SUCH DAMAGE.

 */

#ifndef PLUGIN_MEMCACHED_QUERY_CACHE_QUERY_CACHE_SERVICE_H

#define PLUGIN_MEMCACHED_QUERY_CACHE_QUERY_CACHE_SERVICE_H

#include "drizzled/message/resultset.pb.h"

#include <drizzled/sql_list.h>

#include <map>

#include <vector>

namespace drizzled

{

class TableList;

class Item;

namespace message

{

class Resultset;

}

class QueryCacheService

{

public:

  typedef std::map<std::string, drizzled::message::Resultset> CacheEntries;

  typedef std::pair<const std::string, drizzled::message::Resultset> CacheEntry;

  typedef std::map<std::string, std::vector<std::string>> CachedTablesEntries;

  typedef std::pair<const std::string, std::vector<std::string>> CachedTablesEntry;

  static const size_t DEFAULT_RECORD_SIZE= 100;

  static CacheEntries cache;

  static CachedTablesEntries cachedTables;

  /**

   * Singleton method

   * Returns the singleton instance of QueryCacheService

   */

  static inline QueryCacheService &singleton()

  {

    static QueryCacheService query_cache_service;

    return query_cache_service;

  };

  /**

   * Method which returns the active Resultset message

   * for the supplied Session.  If one is not found, a new Resultset

   * message is allocated, initialized, and returned.

   *

   * @param The session processing the Select

   */

  drizzled::message::Resultset *setCurrentResultsetMessage(drizzled::Session *in_session);

  /**

   * Helper method which initializes the header message for

   * a Resultset.

   *

   * @param[inout] Resultset message container to modify

   * @param[in] Pointer to the Session doing the processing

   * @param[in] Pointer to the Table being inserted into

   */

  void setResultsetHeader(drizzled::message::Resultset &resultset,

                       drizzled::Session *in_session,

                       drizzled::TableList *in_table);

  /**

   * Creates a new SelectRecord GPB message and pushes it to

   * currrent Resultset.

   *

   * @param Pointer to the Session which has inserted a record

   * @param Pointer to the List<Items> to add

   */

  bool addRecord(drizzled::Session *in_session, drizzled::List<drizzled::Item> &list);

  /* cache fetching */

  static bool isCached(std::string query);

}; 

} /* namespace drizzled */

#endif /* PLUGIN_MEMCACHED_QUERY_CACHE_QUERY_CACHE_SERVICE_H */