Enum JournalHeader 

pub enum JournalHeader {
    Valid {
        n_rec: u32,
        mx_page: u32,
        nonce: u32,
        sector_size: u32,
        page_size: u32,
    },
    ReconstructedZeroed {
        page_size: u32,
        sector_size: u32,
    },
}

Parsed (or reconstructed) rollback-journal header (design §5).

Valid is a header whose magic is intact (Tier A — hot journal / crash residue): every parameter, including the checksum nonce, is authoritative. ReconstructedZeroed is the PERSIST post-commit case (Tier B): the first sector was zeroed on commit, so the page size comes from the main database and the sector size from candidate scoring — the nonce is gone, so page checksums cannot be verified.

Variants

Valid

Tier A: header magic present; all fields trusted (pager.c offsets).

Fields

n_rec: u32

Page records declared in this segment (0xFFFFFFFF/0 ⇒ walk to EOF).

mx_page: u32

Database page count at transaction start (dbOrigSize).

nonce: u32

Checksum initializer (cksumInit), offset 12.

sector_size: u32

VFS sector size the header is padded to.

page_size: u32

Database page size at transaction start.

ReconstructedZeroed

Tier B: header zeroed (PERSIST post-commit); parameters reconstructed.

Fields

page_size: u32

Page size taken from the main database header (authoritative).

sector_size: u32

Sector size selected by candidate scoring (record offset stride).

Trait Implementations

impl Clone for JournalHeader

fn clone(&self) -> JournalHeader

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for JournalHeader

impl Debug for JournalHeader

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

Formats the value using the given formatter.

impl Eq for JournalHeader

impl PartialEq for JournalHeader

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for JournalHeader