rpl_data_structures

Binlog/Replication API data structures

Structures and type definitions for Binglog/Replication API are defined in source file include/mariadb_rpl.h.

MARIADB_STRING

MARIADB_STRING is a simple structure (same as MYSQL_STRING and MYSQL_LEX_STRING) which stores a string together with its length.

typedef struct {
  char *str;
  size_t length;
} MARIADB_STRING;

MARIADB_GTID

MARIADB_GTID is used to store the global transaction id. The global transaction id is defined by three numbers: The domain id, the server id and the sequence number.

typedef struct st_mariadb_gtid {
  unsigned int domain_id;
  unsigned int server_id;
  unsigned long long sequence_nr;
} MARIADB_GTID;

MARIADB_RPL

MARIADB_RPL is the generic replication handle, which represents a replication connection and is used by all binlog/replication API calls. The MARIADB_RPL structure is considered to be opaque, instead of accessing its internal members you should use the api functions mariadb_rpl_optionsv and mariadb_rpl_get_optionsv.

typedef struct st_mariadb_rpl {
  unsigned int version;
  MYSQL *mysql;
  char *filename;
  uint32_t filename_length;
  unsigned char *buffer;
  unsigned long buffer_size;
  uint32_t server_id;
  unsigned long start_position;
  uint32_t flags;
  uint8_t fd_header_len; /* header len from last format description event */
} MARIADB_RPL;

Events

MARIADB_RPL_EVENT

MARIADB_RPL_EVENT structure is returned by mariadb_rpl_fetch() API function. Beside a common header it contains different event types which are combined in event union.

typedef struct st_mariadb_rpl_event
{
  /* common header */
  MA_MEM_ROOT memroot;
  unsigned int checksum;
  char ok;
  enum mariadb_rpl_event event_type;
  unsigned int timestamp;
  unsigned int server_id;
  unsigned int event_length;
  unsigned int next_event_pos;
  unsigned short flags;
  /****************/
  union {
    struct st_mariadb_rpl_rotate_event rotate;
    struct st_mariadb_rpl_query_event query;
    struct st_mariadb_rpl_format_description_event format_description;
    struct st_mariadb_rpl_gtid_list_event gtid_list;
    struct st_mariadb_rpl_checkpoint_event checkpoint;
    struct st_mariadb_rpl_xid_event xid;
    struct st_mariadb_rpl_gtid_event gtid;
    struct st_mariadb_rpl_annotate_rows_event annotate_rows;
    struct st_mariadb_rpl_table_map_event table_map;
    struct st_mariadb_rpl_rand_event rand;
    struct st_mariadb_rpl_encryption_event encryption;
    struct st_mariadb_rpl_intvar_event intvar;
    struct st_mariadb_rpl_uservar_event uservar;
    struct st_mariadb_rpl_rows_event rows;
    struct st_mariadb_rpl_heartbeat_event heartbeat;
  } event;
} MARIADB_RPL_EVENT;

Depending on the event type information sent by master will be stored in the corresponding member of the event union:

ANNOTATE_ROWS_EVENT

event_type value= 160 (0xA0)

struct st_mariadb_rpl_annotate_rows_event {
  MARIADB_STRING statement;
};

BINLOG_CHECKPOINT_EVENT

event_type value= 161 (0xA1)

struct st_mariadb_rpl_checkpoint_event {
  MARIADB_STRING filename;
};

START_ENCRYPTION_EVENT

event_type value= 164 (0xA4)

struct st_mariadb_rpl_encryption_event {
  char scheme;
  unsigned int key_version;
  char *nonce;
};

FORMAT_DESCRIPTION_EVENT

event_type value= 15 (0x0F)

struct st_mariadb_rpl_format_description_event
{
  uint16_t format;
  char *server_version;
  uint32_t timestamp;
  uint8_t header_len;
};

GTID_EVENT

event_type value= 162 (0xA2)

struct st_mariadb_rpl_gtid_event {
  uint64_t sequence_nr;
  uint32_t domain_id;
  uint8_t flags;
  uint64_t commit_id;
};

GTID_LIST_EVENT

event_type value= 163 (0xA3)

struct st_mariadb_rpl_gtid_list_event {
  uint32_t gtid_cnt;
  MARIADB_GTID *gtid;
};

HEARTBEAT_LOG_EVENT

event_type value= 27 (0x1B)

struct st_mariadb_rpl_heartbeat_event {
  uint32_t timestamp;
  uint32_t next_position;
  uint8_t type;
  uint16_t flags;
};

INTVAR_EVENT

event_type value=5 (0x05)

struct st_mariadb_rpl_intvar_event {
  char type;
  unsigned long long value;
};

QUERY_EVENT

event_type value=2 (0x02)

struct st_mariadb_rpl_query_event {
  uint32_t thread_id;
  uint32_t seconds;
  MARIADB_STRING database;
  uint32_t errornr;
  MARIADB_STRING status;
  MARIADB_STRING statement;
};

RAND_EVENT

event_type value=13 (0x0D)

struct st_mariadb_rpl_rand_event {
  unsigned long long first_seed;
  unsigned long long second_seed;
};

ROTATE_EVENT

event_type value=4 (0x04)

struct st_mariadb_rpl_rotate_event {
  unsigned long long position;
  MARIADB_STRING filename;
};