~drizzle-trunk/drizzle/development

/* Copyright (C) 2005 MySQL AB

   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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA */

#include <drizzled/server_includes.h>
#include <mysys/my_getopt.h>
#include <mysys/hash.h>

#include <drizzled/authentication.h>
#include <drizzled/logging.h>
#include <drizzled/errmsg.h>
#include <drizzled/qcache.h>
#include <drizzled/sql_parse.h>
#include <drizzled/scheduling.h>
#include <drizzled/replication_services.h>
#include <drizzled/show.h>
#include <drizzled/handler.h>
#include <drizzled/set_var.h>
#include <drizzled/session.h>
#include <drizzled/item/null.h>
#include <drizzled/plugin_registry.h>

#include <string>
#include <vector>
#include <map>
#include <algorithm>

#include <drizzled/error.h>
#include <drizzled/gettext.h>

#define REPORT_TO_LOG  1
#define REPORT_TO_USER 2

using namespace std;
using namespace drizzled;
 
typedef plugin::Manifest builtin_plugin[];
extern builtin_plugin DRIZZLED_BUILTIN_LIST;
static plugin::Manifest *drizzled_builtins[]=
{
  DRIZZLED_BUILTIN_LIST,(plugin::Manifest *)NULL
};

char *opt_plugin_load= NULL;
const char *opt_plugin_load_default= QUOTE_ARG(DRIZZLED_PLUGIN_LIST);
char *opt_plugin_dir_ptr;
char opt_plugin_dir[FN_REFLEN];
static const char *plugin_declarations_sym= "_drizzled_plugin_declaration_";

/* Note that 'int version' must be the first field of every plugin
   sub-structure (plugin->info).
*/

static bool initialized= false;

static DYNAMIC_ARRAY plugin_dl_array;
static DYNAMIC_ARRAY plugin_array;

static bool reap_needed= false;

/*
  write-lock on LOCK_system_variables_hash is required before modifying
  the following variables/structures
*/
static MEM_ROOT plugin_mem_root;
static uint32_t global_variables_dynamic_size= 0;
static HASH bookmark_hash;


/*
  hidden part of opaque value passed to variable check functions.
  Used to provide a object-like structure to non C++ consumers.
*/
struct st_item_value_holder : public st_mysql_value
{
  Item *item;
};


/*
  stored in bookmark_hash, this structure is never removed from the
  hash and is used to mark a single offset for a session local variable
  even if plugins have been uninstalled and reinstalled, repeatedly.
  This structure is allocated from plugin_mem_root.

  The key format is as follows:
    1 byte         - variable type code
    name_len bytes - variable name
    '\0'           - end of key
*/
struct st_bookmark
{
  uint32_t name_len;
  int offset;
  uint32_t version;
  char key[1];
};


/*
  skeleton of a plugin variable - portion of structure common to all.
*/
struct st_mysql_sys_var
{
  DRIZZLE_PLUGIN_VAR_HEADER;
};


/*
  sys_var class for access to all plugin variables visible to the user
*/
class sys_var_pluginvar: public sys_var
{
public:
  plugin::Handle *plugin;
  struct st_mysql_sys_var *plugin_var;

  static void *operator new(size_t size, MEM_ROOT *mem_root)
  { return (void*) alloc_root(mem_root, (uint32_t) size); }
  static void operator delete(void *, size_t)
  { TRASH(ptr_arg, size); }

  sys_var_pluginvar(const char *name_arg,
                    struct st_mysql_sys_var *plugin_var_arg)
    :sys_var(name_arg), plugin_var(plugin_var_arg) {}
  sys_var_pluginvar *cast_pluginvar() { return this; }
  bool is_readonly() const { return plugin_var->flags & PLUGIN_VAR_READONLY; }
  bool check_type(enum_var_type type)
  { return !(plugin_var->flags & PLUGIN_VAR_SessionLOCAL) && type != OPT_GLOBAL; }
  bool check_update_type(Item_result type);
  SHOW_TYPE show_type();
  unsigned char* real_value_ptr(Session *session, enum_var_type type);
  TYPELIB* plugin_var_typelib(void);
  unsigned char* value_ptr(Session *session, enum_var_type type,
                           const LEX_STRING *base);
  bool check(Session *session, set_var *var);
  bool check_default(enum_var_type)
    { return is_readonly(); }
  void set_default(Session *session, enum_var_type);
  bool update(Session *session, set_var *var);
};


/* prototypes */
static bool plugin_load_list(MEM_ROOT *tmp_root, int *argc, char **argv,
                             const char *list);
static int test_plugin_options(MEM_ROOT *, plugin::Handle *,
                               int *, char **);
static bool register_builtin(plugin::Handle *,
                             plugin::Handle **);
static void unlock_variables(Session *session, struct system_variables *vars);
static void cleanup_variables(Session *session, struct system_variables *vars);
static void plugin_vars_free_values(sys_var *vars);
static void plugin_opt_set_limits(struct my_option *options,
                                  const struct st_mysql_sys_var *opt);
static void reap_plugins(void);


/* declared in set_var.cc */
extern sys_var *intern_find_sys_var(const char *str, uint32_t length, bool no_error);
extern bool throw_bounds_warning(Session *session, bool fixed, bool unsignd,
                                 const std::string &name, int64_t val);

static bool throw_bounds_warning(Session *session, bool fixed, bool unsignd,
                                 const char *name, int64_t val)
{
  const std::string name_str(name);
  return throw_bounds_warning(session, fixed, unsignd, name_str, val);
}

/****************************************************************************
  Value type thunks, allows the C world to play in the C++ world
****************************************************************************/

static int item_value_type(struct st_mysql_value *value)
{
  switch (((st_item_value_holder*)value)->item->result_type()) {
  case INT_RESULT:
    return DRIZZLE_VALUE_TYPE_INT;
  case REAL_RESULT:
    return DRIZZLE_VALUE_TYPE_REAL;
  default:
    return DRIZZLE_VALUE_TYPE_STRING;
  }
}

static const char *item_val_str(struct st_mysql_value *value,
                                char *buffer, int *length)
{
  String str(buffer, *length, system_charset_info), *res;
  if (!(res= ((st_item_value_holder*)value)->item->val_str(&str)))
    return NULL;
  *length= res->length();
  if (res->c_ptr_quick() == buffer)
    return buffer;

  /*
    Lets be nice and create a temporary string since the
    buffer was too small
  */
  return current_session->strmake(res->c_ptr_quick(), res->length());
}


static int item_val_int(struct st_mysql_value *value, int64_t *buf)
{
  Item *item= ((st_item_value_holder*)value)->item;
  *buf= item->val_int();
  if (item->is_null())
    return 1;
  return 0;
}


static int item_val_real(struct st_mysql_value *value, double *buf)
{
  Item *item= ((st_item_value_holder*)value)->item;
  *buf= item->val_real();
  if (item->is_null())
    return 1;
  return 0;
}


/****************************************************************************
  Plugin support code
****************************************************************************/

static plugin::Library *plugin_dl_find(const LEX_STRING *dl)
{
  uint32_t i;
  plugin::Library *tmp;

  for (i= 0; i < plugin_dl_array.elements; i++)
  {
    tmp= *dynamic_element(&plugin_dl_array, i, plugin::Library **);
    if (! my_strnncoll(files_charset_info,
                       (const unsigned char *)dl->str, dl->length,
                       (const unsigned char *)tmp->dl.str, tmp->dl.length))
      return(tmp);
  }
  return(0);
}

static plugin::Library *plugin_dl_insert_or_reuse(plugin::Library *plugin_dl)
{
  uint32_t i;
  plugin::Library *tmp;

  for (i= 0; i < plugin_dl_array.elements; i++)
  {
    tmp= *dynamic_element(&plugin_dl_array, i, plugin::Library **);
    {
      memcpy(tmp, plugin_dl, sizeof(plugin::Library));
      return(tmp);
    }
  }
  if (insert_dynamic(&plugin_dl_array, (unsigned char*)&plugin_dl))
    return(0);
  tmp= *dynamic_element(&plugin_dl_array, plugin_dl_array.elements - 1,
                        plugin::Library **)=
      (plugin::Library *) memdup_root(&plugin_mem_root,
                                      (unsigned char*)plugin_dl,
                                      sizeof(plugin::Library));
  return(tmp);
}

static inline void free_plugin_mem(plugin::Library *p)
{
  if (p->handle)
    dlclose(p->handle);
  free(p->dl.str);
}


static plugin::Library *plugin_dl_add(const LEX_STRING *dl, int report)
{
  string dlpath;
  uint32_t plugin_dir_len;
  plugin::Library *tmp, plugin_dl;
  void *sym;
  plugin_dir_len= strlen(opt_plugin_dir);
  dlpath.reserve(FN_REFLEN);
  /*
    Ensure that the dll doesn't have a path.
    This is done to ensure that only approved libraries from the
    plugin directory are used (to make this even remotely secure).
  */
  if (strchr(dl->str, FN_LIBCHAR) ||
      check_string_char_length((LEX_STRING *) dl, "", NAME_CHAR_LEN,
                               system_charset_info, 1) ||
      plugin_dir_len + dl->length + 1 >= FN_REFLEN)
  {
    if (report & REPORT_TO_USER)
      my_error(ER_UDF_NO_PATHS, MYF(0));
    if (report & REPORT_TO_LOG)
      errmsg_printf(ERRMSG_LVL_ERROR, "%s",ER(ER_UDF_NO_PATHS));
    return(0);
  }
  /* If this dll is already loaded just increase ref_count. */
  if ((tmp= plugin_dl_find(dl)))
  {
    return(tmp);
  }
  memset(&plugin_dl, 0, sizeof(plugin_dl));
  /* Compile dll path */
  dlpath.append(opt_plugin_dir);
  dlpath.append("/");
  dlpath.append(dl->str);
  /* Open new dll handle */
  if (!(plugin_dl.handle= dlopen(dlpath.c_str(), RTLD_LAZY|RTLD_GLOBAL)))
  {
    const char *errmsg=dlerror();
    uint32_t dlpathlen= dlpath.length();
    if (!dlpath.compare(0, dlpathlen, errmsg))
    { // if errmsg starts from dlpath, trim this prefix.
      errmsg+=dlpathlen;
      if (*errmsg == ':') errmsg++;
      if (*errmsg == ' ') errmsg++;
    }
    if (report & REPORT_TO_USER)
      my_error(ER_CANT_OPEN_LIBRARY, MYF(0), dlpath.c_str(), errno, errmsg);
    if (report & REPORT_TO_LOG)
      errmsg_printf(ERRMSG_LVL_ERROR, ER(ER_CANT_OPEN_LIBRARY), dlpath.c_str(), errno, errmsg);
    return(0);
  }

  /* Find plugin declarations */
  if (!(sym= dlsym(plugin_dl.handle, plugin_declarations_sym)))
  {
    free_plugin_mem(&plugin_dl);
    if (report & REPORT_TO_USER)
      my_error(ER_CANT_FIND_DL_ENTRY, MYF(0), plugin_declarations_sym);
    if (report & REPORT_TO_LOG)
      errmsg_printf(ERRMSG_LVL_ERROR, ER(ER_CANT_FIND_DL_ENTRY), plugin_declarations_sym);
    return(0);
  }

  plugin_dl.plugins= static_cast<plugin::Manifest *>(sym);

  /* Duplicate and convert dll name */
  plugin_dl.dl.length= dl->length * files_charset_info->mbmaxlen + 1;
  if (! (plugin_dl.dl.str= (char*) calloc(plugin_dl.dl.length, sizeof(char))))
  {
    free_plugin_mem(&plugin_dl);
    if (report & REPORT_TO_USER)
      my_error(ER_OUTOFMEMORY, MYF(0), plugin_dl.dl.length);
    if (report & REPORT_TO_LOG)
      errmsg_printf(ERRMSG_LVL_ERROR, ER(ER_OUTOFMEMORY), plugin_dl.dl.length);
    return(0);
  }
  strcpy(plugin_dl.dl.str, dl->str);
  /* Add this dll to array */
  if (! (tmp= plugin_dl_insert_or_reuse(&plugin_dl)))
  {
    free_plugin_mem(&plugin_dl);
    if (report & REPORT_TO_USER)
      my_error(ER_OUTOFMEMORY, MYF(0), sizeof(plugin::Library));
    if (report & REPORT_TO_LOG)
      errmsg_printf(ERRMSG_LVL_ERROR, ER(ER_OUTOFMEMORY),
                    sizeof(plugin::Library));
    return(0);
  }
  return(tmp);
}


static void plugin_dl_del(const LEX_STRING *dl)
{
  uint32_t i;

  for (i= 0; i < plugin_dl_array.elements; i++)
  {
    plugin::Library *tmp= *dynamic_element(&plugin_dl_array, i,
                                           plugin::Library **);
    if (! my_strnncoll(files_charset_info,
                       (const unsigned char *)dl->str, dl->length,
                       (const unsigned char *)tmp->dl.str, tmp->dl.length))
    {
      /* Do not remove this element, unless no other plugin uses this dll. */
      {
        free_plugin_mem(tmp);
        memset(tmp, 0, sizeof(plugin::Library));
      }
      break;
    }
  }
  return;
}



static plugin::Handle *plugin_insert_or_reuse(plugin::Handle *plugin)
{
  if (insert_dynamic(&plugin_array, (unsigned char*)&plugin))
    return(0);
  plugin= *dynamic_element(&plugin_array, plugin_array.elements - 1,
                        plugin::Handle **);
  return(plugin);
}


/*
  NOTE
    Requires that a write-lock is held on LOCK_system_variables_hash
*/
static bool plugin_add(MEM_ROOT *tmp_root,
                       const LEX_STRING *name, const LEX_STRING *dl,
                       int *argc, char **argv, int report)
{
  PluginRegistry &registry= PluginRegistry::getPluginRegistry();

  plugin::Manifest *manifest;
  if (! initialized)
    return(0);

  if (registry.find(name))
  {
    if (report & REPORT_TO_USER)
      my_error(ER_UDF_EXISTS, MYF(0), name->str);
    if (report & REPORT_TO_LOG)
      errmsg_printf(ERRMSG_LVL_ERROR, ER(ER_UDF_EXISTS), name->str);
    return(true);
  }
  plugin::Library *library= plugin_dl_add(dl, report);
  if (library == NULL)
    return true;

  plugin::Handle *tmp= NULL;
  /* Find plugin by name */
  for (manifest= library->plugins; manifest->name; manifest++)
  {
    if (! my_strnncoll(system_charset_info,
                       (const unsigned char *)name->str, name->length,
                       (const unsigned char *)manifest->name,
                       strlen(manifest->name)))
    {
      tmp= new (std::nothrow) plugin::Handle(manifest, library);
      if (tmp == NULL)
        return true;

      if (!test_plugin_options(tmp_root, tmp, argc, argv))
      {
        if ((tmp= plugin_insert_or_reuse(tmp)))
        {
          registry.add(tmp);
          init_alloc_root(&tmp->mem_root, 4096, 4096);
          return(false);
        }
        mysql_del_sys_var_chain(tmp->system_vars);
        goto err;
      }
      /* plugin was disabled */
      plugin_dl_del(dl);
      return(false);
    }
  }
  if (report & REPORT_TO_USER)
    my_error(ER_CANT_FIND_DL_ENTRY, MYF(0), name->str);
  if (report & REPORT_TO_LOG)
    errmsg_printf(ERRMSG_LVL_ERROR, ER(ER_CANT_FIND_DL_ENTRY), name->str);
err:
  plugin_dl_del(dl);
  return(true);
}


static void plugin_del(plugin::Handle *plugin)
{
  PluginRegistry &registry= PluginRegistry::getPluginRegistry();
  if (plugin->isInited)
  {
    if (plugin->getManifest().status_vars)
    {
      remove_status_vars(plugin->getManifest().status_vars);
    }

    if (plugin->getManifest().deinit)
      plugin->getManifest().deinit(registry);
  }

  /* Free allocated strings before deleting the plugin. */
  plugin_vars_free_values(plugin->system_vars);
  if (plugin->plugin_dl)
    plugin_dl_del(&plugin->plugin_dl->dl);
  plugin->isInited= false;
  pthread_rwlock_wrlock(&LOCK_system_variables_hash);
  mysql_del_sys_var_chain(plugin->system_vars);
  pthread_rwlock_unlock(&LOCK_system_variables_hash);
  delete plugin;
}

static void reap_plugins(void)
{
  size_t count;
  uint32_t idx;
  drizzled::plugin::Handle *plugin;

  count= plugin_array.elements;

  for (idx= 0; idx < count; idx++)
  {
    plugin= *dynamic_element(&plugin_array, idx, drizzled::plugin::Handle **);
    plugin_del(plugin);
  }
}

static bool plugin_initialize(drizzled::plugin::Handle *plugin)
{
  assert(plugin->isInited == false);

  PluginRegistry &registry= PluginRegistry::getPluginRegistry();
  if (plugin->getManifest().init)
  {
    if (plugin->getManifest().init(registry))
    {
      errmsg_printf(ERRMSG_LVL_ERROR,
                    _("Plugin '%s' init function returned error.\n"),
                    plugin->getName().c_str());
      goto err;
    }
  }
  plugin->isInited= true;

  if (plugin->getManifest().status_vars)
  {
    add_status_vars(plugin->getManifest().status_vars); // add_status_vars makes a copy
  }

  /*
    set the plugin attribute of plugin's sys vars so they are pointing
    to the active plugin
  */
  if (plugin->system_vars)
  {
    sys_var_pluginvar *var= plugin->system_vars->cast_pluginvar();
    for (;;)
    {
      var->plugin= plugin;
      if (! var->getNext())
        break;
      var= var->getNext()->cast_pluginvar();
    }
  }

  return false;
err:
  return true;
}


extern "C" unsigned char *get_bookmark_hash_key(const unsigned char *, size_t *, bool);


unsigned char *get_bookmark_hash_key(const unsigned char *buff, size_t *length, bool)
{
  struct st_bookmark *var= (st_bookmark *)buff;
  *length= var->name_len + 1;
  return (unsigned char*) var->key;
}


/*
  The logic is that we first load and initialize all compiled in plugins.
  From there we load up the dynamic types (assuming we have not been told to
  skip this part).

  Finally we initialize everything, aka the dynamic that have yet to initialize.
*/
int plugin_init(int *argc, char **argv, int flags)
{
  uint32_t idx;
  plugin::Manifest **builtins;
  plugin::Manifest *manifest;
  plugin::Handle *handle;
  MEM_ROOT tmp_root;

  if (initialized)
    return(0);

  init_alloc_root(&plugin_mem_root, 4096, 4096);
  init_alloc_root(&tmp_root, 4096, 4096);

  if (hash_init(&bookmark_hash, &my_charset_bin, 16, 0, 0,
                  get_bookmark_hash_key, NULL, HASH_UNIQUE))
      goto err;


  if (my_init_dynamic_array(&plugin_dl_array,
                            sizeof(plugin::Library *),16,16) ||
      my_init_dynamic_array(&plugin_array,
                            sizeof(plugin::Handle *),16,16))
    goto err;

  initialized= 1;

  /*
    First we register builtin plugins
  */
  for (builtins= drizzled_builtins; *builtins; builtins++)
  {
    for (manifest= *builtins; manifest->name; manifest++)
    {
      handle= new (std::nothrow) plugin::Handle(manifest);
      if (handle == NULL)
        return true;

      free_root(&tmp_root, MYF(MY_MARK_BLOCKS_FREE));
      if (test_plugin_options(&tmp_root, handle, argc, argv))
        continue;

      if (register_builtin(handle, &handle))
        goto err_unlock;

      if (plugin_initialize(handle))
        goto err_unlock;

    }
  }


  /* Register all dynamic plugins */
  if (!(flags & PLUGIN_INIT_SKIP_DYNAMIC_LOADING))
  {
    if (opt_plugin_load)
      plugin_load_list(&tmp_root, argc, argv, opt_plugin_load);
  }

  if (flags & PLUGIN_INIT_SKIP_INITIALIZATION)
    goto end;

  /*
    Now we initialize all remaining plugins
  */
  for (idx= 0; idx < plugin_array.elements; idx++)
  {
    handle= *dynamic_element(&plugin_array, idx, plugin::Handle **);
    if (handle->isInited == false)
    {
      if (plugin_initialize(handle))
        plugin_del(handle);
    }
  }


end:
  free_root(&tmp_root, MYF(0));

  return(0);

err_unlock:
err:
  free_root(&tmp_root, MYF(0));
  return(1);
}


static bool register_builtin(plugin::Handle *tmp,
                             plugin::Handle **ptr)
{

  PluginRegistry &registry= PluginRegistry::getPluginRegistry();

  tmp->isInited= false;
  tmp->plugin_dl= 0;

  if (insert_dynamic(&plugin_array, (unsigned char*)&tmp))
    return(1);

  *ptr= *dynamic_element(&plugin_array, plugin_array.elements - 1,
                         plugin::Handle **);

  registry.add(*ptr);

  return(0);
}


/*
  called only by plugin_init()
*/
static bool plugin_load_list(MEM_ROOT *tmp_root, int *argc, char **argv,
                             const char *list)
{
  char buffer[FN_REFLEN];
  LEX_STRING name= {buffer, 0}, dl= {NULL, 0}, *str= &name;
  plugin::Library *plugin_dl;
  plugin::Manifest *plugin;
  char *p= buffer;
  while (list)
  {
    if (p == buffer + sizeof(buffer) - 1)
    {
      errmsg_printf(ERRMSG_LVL_ERROR, _("plugin-load parameter too long"));
      return(true);
    }

    switch ((*(p++)= *(list++))) {
    case '\0':
      list= NULL; /* terminate the loop */
      /* fall through */
    case ':':     /* can't use this as delimiter as it may be drive letter */
    case ';':
      str->str[str->length]= '\0';
      if (str == &name)  // load all plugins in named module
      {
        if (!name.length)
        {
          p--;    /* reset pointer */
          continue;
        }

        dl= name;
        if ((plugin_dl= plugin_dl_add(&dl, REPORT_TO_LOG)))
        {
          for (plugin= plugin_dl->plugins; plugin->name; plugin++)
          {
            name.str= (char *) plugin->name;
            name.length= strlen(name.str);

            free_root(tmp_root, MYF(MY_MARK_BLOCKS_FREE));
            if (plugin_add(tmp_root, &name, &dl, argc, argv, REPORT_TO_LOG))
              goto error;
          }
          plugin_dl_del(&dl); // reduce ref count
        }
      }
      else
      {
        free_root(tmp_root, MYF(MY_MARK_BLOCKS_FREE));
        if (plugin_add(tmp_root, &name, &dl, argc, argv, REPORT_TO_LOG))
          goto error;
      }
      name.length= dl.length= 0;
      dl.str= NULL; name.str= p= buffer;
      str= &name;
      continue;
    case '=':
    case '#':
      if (str == &name)
      {
        name.str[name.length]= '\0';
        str= &dl;
        str->str= p;
        continue;
      }
    default:
      str->length++;
      continue;
    }
  }
  return(false);
error:
  errmsg_printf(ERRMSG_LVL_ERROR, _("Couldn't load plugin named '%s' with soname '%s'."),
                  name.str, dl.str);
  return(true);
}


void plugin_shutdown(void)
{
  uint32_t idx;
  size_t count= plugin_array.elements;
  vector<plugin::Handle *> plugins;
  vector<plugin::Library *> dl;

  if (initialized)
  {
    reap_needed= true;

    reap_plugins();
    unlock_variables(NULL, &global_system_variables);
    unlock_variables(NULL, &max_system_variables);

    cleanup_variables(NULL, &global_system_variables);
    cleanup_variables(NULL, &max_system_variables);

    initialized= 0;
  }

  /* Dispose of the memory */

  delete_dynamic(&plugin_array);

  count= plugin_dl_array.elements;
  dl.reserve(count);
  for (idx= 0; idx < count; idx++)
    dl.push_back(*dynamic_element(&plugin_dl_array, idx,
                 plugin::Library **));
  for (idx= 0; idx < count; idx++)
    free_plugin_mem(dl[idx]);
  delete_dynamic(&plugin_dl_array);

  hash_free(&bookmark_hash);
  free_root(&plugin_mem_root, MYF(0));

  global_variables_dynamic_size= 0;
}

/****************************************************************************
  Internal type declarations for variables support
****************************************************************************/

#undef DRIZZLE_SYSVAR_NAME
#define DRIZZLE_SYSVAR_NAME(name) name
#define PLUGIN_VAR_TYPEMASK 0x007f

#define EXTRA_OPTIONS 3 /* options for: 'foo', 'plugin-foo' and NULL */

typedef DECLARE_DRIZZLE_SYSVAR_BASIC(sysvar_bool_t, bool);
typedef DECLARE_DRIZZLE_SessionVAR_BASIC(sessionvar_bool_t, bool);
typedef DECLARE_DRIZZLE_SYSVAR_BASIC(sysvar_str_t, char *);
typedef DECLARE_DRIZZLE_SessionVAR_BASIC(sessionvar_str_t, char *);

typedef DECLARE_DRIZZLE_SYSVAR_TYPELIB(sysvar_enum_t, unsigned long);
typedef DECLARE_DRIZZLE_SessionVAR_TYPELIB(sessionvar_enum_t, unsigned long);
typedef DECLARE_DRIZZLE_SYSVAR_TYPELIB(sysvar_set_t, uint64_t);
typedef DECLARE_DRIZZLE_SessionVAR_TYPELIB(sessionvar_set_t, uint64_t);

typedef DECLARE_DRIZZLE_SYSVAR_SIMPLE(sysvar_int_t, int);
typedef DECLARE_DRIZZLE_SYSVAR_SIMPLE(sysvar_long_t, long);
typedef DECLARE_DRIZZLE_SYSVAR_SIMPLE(sysvar_int64_t_t, int64_t);
typedef DECLARE_DRIZZLE_SYSVAR_SIMPLE(sysvar_uint_t, uint);
typedef DECLARE_DRIZZLE_SYSVAR_SIMPLE(sysvar_ulong_t, ulong);
typedef DECLARE_DRIZZLE_SYSVAR_SIMPLE(sysvar_uint64_t_t, uint64_t);

typedef DECLARE_DRIZZLE_SessionVAR_SIMPLE(sessionvar_int_t, int);
typedef DECLARE_DRIZZLE_SessionVAR_SIMPLE(sessionvar_long_t, long);
typedef DECLARE_DRIZZLE_SessionVAR_SIMPLE(sessionvar_int64_t_t, int64_t);
typedef DECLARE_DRIZZLE_SessionVAR_SIMPLE(sessionvar_uint_t, uint);
typedef DECLARE_DRIZZLE_SessionVAR_SIMPLE(sessionvar_ulong_t, ulong);
typedef DECLARE_DRIZZLE_SessionVAR_SIMPLE(sessionvar_uint64_t_t, uint64_t);

typedef bool *(*mysql_sys_var_ptr_p)(Session* a_session, int offset);


/****************************************************************************
  default variable data check and update functions
****************************************************************************/

static int check_func_bool(Session *, struct st_mysql_sys_var *var,
                           void *save, st_mysql_value *value)
{
  char buff[STRING_BUFFER_USUAL_SIZE];
  const char *strvalue= "NULL", *str;
  int result, length;
  int64_t tmp;

  if (value->value_type(value) == DRIZZLE_VALUE_TYPE_STRING)
  {
    length= sizeof(buff);
    if (!(str= value->val_str(value, buff, &length)) ||
        (result= find_type(&bool_typelib, str, length, 1)-1) < 0)
    {
      if (str)
        strvalue= str;
      goto err;
    }
  }
  else
  {
    if (value->val_int(value, &tmp) < 0)
      goto err;
    if (tmp > 1)
    {
      llstr(tmp, buff);
      strvalue= buff;
      goto err;
    }
    result= (int) tmp;
  }
  *(int*)save= -result;
  return 0;
err:
  my_error(ER_WRONG_VALUE_FOR_VAR, MYF(0), var->name, strvalue);
  return 1;
}


static int check_func_int(Session *session, struct st_mysql_sys_var *var,
                          void *save, st_mysql_value *value)
{
  bool fixed;
  int64_t tmp;
  struct my_option options;
  value->val_int(value, &tmp);
  plugin_opt_set_limits(&options, var);

  if (var->flags & PLUGIN_VAR_UNSIGNED)
    *(uint32_t *)save= (uint32_t) getopt_ull_limit_value((uint64_t) tmp, &options,
                                                   &fixed);
  else
    *(int *)save= (int) getopt_ll_limit_value(tmp, &options, &fixed);

  return throw_bounds_warning(session, fixed, var->flags & PLUGIN_VAR_UNSIGNED,
                              var->name, (int64_t) tmp);
}


static int check_func_long(Session *session, struct st_mysql_sys_var *var,
                          void *save, st_mysql_value *value)
{
  bool fixed;
  int64_t tmp;
  struct my_option options;
  value->val_int(value, &tmp);
  plugin_opt_set_limits(&options, var);

  if (var->flags & PLUGIN_VAR_UNSIGNED)
    *(ulong *)save= (ulong) getopt_ull_limit_value((uint64_t) tmp, &options,
                                                   &fixed);
  else
    *(long *)save= (long) getopt_ll_limit_value(tmp, &options, &fixed);

  return throw_bounds_warning(session, fixed, var->flags & PLUGIN_VAR_UNSIGNED,
                              var->name, (int64_t) tmp);
}


static int check_func_int64_t(Session *session, struct st_mysql_sys_var *var,
                               void *save, st_mysql_value *value)
{
  bool fixed;
  int64_t tmp;
  struct my_option options;
  value->val_int(value, &tmp);
  plugin_opt_set_limits(&options, var);

  if (var->flags & PLUGIN_VAR_UNSIGNED)
    *(uint64_t *)save= getopt_ull_limit_value((uint64_t) tmp, &options,
                                               &fixed);
  else
    *(int64_t *)save= getopt_ll_limit_value(tmp, &options, &fixed);

  return throw_bounds_warning(session, fixed, var->flags & PLUGIN_VAR_UNSIGNED,
                              var->name, (int64_t) tmp);
}

static int check_func_str(Session *session, struct st_mysql_sys_var *,
                          void *save, st_mysql_value *value)
{
  char buff[STRING_BUFFER_USUAL_SIZE];
  const char *str;
  int length;

  length= sizeof(buff);
  if ((str= value->val_str(value, buff, &length)))
    str= session->strmake(str, length);
  *(const char**)save= str;
  return 0;
}


static int check_func_enum(Session *, struct st_mysql_sys_var *var,
                           void *save, st_mysql_value *value)
{
  char buff[STRING_BUFFER_USUAL_SIZE];
  const char *strvalue= "NULL", *str;
  TYPELIB *typelib;
  int64_t tmp;
  long result;
  int length;

  if (var->flags & PLUGIN_VAR_SessionLOCAL)
    typelib= ((sessionvar_enum_t*) var)->typelib;
  else
    typelib= ((sysvar_enum_t*) var)->typelib;

  if (value->value_type(value) == DRIZZLE_VALUE_TYPE_STRING)
  {
    length= sizeof(buff);
    if (!(str= value->val_str(value, buff, &length)))
      goto err;
    if ((result= (long)find_type(typelib, str, length, 1)-1) < 0)
    {
      strvalue= str;
      goto err;
    }
  }
  else
  {
    if (value->val_int(value, &tmp))
      goto err;
    if (tmp >= typelib->count)
    {
      llstr(tmp, buff);
      strvalue= buff;
      goto err;
    }
    result= (long) tmp;
  }
  *(long*)save= result;
  return 0;
err:
  my_error(ER_WRONG_VALUE_FOR_VAR, MYF(0), var->name, strvalue);
  return 1;
}


static int check_func_set(Session *, struct st_mysql_sys_var *var,
                          void *save, st_mysql_value *value)
{
  char buff[STRING_BUFFER_USUAL_SIZE], *error= 0;
  const char *strvalue= "NULL", *str;
  TYPELIB *typelib;
  uint64_t result;
  uint32_t error_len;
  bool not_used;
  int length;

  if (var->flags & PLUGIN_VAR_SessionLOCAL)
    typelib= ((sessionvar_set_t*) var)->typelib;
  else
    typelib= ((sysvar_set_t*)var)->typelib;

  if (value->value_type(value) == DRIZZLE_VALUE_TYPE_STRING)
  {
    length= sizeof(buff);
    if (!(str= value->val_str(value, buff, &length)))
      goto err;
    result= find_set(typelib, str, length, NULL,
                     &error, &error_len, &not_used);
    if (error_len)
    {
      length= min((uint32_t)sizeof(buff), error_len);
      strncpy(buff, error, length);
      buff[length]= '\0';
      strvalue= buff;
      goto err;
    }
  }
  else
  {
    if (value->val_int(value, (int64_t *)&result))
      goto err;
    if (unlikely((result >= (1UL << typelib->count)) &&
                 (typelib->count < sizeof(long)*8)))
    {
      llstr(result, buff);
      strvalue= buff;
      goto err;
    }
  }
  *(uint64_t*)save= result;
  return 0;
err:
  my_error(ER_WRONG_VALUE_FOR_VAR, MYF(0), var->name, strvalue);
  return 1;
}


static void update_func_bool(Session *, struct st_mysql_sys_var *,
                             void *tgt, const void *save)
{
  *(bool *) tgt= *(int *) save ? 1 : 0;
}


static void update_func_int(Session *, struct st_mysql_sys_var *,
                             void *tgt, const void *save)
{
  *(int *)tgt= *(int *) save;
}


static void update_func_long(Session *, struct st_mysql_sys_var *,
                             void *tgt, const void *save)
{
  *(long *)tgt= *(long *) save;
}


static void update_func_int64_t(Session *, struct st_mysql_sys_var *,
                                 void *tgt, const void *save)
{
  *(int64_t *)tgt= *(uint64_t *) save;
}


static void update_func_str(Session *, struct st_mysql_sys_var *var,
                             void *tgt, const void *save)
{
  char *old= *(char **) tgt;
  *(char **)tgt= *(char **) save;
  if (var->flags & PLUGIN_VAR_MEMALLOC)
  {
    *(char **)tgt= strdup(*(char **) save);
    free(old);
    /*
     * There isn't a _really_ good thing to do here until this whole set_var
     * mess gets redesigned
     */
    if (tgt == NULL)
      errmsg_printf(ERRMSG_LVL_ERROR, _("Out of memory."));

  }
}


/****************************************************************************
  System Variables support
****************************************************************************/


sys_var *find_sys_var(Session *, const char *str, uint32_t length)
{
  sys_var *var;
  sys_var_pluginvar *pi= NULL;
  plugin::Handle *plugin;

  pthread_rwlock_rdlock(&LOCK_system_variables_hash);
  if ((var= intern_find_sys_var(str, length, false)) &&
      (pi= var->cast_pluginvar()))
  {
    pthread_rwlock_unlock(&LOCK_system_variables_hash);
    if (!(plugin= pi->plugin))
      var= NULL; /* failed to lock it, it must be uninstalling */
    else if (plugin->isInited == false)
    {
      var= NULL;
    }
  }
  else
    pthread_rwlock_unlock(&LOCK_system_variables_hash);

  /*
    If the variable exists but the plugin it is associated with is not ready
    then the intern_plugin_lock did not raise an error, so we do it here.
  */
  if (pi && !var)
    my_error(ER_UNKNOWN_SYSTEM_VARIABLE, MYF(0), (char*) str);
  return(var);
}


/*
  called by register_var, construct_options and test_plugin_options.
  Returns the 'bookmark' for the named variable.
  LOCK_system_variables_hash should be at least read locked
*/
static st_bookmark *find_bookmark(const char *plugin, const char *name, int flags)
{
  st_bookmark *result= NULL;
  uint32_t namelen, length, pluginlen= 0;
  char *varname, *p;

  if (!(flags & PLUGIN_VAR_SessionLOCAL))
    return NULL;

  namelen= strlen(name);
  if (plugin)
    pluginlen= strlen(plugin) + 1;
  length= namelen + pluginlen + 2;
  varname= (char*) malloc(length);

  if (plugin)
  {
    sprintf(varname+1,"%s_%s",plugin,name);
    for (p= varname + 1; *p; p++)
      if (*p == '-')
        *p= '_';
  }
  else
    memcpy(varname + 1, name, namelen + 1);

  varname[0]= flags & PLUGIN_VAR_TYPEMASK;

  result= (st_bookmark*) hash_search(&bookmark_hash,
                                     (const unsigned char*) varname, length - 1);

  free(varname);
  return result;
}


/*
  returns a bookmark for session-local variables, creating if neccessary.
  returns null for non session-local variables.
  Requires that a write lock is obtained on LOCK_system_variables_hash
*/
static st_bookmark *register_var(const char *plugin, const char *name,
                                 int flags)
{
  uint32_t length= strlen(plugin) + strlen(name) + 3, size= 0, offset, new_size;
  st_bookmark *result;
  char *varname, *p;

  if (!(flags & PLUGIN_VAR_SessionLOCAL))
    return NULL;

  switch (flags & PLUGIN_VAR_TYPEMASK) {
  case PLUGIN_VAR_BOOL:
    size= ALIGN_SIZE(sizeof(bool));
    break;
  case PLUGIN_VAR_INT:
    size= ALIGN_SIZE(sizeof(int));
    break;
  case PLUGIN_VAR_LONG:
  case PLUGIN_VAR_ENUM:
    size= ALIGN_SIZE(sizeof(long));
    break;
  case PLUGIN_VAR_LONGLONG:
  case PLUGIN_VAR_SET:
    size= ALIGN_SIZE(sizeof(uint64_t));
    break;
  case PLUGIN_VAR_STR:
    size= ALIGN_SIZE(sizeof(char*));
    break;
  default:
    assert(0);
    return NULL;
  };

  varname= ((char*) malloc(length));
  sprintf(varname+1, "%s_%s", plugin, name);
  for (p= varname + 1; *p; p++)
    if (*p == '-')
      *p= '_';

  if (!(result= find_bookmark(NULL, varname + 1, flags)))
  {
    result= (st_bookmark*) alloc_root(&plugin_mem_root,
                                      sizeof(struct st_bookmark) + length-1);
    varname[0]= flags & PLUGIN_VAR_TYPEMASK;
    memcpy(result->key, varname, length);
    result->name_len= length - 2;
    result->offset= -1;

    assert(size && !(size & (size-1))); /* must be power of 2 */

    offset= global_system_variables.dynamic_variables_size;
    offset= (offset + size - 1) & ~(size - 1);
    result->offset= (int) offset;

    new_size= (offset + size + 63) & ~63;

    if (new_size > global_variables_dynamic_size)
    {
      char* tmpptr= NULL;
      if (!(tmpptr=
              (char *)realloc(global_system_variables.dynamic_variables_ptr,
                              new_size)))
        return NULL;
      global_system_variables.dynamic_variables_ptr= tmpptr;
      tmpptr= NULL;
      if (!(tmpptr=
              (char *)realloc(max_system_variables.dynamic_variables_ptr,
                              new_size)))
        return NULL;
      max_system_variables.dynamic_variables_ptr= tmpptr;
           
      /*
        Clear the new variable value space. This is required for string
        variables. If their value is non-NULL, it must point to a valid
        string.
      */
      memset(global_system_variables.dynamic_variables_ptr +
             global_variables_dynamic_size, 0,
             new_size - global_variables_dynamic_size);
      memset(max_system_variables.dynamic_variables_ptr +
             global_variables_dynamic_size, 0,
             new_size - global_variables_dynamic_size);
      global_variables_dynamic_size= new_size;
    }

    global_system_variables.dynamic_variables_head= offset;
    max_system_variables.dynamic_variables_head= offset;
    global_system_variables.dynamic_variables_size= offset + size;
    max_system_variables.dynamic_variables_size= offset + size;
    global_system_variables.dynamic_variables_version++;
    max_system_variables.dynamic_variables_version++;

    result->version= global_system_variables.dynamic_variables_version;

    /* this should succeed because we have already checked if a dup exists */
    if (my_hash_insert(&bookmark_hash, (unsigned char*) result))
    {
      fprintf(stderr, "failed to add placeholder to hash");
      assert(0);
    }
  }
  free(varname);
  return result;
}


/*
  returns a pointer to the memory which holds the session-local variable or
  a pointer to the global variable if session==null.
  If required, will sync with global variables if the requested variable
  has not yet been allocated in the current thread.
*/
static unsigned char *intern_sys_var_ptr(Session* session, int offset, bool global_lock)
{
  assert(offset >= 0);
  assert((uint32_t)offset <= global_system_variables.dynamic_variables_head);

  if (!session)
    return (unsigned char*) global_system_variables.dynamic_variables_ptr + offset;

  /*
    dynamic_variables_head points to the largest valid offset
  */
  if (!session->variables.dynamic_variables_ptr ||
      (uint32_t)offset > session->variables.dynamic_variables_head)
  {
    uint32_t idx;

    pthread_rwlock_rdlock(&LOCK_system_variables_hash);

    char *tmpptr= NULL;
    if (!(tmpptr= (char *)realloc(session->variables.dynamic_variables_ptr,
                                  global_variables_dynamic_size)))
      return NULL;
    session->variables.dynamic_variables_ptr= tmpptr;

    if (global_lock)
      pthread_mutex_lock(&LOCK_global_system_variables);

    safe_mutex_assert_owner(&LOCK_global_system_variables);

    memcpy(session->variables.dynamic_variables_ptr +
             session->variables.dynamic_variables_size,
           global_system_variables.dynamic_variables_ptr +
             session->variables.dynamic_variables_size,
           global_system_variables.dynamic_variables_size -
             session->variables.dynamic_variables_size);

    /*
      now we need to iterate through any newly copied 'defaults'
      and if it is a string type with MEMALLOC flag, we need to strdup
    */
    for (idx= 0; idx < bookmark_hash.records; idx++)
    {
      sys_var_pluginvar *pi;
      sys_var *var;
      st_bookmark *v= (st_bookmark*) hash_element(&bookmark_hash,idx);

      if (v->version <= session->variables.dynamic_variables_version ||
          !(var= intern_find_sys_var(v->key + 1, v->name_len, true)) ||
          !(pi= var->cast_pluginvar()) ||
          v->key[0] != (pi->plugin_var->flags & PLUGIN_VAR_TYPEMASK))
        continue;

      /* Here we do anything special that may be required of the data types */

      if ((pi->plugin_var->flags & PLUGIN_VAR_TYPEMASK) == PLUGIN_VAR_STR &&
          pi->plugin_var->flags & PLUGIN_VAR_MEMALLOC)
      {
         char **pp= (char**) (session->variables.dynamic_variables_ptr +
                             *(int*)(pi->plugin_var + 1));
         if ((*pp= *(char**) (global_system_variables.dynamic_variables_ptr +
                             *(int*)(pi->plugin_var + 1))))
           *pp= strdup(*pp);
         if (*pp == NULL)
           return NULL;
      }
    }

    if (global_lock)
      pthread_mutex_unlock(&LOCK_global_system_variables);

    session->variables.dynamic_variables_version=
           global_system_variables.dynamic_variables_version;
    session->variables.dynamic_variables_head=
           global_system_variables.dynamic_variables_head;
    session->variables.dynamic_variables_size=
           global_system_variables.dynamic_variables_size;

    pthread_rwlock_unlock(&LOCK_system_variables_hash);
  }
  return (unsigned char*)session->variables.dynamic_variables_ptr + offset;
}

static bool *mysql_sys_var_ptr_bool(Session* a_session, int offset)
{
  return (bool *)intern_sys_var_ptr(a_session, offset, true);
}

static int *mysql_sys_var_ptr_int(Session* a_session, int offset)
{
  return (int *)intern_sys_var_ptr(a_session, offset, true);
}

static long *mysql_sys_var_ptr_long(Session* a_session, int offset)
{
  return (long *)intern_sys_var_ptr(a_session, offset, true);
}

static int64_t *mysql_sys_var_ptr_int64_t(Session* a_session, int offset)
{
  return (int64_t *)intern_sys_var_ptr(a_session, offset, true);
}

static char **mysql_sys_var_ptr_str(Session* a_session, int offset)
{
  return (char **)intern_sys_var_ptr(a_session, offset, true);
}

static uint64_t *mysql_sys_var_ptr_set(Session* a_session, int offset)
{
  return (uint64_t *)intern_sys_var_ptr(a_session, offset, true);
}

static unsigned long *mysql_sys_var_ptr_enum(Session* a_session, int offset)
{
  return (unsigned long *)intern_sys_var_ptr(a_session, offset, true);
}


void plugin_sessionvar_init(Session *session)
{
  session->variables.storage_engine= NULL;
  cleanup_variables(session, &session->variables);

  session->variables= global_system_variables;
  session->variables.storage_engine= NULL;

  /* we are going to allocate these lazily */
  session->variables.dynamic_variables_version= 0;
  session->variables.dynamic_variables_size= 0;
  session->variables.dynamic_variables_ptr= 0;

  session->variables.storage_engine= global_system_variables.storage_engine;
}


/*
  Unlocks all system variables which hold a reference
*/
static void unlock_variables(Session *, struct system_variables *vars)
{
  vars->storage_engine= NULL;
}


/*
  Frees memory used by system variables

  Unlike plugin_vars_free_values() it frees all variables of all plugins,
  it's used on shutdown.
*/
static void cleanup_variables(Session *session, struct system_variables *vars)
{
  st_bookmark *v;
  sys_var_pluginvar *pivar;
  sys_var *var;
  int flags;
  uint32_t idx;

  pthread_rwlock_rdlock(&LOCK_system_variables_hash);
  for (idx= 0; idx < bookmark_hash.records; idx++)
  {
    v= (st_bookmark*) hash_element(&bookmark_hash, idx);
    if (v->version > vars->dynamic_variables_version ||
        !(var= intern_find_sys_var(v->key + 1, v->name_len, true)) ||
        !(pivar= var->cast_pluginvar()) ||
        v->key[0] != (pivar->plugin_var->flags & PLUGIN_VAR_TYPEMASK))
      continue;

    flags= pivar->plugin_var->flags;

    if ((flags & PLUGIN_VAR_TYPEMASK) == PLUGIN_VAR_STR &&
        flags & PLUGIN_VAR_SessionLOCAL && flags & PLUGIN_VAR_MEMALLOC)
    {
      char **ptr= (char**) pivar->real_value_ptr(session, OPT_SESSION);
      free(*ptr);
      *ptr= NULL;
    }
  }
  pthread_rwlock_unlock(&LOCK_system_variables_hash);

  assert(vars->storage_engine == NULL);

  free(vars->dynamic_variables_ptr);
  vars->dynamic_variables_ptr= NULL;
  vars->dynamic_variables_size= 0;
  vars->dynamic_variables_version= 0;
}


void plugin_sessionvar_cleanup(Session *session)
{
  unlock_variables(session, &session->variables);
  cleanup_variables(session, &session->variables);
}


/**
  @brief Free values of thread variables of a plugin.

  This must be called before a plugin is deleted. Otherwise its
  variables are no longer accessible and the value space is lost. Note
  that only string values with PLUGIN_VAR_MEMALLOC are allocated and
  must be freed.

  @param[in]        vars        Chain of system variables of a plugin
*/

static void plugin_vars_free_values(sys_var *vars)
{

  for (sys_var *var= vars; var; var= var->getNext())
  {
    sys_var_pluginvar *piv= var->cast_pluginvar();
    if (piv &&
        ((piv->plugin_var->flags & PLUGIN_VAR_TYPEMASK) == PLUGIN_VAR_STR) &&
        (piv->plugin_var->flags & PLUGIN_VAR_MEMALLOC))
    {
      /* Free the string from global_system_variables. */
      char **valptr= (char**) piv->real_value_ptr(NULL, OPT_GLOBAL);
      free(*valptr);
      *valptr= NULL;
    }
  }
  return;
}


bool sys_var_pluginvar::check_update_type(Item_result type)
{
  if (is_readonly())
    return 1;
  switch (plugin_var->flags & PLUGIN_VAR_TYPEMASK) {
  case PLUGIN_VAR_INT:
  case PLUGIN_VAR_LONG:
  case PLUGIN_VAR_LONGLONG:
    return type != INT_RESULT;
  case PLUGIN_VAR_STR:
    return type != STRING_RESULT;
  default:
    return 0;
  }
}


SHOW_TYPE sys_var_pluginvar::show_type()
{
  switch (plugin_var->flags & PLUGIN_VAR_TYPEMASK) {
  case PLUGIN_VAR_BOOL:
    return SHOW_MY_BOOL;
  case PLUGIN_VAR_INT:
    return SHOW_INT;
  case PLUGIN_VAR_LONG:
    return SHOW_LONG;
  case PLUGIN_VAR_LONGLONG:
    return SHOW_LONGLONG;
  case PLUGIN_VAR_STR:
    return SHOW_CHAR_PTR;
  case PLUGIN_VAR_ENUM:
  case PLUGIN_VAR_SET:
    return SHOW_CHAR;
  default:
    assert(0);
    return SHOW_UNDEF;
  }
}


unsigned char* sys_var_pluginvar::real_value_ptr(Session *session, enum_var_type type)
{
  assert(session || (type == OPT_GLOBAL));
  if (plugin_var->flags & PLUGIN_VAR_SessionLOCAL)
  {
    if (type == OPT_GLOBAL)
      session= NULL;

    return intern_sys_var_ptr(session, *(int*) (plugin_var+1), false);
  }
  return *(unsigned char**) (plugin_var+1);
}


TYPELIB* sys_var_pluginvar::plugin_var_typelib(void)
{
  switch (plugin_var->flags & (PLUGIN_VAR_TYPEMASK | PLUGIN_VAR_SessionLOCAL)) {
  case PLUGIN_VAR_ENUM:
    return ((sysvar_enum_t *)plugin_var)->typelib;
  case PLUGIN_VAR_SET:
    return ((sysvar_set_t *)plugin_var)->typelib;
  case PLUGIN_VAR_ENUM | PLUGIN_VAR_SessionLOCAL:
    return ((sessionvar_enum_t *)plugin_var)->typelib;
  case PLUGIN_VAR_SET | PLUGIN_VAR_SessionLOCAL:
    return ((sessionvar_set_t *)plugin_var)->typelib;
  default:
    return NULL;
  }
  return NULL;
}


unsigned char* sys_var_pluginvar::value_ptr(Session *session, enum_var_type type, const LEX_STRING *)
{
  unsigned char* result;

  result= real_value_ptr(session, type);

  if ((plugin_var->flags & PLUGIN_VAR_TYPEMASK) == PLUGIN_VAR_ENUM)
    result= (unsigned char*) get_type(plugin_var_typelib(), *(ulong*)result);
  else if ((plugin_var->flags & PLUGIN_VAR_TYPEMASK) == PLUGIN_VAR_SET)
  {
    char buffer[STRING_BUFFER_USUAL_SIZE];
    String str(buffer, sizeof(buffer), system_charset_info);
    TYPELIB *typelib= plugin_var_typelib();
    uint64_t mask= 1, value= *(uint64_t*) result;
    uint32_t i;

    str.length(0);
    for (i= 0; i < typelib->count; i++, mask<<=1)
    {
      if (!(value & mask))
        continue;
      str.append(typelib->type_names[i], typelib->type_lengths[i]);
      str.append(',');
    }

    result= (unsigned char*) "";
    if (str.length())
      result= (unsigned char*) session->strmake(str.ptr(), str.length()-1);
  }
  return result;
}


bool sys_var_pluginvar::check(Session *session, set_var *var)
{
  st_item_value_holder value;
  assert(is_readonly() || plugin_var->check);

  value.value_type= item_value_type;
  value.val_str= item_val_str;
  value.val_int= item_val_int;
  value.val_real= item_val_real;
  value.item= var->value;

  return is_readonly() ||
         plugin_var->check(session, plugin_var, &var->save_result, &value);
}


void sys_var_pluginvar::set_default(Session *session, enum_var_type type)
{
  const void *src;
  void *tgt;

  assert(is_readonly() || plugin_var->update);

  if (is_readonly())
    return;

  pthread_mutex_lock(&LOCK_global_system_variables);
  tgt= real_value_ptr(session, type);
  src= ((void **) (plugin_var + 1) + 1);

  if (plugin_var->flags & PLUGIN_VAR_SessionLOCAL)
  {
    if (type != OPT_GLOBAL)
      src= real_value_ptr(session, OPT_GLOBAL);
    else
    switch (plugin_var->flags & PLUGIN_VAR_TYPEMASK) {
	case PLUGIN_VAR_INT:
	  src= &((sessionvar_uint_t*) plugin_var)->def_val;
	  break;
	case PLUGIN_VAR_LONG:
	  src= &((sessionvar_ulong_t*) plugin_var)->def_val;
	  break;
	case PLUGIN_VAR_LONGLONG:
	  src= &((sessionvar_uint64_t_t*) plugin_var)->def_val;
	  break;
	case PLUGIN_VAR_ENUM:
	  src= &((sessionvar_enum_t*) plugin_var)->def_val;
	  break;
	case PLUGIN_VAR_SET:
	  src= &((sessionvar_set_t*) plugin_var)->def_val;
	  break;
	case PLUGIN_VAR_BOOL:
	  src= &((sessionvar_bool_t*) plugin_var)->def_val;
	  break;
	case PLUGIN_VAR_STR:
	  src= &((sessionvar_str_t*) plugin_var)->def_val;
	  break;
	default:
	  assert(0);
	}
  }

  /* session must equal current_session if PLUGIN_VAR_SessionLOCAL flag is set */
  assert(!(plugin_var->flags & PLUGIN_VAR_SessionLOCAL) ||
              session == current_session);

  if (!(plugin_var->flags & PLUGIN_VAR_SessionLOCAL) || type == OPT_GLOBAL)
  {
    plugin_var->update(session, plugin_var, tgt, src);
    pthread_mutex_unlock(&LOCK_global_system_variables);
  }
  else
  {
    pthread_mutex_unlock(&LOCK_global_system_variables);
    plugin_var->update(session, plugin_var, tgt, src);
  }
}


bool sys_var_pluginvar::update(Session *session, set_var *var)
{
  void *tgt;

  assert(is_readonly() || plugin_var->update);

  /* session must equal current_session if PLUGIN_VAR_SessionLOCAL flag is set */
  assert(!(plugin_var->flags & PLUGIN_VAR_SessionLOCAL) ||
              session == current_session);

  if (is_readonly())
    return 1;

  pthread_mutex_lock(&LOCK_global_system_variables);
  tgt= real_value_ptr(session, var->type);

  if (!(plugin_var->flags & PLUGIN_VAR_SessionLOCAL) || var->type == OPT_GLOBAL)
  {
    /* variable we are updating has global scope, so we unlock after updating */
    plugin_var->update(session, plugin_var, tgt, &var->save_result);
    pthread_mutex_unlock(&LOCK_global_system_variables);
  }
  else
  {
    pthread_mutex_unlock(&LOCK_global_system_variables);
    plugin_var->update(session, plugin_var, tgt, &var->save_result);
  }
 return 0;
}


#define OPTION_SET_LIMITS(type, options, opt) \
  options->var_type= type;                    \
  options->def_value= (opt)->def_val;         \
  options->min_value= (opt)->min_val;         \
  options->max_value= (opt)->max_val;         \
  options->block_size= (long) (opt)->blk_sz


static void plugin_opt_set_limits(struct my_option *options,
                                  const struct st_mysql_sys_var *opt)
{
  options->sub_size= 0;

  switch (opt->flags & (PLUGIN_VAR_TYPEMASK |
                        PLUGIN_VAR_UNSIGNED | PLUGIN_VAR_SessionLOCAL)) {
  /* global system variables */
  case PLUGIN_VAR_INT:
    OPTION_SET_LIMITS(GET_INT, options, (sysvar_int_t*) opt);
    break;
  case PLUGIN_VAR_INT | PLUGIN_VAR_UNSIGNED:
    OPTION_SET_LIMITS(GET_UINT, options, (sysvar_uint_t*) opt);
    break;
  case PLUGIN_VAR_LONG:
    OPTION_SET_LIMITS(GET_LONG, options, (sysvar_long_t*) opt);
    break;
  case PLUGIN_VAR_LONG | PLUGIN_VAR_UNSIGNED:
    OPTION_SET_LIMITS(GET_ULONG_IS_FAIL, options, (sysvar_ulong_t*) opt);
    break;
  case PLUGIN_VAR_LONGLONG:
    OPTION_SET_LIMITS(GET_LL, options, (sysvar_int64_t_t*) opt);
    break;
  case PLUGIN_VAR_LONGLONG | PLUGIN_VAR_UNSIGNED:
    OPTION_SET_LIMITS(GET_ULL, options, (sysvar_uint64_t_t*) opt);
    break;
  case PLUGIN_VAR_ENUM:
    options->var_type= GET_ENUM;
    options->typelib= ((sysvar_enum_t*) opt)->typelib;
    options->def_value= ((sysvar_enum_t*) opt)->def_val;
    options->min_value= options->block_size= 0;
    options->max_value= options->typelib->count - 1;
    break;
  case PLUGIN_VAR_SET:
    options->var_type= GET_SET;
    options->typelib= ((sysvar_set_t*) opt)->typelib;
    options->def_value= ((sysvar_set_t*) opt)->def_val;
    options->min_value= options->block_size= 0;
    options->max_value= (1UL << options->typelib->count) - 1;
    break;
  case PLUGIN_VAR_BOOL:
    options->var_type= GET_BOOL;
    options->def_value= ((sysvar_bool_t*) opt)->def_val;
    break;
  case PLUGIN_VAR_STR:
    options->var_type= ((opt->flags & PLUGIN_VAR_MEMALLOC) ?
                        GET_STR_ALLOC : GET_STR);
    options->def_value= (intptr_t) ((sysvar_str_t*) opt)->def_val;
    break;
  /* threadlocal variables */
  case PLUGIN_VAR_INT | PLUGIN_VAR_SessionLOCAL:
    OPTION_SET_LIMITS(GET_INT, options, (sessionvar_int_t*) opt);
    break;
  case PLUGIN_VAR_INT | PLUGIN_VAR_UNSIGNED | PLUGIN_VAR_SessionLOCAL:
    OPTION_SET_LIMITS(GET_UINT, options, (sessionvar_uint_t*) opt);
    break;
  case PLUGIN_VAR_LONG | PLUGIN_VAR_SessionLOCAL:
    OPTION_SET_LIMITS(GET_LONG, options, (sessionvar_long_t*) opt);
    break;
  case PLUGIN_VAR_LONG | PLUGIN_VAR_UNSIGNED | PLUGIN_VAR_SessionLOCAL:
    OPTION_SET_LIMITS(GET_ULONG_IS_FAIL, options, (sessionvar_ulong_t*) opt);
    break;
  case PLUGIN_VAR_LONGLONG | PLUGIN_VAR_SessionLOCAL:
    OPTION_SET_LIMITS(GET_LL, options, (sessionvar_int64_t_t*) opt);
    break;
  case PLUGIN_VAR_LONGLONG | PLUGIN_VAR_UNSIGNED | PLUGIN_VAR_SessionLOCAL:
    OPTION_SET_LIMITS(GET_ULL, options, (sessionvar_uint64_t_t*) opt);
    break;
  case PLUGIN_VAR_ENUM | PLUGIN_VAR_SessionLOCAL:
    options->var_type= GET_ENUM;
    options->typelib= ((sessionvar_enum_t*) opt)->typelib;
    options->def_value= ((sessionvar_enum_t*) opt)->def_val;
    options->min_value= options->block_size= 0;
    options->max_value= options->typelib->count - 1;
    break;
  case PLUGIN_VAR_SET | PLUGIN_VAR_SessionLOCAL:
    options->var_type= GET_SET;
    options->typelib= ((sessionvar_set_t*) opt)->typelib;
    options->def_value= ((sessionvar_set_t*) opt)->def_val;
    options->min_value= options->block_size= 0;
    options->max_value= (1UL << options->typelib->count) - 1;
    break;
  case PLUGIN_VAR_BOOL | PLUGIN_VAR_SessionLOCAL:
    options->var_type= GET_BOOL;
    options->def_value= ((sessionvar_bool_t*) opt)->def_val;
    break;
  case PLUGIN_VAR_STR | PLUGIN_VAR_SessionLOCAL:
    options->var_type= ((opt->flags & PLUGIN_VAR_MEMALLOC) ?
                        GET_STR_ALLOC : GET_STR);
    options->def_value= (intptr_t) ((sessionvar_str_t*) opt)->def_val;
    break;
  default:
    assert(0);
  }
  options->arg_type= REQUIRED_ARG;
  if (opt->flags & PLUGIN_VAR_NOCMDARG)
    options->arg_type= NO_ARG;
  if (opt->flags & PLUGIN_VAR_OPCMDARG)
    options->arg_type= OPT_ARG;
}

extern "C" bool get_one_plugin_option(int optid, const struct my_option *,
                                         char *);

bool get_one_plugin_option(int, const struct my_option *, char *)
{
  return 0;
}


static int construct_options(MEM_ROOT *mem_root, plugin::Handle *tmp,
                             my_option *options, bool can_disable)
{
  const char *plugin_name= tmp->getManifest().name;
  uint32_t namelen= strlen(plugin_name), optnamelen;
  uint32_t buffer_length= namelen * 4 + (can_disable ? 75 : 10);
  char *name= (char*) alloc_root(mem_root, buffer_length) + 1;
  char *optname, *p;
  int index= 0, offset= 0;
  st_mysql_sys_var *opt, **plugin_option;
  st_bookmark *v;

  /* support --skip-plugin-foo syntax */
  memcpy(name, plugin_name, namelen + 1);
  my_casedn_str(&my_charset_utf8_general_ci, name);
  sprintf(name+namelen+1, "plugin-%s", name);
  /* Now we have namelen + 1 + 7 + namelen + 1 == namelen * 2 + 9. */

  for (p= name + namelen*2 + 8; p > name; p--)
    if (*p == '_')
      *p= '-';

  if (can_disable)
  {
    sprintf(name+namelen*2+10,
            "Enable %s plugin. Disable with --skip-%s (will save memory).",
            plugin_name, name);
    /*
      Now we have namelen * 2 + 10 (one char unused) + 7 + namelen + 9 +
      20 + namelen + 20 + 1 == namelen * 4 + 67.
    */

    options[0].comment= name + namelen*2 + 10;
  }

  options[1].name= (options[0].name= name) + namelen + 1;
  options[0].id= options[1].id= 256; /* must be >255. dup id ok */
  options[0].var_type= options[1].var_type= GET_BOOL;
  options[0].arg_type= options[1].arg_type= NO_ARG;
  options[0].def_value= options[1].def_value= true;
  options[0].value= options[0].u_max_value=
  options[1].value= options[1].u_max_value= (char**) (name - 1);
  options+= 2;

  /*
    Two passes as the 2nd pass will take pointer addresses for use
    by my_getopt and register_var() in the first pass uses realloc
  */

  for (plugin_option= tmp->getManifest().system_vars;
       plugin_option && *plugin_option; plugin_option++, index++)
  {
    opt= *plugin_option;
    if (!(opt->flags & PLUGIN_VAR_SessionLOCAL))
      continue;
    if (!(register_var(name, opt->name, opt->flags)))
      continue;
    switch (opt->flags & PLUGIN_VAR_TYPEMASK) {
    case PLUGIN_VAR_BOOL:
      (((sessionvar_bool_t *)opt)->resolve)= mysql_sys_var_ptr_bool;
      break;
    case PLUGIN_VAR_INT:
      (((sessionvar_int_t *)opt)->resolve)= mysql_sys_var_ptr_int;
      break;
    case PLUGIN_VAR_LONG:
      (((sessionvar_long_t *)opt)->resolve)= mysql_sys_var_ptr_long;
      break;
    case PLUGIN_VAR_LONGLONG:
      (((sessionvar_int64_t_t *)opt)->resolve)= mysql_sys_var_ptr_int64_t;
      break;
    case PLUGIN_VAR_STR:
      (((sessionvar_str_t *)opt)->resolve)= mysql_sys_var_ptr_str;
      break;
    case PLUGIN_VAR_ENUM:
      (((sessionvar_enum_t *)opt)->resolve)= mysql_sys_var_ptr_enum;
      break;
    case PLUGIN_VAR_SET:
      (((sessionvar_set_t *)opt)->resolve)= mysql_sys_var_ptr_set;
      break;
    default:
      errmsg_printf(ERRMSG_LVL_ERROR, _("Unknown variable type code 0x%x in plugin '%s'."),
                      opt->flags, plugin_name);
      return(-1);
    };
  }

  for (plugin_option= tmp->getManifest().system_vars;
       plugin_option && *plugin_option; plugin_option++, index++)
  {
    switch ((opt= *plugin_option)->flags & PLUGIN_VAR_TYPEMASK) {
    case PLUGIN_VAR_BOOL:
      if (!opt->check)
        opt->check= check_func_bool;
      if (!opt->update)
        opt->update= update_func_bool;
      break;
    case PLUGIN_VAR_INT:
      if (!opt->check)
        opt->check= check_func_int;
      if (!opt->update)
        opt->update= update_func_int;
      break;
    case PLUGIN_VAR_LONG:
      if (!opt->check)
        opt->check= check_func_long;
      if (!opt->update)
        opt->update= update_func_long;
      break;
    case PLUGIN_VAR_LONGLONG:
      if (!opt->check)
        opt->check= check_func_int64_t;
      if (!opt->update)
        opt->update= update_func_int64_t;
      break;
    case PLUGIN_VAR_STR:
      if (!opt->check)
        opt->check= check_func_str;
      if (!opt->update)
      {
        opt->update= update_func_str;
        if ((opt->flags & (PLUGIN_VAR_MEMALLOC | PLUGIN_VAR_READONLY)) == false)
        {
          opt->flags|= PLUGIN_VAR_READONLY;
          errmsg_printf(ERRMSG_LVL_WARN, _("Server variable %s of plugin %s was forced "
                            "to be read-only: string variable without "
                            "update_func and PLUGIN_VAR_MEMALLOC flag"),
                            opt->name, plugin_name);
        }
      }
      break;
    case PLUGIN_VAR_ENUM:
      if (!opt->check)
        opt->check= check_func_enum;
      if (!opt->update)
        opt->update= update_func_long;
      break;
    case PLUGIN_VAR_SET:
      if (!opt->check)
        opt->check= check_func_set;
      if (!opt->update)
        opt->update= update_func_int64_t;
      break;
    default:
      errmsg_printf(ERRMSG_LVL_ERROR, _("Unknown variable type code 0x%x in plugin '%s'."),
                      opt->flags, plugin_name);
      return(-1);
    }

    if ((opt->flags & (PLUGIN_VAR_NOCMDOPT | PLUGIN_VAR_SessionLOCAL))
                    == PLUGIN_VAR_NOCMDOPT)
      continue;

    if (!opt->name)
    {
      errmsg_printf(ERRMSG_LVL_ERROR, _("Missing variable name in plugin '%s'."),
                      plugin_name);
      return(-1);
    }

    if (!(opt->flags & PLUGIN_VAR_SessionLOCAL))
    {
      optnamelen= strlen(opt->name);
      optname= (char*) alloc_root(mem_root, namelen + optnamelen + 2);
      sprintf(optname, "%s-%s", name, opt->name);
      optnamelen= namelen + optnamelen + 1;
    }
    else
    {
      /* this should not fail because register_var should create entry */
      if (!(v= find_bookmark(name, opt->name, opt->flags)))
      {
        errmsg_printf(ERRMSG_LVL_ERROR, _("Thread local variable '%s' not allocated "
                        "in plugin '%s'."), opt->name, plugin_name);
        return(-1);
      }

      *(int*)(opt + 1)= offset= v->offset;

      if (opt->flags & PLUGIN_VAR_NOCMDOPT)
        continue;

      optname= (char*) memdup_root(mem_root, v->key + 1,
                                   (optnamelen= v->name_len) + 1);
    }

    /* convert '_' to '-' */
    for (p= optname; *p; p++)
      if (*p == '_')
        *p= '-';

    options->name= optname;
    options->comment= opt->comment;
    options->app_type= opt;
    options->id= (options-1)->id + 1;

    plugin_opt_set_limits(options, opt);

    if (opt->flags & PLUGIN_VAR_SessionLOCAL)
      options->value= options->u_max_value= (char**)
        (global_system_variables.dynamic_variables_ptr + offset);
    else
      options->value= options->u_max_value= *(char***) (opt + 1);

    options[1]= options[0];
    options[1].name= p= (char*) alloc_root(mem_root, optnamelen + 8);
    options[1].comment= 0; // hidden
    sprintf(p,"plugin-%s",optname);

    options+= 2;
  }

  return(0);
}


static my_option *construct_help_options(MEM_ROOT *mem_root, plugin::Handle *p)
{
  st_mysql_sys_var **opt;
  my_option *opts;
  bool can_disable;
  uint32_t count= EXTRA_OPTIONS;

  for (opt= p->getManifest().system_vars; opt && *opt; opt++, count+= 2) {};

  opts= (my_option*)alloc_root(mem_root, (sizeof(my_option) * count));
  if (opts == NULL)
    return NULL;

  memset(opts, 0, sizeof(my_option) * count);

  if ((my_strcasecmp(&my_charset_utf8_general_ci, p->getName().c_str(), "MyISAM") == 0))
    can_disable= false;
  else if ((my_strcasecmp(&my_charset_utf8_general_ci, p->getName().c_str(), "MEMORY") == 0))
    can_disable= false;
  else
    can_disable= true;


  if (construct_options(mem_root, p, opts, can_disable))
    return NULL;

  return(opts);
}


/*
  SYNOPSIS
    test_plugin_options()
    tmp_root                    temporary scratch space
    plugin                      internal plugin structure
    argc                        user supplied arguments
    argv                        user supplied arguments
    default_enabled             default plugin enable status
  RETURNS:
    0 SUCCESS - plugin should be enabled/loaded
  NOTE:
    Requires that a write-lock is held on LOCK_system_variables_hash
*/
static int test_plugin_options(MEM_ROOT *tmp_root, plugin::Handle *tmp,
                               int *argc, char **argv)
{
  struct sys_var_chain chain= { NULL, NULL };
  bool can_disable;
  MEM_ROOT *mem_root= alloc_root_inited(&tmp->mem_root) ?
                      &tmp->mem_root : &plugin_mem_root;
  st_mysql_sys_var **opt;
  my_option *opts= NULL;
  char *p, *varname;
  int error;
  st_mysql_sys_var *o;
  sys_var *v;
  struct st_bookmark *var;
  uint32_t len, count= EXTRA_OPTIONS;

  for (opt= tmp->getManifest().system_vars; opt && *opt; opt++)
    count+= 2; /* --{plugin}-{optname} and --plugin-{plugin}-{optname} */

  if ((my_strcasecmp(&my_charset_utf8_general_ci, tmp->getName().c_str(), "MyISAM") == 0))
    can_disable= false;
  else if ((my_strcasecmp(&my_charset_utf8_general_ci, tmp->getName().c_str(), "MEMORY") == 0))
    can_disable= false;
  else
    can_disable= true;

  if (count > EXTRA_OPTIONS || (*argc > 1))
  {
    if (!(opts= (my_option*) alloc_root(tmp_root, sizeof(my_option) * count)))
    {
      errmsg_printf(ERRMSG_LVL_ERROR, _("Out of memory for plugin '%s'."), tmp->getName().c_str());
      return(-1);
    }
    memset(opts, 0, sizeof(my_option) * count);

    if (construct_options(tmp_root, tmp, opts, can_disable))
    {
      errmsg_printf(ERRMSG_LVL_ERROR, _("Bad options for plugin '%s'."), tmp->getName().c_str());
      return(-1);
    }

    error= handle_options(argc, &argv, opts, get_one_plugin_option);
    (*argc)++; /* add back one for the program name */

    if (error)
    {
       errmsg_printf(ERRMSG_LVL_ERROR, _("Parsing options for plugin '%s' failed."),
                       tmp->getName().c_str());
       goto err;
    }
  }

  error= 1;

  {
    for (opt= tmp->getManifest().system_vars; opt && *opt; opt++)
    {
      if (((o= *opt)->flags & PLUGIN_VAR_NOSYSVAR))
        continue;

      if ((var= find_bookmark(tmp->getName().c_str(), o->name, o->flags)))
        v= new (mem_root) sys_var_pluginvar(var->key + 1, o);
      else
      {
        len= tmp->getName().length() + strlen(o->name) + 2;
        varname= (char*) alloc_root(mem_root, len);
        sprintf(varname,"%s-%s",tmp->getName().c_str(),o->name);
        my_casedn_str(&my_charset_utf8_general_ci, varname);

        for (p= varname; *p; p++)
          if (*p == '-')
            *p= '_';

        v= new (mem_root) sys_var_pluginvar(varname, o);
      }
      assert(v); /* check that an object was actually constructed */

      /*
        Add to the chain of variables.
        Done like this for easier debugging so that the
        pointer to v is not lost on optimized builds.
      */
      v->chain_sys_var(&chain);
    }
    if (chain.first)
    {
      chain.last->setNext(NULL);
      if (mysql_add_sys_var_chain(chain.first, NULL))
      {
        errmsg_printf(ERRMSG_LVL_ERROR, _("Plugin '%s' has conflicting system variables"),
                        tmp->getName().c_str());
        goto err;
      }
      tmp->system_vars= chain.first;
    }
    return(0);
  }

err:
  if (opts)
    my_cleanup_options(opts);
  return(error);
}


/****************************************************************************
  Help Verbose text with Plugin System Variables
****************************************************************************/

class OptionCmp
{
public:
  bool operator() (const my_option &a, const my_option &b)
  {
    return my_strcasecmp(&my_charset_utf8_general_ci, a.name, b.name);
  }
};


void my_print_help_inc_plugins(my_option *main_options)
{
  vector<my_option> all_options;
  plugin::Handle *p;
  MEM_ROOT mem_root;
  my_option *opt= NULL;

  init_alloc_root(&mem_root, 4096, 4096);

  if (initialized)
    for (uint32_t idx= 0; idx < plugin_array.elements; idx++)
    {
      p= *dynamic_element(&plugin_array, idx, plugin::Handle **);

      if (p->getManifest().system_vars == NULL)
        continue;

      opt= construct_help_options(&mem_root, p);
      if (opt == NULL)
        continue;

      /* Only options with a non-NULL comment are displayed in help text */
      for (;opt->id; opt++)
      {
        if (opt->comment)
        {
          all_options.push_back(*opt);
          
        }
      }
    }

  for (;main_options->id; main_options++)
  {
    if (main_options->comment)
    {
      all_options.push_back(*main_options);
    }
  }

  /** 
   * @TODO: Fix the my_option building so that it doens't break sort
   *
   * sort(all_options.begin(), all_options.end(), OptionCmp());
   */

  /* main_options now points to the empty option terminator */
  all_options.push_back(*main_options);

  my_print_help(&*(all_options.begin()));
  my_print_variables(&*(all_options.begin()));

  free_root(&mem_root, MYF(0));

}