Enum DeltaBase 

pub enum DeltaBase {
    None,
    Offset(u64),
    Ref(Vec<u8>),
}

Where a delta entry’s base is.

The stored form is an OFFSET, never an ordinal (§13, decided): an ordinal indexes the derived objects table, that table is rebuilt whenever the projection is rebuilt, and a rebuild re-derives every ordinal as the new oid-lexicographic rank. An ordinal written down before a rebuild therefore points at a different row afterwards — silently. An offset addresses the bytes, which append-only storage never moves.

Variants

None

A whole object: no base.

Offset(u64)

OFS_DELTA — the base is another entry, at this absolute offset. Absolute in whatever coordinate space the walk was rebased into: within the pack after walk, within the archive after PackWalk::rebased.

Ref(Vec<u8>)

REF_DELTA — the base is named by oid and is usually outside the pack (that is what a thin pack is). Resolving it is the one part of the check that reads objects.oid, exactly as §13’s table says receive-pack does.

Implementations

impl DeltaBase

pub fn as_offset(&self) -> u64

The offset form for the objects.delta_base column.

0 means no offset base and is a safe sentinel rather than a lie: archive offset 0 is the first pack’s PACK magic, so no object entry can ever legitimately start there. A Ref base has no offset until the indexer resolves its oid, and reports 0 for the same reason.

Trait Implementations

impl Clone for DeltaBase

fn clone(&self) -> DeltaBase

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for DeltaBase

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

Formats the value using the given formatter.

impl Eq for DeltaBase

impl PartialEq for DeltaBase

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for DeltaBase