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Diffstat (limited to '.venv/lib/python3.12/site-packages/pip/_internal/resolution/resolvelib/resolver.py')
| -rw-r--r-- | .venv/lib/python3.12/site-packages/pip/_internal/resolution/resolvelib/resolver.py | 317 |
1 files changed, 317 insertions, 0 deletions
diff --git a/.venv/lib/python3.12/site-packages/pip/_internal/resolution/resolvelib/resolver.py b/.venv/lib/python3.12/site-packages/pip/_internal/resolution/resolvelib/resolver.py new file mode 100644 index 00000000..c12beef0 --- /dev/null +++ b/.venv/lib/python3.12/site-packages/pip/_internal/resolution/resolvelib/resolver.py @@ -0,0 +1,317 @@ +import contextlib +import functools +import logging +import os +from typing import TYPE_CHECKING, Dict, List, Optional, Set, Tuple, cast + +from pip._vendor.packaging.utils import canonicalize_name +from pip._vendor.resolvelib import BaseReporter, ResolutionImpossible +from pip._vendor.resolvelib import Resolver as RLResolver +from pip._vendor.resolvelib.structs import DirectedGraph + +from pip._internal.cache import WheelCache +from pip._internal.index.package_finder import PackageFinder +from pip._internal.operations.prepare import RequirementPreparer +from pip._internal.req.constructors import install_req_extend_extras +from pip._internal.req.req_install import InstallRequirement +from pip._internal.req.req_set import RequirementSet +from pip._internal.resolution.base import BaseResolver, InstallRequirementProvider +from pip._internal.resolution.resolvelib.provider import PipProvider +from pip._internal.resolution.resolvelib.reporter import ( + PipDebuggingReporter, + PipReporter, +) +from pip._internal.utils.packaging import get_requirement + +from .base import Candidate, Requirement +from .factory import Factory + +if TYPE_CHECKING: + from pip._vendor.resolvelib.resolvers import Result as RLResult + + Result = RLResult[Requirement, Candidate, str] + + +logger = logging.getLogger(__name__) + + +class Resolver(BaseResolver): + _allowed_strategies = {"eager", "only-if-needed", "to-satisfy-only"} + + def __init__( + self, + preparer: RequirementPreparer, + finder: PackageFinder, + wheel_cache: Optional[WheelCache], + make_install_req: InstallRequirementProvider, + use_user_site: bool, + ignore_dependencies: bool, + ignore_installed: bool, + ignore_requires_python: bool, + force_reinstall: bool, + upgrade_strategy: str, + py_version_info: Optional[Tuple[int, ...]] = None, + ): + super().__init__() + assert upgrade_strategy in self._allowed_strategies + + self.factory = Factory( + finder=finder, + preparer=preparer, + make_install_req=make_install_req, + wheel_cache=wheel_cache, + use_user_site=use_user_site, + force_reinstall=force_reinstall, + ignore_installed=ignore_installed, + ignore_requires_python=ignore_requires_python, + py_version_info=py_version_info, + ) + self.ignore_dependencies = ignore_dependencies + self.upgrade_strategy = upgrade_strategy + self._result: Optional[Result] = None + + def resolve( + self, root_reqs: List[InstallRequirement], check_supported_wheels: bool + ) -> RequirementSet: + collected = self.factory.collect_root_requirements(root_reqs) + provider = PipProvider( + factory=self.factory, + constraints=collected.constraints, + ignore_dependencies=self.ignore_dependencies, + upgrade_strategy=self.upgrade_strategy, + user_requested=collected.user_requested, + ) + if "PIP_RESOLVER_DEBUG" in os.environ: + reporter: BaseReporter = PipDebuggingReporter() + else: + reporter = PipReporter() + resolver: RLResolver[Requirement, Candidate, str] = RLResolver( + provider, + reporter, + ) + + try: + limit_how_complex_resolution_can_be = 200000 + result = self._result = resolver.resolve( + collected.requirements, max_rounds=limit_how_complex_resolution_can_be + ) + + except ResolutionImpossible as e: + error = self.factory.get_installation_error( + cast("ResolutionImpossible[Requirement, Candidate]", e), + collected.constraints, + ) + raise error from e + + req_set = RequirementSet(check_supported_wheels=check_supported_wheels) + # process candidates with extras last to ensure their base equivalent is + # already in the req_set if appropriate. + # Python's sort is stable so using a binary key function keeps relative order + # within both subsets. + for candidate in sorted( + result.mapping.values(), key=lambda c: c.name != c.project_name + ): + ireq = candidate.get_install_requirement() + if ireq is None: + if candidate.name != candidate.project_name: + # extend existing req's extras + with contextlib.suppress(KeyError): + req = req_set.get_requirement(candidate.project_name) + req_set.add_named_requirement( + install_req_extend_extras( + req, get_requirement(candidate.name).extras + ) + ) + continue + + # Check if there is already an installation under the same name, + # and set a flag for later stages to uninstall it, if needed. + installed_dist = self.factory.get_dist_to_uninstall(candidate) + if installed_dist is None: + # There is no existing installation -- nothing to uninstall. + ireq.should_reinstall = False + elif self.factory.force_reinstall: + # The --force-reinstall flag is set -- reinstall. + ireq.should_reinstall = True + elif installed_dist.version != candidate.version: + # The installation is different in version -- reinstall. + ireq.should_reinstall = True + elif candidate.is_editable or installed_dist.editable: + # The incoming distribution is editable, or different in + # editable-ness to installation -- reinstall. + ireq.should_reinstall = True + elif candidate.source_link and candidate.source_link.is_file: + # The incoming distribution is under file:// + if candidate.source_link.is_wheel: + # is a local wheel -- do nothing. + logger.info( + "%s is already installed with the same version as the " + "provided wheel. Use --force-reinstall to force an " + "installation of the wheel.", + ireq.name, + ) + continue + + # is a local sdist or path -- reinstall + ireq.should_reinstall = True + else: + continue + + link = candidate.source_link + if link and link.is_yanked: + # The reason can contain non-ASCII characters, Unicode + # is required for Python 2. + msg = ( + "The candidate selected for download or install is a " + "yanked version: {name!r} candidate (version {version} " + "at {link})\nReason for being yanked: {reason}" + ).format( + name=candidate.name, + version=candidate.version, + link=link, + reason=link.yanked_reason or "<none given>", + ) + logger.warning(msg) + + req_set.add_named_requirement(ireq) + + reqs = req_set.all_requirements + self.factory.preparer.prepare_linked_requirements_more(reqs) + for req in reqs: + req.prepared = True + req.needs_more_preparation = False + return req_set + + def get_installation_order( + self, req_set: RequirementSet + ) -> List[InstallRequirement]: + """Get order for installation of requirements in RequirementSet. + + The returned list contains a requirement before another that depends on + it. This helps ensure that the environment is kept consistent as they + get installed one-by-one. + + The current implementation creates a topological ordering of the + dependency graph, giving more weight to packages with less + or no dependencies, while breaking any cycles in the graph at + arbitrary points. We make no guarantees about where the cycle + would be broken, other than it *would* be broken. + """ + assert self._result is not None, "must call resolve() first" + + if not req_set.requirements: + # Nothing is left to install, so we do not need an order. + return [] + + graph = self._result.graph + weights = get_topological_weights(graph, set(req_set.requirements.keys())) + + sorted_items = sorted( + req_set.requirements.items(), + key=functools.partial(_req_set_item_sorter, weights=weights), + reverse=True, + ) + return [ireq for _, ireq in sorted_items] + + +def get_topological_weights( + graph: "DirectedGraph[Optional[str]]", requirement_keys: Set[str] +) -> Dict[Optional[str], int]: + """Assign weights to each node based on how "deep" they are. + + This implementation may change at any point in the future without prior + notice. + + We first simplify the dependency graph by pruning any leaves and giving them + the highest weight: a package without any dependencies should be installed + first. This is done again and again in the same way, giving ever less weight + to the newly found leaves. The loop stops when no leaves are left: all + remaining packages have at least one dependency left in the graph. + + Then we continue with the remaining graph, by taking the length for the + longest path to any node from root, ignoring any paths that contain a single + node twice (i.e. cycles). This is done through a depth-first search through + the graph, while keeping track of the path to the node. + + Cycles in the graph result would result in node being revisited while also + being on its own path. In this case, take no action. This helps ensure we + don't get stuck in a cycle. + + When assigning weight, the longer path (i.e. larger length) is preferred. + + We are only interested in the weights of packages that are in the + requirement_keys. + """ + path: Set[Optional[str]] = set() + weights: Dict[Optional[str], int] = {} + + def visit(node: Optional[str]) -> None: + if node in path: + # We hit a cycle, so we'll break it here. + return + + # Time to visit the children! + path.add(node) + for child in graph.iter_children(node): + visit(child) + path.remove(node) + + if node not in requirement_keys: + return + + last_known_parent_count = weights.get(node, 0) + weights[node] = max(last_known_parent_count, len(path)) + + # Simplify the graph, pruning leaves that have no dependencies. + # This is needed for large graphs (say over 200 packages) because the + # `visit` function is exponentially slower then, taking minutes. + # See https://github.com/pypa/pip/issues/10557 + # We will loop until we explicitly break the loop. + while True: + leaves = set() + for key in graph: + if key is None: + continue + for _child in graph.iter_children(key): + # This means we have at least one child + break + else: + # No child. + leaves.add(key) + if not leaves: + # We are done simplifying. + break + # Calculate the weight for the leaves. + weight = len(graph) - 1 + for leaf in leaves: + if leaf not in requirement_keys: + continue + weights[leaf] = weight + # Remove the leaves from the graph, making it simpler. + for leaf in leaves: + graph.remove(leaf) + + # Visit the remaining graph. + # `None` is guaranteed to be the root node by resolvelib. + visit(None) + + # Sanity check: all requirement keys should be in the weights, + # and no other keys should be in the weights. + difference = set(weights.keys()).difference(requirement_keys) + assert not difference, difference + + return weights + + +def _req_set_item_sorter( + item: Tuple[str, InstallRequirement], + weights: Dict[Optional[str], int], +) -> Tuple[int, str]: + """Key function used to sort install requirements for installation. + + Based on the "weight" mapping calculated in ``get_installation_order()``. + The canonical package name is returned as the second member as a tie- + breaker to ensure the result is predictable, which is useful in tests. + """ + name = canonicalize_name(item[0]) + return weights[name], name |