/*
   Copyright (c) 2005, 2013, Oracle and/or its affiliates. All rights reserved.

   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, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA
*/

#ifndef __NDB_TUP_PAGE_HPP
#define __NDB_TUP_PAGE_HPP

#include <ndb_types.h>
#include "../diskpage.hpp"

#define JAM_FILE_ID 419


struct Tup_page 
{
  Tup_page() {}
  struct File_formats::Page_header m_page_header;
  Uint32 m_restart_seq;
  Uint32 page_state;
  union {
    Uint32 next_page;
    Uint32 nextList;
  };
  union {
    Uint32 prev_page;
    Uint32 prevList;
  };
  Uint32 first_cluster_page;
  Uint32 last_cluster_page;
  Uint32 next_cluster_page;
  Uint32 prev_cluster_page;
  Uint32 frag_page_id;
  Uint32 physical_page_id;
  Uint32 free_space;
  Uint32 next_free_index;
  Uint32 list_index; // free space in page bits/list, 0x8000 means not in free
  Uint32 uncommitted_used_space;
  Uint32 m_page_no;
  Uint32 m_file_no;
  Uint32 m_table_id;
  Uint32 m_fragment_id;
  Uint32 m_extent_no;
  Uint32 m_extent_info_ptr;
  Uint32 unused_ph[9];

  STATIC_CONST( DATA_WORDS = File_formats::NDB_PAGE_SIZE_WORDS - 32 );
  
  Uint32 m_data[DATA_WORDS];
};

struct Tup_fixsize_page
{
  struct File_formats::Page_header m_page_header;
  Uint32 m_restart_seq;
  Uint32 page_state;
  union {
    Uint32 next_page;
    Uint32 nextList;
  };
  union {
    Uint32 prev_page;
    Uint32 prevList;
  };
  Uint32 first_cluster_page;
  Uint32 last_cluster_page;
  Uint32 next_cluster_page;
  Uint32 prev_cluster_page;
  Uint32 frag_page_id;
  Uint32 physical_page_id;
  Uint32 free_space;
  Uint32 next_free_index;
  Uint32 list_index;
  Uint32 uncommitted_used_space;
  Uint32 m_page_no;
  Uint32 m_file_no;
  Uint32 m_table_id;
  Uint32 m_fragment_id;
  Uint32 m_extent_no;
  Uint32 m_extent_info_ptr;
  Uint32 unused_ph[9];

  STATIC_CONST( FREE_RECORD = ~(Uint32)0 );
  STATIC_CONST( DATA_WORDS = File_formats::NDB_PAGE_SIZE_WORDS - 32 );
  
  Uint32 m_data[DATA_WORDS];
  
  Uint32* get_ptr(Uint32 page_idx, Uint32 rec_size){
    assert(page_idx + rec_size <= DATA_WORDS);
    return m_data + page_idx;
  }
  
  /**
   * Alloc record from page
   *   return page_idx
   **/
  Tup_fixsize_page() {}
  Uint32 alloc_record();
  Uint32 alloc_record(Uint32 page_idx);
  Uint32 free_record(Uint32 page_idx);
};

struct Tup_varsize_page
{
  struct File_formats::Page_header m_page_header;
  Uint32 m_restart_seq;
  Uint32 page_state;
  union {
    Uint32 next_page;
    Uint32 nextList;
  };
  union {
    Uint32 prev_page;
    Uint32 prevList;
  };
  Uint32 first_cluster_page;
  Uint32 last_cluster_page;
  Uint32 next_cluster_page;
  Uint32 prev_cluster_page;
  Uint32 frag_page_id;
  Uint32 physical_page_id;
  Uint32 free_space;
  Uint32 next_free_index;
  Uint32 list_index;
  Uint32 uncommitted_used_space;
  Uint32 m_page_no;
  Uint32 m_file_no;
  Uint32 m_table_id;
  Uint32 m_fragment_id;
  Uint32 m_extent_no;
  Uint32 m_extent_info_ptr;
  Uint32 high_index; // size of index + 1
  Uint32 insert_pos;
  Uint32 unused_ph[7];
  
  STATIC_CONST( DATA_WORDS = File_formats::NDB_PAGE_SIZE_WORDS - 32 );
  STATIC_CONST( CHAIN    = 0x80000000 );
  STATIC_CONST( FREE     = 0x40000000 );
  STATIC_CONST( LEN_MASK = 0x3FFF8000 );
  STATIC_CONST( POS_MASK = 0x00007FFF );
  STATIC_CONST( LEN_SHIFT = 15 );
  STATIC_CONST( POS_SHIFT = 0  );
  STATIC_CONST( END_OF_FREE_LIST = POS_MASK );

  STATIC_CONST( NEXT_MASK = POS_MASK );
  STATIC_CONST( NEXT_SHIFT = POS_SHIFT );
  STATIC_CONST( PREV_MASK = LEN_MASK );
  STATIC_CONST( PREV_SHIFT = LEN_SHIFT );
  
  Uint32 m_data[DATA_WORDS];
  
  Tup_varsize_page() {}
  void init();
  
  Uint32* get_free_space_ptr() { 
    return m_data+insert_pos; 
  }
  
  Uint32 largest_frag_size() const { 
    return DATA_WORDS - (high_index + insert_pos); 
  }
  
  Uint32 *get_index_ptr(Uint32 page_idx) {
    assert(page_idx < high_index);
    return (m_data + (DATA_WORDS - page_idx));
  }
  
  Uint32 get_index_word(Uint32 page_idx) const {
    assert(page_idx < high_index);
    return * (m_data + (DATA_WORDS - page_idx));
  }

  /**
   * Alloc record from page, return page_idx
   *   temp is used when having to reorg page before allocating
   */
  Uint32 alloc_record(Uint32 size, Tup_varsize_page* temp, Uint32 chain);

  /**
   * Alloc page_idx from page, return page_idx
   *   temp is used when having to reorg page before allocating
   */
  Uint32 alloc_record(Uint32 page_idx, Uint32 size, Tup_varsize_page* temp);
  
  /**
   * Free record from page
   */
  Uint32 free_record(Uint32 page_idx, Uint32 chain);

  void reorg(Tup_varsize_page* temp);
  void rebuild_index(Uint32* ptr);
  
  /**
   * Check if one can grow tuple wo/ reorg
   */
  bool is_space_behind_entry(Uint32 page_index, Uint32 growth_len) const {
    Uint32 idx= get_index_word(page_index); 
    Uint32 pos= (idx & POS_MASK) >> POS_SHIFT;
    Uint32 len= (idx & LEN_MASK) >> LEN_SHIFT;
    if ((pos + len == insert_pos) && 
	(insert_pos + growth_len < DATA_WORDS - high_index))
      return true;
    return false;
  }
  
  void grow_entry(Uint32 page_index, Uint32 growth_len) {
    assert(free_space >= growth_len);

    Uint32 *pos= get_index_ptr(page_index);
    Uint32 idx= *pos;
    assert(! (idx & FREE));
    assert((((idx & POS_MASK) >> POS_SHIFT) + ((idx & LEN_MASK) >> LEN_SHIFT))
	   == insert_pos);
    
    * pos= idx + (growth_len << LEN_SHIFT);
    insert_pos+= growth_len;
    free_space-= growth_len;
  }
  
  void shrink_entry(Uint32 page_index, Uint32 new_size){
    Uint32 *pos= get_index_ptr(page_index);
    Uint32 idx= *pos;
    Uint32 old_pos = (idx & POS_MASK) >> POS_SHIFT;
    Uint32 old_size = (idx & LEN_MASK) >> LEN_SHIFT;

    assert( ! (idx & FREE));
    assert(old_size >= new_size);

    * pos= (idx & ~LEN_MASK) + (new_size << LEN_SHIFT);
    Uint32 shrink = old_size - new_size;
#ifdef VM_TRACE
    memset(m_data + old_pos + new_size, 0xF1, 4 * shrink);
#endif
    free_space+= shrink;
    if(insert_pos == (old_pos + old_size))
      insert_pos -= shrink;
  }
  
  Uint32* get_ptr(Uint32 page_idx) {
    return m_data + ((get_index_word(page_idx) & POS_MASK) >> POS_SHIFT);
  }
  
  void set_entry_offset(Uint32 page_idx, Uint32 offset){
    Uint32 *pos= get_index_ptr(page_idx);
    * pos = (* pos & ~POS_MASK) + (offset << POS_SHIFT);
  }
  
  void set_entry_len(Uint32 page_idx, Uint32 len) {
    Uint32 *pos= get_index_ptr(page_idx);
    * pos = (*pos & ~LEN_MASK) + (len << LEN_SHIFT);
  }

  Uint32 get_entry_len(Uint32 page_idx) const {
    return (get_index_word(page_idx) & LEN_MASK) >> LEN_SHIFT;
  }
  
  Uint32 get_entry_chain(Uint32 page_idx) const {
    return get_index_word(page_idx) & CHAIN;
  }

  bool is_free(Uint32 page_idx) const
  {
    return ((get_index_word(page_idx) & FREE) != 0) ? true : false;
  }

  bool is_empty() const
  {
    return high_index == 1;
  }
};

NdbOut& operator<< (NdbOut& out, const Tup_varsize_page& page);
NdbOut& operator<< (NdbOut& out, const Tup_fixsize_page& page);


#undef JAM_FILE_ID

#endif
