/*****************************************************************************

Copyright (c) 2016, 2018, 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 lob0util_h
#define lob0util_h

#include <stdint.h>

#include "buf0buf.h"
#include "fil0fil.h"
#include "fut0lst.h"

namespace lob {

/** Number of times an LOB can be partially updated.  Once this limit is
reached, then the LOB will be fully updated. */
const uint32_t MAX_PARTIAL_UPDATE_LIMIT = 1000;

struct basic_page_t {
  basic_page_t() : m_block(nullptr), m_mtr(nullptr), m_index(nullptr) {}

  basic_page_t(buf_block_t *block, mtr_t *mtr)
      : m_block(block), m_mtr(mtr), m_index(nullptr) {}

  basic_page_t(buf_block_t *block, mtr_t *mtr, dict_index_t *index)
      : m_block(block), m_mtr(mtr), m_index(index) {}

  /** Update the space identifier to given value without generating
  any redo log records.
  @param[in]	space_id	the space identifier. */
  void set_space_id_no_redo(space_id_t space_id) {
    mach_write_to_4(frame() + FIL_PAGE_SPACE_ID, space_id);
  }

  /** Get page number of the current page.
  @return the page number of the current page. */
  page_no_t get_page_no() const {
    ut_ad(m_block != nullptr);
    return (m_block->page.id.page_no());
  }

  /** Get the page id of the current page.
  @return the page id of current page. */
  page_id_t get_page_id() const {
    ut_ad(m_block != nullptr);
    return (m_block->page.id);
  }

  void set_next_page(page_no_t page_no) {
    mlog_write_ulint(frame() + FIL_PAGE_NEXT, page_no, MLOG_4BYTES, m_mtr);
  }

  void set_next_page_null() {
    ut_ad(m_mtr != nullptr);

    mlog_write_ulint(frame() + FIL_PAGE_NEXT, FIL_NULL, MLOG_4BYTES, m_mtr);
  }

  page_no_t get_next_page() {
    return (mach_read_from_4(frame() + FIL_PAGE_NEXT));
  }

  page_type_t get_page_type() const {
    return (mach_read_from_2(frame() + FIL_PAGE_TYPE));
  }

  byte *frame() const { return (buf_block_get_frame(m_block)); }

  flst_node_t *get_flst_node(const fil_addr_t &addr) {
    ut_ad(!addr.is_null());

    flst_node_t *node = nullptr;
    if (addr.page == get_page_no()) {
      node = frame() + addr.boffset;
    }
    return (node);
  }

  static ulint payload();
  ulint max_space_available();

  void set_block(buf_block_t *block) {
    ut_ad(mtr_memo_contains(m_mtr, block, MTR_MEMO_PAGE_X_FIX) ||
          mtr_memo_contains(m_mtr, block, MTR_MEMO_PAGE_S_FIX));

    m_block = block;
  }

 protected:
  buf_block_t *m_block;
  mtr_t *m_mtr;
  dict_index_t *m_index;
};

/** Allocate one LOB page.
@param[in]	index	the index in which LOB exists.
@param[in]	lob_mtr	the mini-transaction context.
@param[in]	hint	the hint page number for allocation.
@param[in]	bulk	true if operation is OPCODE_INSERT_BULK,
                        false otherwise.
@return the allocated block of the BLOB page. */
buf_block_t *alloc_lob_page(dict_index_t *index, mtr_t *lob_mtr, page_no_t hint,
                            bool bulk);

/** Check if the index entry is visible to the given transaction.
@param[in]	index		the index to which LOB belongs.
@param[in]	trx		the transaction reading the index entry.
@param[in]	entry_trx_id	the trx id in the index entry. */
bool entry_visible_to(dict_index_t *index, trx_t *trx, trx_id_t entry_trx_id);

} /* namespace lob */

#endif /* lob0util_h */