polardbxengine/storage/innobase/lob/zlob0first.cc

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

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.

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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.,
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*****************************************************************************/

#include "zlob0first.h"
#include "trx0trx.h"
#include "zlob0index.h"
#include "zlob0read.h"

namespace lob {

/** Given the page size, what is the number of index entries the first page
can contain. */
ulint z_first_page_t::get_n_index_entries() const {
  ut_ad(m_index != nullptr);

  const page_size_t page_size(dict_table_page_size(m_index->table));

  ulint len = page_size.physical();
  switch (len) {
    case KB16:
      /* For a page size of 16KB, there are 100 index entries in
      the first page of the zlob. */
      return (100);
    case 8192:
      /* 8KB. */
      return (80);
    case 4096:
      /* 4KB. */
      return (40);
    case 2048:
      return (20);
    case 1024:
      return (5);
    default:
      ut_error;
  }
}

/** Given the page size, what is the number of frag entries the first page
can contain. */
ulint z_first_page_t::get_n_frag_entries() const {
  ut_ad(m_index != nullptr);

  DBUG_EXECUTE_IF("innodb_zlob_first_use_only_1_frag_entries", return (1););

  const page_size_t page_size(dict_table_page_size(m_index->table));
  ulint len = page_size.physical();
  switch (len) {
    case KB16:
      /* For a page size of 16KB, there are 200 frag entries in
      the first page of the zlob. */
      return (200);
    case 8192:
      return (100);
    case 4096:
      return (40);
    case 2048:
      return (20);
    case 1024:
      return (5);
    default:
      ut_error;
  }
}

buf_block_t *z_first_page_t::alloc(bool bulk) {
  ut_ad(m_block == nullptr);

  page_no_t hint = FIL_NULL;
  m_block = alloc_lob_page(m_index, m_mtr, hint, bulk);

  if (m_block == nullptr) {
    return (nullptr);
  }

  init();

  ut_ad(m_block->get_page_type() == FIL_PAGE_TYPE_ZLOB_FIRST);
  return (m_block);
}

/** Print the index entries. */
std::ostream &z_first_page_t::print_index_entries(std::ostream &out) const {
  flst_base_node_t *flst = index_list();
  fil_addr_t node_loc = flst_get_first(flst, m_mtr);

  space_id_t space = dict_index_get_space(m_index);
  const page_size_t page_size = dict_table_page_size(m_index->table);

  out << "Index Entries: " << flst_bnode_t(flst, m_mtr) << std::endl;

  while (!fil_addr_is_null(node_loc)) {
    flst_node_t *node =
        fut_get_ptr(space, page_size, node_loc, RW_X_LATCH, m_mtr);
    z_index_entry_t entry(node, m_mtr, m_index);
    out << entry << std::endl;

    flst_base_node_t *vers = entry.get_versions_list();
    fil_addr_t ver_loc = flst_get_first(vers, m_mtr);

    uint32_t depth = 0;
    while (!fil_addr_is_null(ver_loc)) {
      depth++;

      for (uint32_t i = 0; i < depth; ++i) {
        out << "+";
      }
      flst_node_t *ver_node = addr2ptr_x(ver_loc);
      z_index_entry_t vers_entry(ver_node, m_mtr, m_index);
      out << vers_entry << std::endl;
      ver_loc = vers_entry.get_next();
    }

    node_loc = entry.get_next();
  }

  return (out);
}

/** Print the frag entries. */
std::ostream &z_first_page_t::print_frag_entries(std::ostream &out) const {
  flst_base_node_t *flst = frag_list();
  fil_addr_t node_loc = flst_get_first(flst, m_mtr);
  space_id_t space = dict_index_get_space(m_index);
  const page_size_t page_size = dict_table_page_size(m_index->table);

  out << "Frag Entries: " << flst_bnode_t(flst, m_mtr) << std::endl;

  while (!fil_addr_is_null(node_loc)) {
    flst_node_t *node =
        fut_get_ptr(space, page_size, node_loc, RW_X_LATCH, m_mtr);
    z_frag_entry_t entry(node, m_mtr);
    out << entry << std::endl;
    node_loc = entry.get_next();
  }

  return (out);
}

/** Allocate one index entry.  If there is no free index entry, allocate
an index page (a page full of z_index_entry_t objects) and service the
request.
@return the allocated index entry. */
z_index_entry_t z_first_page_t::alloc_index_entry(bool bulk) {
  flst_base_node_t *free_lst = free_list();
  fil_addr_t first_loc = flst_get_first(free_lst, m_mtr);

  if (fil_addr_is_null(first_loc)) {
    z_index_page_t page(m_mtr, m_index);
    page.alloc(*this, bulk);
    first_loc = flst_get_first(free_lst, m_mtr);
  }

  if (fil_addr_is_null(first_loc)) {
    return (z_index_entry_t());
  }

  flst_node_t *first_ptr = addr2ptr_x(first_loc);
  z_index_entry_t entry(first_ptr, m_mtr);
  entry.remove(free_lst);

  return (entry);
}

/** Allocate one frag page entry.  If there is no free frag entry, allocate
an frag node page (a page full of z_frag_entry_t objects) and service the
request.
@return the allocated frag entry. */
z_frag_entry_t z_first_page_t::alloc_frag_entry(bool bulk) {
  flst_base_node_t *free_lst = free_frag_list();
  flst_base_node_t *used_lst = frag_list();

  fil_addr_t first_loc = flst_get_first(free_lst, m_mtr);

  if (fil_addr_is_null(first_loc)) {
    z_frag_node_page_t page(m_mtr, m_index);
    page.alloc(*this, bulk);
    first_loc = flst_get_first(free_lst, m_mtr);
  }

  if (fil_addr_is_null(first_loc)) {
    return (z_frag_entry_t());
  }

  flst_node_t *first_ptr = addr2ptr_x(first_loc);
  z_frag_entry_t entry(first_ptr, m_mtr);
  entry.remove(free_lst);
  entry.push_front(used_lst);
  return (entry);
}

frag_id_t z_first_page_t::alloc_fragment(bool bulk, ulint len,
                                         z_frag_page_t &frag_page,
                                         z_frag_entry_t &entry) {
  ut_ad(m_mtr != nullptr);

  frag_id_t frag_id = FRAG_ID_NULL;

  frag_page.set_mtr(m_mtr);
  frag_page.set_index(m_index);
  frag_page.set_block_null();

  const page_no_t first_page_no = get_page_no();

  /* Make sure that there will be some extra space for page directory
  entry and meta data.  Adding a margin to provide for this.  This is
  for exact fit. */
  const ulint look_size = len + frag_node_t::header_size();

  ut_ad(look_size <= z_frag_page_t::max_payload(m_index));

  flst_base_node_t *frag_lst = frag_list();

  /* Iterate through the list of frag entries in the page. */
  fil_addr_t loc = flst_get_first(frag_lst, m_mtr);

  while (!fil_addr_is_null(loc)) {
    flst_node_t *node = addr2ptr_x(loc);
    entry.reset(node);

    ulint big_free = entry.get_big_free_len();

    if (big_free >= look_size) {
      /* Double check if the information in the index
      entry matches with the fragment page. If not, update
      the index entry. */
      frag_page.load_x(entry.get_page_no());

      const ulint big_free_len_1 = frag_page.get_big_free_len();
      const ulint big_free_len_2 = entry.get_big_free_len();

      if (big_free_len_1 == big_free_len_2) {
        frag_id = frag_page.alloc_fragment(len, entry);
        if (frag_id != FRAG_ID_NULL) {
          break;
        }
      } else {
        entry.update(frag_page);

        /* Check again */
        big_free = entry.get_big_free_len();

        if (big_free >= look_size) {
          frag_id = frag_page.alloc_fragment(len, entry);
          if (frag_id != FRAG_ID_NULL) {
            break;
          }
        }
      }
    }

    loc = flst_get_next_addr(node, m_mtr);
    entry.reset(nullptr);
  }

  if (frag_id != FRAG_ID_NULL) {
    return (frag_id);
  }

  if (fil_addr_is_null(loc)) {
    /* Need to allocate a new fragment page. */
    buf_block_t *tmp_block = frag_page.alloc(first_page_no + 1, bulk);

    if (tmp_block == nullptr) {
      return (FRAG_ID_NULL);
    }

    entry = alloc_frag_entry(bulk);

    if (entry.is_null()) {
      return (FRAG_ID_NULL);
    }

    entry.set_page_no(frag_page.get_page_no());
    frag_page.set_frag_entry(entry.get_self_addr());

    /* Update the index entry with new space information. */
    entry.update(frag_page);
  }

#ifdef UNIV_DEBUG
  /* Adding more checks to ensure that an alloc fragment doesn't fail
  for the selected fragment page. */
  fil_addr_t addr1 = frag_page.get_frag_entry();
  fil_addr_t addr2 = entry.get_self_addr();
  ut_ad(addr1.is_equal(addr2));

  const ulint big_free_len_1 = frag_page.get_big_free_len();
  const ulint big_free_len_2 = entry.get_big_free_len();
  ut_ad(big_free_len_1 == big_free_len_2);

  ut_ad(big_free_len_1 >= look_size);
  ut_ad(big_free_len_1 > len);
#endif /* UNIV_DEBUG */

  frag_id = frag_page.alloc_fragment(len, entry);

  ut_ad(frag_id != FRAG_ID_NULL);

  return (frag_id);
}

/** Print the page. */
std::ostream &z_first_page_t::print(std::ostream &out) const {
  print_index_entries(out);
  print_frag_entries(out);
  return (out);
}

/** Free all the z_frag_page_t pages. All the z_frag_page_t pages are
singly linked to each other.  The head of the list is maintained in the
first page. */
void z_first_page_t::free_all_frag_node_pages() {
  while (true) {
    page_no_t page_no = get_frag_node_page_no();
    if (page_no == FIL_NULL) {
      break;
    }

    z_frag_node_page_t frag_node_page(m_mtr, m_index);
    frag_node_page.load_x(page_no);
    page_no_t next_page = frag_node_page.get_next_page_no();
    set_frag_node_page_no(next_page);
    frag_node_page.dealloc();
  }
}

/** Free all the index pages. */
void z_first_page_t::free_all_index_pages() {
  while (true) {
    page_no_t page_no = get_index_page_no();
    if (page_no == FIL_NULL) {
      break;
    }
    z_index_page_t index_page(m_mtr, m_index);
    index_page.load_x(page_no);
    page_no_t next_page = index_page.get_next_page_no();
    set_index_page_no(next_page);
    index_page.dealloc();
  }
}

ulint z_first_page_t::size_of_index_entries() const {
  return (z_index_entry_t::SIZE * get_n_index_entries());
}

void z_first_page_t::init_index_entries() {
  flst_base_node_t *flst = free_list();
  ulint n = get_n_index_entries();
  for (ulint i = 0; i < n; ++i) {
    flst_node_t *ptr = frame() + OFFSET_INDEX_BEGIN;
    ptr += (i * z_index_entry_t::SIZE);
    z_index_entry_t entry(ptr, m_mtr);
    entry.init();
    entry.push_back(flst);
  }
}

void z_first_page_t::load_entry_s(fil_addr_t &addr, z_index_entry_t &entry) {
  entry.load_s(addr);
}

void z_first_page_t::load_entry_x(fil_addr_t &addr, z_index_entry_t &entry) {
  entry.load_x(addr);
}

/** Deallocate the first page of a compressed LOB. */
void z_first_page_t::dealloc() {
  ut_ad(m_mtr != nullptr);
  btr_page_free_low(m_index, m_block, ULINT_UNDEFINED, m_mtr);
  m_block = nullptr;
}

/** Load the first page of the compressed LOB with x-latch.
@param[in]   page_id   the page identifier of first page
@param[in]   page_size the page size information of table.
@return buffer block of the first page. */
buf_block_t *z_first_page_t::load_x(const page_id_t &page_id,
                                    const page_size_t &page_size) {
  m_block = buf_page_get(page_id, page_size, RW_X_LATCH, m_mtr);

#ifdef UNIV_DEBUG
  /* Dump the page into the log file, if the page type is not matching
  one of the first page types. */
  page_type_t page_type = get_page_type();

  switch (page_type) {
    case FIL_PAGE_TYPE_ZBLOB:
    case FIL_PAGE_TYPE_ZLOB_FIRST:
      /* Valid first page type for compressed LOB.*/
      break;
    default:
      ut_print_buf(std::cout, m_block->frame, page_size.physical());
      ut_error;
  }
#endif /* UNIV_DEBUG */

  return (m_block);
}

/** Destroy the given ZLOB.  It frees all the pages of the given LOB,
including its first page.
@param[in]	index		the clustered index containing LOB.
@param[in]	first_page_no	first page number of LOB. */
void z_first_page_t::destroy(dict_index_t *index, page_no_t first_page_no) {
  mtr_t mtr;
  z_first_page_t first_page(&mtr, index);
  const space_id_t space = dict_index_get_space(index);
  const page_size_t page_size = dict_table_page_size(index->table);
  const page_id_t first_page_id(space, first_page_no);

  mtr_start(&mtr);
  first_page.load_x(first_page_id, page_size);
  first_page.free_all_frag_node_pages();
  first_page.free_all_index_pages();
  first_page.dealloc();
  mtr_commit(&mtr);
}

/** Increment the LOB version by 1. */
uint32_t z_first_page_t::incr_lob_version() {
  ut_ad(m_mtr != nullptr);

  const uint32_t cur = get_lob_version();
  const uint32_t val = cur + 1;
  mlog_write_ulint(frame() + OFFSET_LOB_VERSION, val, MLOG_4BYTES, m_mtr);

  return (val);
}

/** When the bit is set, the LOB is not partially updatable anymore.
Enable the bit.
@param[in]	trx	the current transaction.*/
void z_first_page_t::mark_cannot_be_partially_updated(trx_t *trx) {
  const trx_id_t trxid = (trx == nullptr) ? 0 : trx->id;
  const undo_no_t undo_no = (trx == nullptr) ? 0 : (trx->undo_no - 1);

#ifdef LOB_DEBUG
  std::cout << "thread=" << std::this_thread::get_id()
            << ", ZLOB first page=" << get_page_id()
            << ", mark_cannot_be_partially_updated()" << std::endl;
#endif /* LOB_DEBUG */

  uint8_t flags = get_flags();
  flags |= 0x01;
  mlog_write_ulint(frame() + OFFSET_FLAGS, flags, MLOG_1BYTE, m_mtr);

  set_last_trx_id(trxid);
  set_last_trx_undo_no(undo_no);
}

#ifdef UNIV_DEBUG
bool z_first_page_t::validate() {
  ut_ad(get_page_type() == FIL_PAGE_TYPE_ZLOB_FIRST);

  flst_base_node_t *flst = index_list();
  fil_addr_t node_loc = flst_get_first(flst, m_mtr);

  z_index_entry_t cur_entry(m_mtr, m_index);

  while (!fil_addr_is_null(node_loc)) {
    flst_node_t *node = addr2ptr_x(node_loc);
    cur_entry.reset(node);

    ut_ad(z_validate_strm(m_index, cur_entry, m_mtr));

    flst_base_node_t *vers = cur_entry.get_versions_list();
    fil_addr_t ver_loc = flst_get_first(vers, m_mtr);

    while (!fil_addr_is_null(ver_loc)) {
      flst_node_t *ver_node = addr2ptr_x(ver_loc);
      z_index_entry_t vers_entry(ver_node, m_mtr, m_index);
      ut_ad(z_validate_strm(m_index, vers_entry, m_mtr));
      ver_loc = vers_entry.get_next();
    }

    node_loc = cur_entry.get_next();
    cur_entry.reset(nullptr);
  }
  return (true);
}
#endif /* UNIV_DEBUG */

void z_first_page_t::import(trx_id_t trx_id) {
  set_trx_id_no_redo(trx_id);
  set_last_trx_id_no_redo(trx_id);

  ulint n = get_n_index_entries();
  for (ulint i = 0; i < n; ++i) {
    flst_node_t *ptr = frame() + OFFSET_INDEX_BEGIN;
    ptr += (i * z_index_entry_t::SIZE);
    z_index_entry_t entry(ptr);
    entry.set_trx_id_no_redo(trx_id);
    entry.set_trx_id_modifier_no_redo(trx_id);
  }
}

} /* namespace lob */