~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

 */

/**

 * @TODO There is plugin.h and also sql_plugin.h.  Ostensibly,

 * it seems that the two files exist so that plugin.h can provide an

 * external API for plugin developers and sql_plugin.h will provide

 * and internal server API for dealing with those plugins.

 *

 * However, there are parts of plugin.h marked "INTERNAL USE ONLY" which

 * seems to contradict the above...

 *

 * Let's figure out a better way of dividing the public and internal API

 * and name the files more appropriately.

 *

 * Also, less #defines, more enums and bitmaps...

 *

 */

#ifndef DRIZZLE_SERVER_PLUGIN_H

#define DRIZZLE_SERVER_PLUGIN_H

#include <drizzled/lex_string.h>

#include <mysys/my_alloc.h>

class sys_var;

class Session;

/*

  the following flags are valid for plugin_init()

*/

#define PLUGIN_INIT_SKIP_DYNAMIC_LOADING 1

#define PLUGIN_INIT_SKIP_PLUGIN_TABLE    2

#define PLUGIN_INIT_SKIP_INITIALIZATION  4

#define INITIAL_LEX_PLUGIN_LIST_SIZE    16

/*

  the following #define adds server-only members to enum_mysql_show_type,

  that is defined in plugin.h

*/

#define SHOW_FUNC    SHOW_FUNC, SHOW_KEY_CACHE_LONG, SHOW_KEY_CACHE_LONGLONG, \

                     SHOW_LONG_STATUS, SHOW_DOUBLE_STATUS, SHOW_HAVE,   \

                     SHOW_MY_BOOL, SHOW_HA_ROWS, SHOW_SYS, SHOW_LONG_NOFLUSH, \

                     SHOW_LONGLONG_STATUS

#include <drizzled/plugin.h>

#undef SHOW_FUNC

typedef enum enum_mysql_show_type SHOW_TYPE;

typedef struct st_mysql_show_var SHOW_VAR;

#define DRIZZLE_ANY_PLUGIN         -1

/*

  different values of st_plugin_int::state

  though they look like a bitmap, plugin may only

  be in one of those eigenstates, not in a superposition of them :)

  It's a bitmap, because it makes it easier to test

  "whether the state is one of those..."

*/

#define PLUGIN_IS_FREED         1

#define PLUGIN_IS_DELETED       2

#define PLUGIN_IS_UNINITIALIZED 4

#define PLUGIN_IS_READY         8

#define PLUGIN_IS_DYING         16

/* A handle for the dynamic library containing a plugin or plugins. */

struct st_plugin_dl

{

  LEX_STRING dl;

  void *handle;

  struct st_mysql_plugin *plugins;

  uint32_t ref_count;            /* number of plugins loaded from the library */

};

/* A handle of a plugin */

struct st_plugin_int

{

  LEX_STRING name;

  struct st_mysql_plugin *plugin;

  struct st_plugin_dl *plugin_dl;

  uint32_t state;

  uint32_t ref_count;               /* number of threads using the plugin */

  void *data;                   /* plugin type specific, e.g. handlerton */

  MEM_ROOT mem_root;            /* memory for dynamic plugin structures */

  sys_var *system_vars;         /* server variables for this plugin */

};

/*

  See intern_plugin_lock() for the explanation for the

  conditionally defined plugin_ref type

*/

typedef struct st_plugin_int **plugin_ref;

#define plugin_decl(pi) ((pi)[0]->plugin)

#define plugin_dlib(pi) ((pi)[0]->plugin_dl)

#define plugin_data(pi,cast) ((cast)((pi)[0]->data))

#define plugin_name(pi) (&((pi)[0]->name))

#define plugin_state(pi) ((pi)[0]->state)

#define plugin_equals(p1,p2) ((p1) && (p2) && (p1)[0] == (p2)[0])

typedef int (*plugin_type_init)(struct st_plugin_int *);

extern char *opt_plugin_load;

extern char *opt_plugin_dir_ptr;

extern char opt_plugin_dir[FN_REFLEN];

extern const LEX_STRING plugin_type_names[];

extern int plugin_init(int *argc, char **argv, int init_flags);

extern void plugin_shutdown(void);

extern void my_print_help_inc_plugins(struct my_option *options, uint32_t size);

extern bool plugin_is_ready(const LEX_STRING *name, int type);

#define my_plugin_lock_by_name(A,B,C) plugin_lock_by_name(A,B,C)

#define my_plugin_lock_by_name_ci(A,B,C) plugin_lock_by_name(A,B,C)

#define my_plugin_lock(A,B) plugin_lock(A,B)

#define my_plugin_lock_ci(A,B) plugin_lock(A,B)

extern plugin_ref plugin_lock(Session *session, plugin_ref *ptr);

extern plugin_ref plugin_lock_by_name(Session *session, const LEX_STRING *name,

                                      int type);

extern void plugin_unlock(Session *session, plugin_ref plugin);

extern void plugin_unlock_list(Session *session, plugin_ref *list, uint32_t count);

extern bool mysql_install_plugin(Session *session, const LEX_STRING *name,

                                 const LEX_STRING *dl);

extern bool mysql_uninstall_plugin(Session *session, const LEX_STRING *name);

extern bool plugin_register_builtin(struct st_mysql_plugin *plugin);

extern void plugin_sessionvar_init(Session *session);

extern void plugin_sessionvar_cleanup(Session *session);

typedef bool (plugin_foreach_func)(Session *session,

                                   plugin_ref plugin,

                                   void *arg);

#define plugin_foreach(A,B,C,D) plugin_foreach_with_mask(A,B,C,PLUGIN_IS_READY,D)

extern bool plugin_foreach_with_mask(Session *session, plugin_foreach_func *func,

                                     int type, uint32_t state_mask, void *arg);

#endif /* DRIZZLE_SERVER_PLUGIN_H */