Struct ObjectMap 

#[non_exhaustive]
pub struct ObjectMap { /* private fields */ }

An object map header (omap_phys_t): the entry point into a volume/container object map’s backing B-tree.

Implementations

impl ObjectMap

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

Parse and validate an omap_phys_t header from a block.

Validates magic-by-type (o_type & 0xffff == OBJECT_TYPE_OMAP) and the Fletcher-64 checksum before trusting any field (checksum-before-trust).

Errors

crate::ApfsError::NoValidSuperblock-style failures are not used here; instead crate::ApfsError::UnexpectedObjectType is returned for a short block or a non-omap object (carrying the offending type), and crate::ApfsError::ChecksumMismatch for a Fletcher-64 failure.

pub fn tree_oid(&self) -> u64

om_tree_oid — the oid of the B-tree backing this object map. For a container omap the tree is stored physically (om_tree_type carries the physical storage flag), so this oid is also the tree root’s block address.

pub fn tree_type(&self) -> u32

om_tree_type (storage flags in the high bits | object type in the low).

pub fn flags(&self) -> u32

om_flags (OMAP_MANUALLY_MANAGED 0x1, OMAP_ENCRYPTING 0x2, …).

pub fn snapshot_tree_oid(&self) -> u64

om_snapshot_tree_oid — 0 when the omap has no snapshot tree.

pub fn resolve<R: Read + Seek>( &self, reader: &mut R, oid: u64, xid: u64, block_size: usize, ) -> Result<OmapEntry>

Resolve a virtual oid at transaction xid to a physical block address by walking the omap B-tree, choosing the entry with the largest ok_xid ≤ xid for the matching ok_oid (the most-recent state at or before the requested transaction).

The container omap tree is stored physically, so Self::tree_oid is the root node’s block address; the walk reads each node by its physical address, verifying its Fletcher-64 checksum and guarding against cyclic node links.

Errors

crate::ApfsError::OmapUnresolved if no mapping for oid at or before xid exists; crate::ApfsError::ChecksumMismatch / crate::ApfsError::CycleGuard / crate::ApfsError::Io on a structurally invalid tree or a read failure.

Trait Implementations

impl Clone for ObjectMap

fn clone(&self) -> ObjectMap

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for ObjectMap

impl Debug for ObjectMap

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

Formats the value using the given formatter.