chunk_contract

method of dascore.core.processor.PatchProcessor

source

chunk_contract(
    self ,
    dtype ,
    plan: ‘dict[str, Any]’ ,
)-> ‘ChunkContract | None’

Return what a chunk of the output needs of the input, or None.

Asked when the operation runs on a lazy array, with the input’s dtype and the plan get_metadata returned, before anything is read. A contract from dascore.lazy.contract lets it run there; None, the default, says it cannot, and the operation is refused rather than the data loaded for it.