polardbxengine/storage/innobase/lob/lob0purge.cc

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

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

#include "lob0del.h"
#include "lob0first.h"
#include "lob0index.h"
#include "lob0inf.h"
#include "lob0lob.h"
#include "row0upd.h"
#include "trx0purge.h"
#include "trx0rec.h"
#include "zlob0first.h"
#include "zlob0index.h"
#include "zlob0read.h"

namespace lob {

/** Rollback from undo log information.
@param[in]	ctx	the delete operation context.
@param[in]	index	the clustered index to which LOB belongs.
@param[in]	ref	the LOB reference object.
@param[in]	uf	the update vector of concerned field. */
static void rollback_from_undolog(DeleteContext *ctx, dict_index_t *index,
                                  ref_t &ref, const upd_field_t *uf) {
  DBUG_TRACE;

  trx_t *trx = nullptr;

  dberr_t err = apply_undolog(ctx->get_mtr(), trx, index, ref, uf);
  ut_a(err == DB_SUCCESS);
}

/** Rollback modification of a uncompressed LOB.
@param[in]	ctx		the delete operation context information.
@param[in]	index		clustered index in which LOB is present
@param[in]	trxid		the transaction that is being rolled back.
@param[in]	undo_no		during rollback to savepoint, rollback only
                                upto this undo number.
@param[in]	ref		reference to LOB that is being rolled back.
@param[in]	rec_type	undo record type.
@param[in]	uf		update vector of the concerned field. */
static void rollback(DeleteContext *ctx, dict_index_t *index, trx_id_t trxid,
                     undo_no_t undo_no, ref_t &ref, ulint rec_type,
                     const upd_field_t *uf) {
  DBUG_TRACE;

  ut_ad(ctx->m_rollback);

  if (uf != nullptr && uf->lob_diffs != nullptr && uf->lob_diffs->size() > 0) {
    /* Undo log contains changes done to the LOB.  This must have
    been a small change done to LOB.  Apply the undo log on the
    LOB.*/
    rollback_from_undolog(ctx, index, ref, uf);
    return;
  }

  mtr_t *mtr = ctx->get_mtr();

  page_no_t first_page_no = ref.page_no();
  page_id_t page_id(ref.space_id(), first_page_no);
  page_size_t page_size(dict_table_page_size(index->table));

  first_page_t first(mtr, index);
  first.load_x(page_id, page_size);

  flst_base_node_t *flst = first.index_list();
  fil_addr_t node_loc = flst_get_first(flst, mtr);

  while (!fil_addr_is_null(node_loc)) {
    flst_node_t *node = first.addr2ptr_x(node_loc);
    index_entry_t cur_entry(node, mtr, index);

    if (cur_entry.can_rollback(trxid, undo_no)) {
      node_loc = cur_entry.make_old_version_current(index, trxid, first);

    } else {
      node_loc = cur_entry.get_next();
    }
  }

  if (rec_type == TRX_UNDO_INSERT_REC || first.is_empty()) {
    if (dict_index_is_online_ddl(index)) {
      row_log_table_blob_free(index, ref.page_no());
    }

    first.free_all_index_pages();
    first.dealloc();

  } else {
#ifdef UNIV_DEBUG
    const ulint lob_size = ref.length();
    fil_addr_t first_node_loc = flst_get_first(flst, mtr);
    ut_ad(validate_size(lob_size, index, first_node_loc, mtr));
#endif /* UNIV_DEBUG */
  }

  ref.set_page_no(FIL_NULL, mtr);
  ref.set_length(0, mtr);

  DBUG_EXECUTE_IF("crash_endof_lob_rollback", DBUG_SUICIDE(););
}

/** Rollback modification of a compressed LOB.
@param[in]	ctx		the delete operation context information.
@param[in]	index		clustered index in which LOB is present
@param[in]	trxid		the transaction that is being rolled back.
@param[in]	undo_no		during rollback to savepoint, rollback only
                                upto this undo number.
@param[in]	ref		reference to LOB that is purged.
@param[in]	rec_type	undo record type. */
static void z_rollback(DeleteContext *ctx, dict_index_t *index, trx_id_t trxid,
                       undo_no_t undo_no, ref_t &ref, ulint rec_type) {
  ut_ad(ctx->m_rollback);
  const ulint commit_freq = 1;
  ulint n_entries = 0;

  mtr_t local_mtr;
  mtr_start(&local_mtr);

  page_no_t first_page_no = ref.page_no();
  page_id_t page_id(ref.space_id(), first_page_no);
  page_size_t page_size(dict_table_page_size(index->table));

  z_first_page_t first(&local_mtr, index);
  first.load_x(page_id, page_size);

  flst_base_node_t *flst = first.index_list();
  fil_addr_t node_loc = flst_get_first(flst, &local_mtr);

  while (!fil_addr_is_null(node_loc)) {
    flst_node_t *node = first.addr2ptr_x(node_loc);
    z_index_entry_t cur_entry(node, &local_mtr, index);

#ifdef UNIV_DEBUG
    ulint idx_len = first.get_index_list_length();
#endif /* UNIV_DEBUG */

    if (cur_entry.can_rollback(trxid, undo_no)) {
      node_loc = cur_entry.make_old_version_current(index, trxid, first);

      n_entries++;

    } else {
      node_loc = cur_entry.get_next();
    }

    if ((n_entries % commit_freq == 0) && !first.is_empty()) {
      mtr_commit(&local_mtr);

#ifdef UNIV_DEBUG
      if (idx_len == 1) {
        DBUG_EXECUTE_IF("crash_middle_zlob_rollback", DBUG_SUICIDE(););
      }
#endif /* UNIV_DEBUG */

      mtr_start(&local_mtr);
      first.load_x(page_id, page_size);
    }
  }

  if (rec_type == TRX_UNDO_INSERT_REC || first.is_empty()) {
    if (dict_index_is_online_ddl(index)) {
      row_log_table_blob_free(index, ref.page_no());
    }

    /* Ensure that the btr mtr is not holding any x-latch on the first page of
     * LOB. */
    ut_ad(!mtr_is_block_fix(ctx->get_mtr(), first.get_block(),
                            MTR_MEMO_PAGE_X_FIX, index->table));

    first.free_all_frag_node_pages();
    first.free_all_index_pages();
    first.dealloc();

  } else {
    ut_ad(first.validate());
  }

  ut_ad(ctx->get_page_zip() != nullptr);
  ref.set_page_no(FIL_NULL, 0);
  ref.set_length(0, 0);
  ctx->x_latch_rec_page(&local_mtr);
  ctx->zblob_write_blobref(ctx->m_field_no, &local_mtr);

  mtr_commit(&local_mtr);

  DBUG_EXECUTE_IF("crash_endof_zlob_rollback", DBUG_SUICIDE(););
}

/** Purge a compressed LOB.
@param[in]	ctx		the delete operation context information.
@param[in]	index		clustered index in which LOB is present
@param[in]	trxid		the transaction that is being purged.
@param[in]	undo_no		during rollback to savepoint, purge only upto
                                this undo number.
@param[in]	ref		reference to LOB that is purged.
@param[in]	rec_type	undo record type. */
static void z_purge(DeleteContext *ctx, dict_index_t *index, trx_id_t trxid,
                    undo_no_t undo_no, ref_t &ref, ulint rec_type) {
  const bool is_rollback = ctx->m_rollback;

  if (is_rollback) {
    z_rollback(ctx, index, trxid, undo_no, ref, rec_type);
    return;
  }

  mtr_t *mtr = ctx->get_mtr();

  page_no_t first_page_no = ref.page_no();
  page_id_t page_id(ref.space_id(), first_page_no);

  z_first_page_t first(mtr, index);
  first.load_x(first_page_no);

  ut_ad(first.validate());

  trx_id_t last_trx_id = first.get_last_trx_id();
  undo_no_t last_undo_no = first.get_last_trx_undo_no();
  ut_ad(first.get_page_type() == FIL_PAGE_TYPE_ZLOB_FIRST);

  flst_base_node_t *flst = first.index_list();
  flst_base_node_t *free_list = first.free_list();
  fil_addr_t node_loc = flst_get_first(flst, mtr);

  z_index_entry_t cur_entry(mtr, index);

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

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

    /* Scan the older versions. */
    while (!fil_addr_is_null(ver_loc)) {
      flst_node_t *ver_node = first.addr2ptr_x(ver_loc);
      z_index_entry_t vers_entry(ver_node, mtr, index);

      if (vers_entry.can_be_purged(trxid, undo_no)) {
        ver_loc =
            vers_entry.purge_version(index, trxid, first, vers, free_list);
      } else {
        ver_loc = vers_entry.get_next();
      }
    }

    node_loc = cur_entry.get_next();
    cur_entry.reset(nullptr);
  }

  bool ok_to_free_2 = (rec_type == TRX_UNDO_UPD_EXIST_REC) &&
                      !first.can_be_partially_updated() &&
                      (last_trx_id == trxid) && (last_undo_no == undo_no);

  if (rec_type == TRX_UNDO_DEL_MARK_REC || ok_to_free_2) {
    if (dict_index_is_online_ddl(index)) {
      row_log_table_blob_free(index, ref.page_no());
    }

    first.free_all_frag_node_pages();
    first.free_all_index_pages();
    first.dealloc();

  } else {
    ut_ad(first.validate());
  }

  if (ctx->get_page_zip() != nullptr) {
    ref.set_page_no(FIL_NULL, 0);
    ref.set_length(0, 0);
    ctx->zblob_write_blobref(ctx->m_field_no, mtr);
  } else {
    /* Note that page_zip will be NULL in
    row_purge_upd_exist_or_extern(). */
    ref.set_page_no(FIL_NULL, mtr);
    ref.set_length(0, mtr);
  }
}

/** Purge an uncompressed LOB.
@param[in]	ctx		the delete operation context information.
@param[in]	index		clustered index in which LOB is present
@param[in]	trxid		the transaction that is being purged.
@param[in]	undo_no		during rollback to savepoint, purge only upto
                                this undo number.
@param[in]	ref		reference to LOB that is purged.
@param[in]	rec_type	undo record type.
@param[in]	uf		the update vector for the field. */
void purge(DeleteContext *ctx, dict_index_t *index, trx_id_t trxid,
           undo_no_t undo_no, ref_t ref, ulint rec_type,
           const upd_field_t *uf) {
  DBUG_TRACE;

  mtr_t *mtr = ctx->get_mtr();
  const bool is_rollback = ctx->m_rollback;

  if (ref.is_null()) {
    /* In the rollback, we may encounter a clustered index
    record with some unwritten off-page columns. There is
    nothing to free then. */
    ut_a(ctx->m_rollback);
    return;
  }

  if (!ref.is_owner() || ref.page_no() == FIL_NULL || ref.length() == 0 ||
      (ctx->m_rollback && ref.is_inherited())) {
    return;
  }

  if (!is_rollback && uf != nullptr && uf->lob_diffs != nullptr &&
      uf->lob_diffs->size() > 0) {
    /* Undo record contains LOB diffs.  So purge shouldn't look
    at the LOB. */
    return;
  }

  space_id_t space_id = ref.space_id();

  /* The current entry - it is the latest version. */
  index_entry_t cur_entry(mtr, index);

  page_no_t first_page_no = ref.page_no();
  page_id_t page_id(space_id, first_page_no);
  page_size_t page_size(dict_table_page_size(index->table));
  page_type_t page_type =
      first_page_t::get_page_type(index, page_id, page_size);

  if (page_type == FIL_PAGE_TYPE_ZBLOB || page_type == FIL_PAGE_TYPE_BLOB ||
      page_type == FIL_PAGE_SDI_BLOB || page_type == FIL_PAGE_SDI_ZBLOB) {
    lob::Deleter free_blob(*ctx);
    free_blob.destroy();
    return;
  }

  if (page_type == FIL_PAGE_TYPE_ZLOB_FIRST) {
    z_purge(ctx, index, trxid, undo_no, ref, rec_type);
    return;
  }

  first_page_t first(mtr, index);
  first.load_x(page_id, page_size);

  ut_a(page_type == FIL_PAGE_TYPE_LOB_FIRST);

  if (is_rollback) {
    rollback(ctx, index, trxid, undo_no, ref, rec_type, uf);
    return;
  }

  trx_id_t last_trx_id = first.get_last_trx_id();
  undo_no_t last_undo_no = first.get_last_trx_undo_no();

  flst_base_node_t *flst = first.index_list();
  flst_base_node_t *free_list = first.free_list();
  fil_addr_t node_loc = flst_get_first(flst, mtr);

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

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

    /* Scan the older versions. */
    while (!fil_addr_is_null(ver_loc)) {
      flst_node_t *ver_node = first.addr2ptr_x(ver_loc);
      index_entry_t vers_entry(ver_node, mtr, index);

      if (vers_entry.can_be_purged(trxid, undo_no)) {
        ver_loc = vers_entry.purge_version(index, trxid, vers, free_list);
      } else {
        ver_loc = vers_entry.get_next();
      }
    }

    node_loc = cur_entry.get_next();
    cur_entry.reset(nullptr);
  }

  bool ok_to_free = (rec_type == TRX_UNDO_UPD_EXIST_REC) &&
                    !first.can_be_partially_updated() &&
                    (last_trx_id == trxid) && (last_undo_no == undo_no);

  if (rec_type == TRX_UNDO_DEL_MARK_REC || ok_to_free) {
    ut_ad(first.get_page_type() == FIL_PAGE_TYPE_LOB_FIRST);

    if (dict_index_is_online_ddl(index)) {
      row_log_table_blob_free(index, ref.page_no());
    }
    first.free_all_data_pages();

    first.free_all_index_pages();
    first.dealloc();
  }

  ref.set_page_no(FIL_NULL, mtr);
  ref.set_length(0, mtr);
}

} /* namespace lob */