mtr0log.h

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/** @file include/mtr0log.h
 Mini-transaction logging routines
 
 Created 12/7/1995 Heikki Tuuri
 *******************************************************/
 
#ifndef mtr0log_h
#define mtr0log_h
 
#include "dyn0buf.h"
#include "mtr0mtr.h"
#include "univ.i"
 
// Forward declaration
struct dict_index_t;
 
/* Index logging version */
constexpr uint8_t INDEX_LOG_VERSION_0 = 0;
constexpr uint8_t INDEX_LOG_VERSION_CURRENT = 1;
constexpr uint8_t INDEX_LOG_VERSION_MAX = INDEX_LOG_VERSION_CURRENT;
 
#define COMPACT_FLAG 0x01
#define VERSION_FLAG 0x02
#define INSTANT_FLAG 0x04
 
#define IS_INSTANT(flags) (flags & INSTANT_FLAG)
#define IS_VERSIONED(flags) (flags & VERSION_FLAG)
#define IS_COMPACT(flags) (flags & COMPACT_FLAG)
 
#define SET_INSTANT(flags) (flag |= INSTANT_FLAG)
#define SET_VERSIONED(flags) (flag |= VERSION_FLAG)
#define SET_COMPACT(flags) (flag |= COMPACT_FLAG)
 
/* Size of initial info on REDO log
  1   byte  for LOG TYPE
  3-5 bytes for SPACE ID
  3-5 bytes for PAGE OFFSET */
constexpr size_t REDO_LOG_INITIAL_INFO_SIZE = 11;
 
/** Writes 1, 2 or 4 bytes to a file page. Writes the corresponding log
 record to the mini-transaction log if mtr is not NULL. */
void mlog_write_ulint(
    byte *ptr,      /*!< in: pointer where to write */
    ulint val,      /*!< in: value to write */
    mlog_id_t type, /*!< in: MLOG_1BYTE, MLOG_2BYTES, MLOG_4BYTES */
    mtr_t *mtr);    /*!< in: mini-transaction handle */
 
/** Writes 8 bytes to a file page. Writes the corresponding log
 record to the mini-transaction log, only if mtr is not NULL */
void mlog_write_ull(byte *ptr,    /*!< in: pointer where to write */
                    uint64_t val, /*!< in: value to write */
                    mtr_t *mtr);  /*!< in: mini-transaction handle */
/** Writes a string to a file page buffered in the buffer pool. Writes the
 corresponding log record to the mini-transaction log. */
void mlog_write_string(byte *ptr,       /*!< in: pointer where to write */
                       const byte *str, /*!< in: string to write */
                       ulint len,       /*!< in: string length */
                       mtr_t *mtr);     /*!< in: mini-transaction handle */
/** Logs a write of a string to a file page buffered in the buffer pool.
 Writes the corresponding log record to the mini-transaction log. */
void mlog_log_string(byte *ptr,   /*!< in: pointer written to */
                     ulint len,   /*!< in: string length */
                     mtr_t *mtr); /*!< in: mini-transaction handle */
/** Writes initial part of a log record consisting of one-byte item
 type and four-byte space and page numbers. */
void mlog_write_initial_log_record(
    const byte *ptr, /*!< in: pointer to (inside) a buffer
                     frame holding the file page where
                     modification is made */
    mlog_id_t type,  /*!< in: log item type: MLOG_1BYTE, ... */
    mtr_t *mtr);     /*!< in: mini-transaction handle */
 
/** Catenates 1 - 4 bytes to the mtr log. The value is not compressed.
@param[in,out]  dyn_buf buffer to write
@param[in]      val     value to write
@param[in]      type    type of value to write */
static inline void mlog_catenate_ulint(mtr_buf_t *dyn_buf, ulint val,
                                       mlog_id_t type);
 
/** Catenates 1 - 4 bytes to the mtr log.
@param[in]      mtr     mtr
@param[in]      val     value to write
@param[in]      type    MLOG_1BYTE, MLOG_2BYTES, MLOG_4BYTES */
static inline void mlog_catenate_ulint(mtr_t *mtr, ulint val, mlog_id_t type);
 
/** Catenates n bytes to the mtr log.
@param[in] mtr Mini-transaction
@param[in] str String to write
@param[in] len String length */
void mlog_catenate_string(mtr_t *mtr, const byte *str, ulint len);
 
/** Catenates a compressed ulint to mlog.
@param[in]      mtr     mtr
@param[in]      val     value to write */
static inline void mlog_catenate_ulint_compressed(mtr_t *mtr, ulint val);
 
/** Catenates a compressed 64-bit integer to mlog.
@param[in]      mtr     mtr
@param[in]      val     value to write */
static inline void mlog_catenate_ull_compressed(mtr_t *mtr, uint64_t val);
 
/** Opens a buffer to mlog. It must be closed with mlog_close.
@param[in,out]  mtr     mtr
@param[in]      size    buffer size in bytes; MUST be smaller than
                        DYN_ARRAY_DATA_SIZE!
@param[out]     buffer  mlog buffer pointer if opened successfully
@retval true if opened successfully.
@retval false if not opened. One case is when redo is disabled for mtr. */
[[nodiscard]] static inline bool mlog_open(mtr_t *mtr, ulint size,
                                           byte *&buffer);
 
/** Opens a buffer to mlog. It must be closed with mlog_close.
This is used for writing log for metadata changes
@param[in,out]  mtr     mtr
@param[in]      size    buffer size in bytes; MUST be smaller than
                        DYN_ARRAY_DATA_SIZE!
@param[out]     buffer  mlog buffer pointer if opened successfully
@retval true if opened successfully.
@retval false if not opened. One case is when redo is disabled for mtr. */
[[nodiscard]] static inline bool mlog_open_metadata(mtr_t *mtr, ulint size,
                                                    byte *&buffer);
 
/** Closes a buffer opened to mlog.
@param[in]      mtr     mtr
@param[in]      ptr     buffer space from ptr up was not used */
static inline void mlog_close(mtr_t *mtr, byte *ptr);
 
/** Writes a log record about a dictionary operation, which would cost
at most 23 bytes.
@param[in]      type            Redo log record type
@param[in]      id              Table id
@param[in]      version         Table dynamic metadata version
@param[in,out]  log_ptr         Current end of mini-transaction log
@param[in,out]  mtr             Mini-transaction
@return end of mini-transaction log */
static inline byte *mlog_write_initial_dict_log_record(
    mlog_id_t type, table_id_t id, uint64_t version, byte *log_ptr, mtr_t *mtr);
 
/** Writes a log record about an operation.
@param[in]      type            Redo log record type
@param[in]      space_id        Tablespace identifier
@param[in]      page_no         Page number
@param[in,out]  log_ptr         Current end of mini-transaction log
@param[in,out]  mtr             Mini-transaction
@return end of mini-transaction log */
static inline byte *mlog_write_initial_log_record_low(mlog_id_t type,
                                                      space_id_t space_id,
                                                      page_no_t page_no,
                                                      byte *log_ptr,
                                                      mtr_t *mtr);
 
#ifndef UNIV_HOTBACKUP
/** Writes the initial part of a log record (3..11 bytes).
If the implementation of this function is changed, all size parameters to
mlog_open() should be adjusted accordingly!
@param[in]      ptr     pointer to (inside) a buffer frame holding the file
                        page where modification is made
@param[in]      type    log item type: MLOG_1BYTE, ...
@param[in]      log_ptr pointer to mtr log which has been opened
@param[in]      mtr     mtr
@return new value of log_ptr */
static inline byte *mlog_write_initial_log_record_fast(const byte *ptr,
                                                       mlog_id_t type,
                                                       byte *log_ptr,
                                                       mtr_t *mtr);
#else /* !UNIV_HOTBACKUP */
#define mlog_write_initial_log_record(ptr, type, mtr) ((void)0)
#define mlog_write_initial_log_record_fast(ptr, type, log_ptr, mtr) ((byte *)0)
#endif /* !UNIV_HOTBACKUP */
 
/** Parses an initial log record written by mlog_write_initial_dict_log_record.
@param[in]      ptr             buffer
@param[in]      end_ptr         buffer end
@param[out]     type            log record type, should be
                                MLOG_TABLE_DYNAMIC_META
@param[out]     id              table id
@param[out]     version         table dynamic metadata version
@return parsed record end, NULL if not a complete record */
byte *mlog_parse_initial_dict_log_record(const byte *ptr, const byte *end_ptr,
                                         mlog_id_t *type, table_id_t *id,
                                         uint64_t *version);
 
/** Parses an initial log record written by mlog_write_initial_log_record.
 @return parsed record end, NULL if not a complete record */
byte *mlog_parse_initial_log_record(
    const byte *ptr,     /*!< in: buffer */
    const byte *end_ptr, /*!< in: buffer end */
    mlog_id_t *type,     /*!< out: log record type: MLOG_1BYTE, ... */
    space_id_t *space,   /*!< out: space id */
    page_no_t *page_no); /*!< out: page number */
/** Parses a log record written by mlog_write_ulint or mlog_write_ull.
 @return parsed record end, NULL if not a complete record */
byte *mlog_parse_nbytes(
    mlog_id_t type,      /*!< in: log record type: MLOG_1BYTE, ... */
    const byte *ptr,     /*!< in: buffer */
    const byte *end_ptr, /*!< in: buffer end */
    byte *page,          /*!< in: page where to apply the log record,
                         or NULL */
    void *page_zip);     /*!< in/out: compressed page, or NULL */
/** Parses a log record written by mlog_write_string.
 @return parsed record end, NULL if not a complete record */
byte *mlog_parse_string(
    byte *ptr,       /*!< in: buffer */
    byte *end_ptr,   /*!< in: buffer end */
    byte *page,      /*!< in: page where to apply the log record, or NULL */
    void *page_zip); /*!< in/out: compressed page, or NULL */
 
/** Opens a buffer for mlog, writes the initial log record and, if needed, the
field lengths of an index. Reserves space for further log entries. The log
entry must be closed with mtr_close().
@param[in,out]  mtr     Mini-transaction
@param[in]      rec     Index record or page
@param[in]      index   Record descriptor
@param[in]      type    Log item type
@param[in]      size    Requested buffer size in bytes. if 0, calls
                        mlog_close() and returns false.
@param[out]     log_ptr Log buffer pointer
@retval true if opened successfully.
@retval false if not opened. One case is when redo is disabled for mtr. */
bool mlog_open_and_write_index(mtr_t *mtr, const byte *rec,
                               const dict_index_t *index, mlog_id_t type,
                               size_t size, byte *&log_ptr);
 
/** Parses a log record written by mlog_open_and_write_index.
@param[in]  ptr      buffer
@param[in]  end_ptr  buffer end
@param[out] index    own: dummy index
@return parsed record end, NULL if not a complete record */
byte *mlog_parse_index(byte *ptr, const byte *end_ptr, dict_index_t **index);
 
/** Parses a log record written by mlog_open_and_write_index in version <= 8027.
This function should never be changed and should be removed once recovery from
mysql-8.0.27 is not needed anymore.
@param[in]  ptr      buffer
@param[in]  end_ptr  buffer end
@param[in]  comp     true=compact row format
@param[out] index    own: dummy index
@return parsed record end, NULL if not a complete record */
byte *mlog_parse_index_8027(byte *ptr, const byte *end_ptr, bool comp,
                            dict_index_t **index);
 
/** Insert, update, and maybe other functions may use this value to define an
extra mlog buffer size for variable size data */
constexpr auto MLOG_BUF_MARGIN = 256;
 
#include "mtr0log.ic"
 
#endif /* mtr0log_h */