Struct EmittedLayer 

pub struct EmittedLayer {
    pub media_type: String,
    pub digest: String,
    pub size: u64,
    pub diff_id: String,
    pub local_path: PathBuf,
    pub urls: Option<Vec<String>>,
}

Locally-produced layer blob staged on disk for push (task 4.E).

Carries everything 4.E needs to upload a layer to a registry: the media type to advertise on the descriptor, the digest + size of the compressed blob, the diff_id for the image-config rootfs.diff_ids array, the on-disk path to the blob, and (for foreign base layers only) the upstream urls[] mirror list so the emitted manifest can point Windows daemons at the original MCR foreign-layer descriptor instead of forcing the daemon to re-download the bytes from the user’s own registry.

Fields

media_type: String

OCI media type used in the manifest’s layers[].mediaType. For the foreign Windows base layer this is application/vnd.docker.image.rootfs.foreign.diff.tar.gzip (so Windows daemons recognise it as a foreign layer and skip the download path); for builder-produced RUN/COPY/ADD layers this is application/vnd.oci.image.layer.v1.tar+gzip.

digest: String

sha256:... digest of the COMPRESSED (gzipped) tar blob.

size: u64

Compressed size in bytes (matches the descriptor’s size field).

diff_id: String

sha256:... of the UNCOMPRESSED tar blob — what rootfs.diff_ids[] references in the image config. For foreign base layers this is sourced from the base image config blob; for builder-produced layers this is computed at export time.

local_path: PathBuf

On-disk path to the compressed layer blob the registry client will upload during the 4.E push. Empty for foreign base layers (they’re never re-uploaded — the registry rehydrates them from urls[]).

urls: Option<Vec<String>>

For foreign layers: the MCR / mirror URL list preserved verbatim from the base manifest’s urls[]. None for builder-produced layers.

Trait Implementations

impl Clone for EmittedLayer

fn clone(&self) -> EmittedLayer

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for EmittedLayer

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

Formats the value using the given formatter.