polardbxengine/storage/innobase/include/fut0lst.ic

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/** @file include/fut0lst.ic
 File-based list utilities

 Created 11/28/1995 Heikki Tuuri
 ***********************************************************************/

#include "buf0buf.h"
#include "fut0fut.h"
#include "mtr0log.h"

/* We define the field offsets of a node for the list */
#define FLST_PREV                                   \
  0 /* 6-byte address of the previous list element; \
    the page part of address is FIL_NULL, if no     \
    previous element */
#define FLST_NEXT                              \
  FIL_ADDR_SIZE /* 6-byte address of the next  \
        list element; the page part of address \
        is FIL_NULL, if no next element */

/* We define the field offsets of a base node for the list */
#define FLST_LEN 0 /* 32-bit list length field */
#define FLST_FIRST                         \
  4 /* 6-byte address of the first element \
    of the list; undefined if empty list */
#define FLST_LAST                              \
  (4 + FIL_ADDR_SIZE) /* 6-byte address of the \
          last element of the list; undefined  \
          if empty list */

/** Writes a file address. */
UNIV_INLINE
void flst_write_addr(fil_faddr_t *faddr, /*!< in: pointer to file faddress */
                     fil_addr_t addr,    /*!< in: file address */
                     mtr_t *mtr)         /*!< in: mini-transaction handle */
{
  ut_ad(faddr && mtr);
  ut_ad(mtr_memo_contains_page_flagged(
      mtr, faddr, MTR_MEMO_PAGE_X_FIX | MTR_MEMO_PAGE_SX_FIX));
  ut_a(addr.page == FIL_NULL || addr.boffset >= FIL_PAGE_DATA);
  ut_a(ut_align_offset(faddr, UNIV_PAGE_SIZE) >= FIL_PAGE_DATA);

  mlog_write_ulint(faddr + FIL_ADDR_PAGE, addr.page, MLOG_4BYTES, mtr);
  mlog_write_ulint(faddr + FIL_ADDR_BYTE, addr.boffset, MLOG_2BYTES, mtr);
}

/** Reads a file address.
 @return file address */
UNIV_INLINE
fil_addr_t flst_read_addr(
    const fil_faddr_t *faddr, /*!< in: pointer to file faddress */
    mtr_t *mtr)               /*!< in: mini-transaction handle */
{
  fil_addr_t addr;

  ut_ad(faddr && mtr);

  addr.page = mtr_read_ulint(faddr + FIL_ADDR_PAGE, MLOG_4BYTES, mtr);
  addr.boffset = mtr_read_ulint(faddr + FIL_ADDR_BYTE, MLOG_2BYTES, mtr);
  ut_a(addr.page == FIL_NULL || addr.boffset >= FIL_PAGE_DATA);
  ut_a(ut_align_offset(faddr, UNIV_PAGE_SIZE) >= FIL_PAGE_DATA);
  return (addr);
}

/** Initializes a list base node. */
UNIV_INLINE
void flst_init(flst_base_node_t *base, /*!< in: pointer to base node */
               mtr_t *mtr)             /*!< in: mini-transaction handle */
{
  ut_ad(mtr_memo_contains_page_flagged(
      mtr, base, MTR_MEMO_PAGE_X_FIX | MTR_MEMO_PAGE_SX_FIX));

  mlog_write_ulint(base + FLST_LEN, 0, MLOG_4BYTES, mtr);
  flst_write_addr(base + FLST_FIRST, fil_addr_null, mtr);
  flst_write_addr(base + FLST_LAST, fil_addr_null, mtr);
}

/** Get the length of a list.
@param[in]	base	base node
@return length */
UNIV_INLINE
ulint flst_get_len(const flst_base_node_t *base) {
  return (mach_read_from_4(base + FLST_LEN));
}

/** Gets list first node address.
 @return file address */
UNIV_INLINE
fil_addr_t flst_get_first(
    const flst_base_node_t *base, /*!< in: pointer to base node */
    mtr_t *mtr)                   /*!< in: mini-transaction handle */
{
  return (flst_read_addr(base + FLST_FIRST, mtr));
}

/** Gets list last node address.
 @return file address */
UNIV_INLINE
fil_addr_t flst_get_last(
    const flst_base_node_t *base, /*!< in: pointer to base node */
    mtr_t *mtr)                   /*!< in: mini-transaction handle */
{
  return (flst_read_addr(base + FLST_LAST, mtr));
}

/** Gets list next node address.
 @return file address */
UNIV_INLINE
fil_addr_t flst_get_next_addr(
    const flst_node_t *node, /*!< in: pointer to node */
    mtr_t *mtr)              /*!< in: mini-transaction handle */
{
  return (flst_read_addr(node + FLST_NEXT, mtr));
}

/** Gets list prev node address.
 @return file address */
UNIV_INLINE
fil_addr_t flst_get_prev_addr(
    const flst_node_t *node, /*!< in: pointer to node */
    mtr_t *mtr)              /*!< in: mini-transaction handle */
{
  return (flst_read_addr(node + FLST_PREV, mtr));
}