/* Copyright (c) 2002, 2023, Oracle and/or its affiliates.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License, version 2.0,
   as published by the Free Software Foundation.

   This program is also distributed with certain software (including
   but not limited to OpenSSL) that is licensed under separate terms,
   as designated in a particular file or component or in included license
   documentation.  The authors of MySQL hereby grant you an additional
   permission to link the program and your derivative works with the
   separately licensed software that they have included with MySQL.

   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, version 2.0, 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,
   51 Franklin Street, Suite 500, Boston, MA 02110-1335 USA */

#include "keycaches.h"
/* key_memory_KEY_CACHE */
#include "../mysys/mysys_priv.h"

/****************************************************************************
  Named list handling
****************************************************************************/

NAMED_ILIST key_caches;

uchar* find_named(I_List<NAMED_ILINK> *list, const char *name, size_t length,
                NAMED_ILINK **found)
{
  I_List_iterator<NAMED_ILINK> it(*list);
  NAMED_ILINK *element;
  while ((element= it++))
  {
    if (element->cmp(name, length))
    {
      if (found)
        *found= element;
      return element->data;
    }
  }
  return 0;
}


void NAMED_ILIST::delete_elements(void (*free_element)(const char *name, uchar*))
{
  NAMED_ILINK *element;
  DBUG_ENTER("NAMED_ILIST::delete_elements");
  while ((element= get()))
  {
    (*free_element)(element->name, element->data);
    delete element;
  }
  DBUG_VOID_RETURN;
}


/* Key cache functions */

LEX_STRING default_key_cache_base= {C_STRING_WITH_LEN("default")};

KEY_CACHE zero_key_cache; ///< @@nonexistent_cache.param->value_ptr() points here

KEY_CACHE *get_key_cache(LEX_STRING *cache_name)
{
  if (!cache_name || ! cache_name->length)
    cache_name= &default_key_cache_base;
  return ((KEY_CACHE*) find_named(&key_caches,
                                  cache_name->str, cache_name->length, 0));
}

KEY_CACHE *create_key_cache(const char *name, size_t length)
{
  KEY_CACHE *key_cache;
  DBUG_ENTER("create_key_cache");
  DBUG_PRINT("enter",("name: %.*s", static_cast<int>(length), name));
  
  if ((key_cache= (KEY_CACHE*) my_malloc(key_memory_KEY_CACHE,
                                         sizeof(KEY_CACHE),
                                             MYF(MY_ZEROFILL | MY_WME))))
  {
    if (!new NAMED_ILINK(&key_caches, name, length, (uchar*) key_cache))
    {
      my_free(key_cache);
      key_cache= 0;
    }
    else
    {
      /*
        Set default values for a key cache
        The values in dflt_key_cache_var is set by my_getopt() at startup

        We don't set 'buff_size' as this is used to enable the key cache
      */
      key_cache->param_block_size=     dflt_key_cache_var.param_block_size;
      key_cache->param_division_limit= dflt_key_cache_var.param_division_limit;
      key_cache->param_age_threshold=  dflt_key_cache_var.param_age_threshold;
    }
  }
  DBUG_RETURN(key_cache);
}


KEY_CACHE *get_or_create_key_cache(const char *name, size_t length)
{
  LEX_STRING key_cache_name;
  KEY_CACHE *key_cache;

  key_cache_name.str= (char *) name;
  key_cache_name.length= length;
  if (!(key_cache= get_key_cache(&key_cache_name)))
    key_cache= create_key_cache(name, length);
  return key_cache;
}


void free_key_cache(const char *name, KEY_CACHE *key_cache)
{
  end_key_cache(key_cache, 1);		// Can never fail
  my_free(key_cache);
}


bool process_key_caches(process_key_cache_t func)
{
  I_List_iterator<NAMED_ILINK> it(key_caches);
  NAMED_ILINK *element;

  while ((element= it++))
  {
    KEY_CACHE *key_cache= (KEY_CACHE *) element->data;
    func(element->name, key_cache);
  }
  return 0;
}