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Diffstat (limited to '.venv/lib/python3.12/site-packages/pip/_internal/resolution/resolvelib/provider.py')
| -rw-r--r-- | .venv/lib/python3.12/site-packages/pip/_internal/resolution/resolvelib/provider.py | 258 |
1 files changed, 258 insertions, 0 deletions
diff --git a/.venv/lib/python3.12/site-packages/pip/_internal/resolution/resolvelib/provider.py b/.venv/lib/python3.12/site-packages/pip/_internal/resolution/resolvelib/provider.py new file mode 100644 index 00000000..fb0dd85f --- /dev/null +++ b/.venv/lib/python3.12/site-packages/pip/_internal/resolution/resolvelib/provider.py @@ -0,0 +1,258 @@ +import collections +import math +from functools import lru_cache +from typing import ( + TYPE_CHECKING, + Dict, + Iterable, + Iterator, + Mapping, + Sequence, + TypeVar, + Union, +) + +from pip._vendor.resolvelib.providers import AbstractProvider + +from .base import Candidate, Constraint, Requirement +from .candidates import REQUIRES_PYTHON_IDENTIFIER +from .factory import Factory + +if TYPE_CHECKING: + from pip._vendor.resolvelib.providers import Preference + from pip._vendor.resolvelib.resolvers import RequirementInformation + + PreferenceInformation = RequirementInformation[Requirement, Candidate] + + _ProviderBase = AbstractProvider[Requirement, Candidate, str] +else: + _ProviderBase = AbstractProvider + +# Notes on the relationship between the provider, the factory, and the +# candidate and requirement classes. +# +# The provider is a direct implementation of the resolvelib class. Its role +# is to deliver the API that resolvelib expects. +# +# Rather than work with completely abstract "requirement" and "candidate" +# concepts as resolvelib does, pip has concrete classes implementing these two +# ideas. The API of Requirement and Candidate objects are defined in the base +# classes, but essentially map fairly directly to the equivalent provider +# methods. In particular, `find_matches` and `is_satisfied_by` are +# requirement methods, and `get_dependencies` is a candidate method. +# +# The factory is the interface to pip's internal mechanisms. It is stateless, +# and is created by the resolver and held as a property of the provider. It is +# responsible for creating Requirement and Candidate objects, and provides +# services to those objects (access to pip's finder and preparer). + + +D = TypeVar("D") +V = TypeVar("V") + + +def _get_with_identifier( + mapping: Mapping[str, V], + identifier: str, + default: D, +) -> Union[D, V]: + """Get item from a package name lookup mapping with a resolver identifier. + + This extra logic is needed when the target mapping is keyed by package + name, which cannot be directly looked up with an identifier (which may + contain requested extras). Additional logic is added to also look up a value + by "cleaning up" the extras from the identifier. + """ + if identifier in mapping: + return mapping[identifier] + # HACK: Theoretically we should check whether this identifier is a valid + # "NAME[EXTRAS]" format, and parse out the name part with packaging or + # some regular expression. But since pip's resolver only spits out three + # kinds of identifiers: normalized PEP 503 names, normalized names plus + # extras, and Requires-Python, we can cheat a bit here. + name, open_bracket, _ = identifier.partition("[") + if open_bracket and name in mapping: + return mapping[name] + return default + + +class PipProvider(_ProviderBase): + """Pip's provider implementation for resolvelib. + + :params constraints: A mapping of constraints specified by the user. Keys + are canonicalized project names. + :params ignore_dependencies: Whether the user specified ``--no-deps``. + :params upgrade_strategy: The user-specified upgrade strategy. + :params user_requested: A set of canonicalized package names that the user + supplied for pip to install/upgrade. + """ + + def __init__( + self, + factory: Factory, + constraints: Dict[str, Constraint], + ignore_dependencies: bool, + upgrade_strategy: str, + user_requested: Dict[str, int], + ) -> None: + self._factory = factory + self._constraints = constraints + self._ignore_dependencies = ignore_dependencies + self._upgrade_strategy = upgrade_strategy + self._user_requested = user_requested + self._known_depths: Dict[str, float] = collections.defaultdict(lambda: math.inf) + + def identify(self, requirement_or_candidate: Union[Requirement, Candidate]) -> str: + return requirement_or_candidate.name + + def get_preference( + self, + identifier: str, + resolutions: Mapping[str, Candidate], + candidates: Mapping[str, Iterator[Candidate]], + information: Mapping[str, Iterable["PreferenceInformation"]], + backtrack_causes: Sequence["PreferenceInformation"], + ) -> "Preference": + """Produce a sort key for given requirement based on preference. + + The lower the return value is, the more preferred this group of + arguments is. + + Currently pip considers the following in order: + + * Prefer if any of the known requirements is "direct", e.g. points to an + explicit URL. + * If equal, prefer if any requirement is "pinned", i.e. contains + operator ``===`` or ``==``. + * If equal, calculate an approximate "depth" and resolve requirements + closer to the user-specified requirements first. If the depth cannot + by determined (eg: due to no matching parents), it is considered + infinite. + * Order user-specified requirements by the order they are specified. + * If equal, prefers "non-free" requirements, i.e. contains at least one + operator, such as ``>=`` or ``<``. + * If equal, order alphabetically for consistency (helps debuggability). + """ + try: + next(iter(information[identifier])) + except StopIteration: + # There is no information for this identifier, so there's no known + # candidates. + has_information = False + else: + has_information = True + + if has_information: + lookups = (r.get_candidate_lookup() for r, _ in information[identifier]) + candidate, ireqs = zip(*lookups) + else: + candidate, ireqs = None, () + + operators = [ + specifier.operator + for specifier_set in (ireq.specifier for ireq in ireqs if ireq) + for specifier in specifier_set + ] + + direct = candidate is not None + pinned = any(op[:2] == "==" for op in operators) + unfree = bool(operators) + + try: + requested_order: Union[int, float] = self._user_requested[identifier] + except KeyError: + requested_order = math.inf + if has_information: + parent_depths = ( + self._known_depths[parent.name] if parent is not None else 0.0 + for _, parent in information[identifier] + ) + inferred_depth = min(d for d in parent_depths) + 1.0 + else: + inferred_depth = math.inf + else: + inferred_depth = 1.0 + self._known_depths[identifier] = inferred_depth + + requested_order = self._user_requested.get(identifier, math.inf) + + # Requires-Python has only one candidate and the check is basically + # free, so we always do it first to avoid needless work if it fails. + requires_python = identifier == REQUIRES_PYTHON_IDENTIFIER + + # Prefer the causes of backtracking on the assumption that the problem + # resolving the dependency tree is related to the failures that caused + # the backtracking + backtrack_cause = self.is_backtrack_cause(identifier, backtrack_causes) + + return ( + not requires_python, + not direct, + not pinned, + not backtrack_cause, + inferred_depth, + requested_order, + not unfree, + identifier, + ) + + def find_matches( + self, + identifier: str, + requirements: Mapping[str, Iterator[Requirement]], + incompatibilities: Mapping[str, Iterator[Candidate]], + ) -> Iterable[Candidate]: + def _eligible_for_upgrade(identifier: str) -> bool: + """Are upgrades allowed for this project? + + This checks the upgrade strategy, and whether the project was one + that the user specified in the command line, in order to decide + whether we should upgrade if there's a newer version available. + + (Note that we don't need access to the `--upgrade` flag, because + an upgrade strategy of "to-satisfy-only" means that `--upgrade` + was not specified). + """ + if self._upgrade_strategy == "eager": + return True + elif self._upgrade_strategy == "only-if-needed": + user_order = _get_with_identifier( + self._user_requested, + identifier, + default=None, + ) + return user_order is not None + return False + + constraint = _get_with_identifier( + self._constraints, + identifier, + default=Constraint.empty(), + ) + return self._factory.find_candidates( + identifier=identifier, + requirements=requirements, + constraint=constraint, + prefers_installed=(not _eligible_for_upgrade(identifier)), + incompatibilities=incompatibilities, + is_satisfied_by=self.is_satisfied_by, + ) + + @lru_cache(maxsize=None) + def is_satisfied_by(self, requirement: Requirement, candidate: Candidate) -> bool: + return requirement.is_satisfied_by(candidate) + + def get_dependencies(self, candidate: Candidate) -> Sequence[Requirement]: + with_requires = not self._ignore_dependencies + return [r for r in candidate.iter_dependencies(with_requires) if r is not None] + + @staticmethod + def is_backtrack_cause( + identifier: str, backtrack_causes: Sequence["PreferenceInformation"] + ) -> bool: + for backtrack_cause in backtrack_causes: + if identifier == backtrack_cause.requirement.name: + return True + if backtrack_cause.parent and identifier == backtrack_cause.parent.name: + return True + return False |