~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, Inc.

 *

 *  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

 */

#pragma once

#include <drizzled/catalog/instance.h>

#include <drizzled/catalog/local.h>

#include <drizzled/error_t.h>

#include <drizzled/item.h>

#include <drizzled/sql_list.h>

#include <drizzled/visibility.h>

namespace drizzled {

namespace plugin {

/**

 * This class allows new client sources to be written. This could be through

 * network protocols, in-process threads, or any other client source that can

 * provide commands and handle result sets. The current implementation is

 * file-descriptor based, so for non-fd client sources (like from another

 * thread), derived classes will need to use a pipe() for event notifications.

 */

class DRIZZLED_API Client

{

protected:

  Session *session;

public:

  virtual ~Client() {}

  /**

   * Get attached session from the client object.

   * @retval Session object that is attached, NULL if none.

   */

  virtual Session *getSession(void)

  {

    return session;

  }

  /**

   * Attach session to the client object.

   * @param[in] session_arg Session object to attach, or NULL to clear.

   */

  virtual void setSession(Session *session_arg)

  {

    session= session_arg;

  }

  /**

   * Get file descriptor associated with client object.

   * @retval File descriptor that is attached, -1 if none.

   */

  virtual int getFileDescriptor(void)= 0;

  /**

   * Check to see if the client is currently connected.

   * @retval Boolean value representing connected state.

   */

  virtual bool isConnected(void)= 0;

  /**

   * Check to see if the client is actively reading.

   * @retval Boolean value representing reading state.

   */

  virtual bool isReading(void)= 0;

  /**

   * Check to see if the client is actively writing.

   * @retval Boolean value representing writing state.

   */

  virtual bool isWriting(void)= 0;

  /**

   * Flush all data that has been buffered with store() methods.

   * @retval Boolean indicating success or failure.

   */

  virtual bool flush(void)= 0;

  /**

   * Close the client object.

   */

  virtual void close(void)= 0;

  /**

   * Perform handshake and authorize client if needed.

   */

  virtual bool authenticate(void)= 0;

  virtual bool isConsole() const

  {

    return false;

  }

  virtual bool isInteractive() const

  {

    return false;

  }

  virtual bool isAdmin() const

  {

    return false;

  }

  virtual catalog::Instance::shared_ptr catalog()

  {

    return catalog::local();

  }

  /**

   * Read command from client.

   */

  virtual bool readCommand(char **packet, uint32_t *packet_length)= 0;

  /* Send responses. */

  virtual void sendOK(void)= 0;

  virtual void sendEOF(void)= 0;

  virtual void sendError(const drizzled::error_t sql_errno, const char *err)= 0;

  /**

   * Send field list for result set.

   */

  virtual bool sendFields(List<Item> *list)= 0;

  /* Send result fields in various forms. */

  virtual bool store(Field *from)= 0;

  virtual bool store(void)= 0;

  virtual bool store(int32_t from)= 0;

  virtual bool store(uint32_t from)= 0;

  virtual bool store(int64_t from)= 0;

  virtual bool store(uint64_t from)= 0;

  virtual bool store(double from, uint32_t decimals, String *buffer)= 0;

  virtual bool store(const type::Time *from);

  virtual bool store(const char *from);

  virtual bool store(const char *from, size_t length)= 0;

  virtual bool store(const std::string &from)

  {

    return store(from.c_str(), from.size());

  }

  /* Try to remove these. */

  virtual bool haveMoreData(void)= 0;

  virtual bool haveError(void)= 0;

  virtual bool wasAborted(void)= 0;

};

} /* namespace plugin */

} /* namespace drizzled */