Enum WalRecord 

pub enum WalRecord {
    Begin {
        tx_id: u64,
    },
    Commit {
        tx_id: u64,
    },
    Rollback {
        tx_id: u64,
    },
    PageWrite {
        tx_id: u64,
        page_id: u32,
        data: Vec<u8>,
    },
    TxCommitBatch {
        tx_id: u64,
        actions: Vec<Vec<u8>>,
    },
    Checkpoint {
        lsn: u64,
    },
}

A single entry in the write-ahead log

Variants

Begin

Start of a transaction

Fields

tx_id: u64

Commit

Commit of a transaction

Fields

tx_id: u64

Rollback

Rollback of a transaction

Fields

tx_id: u64

PageWrite

Write of a page — always carries uncompressed data (transparent to callers: read() decompresses on-the-fly).

Fields

tx_id: u64

page_id: u32

data: Vec<u8>

TxCommitBatch

Atomic logical commit batch. Recovery applies all actions in order iff this complete record and checksum are present.

Fields

tx_id: u64

actions: Vec<Vec<u8>>

Checkpoint

Checkpoint marker (indicates up to which LSN pages are flushed)

Fields

lsn: u64

Implementations

impl WalRecord

pub fn encode(&self) -> Vec<u8>

Serialize record to bytes (including checksum).

PageWrite records whose payload is ≥ COMPRESS_THRESHOLD bytes are compressed with zstd level 3 and emitted as PageWriteCompressed. Smaller payloads use the plain PageWrite encoding (no overhead).

pub fn read<R>(reader: &mut R) -> Result<Option<WalRecord>, Error>

where R: Read,

Read a record from a reader.

Handles both v1 (PageWrite) and v2 (PageWriteCompressed) record formats transparently — callers always receive uncompressed data.

Trait Implementations

impl Clone for WalRecord

fn clone(&self) -> WalRecord

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for WalRecord

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

Formats the value using the given formatter.

impl PartialEq for WalRecord

fn eq(&self, other: &WalRecord) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl StructuralPartialEq for WalRecord