Class SCC

mypy/build.py:216–243

A simple class that represents a strongly connected component (import cycle).

class SCC:
    """A simple class that represents a strongly connected component (import cycle)."""

    id_counter: ClassVar[int] = 0

    def __init__(
        self, ids: set[str], scc_id: int | None = None, deps: list[int] | None = None
    ) -> None:
        if scc_id is None:
            self.id = SCC.id_counter
            SCC.id_counter += 1
        else:
            self.id = scc_id
        # Ids of modules in this cycle.
        self.mod_ids = ids
        # Direct dependencies, should be populated by the caller.
        self.deps: set[int] = set(deps) if deps is not None else set()
        # Direct dependencies that have not been processed yet.
        # Should be populated by the caller. This set may change during graph
        # processing, while the above stays constant.
        self.not_ready_deps: set[int] = set()
        # SCCs that (directly) depend on this SCC. Note this is a list to
        # make processing order more predictable. Dependents will be notified
        # that they may be ready in the order in this list.
        self.direct_dependents: list[int] = []
        # Rough estimate of how much time processing this SCC will take, this
        # is used for more efficient scheduling across multiple build workers.
        self.size_hint: int = MIN_SIZE_HINT


# TODO: Get rid of BuildResult.  We might as well return a BuildManager.