s1tiling.libs.steps.StepFactory

class s1tiling.libs.steps.StepFactory(name: str, *unused_argv, **kwargs)

Bases: ABC

Abstract factory for AbstractStep

Meant to be inherited for each possible OTB application or external application used in a pipeline.

Sometimes we may also want to add some artificial steps that analyse products, filenames…, or step that help filter products for following pipelines.

See: Existing processings

New methods & Specialized methods

__init__
_do_create_actual_step	Generic variation point for the exact step creation.
_get_canonical_input	Helper function to retrieve the canonical input associated to a list of inputs.
_get_inputs	Extract the last inputs to use at the current level from all previous products seen in the pipeline.
_update_filename_meta_post_hook	Hook meant to be overridden to fix product metadata by overriding their default definition.
_update_filename_meta_pre_hook	Hook meant to be overridden to complete product metadata before they are used to produce filenames or tasknames.
build_step_output_filename	Filename of the step output.
build_step_output_tmp_filename	Returns a filename to a temporary file to use in output of the current application.
check_requirements	Abstract method used to test whether a StepFactory has all its external requirements fulfilled.
complete_meta	Duplicates, completes, and returns, the meta dictionary with specific information for the current factory regarding Step instanciation.
create_step	Instanciates the step related to the current StepFactory, that consumes results from the previous input steps.
update_filename_meta	Duplicates, completes, and returns, the meta dictionary with specific information for the current factory regarding tasks analysis.
update_image_metadata	Root implementation of update_image_metadata() that shall be specialized in every file producing Step Factory.

Attributes and properties

image_description	Property image_description, used to fill TIFFTAG_IMAGEDESCRIPTION
name	Step Name property.

_do_create_actual_step(execution_parameters: Dict, input_step: AbstractStep, meta: Dict) → AbstractStep

Generic variation point for the exact step creation. The default implementation returns a new AbstractStep.

_update_filename_meta_post_hook(meta: Dict) → None

Hook meant to be overridden to fix product metadata by overriding their default definition.

Called from update_filename_meta()

_update_filename_meta_pre_hook(meta: Dict) → Dict

Hook meant to be overridden to complete product metadata before they are used to produce filenames or tasknames.

Called from update_filename_meta()

abstract build_step_output_filename(meta: Dict) → str | List[str]

Filename of the step output.

See also build_step_output_tmp_filename() regarding the actual processing.

abstract build_step_output_tmp_filename(meta: Dict) → str | List[str]

Returns a filename to a temporary file to use in output of the current application.

When an OTB (/External) application is harshly interrupted (crash or user interruption), it leaves behind an incomplete (and thus invalid) file. In order to ignore those files when a pipeline is restarted, an temporary filename is used by the application. Once the application exits with success, the file will be renamed into build_step_output_filename(), and possibly moved into _FileProducingStepFactory.output_directory() if this is a final product.

check_requirements() → Tuple[str, str] | None

Abstract method used to test whether a StepFactory has all its external requirements fulfilled. For instance, OTBStepFactory’s will check their related OTB application can be executed.

Returns:

None if requirements are fulfilled.

Returns:

A message indicating what is missing otherwise, and some context how to fix it.

complete_meta(meta: Dict, all_inputs: List[Dict[str, AbstractStep]]) → Dict

Duplicates, completes, and returns, the meta dictionary with specific information for the current factory regarding Step instanciation.

create_step(execution_parameters: Dict, previous_steps: List[List[Dict[str, AbstractStep]]]) → AbstractStep

Instanciates the step related to the current StepFactory, that consumes results from the previous input steps.

1. This methods starts by updating metadata information through: complete_meta() on the input metadatas.

2. Then it updates the GDAL image metadata information that will need to be written in the pipeline output image through update_image_metadata().

3. Eventually the actual step creation method is executed according to the exact kind of step factory (ExecutableStepFactory, AnyProducerStepFactory, OTBStepFactory) through the variation point _do_create_actual_step().

While this method is not meant to be overridden, for simplity it will be in Store factory.

Note: it’s possible to override this method to return no step (None). In that case, no OTB Application would be registered in the actual Pipeline.

property image_description: str

Property image_description, used to fill TIFFTAG_IMAGEDESCRIPTION

property name: str

Step Name property.

update_filename_meta(meta: Dict) → Dict

Duplicates, completes, and returns, the meta dictionary with specific information for the current factory regarding tasks analysis.

This method is used:

• while analysing the dependencies to build the task graph – in this use case the relevant information are the file names and paths.

• and indirectly before instanciating a new Step

Other metadata not filled here:

• get_task_name() which is deduced from out_filename by default

• out_extended_filename_complement()

It’s possible to inject some other metadata (that could be used from _get_canonical_input() for instance) thanks to _update_filename_meta_pre_hook().

This method is not meant to be overridden. Instead it implements the template method design pattern, and expects the customization to be done through the specialization of the hooks:

• _update_filename_meta_pre_hook(),

• _update_filename_meta_post_hook().

update_image_metadata(meta: Dict, all_inputs: List[Dict[str, AbstractStep]]) → None

Root implementation of update_image_metadata() that shall be specialized in every file producing Step Factory.