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pip/src/pip/_internal/resolution/resolvelib/factory.py

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import logging
from pip._vendor.packaging.utils import canonicalize_name
from pip._internal.exceptions import (
DistributionNotFound,
InstallationError,
UnsupportedPythonVersion,
UnsupportedWheel,
)
from pip._internal.models.wheel import Wheel
from pip._internal.req.req_install import InstallRequirement
from pip._internal.utils.compatibility_tags import get_supported
from pip._internal.utils.hashes import Hashes
from pip._internal.utils.misc import (
dist_in_site_packages,
dist_in_usersite,
get_installed_distributions,
)
from pip._internal.utils.typing import MYPY_CHECK_RUNNING
from pip._internal.utils.virtualenv import running_under_virtualenv
from .base import Constraint
from .candidates import (
AlreadyInstalledCandidate,
EditableCandidate,
ExtrasCandidate,
LinkCandidate,
RequiresPythonCandidate,
)
from .found_candidates import FoundCandidates
from .requirements import (
ExplicitRequirement,
RequiresPythonRequirement,
SpecifierRequirement,
)
if MYPY_CHECK_RUNNING:
from typing import (
FrozenSet,
Dict,
Iterable,
Iterator,
List,
Optional,
Sequence,
Set,
Tuple,
TypeVar,
)
from pip._vendor.packaging.specifiers import SpecifierSet
from pip._vendor.packaging.version import _BaseVersion
from pip._vendor.pkg_resources import Distribution
from pip._vendor.resolvelib import ResolutionImpossible
from pip._internal.cache import CacheEntry, WheelCache
from pip._internal.index.package_finder import PackageFinder
from pip._internal.models.link import Link
from pip._internal.operations.prepare import RequirementPreparer
from pip._internal.resolution.base import InstallRequirementProvider
from .base import Candidate, Requirement
from .candidates import BaseCandidate
C = TypeVar("C")
Cache = Dict[Link, C]
VersionCandidates = Dict[_BaseVersion, Candidate]
logger = logging.getLogger(__name__)
class Factory(object):
def __init__(
self,
finder, # type: PackageFinder
preparer, # type: RequirementPreparer
make_install_req, # type: InstallRequirementProvider
wheel_cache, # type: Optional[WheelCache]
use_user_site, # type: bool
force_reinstall, # type: bool
ignore_installed, # type: bool
ignore_requires_python, # type: bool
py_version_info=None, # type: Optional[Tuple[int, ...]]
lazy_wheel=False, # type: bool
):
# type: (...) -> None
self._finder = finder
self.preparer = preparer
self._wheel_cache = wheel_cache
self._python_candidate = RequiresPythonCandidate(py_version_info)
self._make_install_req_from_spec = make_install_req
self._use_user_site = use_user_site
self._force_reinstall = force_reinstall
self._ignore_requires_python = ignore_requires_python
self.use_lazy_wheel = lazy_wheel
self._link_candidate_cache = {} # type: Cache[LinkCandidate]
self._editable_candidate_cache = {} # type: Cache[EditableCandidate]
if not ignore_installed:
self._installed_dists = {
canonicalize_name(dist.project_name): dist
for dist in get_installed_distributions(local_only=False)
}
else:
self._installed_dists = {}
@property
def force_reinstall(self):
# type: () -> bool
return self._force_reinstall
def _make_candidate_from_dist(
self,
dist, # type: Distribution
extras, # type: FrozenSet[str]
template, # type: InstallRequirement
):
# type: (...) -> Candidate
base = AlreadyInstalledCandidate(dist, template, factory=self)
if extras:
return ExtrasCandidate(base, extras)
return base
def _make_candidate_from_link(
self,
link, # type: Link
extras, # type: FrozenSet[str]
template, # type: InstallRequirement
name, # type: Optional[str]
version, # type: Optional[_BaseVersion]
):
# type: (...) -> Candidate
# TODO: Check already installed candidate, and use it if the link and
# editable flag match.
if template.editable:
if link not in self._editable_candidate_cache:
self._editable_candidate_cache[link] = EditableCandidate(
link, template, factory=self, name=name, version=version,
)
base = self._editable_candidate_cache[link] # type: BaseCandidate
else:
if link not in self._link_candidate_cache:
self._link_candidate_cache[link] = LinkCandidate(
link, template, factory=self, name=name, version=version,
)
base = self._link_candidate_cache[link]
if extras:
return ExtrasCandidate(base, extras)
return base
def _iter_found_candidates(
self,
ireqs, # type: Sequence[InstallRequirement]
specifier, # type: SpecifierSet
hashes, # type: Hashes
prefers_installed, # type: bool
):
# type: (...) -> Iterable[Candidate]
if not ireqs:
return ()
# The InstallRequirement implementation requires us to give it a
# "template". Here we just choose the first requirement to represent
# all of them.
# Hopefully the Project model can correct this mismatch in the future.
template = ireqs[0]
name = canonicalize_name(template.req.name)
extras = frozenset() # type: FrozenSet[str]
for ireq in ireqs:
specifier &= ireq.req.specifier
hashes &= ireq.hashes(trust_internet=False)
extras |= frozenset(ireq.extras)
# Get the installed version, if it matches, unless the user
# specified `--force-reinstall`, when we want the version from
# the index instead.
installed_candidate = None
if not self._force_reinstall and name in self._installed_dists:
installed_dist = self._installed_dists[name]
if specifier.contains(installed_dist.version, prereleases=True):
installed_candidate = self._make_candidate_from_dist(
dist=installed_dist,
extras=extras,
template=template,
)
def iter_index_candidates():
# type: () -> Iterator[Candidate]
result = self._finder.find_best_candidate(
project_name=name,
specifier=specifier,
hashes=hashes,
)
# PackageFinder returns earlier versions first, so we reverse.
for ican in reversed(list(result.iter_applicable())):
yield self._make_candidate_from_link(
link=ican.link,
extras=extras,
template=template,
name=name,
version=ican.version,
)
return FoundCandidates(
iter_index_candidates,
installed_candidate,
prefers_installed,
)
def find_candidates(
self,
requirements, # type: Sequence[Requirement]
constraint, # type: Constraint
prefers_installed, # type: bool
):
# type: (...) -> Iterable[Candidate]
explicit_candidates = set() # type: Set[Candidate]
ireqs = [] # type: List[InstallRequirement]
for req in requirements:
cand, ireq = req.get_candidate_lookup()
if cand is not None:
explicit_candidates.add(cand)
if ireq is not None:
ireqs.append(ireq)
# If none of the requirements want an explicit candidate, we can ask
# the finder for candidates.
if not explicit_candidates:
return self._iter_found_candidates(
ireqs,
constraint.specifier,
constraint.hashes,
prefers_installed,
)
if constraint:
name = explicit_candidates.pop().name
raise InstallationError(
"Could not satisfy constraints for {!r}: installation from "
"path or url cannot be constrained to a version".format(name)
)
return (
c for c in explicit_candidates
if all(req.is_satisfied_by(c) for req in requirements)
)
def make_requirement_from_install_req(self, ireq, requested_extras):
# type: (InstallRequirement, Iterable[str]) -> Optional[Requirement]
if not ireq.match_markers(requested_extras):
logger.info(
"Ignoring %s: markers '%s' don't match your environment",
ireq.name, ireq.markers,
)
return None
if not ireq.link:
return SpecifierRequirement(ireq)
if ireq.link.is_wheel:
wheel = Wheel(ireq.link.filename)
if not wheel.supported(self._finder.target_python.get_tags()):
msg = "{} is not a supported wheel on this platform.".format(
wheel.filename,
)
raise UnsupportedWheel(msg)
cand = self._make_candidate_from_link(
ireq.link,
extras=frozenset(ireq.extras),
template=ireq,
name=canonicalize_name(ireq.name) if ireq.name else None,
version=None,
)
return self.make_requirement_from_candidate(cand)
def make_requirement_from_candidate(self, candidate):
# type: (Candidate) -> ExplicitRequirement
return ExplicitRequirement(candidate)
def make_requirement_from_spec(
self,
specifier, # type: str
comes_from, # type: InstallRequirement
requested_extras=(), # type: Iterable[str]
):
# type: (...) -> Optional[Requirement]
ireq = self._make_install_req_from_spec(specifier, comes_from)
return self.make_requirement_from_install_req(ireq, requested_extras)
def make_requires_python_requirement(self, specifier):
# type: (Optional[SpecifierSet]) -> Optional[Requirement]
if self._ignore_requires_python or specifier is None:
return None
return RequiresPythonRequirement(specifier, self._python_candidate)
def get_wheel_cache_entry(self, link, name):
# type: (Link, Optional[str]) -> Optional[CacheEntry]
"""Look up the link in the wheel cache.
If ``preparer.require_hashes`` is True, don't use the wheel cache,
because cached wheels, always built locally, have different hashes
than the files downloaded from the index server and thus throw false
hash mismatches. Furthermore, cached wheels at present have
nondeterministic contents due to file modification times.
"""
if self._wheel_cache is None or self.preparer.require_hashes:
return None
return self._wheel_cache.get_cache_entry(
link=link,
package_name=name,
supported_tags=get_supported(),
)
def get_dist_to_uninstall(self, candidate):
# type: (Candidate) -> Optional[Distribution]
# TODO: Are there more cases this needs to return True? Editable?
dist = self._installed_dists.get(candidate.name)
if dist is None: # Not installed, no uninstallation required.
return None
# We're installing into global site. The current installation must
# be uninstalled, no matter it's in global or user site, because the
# user site installation has precedence over global.
if not self._use_user_site:
return dist
# We're installing into user site. Remove the user site installation.
if dist_in_usersite(dist):
return dist
# We're installing into user site, but the installed incompatible
# package is in global site. We can't uninstall that, and would let
# the new user installation to "shadow" it. But shadowing won't work
# in virtual environments, so we error out.
if running_under_virtualenv() and dist_in_site_packages(dist):
raise InstallationError(
"Will not install to the user site because it will "
"lack sys.path precedence to {} in {}".format(
dist.project_name, dist.location,
)
)
return None
def _report_requires_python_error(
self,
requirement, # type: RequiresPythonRequirement
template, # type: Candidate
):
# type: (...) -> UnsupportedPythonVersion
message_format = (
"Package {package!r} requires a different Python: "
"{version} not in {specifier!r}"
)
message = message_format.format(
package=template.name,
version=self._python_candidate.version,
specifier=str(requirement.specifier),
)
return UnsupportedPythonVersion(message)
def get_installation_error(self, e):
# type: (ResolutionImpossible) -> InstallationError
assert e.causes, "Installation error reported with no cause"
# If one of the things we can't solve is "we need Python X.Y",
# that is what we report.
for cause in e.causes:
if isinstance(cause.requirement, RequiresPythonRequirement):
return self._report_requires_python_error(
cause.requirement,
cause.parent,
)
# Otherwise, we have a set of causes which can't all be satisfied
# at once.
# The simplest case is when we have *one* cause that can't be
# satisfied. We just report that case.
if len(e.causes) == 1:
req, parent = e.causes[0]
if parent is None:
req_disp = str(req)
else:
req_disp = '{} (from {})'.format(req, parent.name)
logger.critical(
"Could not find a version that satisfies the requirement %s",
req_disp,
)
return DistributionNotFound(
'No matching distribution found for {}'.format(req)
)
# OK, we now have a list of requirements that can't all be
# satisfied at once.
# A couple of formatting helpers
def text_join(parts):
# type: (List[str]) -> str
if len(parts) == 1:
return parts[0]
return ", ".join(parts[:-1]) + " and " + parts[-1]
def readable_form(cand):
# type: (Candidate) -> str
return "{} {}".format(cand.name, cand.version)
def describe_trigger(parent):
# type: (Candidate) -> str
ireq = parent.get_install_requirement()
if not ireq or not ireq.comes_from:
return "{} {}".format(parent.name, parent.version)
if isinstance(ireq.comes_from, InstallRequirement):
return str(ireq.comes_from.name)
return str(ireq.comes_from)
triggers = []
for req, parent in e.causes:
if parent is None:
# This is a root requirement, so we can report it directly
trigger = req.format_for_error()
else:
trigger = describe_trigger(parent)
triggers.append(trigger)
if triggers:
info = text_join(triggers)
else:
info = "the requested packages"
msg = "Cannot install {} because these package versions " \
"have conflicting dependencies.".format(info)
logger.critical(msg)
msg = "\nThe conflict is caused by:"
for req, parent in e.causes:
msg = msg + "\n "
if parent:
msg = msg + "{} {} depends on ".format(
parent.name,
parent.version
)
else:
msg = msg + "The user requested "
msg = msg + req.format_for_error()
msg = msg + "\n\n" + \
"To fix this you could try to:\n" + \
"1. loosen the range of package versions you've specified\n" + \
"2. remove package versions to allow pip attempt to solve " + \
"the dependency conflict\n"
logger.info(msg)
return DistributionNotFound(
"ResolutionImpossible: for help visit "
"https://pip.pypa.io/en/latest/user_guide/"
"#fixing-conflicting-dependencies"
)
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