/* Copyright (C) 2000 MySQL AB & MySQL Finland AB & TCX DataKonsult 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; either version 2 of the License, or
   (at your option) any later version.
   
   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 */

/* Check that heap-structure is ok */

#include "heapdef.h"

static int check_one_key(HP_KEYDEF *keydef,ulong records,ulong blength);

/* Returns 0 if the HEAP is ok */

int heap_check_heap(HP_INFO *info)
{
  int error;
  uint key;
  HP_SHARE *share=info->s;
  DBUG_ENTER("heap_check_keys");

  for (error=key=0 ; key < share->keys ; key++)
    error|=check_one_key(share->keydef+key,share->records,share->blength);

  DBUG_RETURN(error);
}


static int check_one_key(HP_KEYDEF *keydef, ulong records, ulong blength)
{
  int error;
  uint i,found,max_links,seek,links;
  uint rec_link;				/* Only used with debugging */
  HASH_INFO *hash_info;

  error=0;
  for (i=found=max_links=seek=0 ; i < records ; i++)
  {
    hash_info=hp_find_hash(&keydef->block,i);
    if (_hp_mask(_hp_rec_hashnr(keydef,hash_info->ptr_to_rec),
		 blength,records) == i)
    {
      found++;
      seek++;
      links=1;
      while ((hash_info=hash_info->next_key) && found < records + 1)
      {
	seek+= ++links;
	if ((rec_link=_hp_mask(_hp_rec_hashnr(keydef,hash_info->ptr_to_rec),
			       blength,records))
	    != i)
	{
	  DBUG_PRINT("error",("Record in wrong link: Link %d  Record: %lx  Record-link %d", i,hash_info->ptr_to_rec,rec_link));
	  error=1;
	}
	else
	  found++;
      }
      if (links > max_links) max_links=links;
    }
  }
  if (found != records)
  {
    DBUG_PRINT("error",("Found %ld of %ld records"));
    error=1;
  }
  DBUG_PRINT("info",
	     ("records: %ld   seeks: %d   max links: %d   hitrate: %.2f",
	      records,seek,max_links,(float) seek / (float) records));
  return error;
}