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Diffstat (limited to '.venv/lib/python3.12/site-packages/pip/_vendor/resolvelib/resolvers')
10 files changed, 801 insertions, 0 deletions
diff --git a/.venv/lib/python3.12/site-packages/pip/_vendor/resolvelib/resolvers/__init__.py b/.venv/lib/python3.12/site-packages/pip/_vendor/resolvelib/resolvers/__init__.py new file mode 100644 index 0000000..b249221 --- /dev/null +++ b/.venv/lib/python3.12/site-packages/pip/_vendor/resolvelib/resolvers/__init__.py @@ -0,0 +1,27 @@ +from ..structs import RequirementInformation +from .abstract import AbstractResolver, Result +from .criterion import Criterion +from .exceptions import ( + InconsistentCandidate, + RequirementsConflicted, + ResolutionError, + ResolutionImpossible, + ResolutionTooDeep, + ResolverException, +) +from .resolution import Resolution, Resolver + +__all__ = [ + "AbstractResolver", + "Criterion", + "InconsistentCandidate", + "RequirementInformation", + "RequirementsConflicted", + "Resolution", + "ResolutionError", + "ResolutionImpossible", + "ResolutionTooDeep", + "Resolver", + "ResolverException", + "Result", +] diff --git a/.venv/lib/python3.12/site-packages/pip/_vendor/resolvelib/resolvers/__pycache__/__init__.cpython-312.pyc b/.venv/lib/python3.12/site-packages/pip/_vendor/resolvelib/resolvers/__pycache__/__init__.cpython-312.pyc Binary files differnew file mode 100644 index 0000000..9401280 --- /dev/null +++ b/.venv/lib/python3.12/site-packages/pip/_vendor/resolvelib/resolvers/__pycache__/__init__.cpython-312.pyc diff --git a/.venv/lib/python3.12/site-packages/pip/_vendor/resolvelib/resolvers/__pycache__/abstract.cpython-312.pyc b/.venv/lib/python3.12/site-packages/pip/_vendor/resolvelib/resolvers/__pycache__/abstract.cpython-312.pyc Binary files differnew file mode 100644 index 0000000..b6e0cbc --- /dev/null +++ b/.venv/lib/python3.12/site-packages/pip/_vendor/resolvelib/resolvers/__pycache__/abstract.cpython-312.pyc diff --git a/.venv/lib/python3.12/site-packages/pip/_vendor/resolvelib/resolvers/__pycache__/criterion.cpython-312.pyc b/.venv/lib/python3.12/site-packages/pip/_vendor/resolvelib/resolvers/__pycache__/criterion.cpython-312.pyc Binary files differnew file mode 100644 index 0000000..2f17d80 --- /dev/null +++ b/.venv/lib/python3.12/site-packages/pip/_vendor/resolvelib/resolvers/__pycache__/criterion.cpython-312.pyc diff --git a/.venv/lib/python3.12/site-packages/pip/_vendor/resolvelib/resolvers/__pycache__/exceptions.cpython-312.pyc b/.venv/lib/python3.12/site-packages/pip/_vendor/resolvelib/resolvers/__pycache__/exceptions.cpython-312.pyc Binary files differnew file mode 100644 index 0000000..7e10f00 --- /dev/null +++ b/.venv/lib/python3.12/site-packages/pip/_vendor/resolvelib/resolvers/__pycache__/exceptions.cpython-312.pyc diff --git a/.venv/lib/python3.12/site-packages/pip/_vendor/resolvelib/resolvers/__pycache__/resolution.cpython-312.pyc b/.venv/lib/python3.12/site-packages/pip/_vendor/resolvelib/resolvers/__pycache__/resolution.cpython-312.pyc Binary files differnew file mode 100644 index 0000000..3e7c9b4 --- /dev/null +++ b/.venv/lib/python3.12/site-packages/pip/_vendor/resolvelib/resolvers/__pycache__/resolution.cpython-312.pyc diff --git a/.venv/lib/python3.12/site-packages/pip/_vendor/resolvelib/resolvers/abstract.py b/.venv/lib/python3.12/site-packages/pip/_vendor/resolvelib/resolvers/abstract.py new file mode 100644 index 0000000..f9b5a7a --- /dev/null +++ b/.venv/lib/python3.12/site-packages/pip/_vendor/resolvelib/resolvers/abstract.py @@ -0,0 +1,47 @@ +from __future__ import annotations + +import collections +from typing import TYPE_CHECKING, Any, Generic, Iterable, Mapping, NamedTuple + +from ..structs import CT, KT, RT, DirectedGraph + +if TYPE_CHECKING: + from ..providers import AbstractProvider + from ..reporters import BaseReporter + from .criterion import Criterion + + class Result(NamedTuple, Generic[RT, CT, KT]): + mapping: Mapping[KT, CT] + graph: DirectedGraph[KT | None] + criteria: Mapping[KT, Criterion[RT, CT]] + +else: + Result = collections.namedtuple("Result", ["mapping", "graph", "criteria"]) + + +class AbstractResolver(Generic[RT, CT, KT]): + """The thing that performs the actual resolution work.""" + + base_exception = Exception + + def __init__( + self, + provider: AbstractProvider[RT, CT, KT], + reporter: BaseReporter[RT, CT, KT], + ) -> None: + self.provider = provider + self.reporter = reporter + + def resolve(self, requirements: Iterable[RT], **kwargs: Any) -> Result[RT, CT, KT]: + """Take a collection of constraints, spit out the resolution result. + + This returns a representation of the final resolution state, with one + guarenteed attribute ``mapping`` that contains resolved candidates as + values. The keys are their respective identifiers. + + :param requirements: A collection of constraints. + :param kwargs: Additional keyword arguments that subclasses may accept. + + :raises: ``self.base_exception`` or its subclass. + """ + raise NotImplementedError diff --git a/.venv/lib/python3.12/site-packages/pip/_vendor/resolvelib/resolvers/criterion.py b/.venv/lib/python3.12/site-packages/pip/_vendor/resolvelib/resolvers/criterion.py new file mode 100644 index 0000000..ee5019c --- /dev/null +++ b/.venv/lib/python3.12/site-packages/pip/_vendor/resolvelib/resolvers/criterion.py @@ -0,0 +1,48 @@ +from __future__ import annotations + +from typing import Collection, Generic, Iterable, Iterator + +from ..structs import CT, RT, RequirementInformation + + +class Criterion(Generic[RT, CT]): + """Representation of possible resolution results of a package. + + This holds three attributes: + + * `information` is a collection of `RequirementInformation` pairs. + Each pair is a requirement contributing to this criterion, and the + candidate that provides the requirement. + * `incompatibilities` is a collection of all known not-to-work candidates + to exclude from consideration. + * `candidates` is a collection containing all possible candidates deducted + from the union of contributing requirements and known incompatibilities. + It should never be empty, except when the criterion is an attribute of a + raised `RequirementsConflicted` (in which case it is always empty). + + .. note:: + This class is intended to be externally immutable. **Do not** mutate + any of its attribute containers. + """ + + def __init__( + self, + candidates: Iterable[CT], + information: Collection[RequirementInformation[RT, CT]], + incompatibilities: Collection[CT], + ) -> None: + self.candidates = candidates + self.information = information + self.incompatibilities = incompatibilities + + def __repr__(self) -> str: + requirements = ", ".join( + f"({req!r}, via={parent!r})" for req, parent in self.information + ) + return f"Criterion({requirements})" + + def iter_requirement(self) -> Iterator[RT]: + return (i.requirement for i in self.information) + + def iter_parent(self) -> Iterator[CT | None]: + return (i.parent for i in self.information) diff --git a/.venv/lib/python3.12/site-packages/pip/_vendor/resolvelib/resolvers/exceptions.py b/.venv/lib/python3.12/site-packages/pip/_vendor/resolvelib/resolvers/exceptions.py new file mode 100644 index 0000000..35e2755 --- /dev/null +++ b/.venv/lib/python3.12/site-packages/pip/_vendor/resolvelib/resolvers/exceptions.py @@ -0,0 +1,57 @@ +from __future__ import annotations + +from typing import TYPE_CHECKING, Collection, Generic + +from ..structs import CT, RT, RequirementInformation + +if TYPE_CHECKING: + from .criterion import Criterion + + +class ResolverException(Exception): + """A base class for all exceptions raised by this module. + + Exceptions derived by this class should all be handled in this module. Any + bubbling pass the resolver should be treated as a bug. + """ + + +class RequirementsConflicted(ResolverException, Generic[RT, CT]): + def __init__(self, criterion: Criterion[RT, CT]) -> None: + super().__init__(criterion) + self.criterion = criterion + + def __str__(self) -> str: + return "Requirements conflict: {}".format( + ", ".join(repr(r) for r in self.criterion.iter_requirement()), + ) + + +class InconsistentCandidate(ResolverException, Generic[RT, CT]): + def __init__(self, candidate: CT, criterion: Criterion[RT, CT]): + super().__init__(candidate, criterion) + self.candidate = candidate + self.criterion = criterion + + def __str__(self) -> str: + return "Provided candidate {!r} does not satisfy {}".format( + self.candidate, + ", ".join(repr(r) for r in self.criterion.iter_requirement()), + ) + + +class ResolutionError(ResolverException): + pass + + +class ResolutionImpossible(ResolutionError, Generic[RT, CT]): + def __init__(self, causes: Collection[RequirementInformation[RT, CT]]): + super().__init__(causes) + # causes is a list of RequirementInformation objects + self.causes = causes + + +class ResolutionTooDeep(ResolutionError): + def __init__(self, round_count: int) -> None: + super().__init__(round_count) + self.round_count = round_count diff --git a/.venv/lib/python3.12/site-packages/pip/_vendor/resolvelib/resolvers/resolution.py b/.venv/lib/python3.12/site-packages/pip/_vendor/resolvelib/resolvers/resolution.py new file mode 100644 index 0000000..f55ac7a --- /dev/null +++ b/.venv/lib/python3.12/site-packages/pip/_vendor/resolvelib/resolvers/resolution.py @@ -0,0 +1,622 @@ +from __future__ import annotations + +import collections +import itertools +import operator +from typing import TYPE_CHECKING, Generic + +from ..structs import ( + CT, + KT, + RT, + DirectedGraph, + IterableView, + IteratorMapping, + RequirementInformation, + State, + build_iter_view, +) +from .abstract import AbstractResolver, Result +from .criterion import Criterion +from .exceptions import ( + InconsistentCandidate, + RequirementsConflicted, + ResolutionImpossible, + ResolutionTooDeep, + ResolverException, +) + +if TYPE_CHECKING: + from collections.abc import Collection, Iterable, Mapping + + from ..providers import AbstractProvider, Preference + from ..reporters import BaseReporter + +_OPTIMISTIC_BACKJUMPING_RATIO: float = 0.1 + + +def _build_result(state: State[RT, CT, KT]) -> Result[RT, CT, KT]: + mapping = state.mapping + all_keys: dict[int, KT | None] = {id(v): k for k, v in mapping.items()} + all_keys[id(None)] = None + + graph: DirectedGraph[KT | None] = DirectedGraph() + graph.add(None) # Sentinel as root dependencies' parent. + + connected: set[KT | None] = {None} + for key, criterion in state.criteria.items(): + if not _has_route_to_root(state.criteria, key, all_keys, connected): + continue + if key not in graph: + graph.add(key) + for p in criterion.iter_parent(): + try: + pkey = all_keys[id(p)] + except KeyError: + continue + if pkey not in graph: + graph.add(pkey) + graph.connect(pkey, key) + + return Result( + mapping={k: v for k, v in mapping.items() if k in connected}, + graph=graph, + criteria=state.criteria, + ) + + +class Resolution(Generic[RT, CT, KT]): + """Stateful resolution object. + + This is designed as a one-off object that holds information to kick start + the resolution process, and holds the results afterwards. + """ + + def __init__( + self, + provider: AbstractProvider[RT, CT, KT], + reporter: BaseReporter[RT, CT, KT], + ) -> None: + self._p = provider + self._r = reporter + self._states: list[State[RT, CT, KT]] = [] + + # Optimistic backjumping variables + self._optimistic_backjumping_ratio = _OPTIMISTIC_BACKJUMPING_RATIO + self._save_states: list[State[RT, CT, KT]] | None = None + self._optimistic_start_round: int | None = None + + @property + def state(self) -> State[RT, CT, KT]: + try: + return self._states[-1] + except IndexError as e: + raise AttributeError("state") from e + + def _push_new_state(self) -> None: + """Push a new state into history. + + This new state will be used to hold resolution results of the next + coming round. + """ + base = self._states[-1] + state = State( + mapping=base.mapping.copy(), + criteria=base.criteria.copy(), + backtrack_causes=base.backtrack_causes[:], + ) + self._states.append(state) + + def _add_to_criteria( + self, + criteria: dict[KT, Criterion[RT, CT]], + requirement: RT, + parent: CT | None, + ) -> None: + self._r.adding_requirement(requirement=requirement, parent=parent) + + identifier = self._p.identify(requirement_or_candidate=requirement) + criterion = criteria.get(identifier) + if criterion: + incompatibilities = list(criterion.incompatibilities) + else: + incompatibilities = [] + + matches = self._p.find_matches( + identifier=identifier, + requirements=IteratorMapping( + criteria, + operator.methodcaller("iter_requirement"), + {identifier: [requirement]}, + ), + incompatibilities=IteratorMapping( + criteria, + operator.attrgetter("incompatibilities"), + {identifier: incompatibilities}, + ), + ) + + if criterion: + information = list(criterion.information) + information.append(RequirementInformation(requirement, parent)) + else: + information = [RequirementInformation(requirement, parent)] + + criterion = Criterion( + candidates=build_iter_view(matches), + information=information, + incompatibilities=incompatibilities, + ) + if not criterion.candidates: + raise RequirementsConflicted(criterion) + criteria[identifier] = criterion + + def _remove_information_from_criteria( + self, criteria: dict[KT, Criterion[RT, CT]], parents: Collection[KT] + ) -> None: + """Remove information from parents of criteria. + + Concretely, removes all values from each criterion's ``information`` + field that have one of ``parents`` as provider of the requirement. + + :param criteria: The criteria to update. + :param parents: Identifiers for which to remove information from all criteria. + """ + if not parents: + return + for key, criterion in criteria.items(): + criteria[key] = Criterion( + criterion.candidates, + [ + information + for information in criterion.information + if ( + information.parent is None + or self._p.identify(information.parent) not in parents + ) + ], + criterion.incompatibilities, + ) + + def _get_preference(self, name: KT) -> Preference: + return self._p.get_preference( + identifier=name, + resolutions=self.state.mapping, + candidates=IteratorMapping( + self.state.criteria, + operator.attrgetter("candidates"), + ), + information=IteratorMapping( + self.state.criteria, + operator.attrgetter("information"), + ), + backtrack_causes=self.state.backtrack_causes, + ) + + def _is_current_pin_satisfying( + self, name: KT, criterion: Criterion[RT, CT] + ) -> bool: + try: + current_pin = self.state.mapping[name] + except KeyError: + return False + return all( + self._p.is_satisfied_by(requirement=r, candidate=current_pin) + for r in criterion.iter_requirement() + ) + + def _get_updated_criteria(self, candidate: CT) -> dict[KT, Criterion[RT, CT]]: + criteria = self.state.criteria.copy() + for requirement in self._p.get_dependencies(candidate=candidate): + self._add_to_criteria(criteria, requirement, parent=candidate) + return criteria + + def _attempt_to_pin_criterion(self, name: KT) -> list[Criterion[RT, CT]]: + criterion = self.state.criteria[name] + + causes: list[Criterion[RT, CT]] = [] + for candidate in criterion.candidates: + try: + criteria = self._get_updated_criteria(candidate) + except RequirementsConflicted as e: + self._r.rejecting_candidate(e.criterion, candidate) + causes.append(e.criterion) + continue + + # Check the newly-pinned candidate actually works. This should + # always pass under normal circumstances, but in the case of a + # faulty provider, we will raise an error to notify the implementer + # to fix find_matches() and/or is_satisfied_by(). + satisfied = all( + self._p.is_satisfied_by(requirement=r, candidate=candidate) + for r in criterion.iter_requirement() + ) + if not satisfied: + raise InconsistentCandidate(candidate, criterion) + + self._r.pinning(candidate=candidate) + self.state.criteria.update(criteria) + + # Put newly-pinned candidate at the end. This is essential because + # backtracking looks at this mapping to get the last pin. + self.state.mapping.pop(name, None) + self.state.mapping[name] = candidate + + return [] + + # All candidates tried, nothing works. This criterion is a dead + # end, signal for backtracking. + return causes + + def _patch_criteria( + self, incompatibilities_from_broken: list[tuple[KT, list[CT]]] + ) -> bool: + # Create a new state from the last known-to-work one, and apply + # the previously gathered incompatibility information. + for k, incompatibilities in incompatibilities_from_broken: + if not incompatibilities: + continue + try: + criterion = self.state.criteria[k] + except KeyError: + continue + matches = self._p.find_matches( + identifier=k, + requirements=IteratorMapping( + self.state.criteria, + operator.methodcaller("iter_requirement"), + ), + incompatibilities=IteratorMapping( + self.state.criteria, + operator.attrgetter("incompatibilities"), + {k: incompatibilities}, + ), + ) + candidates: IterableView[CT] = build_iter_view(matches) + if not candidates: + return False + incompatibilities.extend(criterion.incompatibilities) + self.state.criteria[k] = Criterion( + candidates=candidates, + information=list(criterion.information), + incompatibilities=incompatibilities, + ) + return True + + def _save_state(self) -> None: + """Save states for potential rollback if optimistic backjumping fails.""" + if self._save_states is None: + self._save_states = [ + State( + mapping=s.mapping.copy(), + criteria=s.criteria.copy(), + backtrack_causes=s.backtrack_causes[:], + ) + for s in self._states + ] + + def _rollback_states(self) -> None: + """Rollback states and disable optimistic backjumping.""" + self._optimistic_backjumping_ratio = 0.0 + if self._save_states: + self._states = self._save_states + self._save_states = None + + def _backjump(self, causes: list[RequirementInformation[RT, CT]]) -> bool: + """Perform backjumping. + + When we enter here, the stack is like this:: + + [ state Z ] + [ state Y ] + [ state X ] + .... earlier states are irrelevant. + + 1. No pins worked for Z, so it does not have a pin. + 2. We want to reset state Y to unpinned, and pin another candidate. + 3. State X holds what state Y was before the pin, but does not + have the incompatibility information gathered in state Y. + + Each iteration of the loop will: + + 1. Identify Z. The incompatibility is not always caused by the latest + state. For example, given three requirements A, B and C, with + dependencies A1, B1 and C1, where A1 and B1 are incompatible: the + last state might be related to C, so we want to discard the + previous state. + 2. Discard Z. + 3. Discard Y but remember its incompatibility information gathered + previously, and the failure we're dealing with right now. + 4. Push a new state Y' based on X, and apply the incompatibility + information from Y to Y'. + 5a. If this causes Y' to conflict, we need to backtrack again. Make Y' + the new Z and go back to step 2. + 5b. If the incompatibilities apply cleanly, end backtracking. + """ + incompatible_reqs: Iterable[CT | RT] = itertools.chain( + (c.parent for c in causes if c.parent is not None), + (c.requirement for c in causes), + ) + incompatible_deps = {self._p.identify(r) for r in incompatible_reqs} + while len(self._states) >= 3: + # Remove the state that triggered backtracking. + del self._states[-1] + + # Optimistically backtrack to a state that caused the incompatibility + broken_state = self.state + while True: + # Retrieve the last candidate pin and known incompatibilities. + try: + broken_state = self._states.pop() + name, candidate = broken_state.mapping.popitem() + except (IndexError, KeyError): + raise ResolutionImpossible(causes) from None + + if ( + not self._optimistic_backjumping_ratio + and name not in incompatible_deps + ): + # For safe backjumping only backjump if the current dependency + # is not the same as the incompatible dependency + break + + # On the first time a non-safe backjump is done the state + # is saved so we can restore it later if the resolution fails + if ( + self._optimistic_backjumping_ratio + and self._save_states is None + and name not in incompatible_deps + ): + self._save_state() + + # If the current dependencies and the incompatible dependencies + # are overlapping then we have likely found a cause of the + # incompatibility + current_dependencies = { + self._p.identify(d) for d in self._p.get_dependencies(candidate) + } + if not current_dependencies.isdisjoint(incompatible_deps): + break + + # Fallback: We should not backtrack to the point where + # broken_state.mapping is empty, so stop backtracking for + # a chance for the resolution to recover + if not broken_state.mapping: + break + + incompatibilities_from_broken = [ + (k, list(v.incompatibilities)) for k, v in broken_state.criteria.items() + ] + + # Also mark the newly known incompatibility. + incompatibilities_from_broken.append((name, [candidate])) + + self._push_new_state() + success = self._patch_criteria(incompatibilities_from_broken) + + # It works! Let's work on this new state. + if success: + return True + + # State does not work after applying known incompatibilities. + # Try the still previous state. + + # No way to backtrack anymore. + return False + + def _extract_causes( + self, criteron: list[Criterion[RT, CT]] + ) -> list[RequirementInformation[RT, CT]]: + """Extract causes from list of criterion and deduplicate""" + return list({id(i): i for c in criteron for i in c.information}.values()) + + def resolve(self, requirements: Iterable[RT], max_rounds: int) -> State[RT, CT, KT]: + if self._states: + raise RuntimeError("already resolved") + + self._r.starting() + + # Initialize the root state. + self._states = [ + State( + mapping=collections.OrderedDict(), + criteria={}, + backtrack_causes=[], + ) + ] + for r in requirements: + try: + self._add_to_criteria(self.state.criteria, r, parent=None) + except RequirementsConflicted as e: + raise ResolutionImpossible(e.criterion.information) from e + + # The root state is saved as a sentinel so the first ever pin can have + # something to backtrack to if it fails. The root state is basically + # pinning the virtual "root" package in the graph. + self._push_new_state() + + # Variables for optimistic backjumping + optimistic_rounds_cutoff: int | None = None + optimistic_backjumping_start_round: int | None = None + + for round_index in range(max_rounds): + self._r.starting_round(index=round_index) + + # Handle if optimistic backjumping has been running for too long + if self._optimistic_backjumping_ratio and self._save_states is not None: + if optimistic_backjumping_start_round is None: + optimistic_backjumping_start_round = round_index + optimistic_rounds_cutoff = int( + (max_rounds - round_index) * self._optimistic_backjumping_ratio + ) + + if optimistic_rounds_cutoff <= 0: + self._rollback_states() + continue + elif optimistic_rounds_cutoff is not None: + if ( + round_index - optimistic_backjumping_start_round + >= optimistic_rounds_cutoff + ): + self._rollback_states() + continue + + unsatisfied_names = [ + key + for key, criterion in self.state.criteria.items() + if not self._is_current_pin_satisfying(key, criterion) + ] + + # All criteria are accounted for. Nothing more to pin, we are done! + if not unsatisfied_names: + self._r.ending(state=self.state) + return self.state + + # keep track of satisfied names to calculate diff after pinning + satisfied_names = set(self.state.criteria.keys()) - set(unsatisfied_names) + + if len(unsatisfied_names) > 1: + narrowed_unstatisfied_names = list( + self._p.narrow_requirement_selection( + identifiers=unsatisfied_names, + resolutions=self.state.mapping, + candidates=IteratorMapping( + self.state.criteria, + operator.attrgetter("candidates"), + ), + information=IteratorMapping( + self.state.criteria, + operator.attrgetter("information"), + ), + backtrack_causes=self.state.backtrack_causes, + ) + ) + else: + narrowed_unstatisfied_names = unsatisfied_names + + # If there are no unsatisfied names use unsatisfied names + if not narrowed_unstatisfied_names: + raise RuntimeError("narrow_requirement_selection returned 0 names") + + # If there is only 1 unsatisfied name skip calling self._get_preference + if len(narrowed_unstatisfied_names) > 1: + # Choose the most preferred unpinned criterion to try. + name = min(narrowed_unstatisfied_names, key=self._get_preference) + else: + name = narrowed_unstatisfied_names[0] + + failure_criterion = self._attempt_to_pin_criterion(name) + + if failure_criterion: + causes = self._extract_causes(failure_criterion) + # Backjump if pinning fails. The backjump process puts us in + # an unpinned state, so we can work on it in the next round. + self._r.resolving_conflicts(causes=causes) + + try: + success = self._backjump(causes) + except ResolutionImpossible: + if self._optimistic_backjumping_ratio and self._save_states: + failed_optimistic_backjumping = True + else: + raise + else: + failed_optimistic_backjumping = bool( + not success + and self._optimistic_backjumping_ratio + and self._save_states + ) + + if failed_optimistic_backjumping and self._save_states: + self._rollback_states() + else: + self.state.backtrack_causes[:] = causes + + # Dead ends everywhere. Give up. + if not success: + raise ResolutionImpossible(self.state.backtrack_causes) + else: + # discard as information sources any invalidated names + # (unsatisfied names that were previously satisfied) + newly_unsatisfied_names = { + key + for key, criterion in self.state.criteria.items() + if key in satisfied_names + and not self._is_current_pin_satisfying(key, criterion) + } + self._remove_information_from_criteria( + self.state.criteria, newly_unsatisfied_names + ) + # Pinning was successful. Push a new state to do another pin. + self._push_new_state() + + self._r.ending_round(index=round_index, state=self.state) + + raise ResolutionTooDeep(max_rounds) + + +class Resolver(AbstractResolver[RT, CT, KT]): + """The thing that performs the actual resolution work.""" + + base_exception = ResolverException + + def resolve( # type: ignore[override] + self, + requirements: Iterable[RT], + max_rounds: int = 100, + ) -> Result[RT, CT, KT]: + """Take a collection of constraints, spit out the resolution result. + + The return value is a representation to the final resolution result. It + is a tuple subclass with three public members: + + * `mapping`: A dict of resolved candidates. Each key is an identifier + of a requirement (as returned by the provider's `identify` method), + and the value is the resolved candidate. + * `graph`: A `DirectedGraph` instance representing the dependency tree. + The vertices are keys of `mapping`, and each edge represents *why* + a particular package is included. A special vertex `None` is + included to represent parents of user-supplied requirements. + * `criteria`: A dict of "criteria" that hold detailed information on + how edges in the graph are derived. Each key is an identifier of a + requirement, and the value is a `Criterion` instance. + + The following exceptions may be raised if a resolution cannot be found: + + * `ResolutionImpossible`: A resolution cannot be found for the given + combination of requirements. The `causes` attribute of the + exception is a list of (requirement, parent), giving the + requirements that could not be satisfied. + * `ResolutionTooDeep`: The dependency tree is too deeply nested and + the resolver gave up. This is usually caused by a circular + dependency, but you can try to resolve this by increasing the + `max_rounds` argument. + """ + resolution = Resolution(self.provider, self.reporter) + state = resolution.resolve(requirements, max_rounds=max_rounds) + return _build_result(state) + + +def _has_route_to_root( + criteria: Mapping[KT, Criterion[RT, CT]], + key: KT | None, + all_keys: dict[int, KT | None], + connected: set[KT | None], +) -> bool: + if key in connected: + return True + if key not in criteria: + return False + assert key is not None + for p in criteria[key].iter_parent(): + try: + pkey = all_keys[id(p)] + except KeyError: + continue + if pkey in connected: + connected.add(key) + return True + if _has_route_to_root(criteria, pkey, all_keys, connected): + connected.add(key) + return True + return False |