craft_parts.overlays.layers module

Layer management and helpers.

class craft_parts.overlays.layers.LayerHash(layer_hash)

Bases: object

The layer validation hash for a part.

Parameters:

layer_hash (bytes)

classmethod for_part(part, *, previous_layer_hash)

Obtain the validation hash for a part.

Parameters:

• part (Part) – The part being processed.

• previous_layer_hash (LayerHash | None) – The validation hash of the previous layer in the overlay stack.

Return type:

LayerHash

Returns:

The validation hash computed for the layer corresponding to the given part.

hex()

Return the current hash value as a hexadecimal string.

Return type:

str

classmethod load(part)

Read the part layer validation hash from persistent state.

Parameters:

part (Part) – The part whose layer hash will be loaded.

Return type:

LayerHash | None

Returns:

A layer hash object containing the loaded validation hash, or None if the file doesn’t exist.

save(part)

Save the part layer validation hash to persistent storage.

Parameters:

part (Part) – The part whose layer hash will be saved.

Return type:

None

class craft_parts.overlays.layers.LayerStateManager(part_list, base_layer_hash)

Bases: object

An in-memory layer state management helper for action planning.

Parameters:

• part_list (list[Part]) – The list of parts in the project.

• base_layer_hash (LayerHash | None) – The verification hash of the overlay base layer.

compute_layer_hash(part)

Calculate the layer validation hash for the given part.

Parameters:

part (Part) – The part being processed.

Return type:

LayerHash

Returns:

The validation hash of the layer corresponding to the given part.

get_layer_hash(part)

Obtain the layer hash for the given part.

Parameters:

part (Part)

Return type:

LayerHash | None

get_overlay_hash()

Obtain the overlay validation hash.

Return type:

bytes

set_layer_hash(part, layer_hash)

Store the value of the layer hash for the given part.

Parameters:

• part (Part)

• layer_hash (LayerHash | None)

Return type:

None