Enum CloneCapability 

pub enum CloneCapability {
    None,
    WholeFile,
    Range,
}

What kind of zero-copy extent sharing — reflinks — the backend can express. Returned by Filesystem::clone_capability.

Reflinks let a destination file (or a range of it) point at the same physical extents as a source, with copy-on-write semantics on the next write to either side. The on-disk encoding differs per backend (XFS refcount-btree, APFS clone records, Btrfs shared extents), so the trait surface offers two operations and a capability gate, with sensible byte-copy fallbacks for backends that can’t share extents natively.

Variants

None

No extent sharing. clone_file falls back to a stream-copy (semantically equivalent, just not zero-copy); clone_range returns crate::Error::Unsupported.

WholeFile

Whole-file clone only — the backend can share every extent of the source into the destination as one atomic operation (e.g. APFS file-clone records). Sub-file ranges aren’t individually shareable, so clone_range still errors Unsupported unless the range exactly covers the whole file.

Range

Arbitrary range clone — clone_range works for any allocation- unit-aligned (src_off, dst_off, len) triple. XFS reflink, Btrfs BTRFS_IOC_CLONE_RANGE, and FICLONERANGE in general.

Implementations

impl CloneCapability

pub fn shares_extents(self) -> bool

True for CloneCapability::WholeFile or CloneCapability::Range. clone_file is guaranteed not to byte-copy in this case.

pub fn supports_range(self) -> bool

True only for CloneCapability::Range — i.e. sub-file clone_range calls will succeed (assuming alignment etc.).

Trait Implementations

impl Clone for CloneCapability

fn clone(&self) -> CloneCapability

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for CloneCapability

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

Formats the value using the given formatter.

impl PartialEq for CloneCapability

fn eq(&self, other: &CloneCapability) -> 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 Copy for CloneCapability

impl Eq for CloneCapability

impl StructuralPartialEq for CloneCapability