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Diffstat (limited to '.venv/lib/python3.12/site-packages/pip/_vendor/resolvelib/providers.py')
| -rw-r--r-- | .venv/lib/python3.12/site-packages/pip/_vendor/resolvelib/providers.py | 133 |
1 files changed, 133 insertions, 0 deletions
diff --git a/.venv/lib/python3.12/site-packages/pip/_vendor/resolvelib/providers.py b/.venv/lib/python3.12/site-packages/pip/_vendor/resolvelib/providers.py new file mode 100644 index 00000000..e99d87ee --- /dev/null +++ b/.venv/lib/python3.12/site-packages/pip/_vendor/resolvelib/providers.py @@ -0,0 +1,133 @@ +class AbstractProvider(object): + """Delegate class to provide the required interface for the resolver.""" + + def identify(self, requirement_or_candidate): + """Given a requirement, return an identifier for it. + + This is used to identify a requirement, e.g. whether two requirements + should have their specifier parts merged. + """ + raise NotImplementedError + + def get_preference( + self, + identifier, + resolutions, + candidates, + information, + backtrack_causes, + ): + """Produce a sort key for given requirement based on preference. + + The preference is defined as "I think this requirement should be + resolved first". The lower the return value is, the more preferred + this group of arguments is. + + :param identifier: An identifier as returned by ``identify()``. This + identifies the dependency matches which should be returned. + :param resolutions: Mapping of candidates currently pinned by the + resolver. Each key is an identifier, and the value is a candidate. + The candidate may conflict with requirements from ``information``. + :param candidates: Mapping of each dependency's possible candidates. + Each value is an iterator of candidates. + :param information: Mapping of requirement information of each package. + Each value is an iterator of *requirement information*. + :param backtrack_causes: Sequence of requirement information that were + the requirements that caused the resolver to most recently backtrack. + + A *requirement information* instance is a named tuple with two members: + + * ``requirement`` specifies a requirement contributing to the current + list of candidates. + * ``parent`` specifies the candidate that provides (depended on) the + requirement, or ``None`` to indicate a root requirement. + + The preference could depend on various issues, including (not + necessarily in this order): + + * Is this package pinned in the current resolution result? + * How relaxed is the requirement? Stricter ones should probably be + worked on first? (I don't know, actually.) + * How many possibilities are there to satisfy this requirement? Those + with few left should likely be worked on first, I guess? + * Are there any known conflicts for this requirement? We should + probably work on those with the most known conflicts. + + A sortable value should be returned (this will be used as the ``key`` + parameter of the built-in sorting function). The smaller the value is, + the more preferred this requirement is (i.e. the sorting function + is called with ``reverse=False``). + """ + raise NotImplementedError + + def find_matches(self, identifier, requirements, incompatibilities): + """Find all possible candidates that satisfy the given constraints. + + :param identifier: An identifier as returned by ``identify()``. This + identifies the dependency matches of which should be returned. + :param requirements: A mapping of requirements that all returned + candidates must satisfy. Each key is an identifier, and the value + an iterator of requirements for that dependency. + :param incompatibilities: A mapping of known incompatibilities of + each dependency. Each key is an identifier, and the value an + iterator of incompatibilities known to the resolver. All + incompatibilities *must* be excluded from the return value. + + This should try to get candidates based on the requirements' types. + For VCS, local, and archive requirements, the one-and-only match is + returned, and for a "named" requirement, the index(es) should be + consulted to find concrete candidates for this requirement. + + The return value should produce candidates ordered by preference; the + most preferred candidate should come first. The return type may be one + of the following: + + * A callable that returns an iterator that yields candidates. + * An collection of candidates. + * An iterable of candidates. This will be consumed immediately into a + list of candidates. + """ + raise NotImplementedError + + def is_satisfied_by(self, requirement, candidate): + """Whether the given requirement can be satisfied by a candidate. + + The candidate is guaranteed to have been generated from the + requirement. + + A boolean should be returned to indicate whether ``candidate`` is a + viable solution to the requirement. + """ + raise NotImplementedError + + def get_dependencies(self, candidate): + """Get dependencies of a candidate. + + This should return a collection of requirements that `candidate` + specifies as its dependencies. + """ + raise NotImplementedError + + +class AbstractResolver(object): + """The thing that performs the actual resolution work.""" + + base_exception = Exception + + def __init__(self, provider, reporter): + self.provider = provider + self.reporter = reporter + + def resolve(self, requirements, **kwargs): + """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 |