Struct LogCheckpoint 

pub struct LogCheckpoint {
    pub number: u64,
    pub lsn: u64,
    pub offset: u32,
    pub buf_size: u32,
    pub archived_lsn: u64,
}

Checkpoint record (blocks 1 and 3 of the redo log file).

In MySQL 8.0.30+ (format version 6, including MySQL 9.x), the checkpoint block only contains the checkpoint LSN at offset 8. The number, offset, buf_size, and archived_lsn fields are not written and will be zero.

Fields

number: u64

Checkpoint sequence number (pre-8.0.30 only; zero in 8.0.30+).

lsn: u64

LSN at the time of this checkpoint.

offset: u32

Byte offset of the checkpoint within the log file (pre-8.0.30 only).

buf_size: u32

Log buffer size at checkpoint time (pre-8.0.30 only).

archived_lsn: u64

LSN up to which log has been archived (pre-8.0.30 only).

Implementations

impl LogCheckpoint

pub fn parse(block: &[u8]) -> Option<Self>

Parse a checkpoint from a 512-byte block.

Reads all fields for backward compatibility. In MySQL 8.0.30+ (format version 6), only the lsn field at offset 8 is meaningful; all other fields will be zero.

Examples

use idb::innodb::log::{LogCheckpoint, LOG_BLOCK_SIZE,
    LOG_CHECKPOINT_NO, LOG_CHECKPOINT_LSN, LOG_CHECKPOINT_OFFSET,
    LOG_CHECKPOINT_BUF_SIZE, LOG_CHECKPOINT_ARCHIVED_LSN};
use byteorder::{BigEndian, ByteOrder};

let mut block = vec![0u8; LOG_BLOCK_SIZE];
BigEndian::write_u64(&mut block[LOG_CHECKPOINT_NO..], 42);
BigEndian::write_u64(&mut block[LOG_CHECKPOINT_LSN..], 0xDEADBEEF);
BigEndian::write_u32(&mut block[LOG_CHECKPOINT_OFFSET..], 2048);
BigEndian::write_u32(&mut block[LOG_CHECKPOINT_BUF_SIZE..], 65536);
BigEndian::write_u64(&mut block[LOG_CHECKPOINT_ARCHIVED_LSN..], 0xCAFEBABE);

let cp = LogCheckpoint::parse(&block).unwrap();
assert_eq!(cp.number, 42);
assert_eq!(cp.lsn, 0xDEADBEEF);
assert_eq!(cp.offset, 2048);
assert_eq!(cp.buf_size, 65536);
assert_eq!(cp.archived_lsn, 0xCAFEBABE);

Trait Implementations

impl Clone for LogCheckpoint

fn clone(&self) -> LogCheckpoint

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for LogCheckpoint

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Serialize for LogCheckpoint

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.