Upgrade resolvelib to 0.5.2

news/resolvelib.vendor.rst

@@ -0,0 +1 @@
+Upgrade resolvelib to 0.5.2

src/pip/_vendor/resolvelib/__init__.py

@@ -11,7 +11,7 @@ __all__ = [
     "ResolutionTooDeep",
 ]
 
-__version__ = "0.4.0"
+__version__ = "0.5.2"
 
 
 from .providers import AbstractProvider, AbstractResolver

src/pip/_vendor/resolvelib/providers.py

@@ -1,32 +1,36 @@
 class AbstractProvider(object):
-    """Delegate class to provide requirement interface for the resolver.
+    """Delegate class to provide requirement interface for the resolver."""
-    """
 
-    def identify(self, dependency):
+    def identify(self, requirement_or_candidate):
-        """Given a dependency, return an identifier for it.
+        """Given a requirement or candidate, return an identifier for it.
 
-        This is used in many places to identify the dependency, e.g. whether
+        This is used in many places to identify a requirement or candidate,
-        two requirements should have their specifier parts merged, whether
+        e.g. whether two requirements should have their specifier parts merged,
-        two specifications would conflict with each other (because they the
+        whether two candidates would conflict with each other (because they
-        same name but different versions).
+        have same name but different versions).
         """
         raise NotImplementedError
 
     def get_preference(self, resolution, candidates, information):
-        """Produce a sort key for given specification based on preference.
+        """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 resolution: Currently pinned candidate, or `None`.
-        :param candidates: A list of possible candidates.
+        :param candidates: An iterable of possible candidates.
         :param information: A list of requirement information.
 
-        Each information instance is a named tuple with two entries:
+        The `candidates` iterable's exact type depends on the return type of
+        `find_matches()`. A sequence is passed-in as-is if possible. If it
+        returns a callble, the iterator returned by that callable is passed
+        in here.
+
+        Each element in `information` is a named tuple with two entries:
 
         * `requirement` specifies a requirement contributing to the current
-          candidate list
+          candidate list.
         * `parent` specifies the candidate that provides (dependend on) the
           requirement, or `None` to indicate a root requirement.
 
@@ -43,7 +47,7 @@ class AbstractProvider(object):
 
         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 specification is (i.e. the sorting function
+        the more preferred this requirement is (i.e. the sorting function
         is called with `reverse=False`).
         """
         raise NotImplementedError
@@ -56,11 +60,18 @@ class AbstractProvider(object):
         returned, and for a "named" requirement, the index(es) should be
         consulted to find concrete candidates for this requirement.
 
-        :param requirements: A collection of requirements which all of the the
+        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.
+
+        :param requirements: A collection of requirements which all of the
             returned candidates must match. All requirements are guaranteed to
             have the same identifier. The collection is never empty.
-        :returns: An iterable that orders candidates by preference, e.g. the
-            most preferred candidate should come first.
         """
         raise NotImplementedError
 
@@ -85,8 +96,7 @@ class AbstractProvider(object):
 
 
 class AbstractResolver(object):
-    """The thing that performs the actual resolution work.
+    """The thing that performs the actual resolution work."""
-    """
 
     base_exception = Exception
 

src/pip/_vendor/resolvelib/reporters.py

@@ -1,10 +1,8 @@
 class BaseReporter(object):
-    """Delegate class to provider progress reporting for the resolver.
+    """Delegate class to provider progress reporting for the resolver."""
-    """
 
     def starting(self):
-        """Called before the resolution actually starts.
+        """Called before the resolution actually starts."""
-        """
 
     def starting_round(self, index):
         """Called before each round of resolution starts.
@@ -20,8 +18,7 @@ class BaseReporter(object):
         """
 
     def ending(self, state):
-        """Called before the resolution ends successfully.
+        """Called before the resolution ends successfully."""
-        """
 
     def adding_requirement(self, requirement, parent):
         """Called when adding a new requirement into the resolve criteria.
@@ -34,9 +31,7 @@ class BaseReporter(object):
         """
 
     def backtracking(self, candidate):
-        """Called when rejecting a candidate during backtracking.
+        """Called when rejecting a candidate during backtracking."""
-        """
 
     def pinning(self, candidate):
-        """Called when adding a candidate to the potential solution.
+        """Called when adding a candidate to the potential solution."""
-        """

src/pip/_vendor/resolvelib/resolvers.py

@@ -1,8 +1,7 @@
 import collections
 
-from .compat import collections_abc
 from .providers import AbstractResolver
-from .structs import DirectedGraph
+from .structs import DirectedGraph, build_iter_view
 
 
 RequirementInformation = collections.namedtuple(
@@ -76,17 +75,11 @@ class Criterion(object):
 
     @classmethod
     def from_requirement(cls, provider, requirement, parent):
-        """Build an instance from a requirement.
+        """Build an instance from a requirement."""
-        """
+        cands = build_iter_view(provider.find_matches([requirement]))
-        candidates = provider.find_matches([requirement])
+        infos = [RequirementInformation(requirement, parent)]
-        if not isinstance(candidates, collections_abc.Sequence):
+        criterion = cls(cands, infos, incompatibilities=[])
-            candidates = list(candidates)
+        if not cands:
-        criterion = cls(
-            candidates=candidates,
-            information=[RequirementInformation(requirement, parent)],
-            incompatibilities=[],
-        )
-        if not candidates:
             raise RequirementsConflicted(criterion)
         return criterion
 
@@ -97,15 +90,12 @@ class Criterion(object):
         return (i.parent for i in self.information)
 
     def merged_with(self, provider, requirement, parent):
-        """Build a new instance from this and a new requirement.
+        """Build a new instance from this and a new requirement."""
-        """
         infos = list(self.information)
         infos.append(RequirementInformation(requirement, parent))
-        candidates = provider.find_matches([r for r, _ in infos])
+        cands = build_iter_view(provider.find_matches([r for r, _ in infos]))
-        if not isinstance(candidates, collections_abc.Sequence):
+        criterion = type(self)(cands, infos, list(self.incompatibilities))
-            candidates = list(candidates)
+        if not cands:
-        criterion = type(self)(candidates, infos, list(self.incompatibilities))
-        if not candidates:
             raise RequirementsConflicted(criterion)
         return criterion
 
@@ -114,13 +104,12 @@ class Criterion(object):
 
         Returns the new instance, or None if we still have no valid candidates.
         """
+        cands = self.candidates.excluding(candidate)
+        if not cands:
+            return None
         incompats = list(self.incompatibilities)
         incompats.append(candidate)
-        candidates = [c for c in self.candidates if c != candidate]
+        return type(self)(cands, list(self.information), incompats)
-        if not candidates:
-            return None
-        criterion = type(self)(candidates, list(self.information), incompats)
-        return criterion
 
 
 class ResolutionError(ResolverException):
@@ -175,7 +164,8 @@ class Resolution(object):
             state = State(mapping=collections.OrderedDict(), criteria={})
         else:
             state = State(
-                mapping=base.mapping.copy(), criteria=base.criteria.copy(),
+                mapping=base.mapping.copy(),
+                criteria=base.criteria.copy(),
             )
         self._states.append(state)
 
@@ -192,12 +182,10 @@ class Resolution(object):
 
     def _get_criterion_item_preference(self, item):
         name, criterion = item
-        try:
-            pinned = self.state.mapping[name]
-        except KeyError:
-            pinned = None
         return self._p.get_preference(
-            pinned, criterion.candidates, criterion.information,
+            self.state.mapping.get(name),
+            criterion.candidates.for_preference(),
+            criterion.information,
         )
 
     def _is_current_pin_satisfying(self, name, criterion):
@@ -390,8 +378,7 @@ def _build_result(state):
 
 
 class Resolver(AbstractResolver):
-    """The thing that performs the actual resolution work.
+    """The thing that performs the actual resolution work."""
-    """
 
     base_exception = ResolverException
 

src/pip/_vendor/resolvelib/structs.py

@@ -1,6 +1,8 @@
+from .compat import collections_abc
+
+
 class DirectedGraph(object):
-    """A graph structure with directed edges.
+    """A graph structure with directed edges."""
-    """
 
     def __init__(self):
         self._vertices = set()
@@ -17,8 +19,7 @@ class DirectedGraph(object):
         return key in self._vertices
 
     def copy(self):
-        """Return a shallow copy of this graph.
+        """Return a shallow copy of this graph."""
-        """
         other = DirectedGraph()
         other._vertices = set(self._vertices)
         other._forwards = {k: set(v) for k, v in self._forwards.items()}
@@ -26,8 +27,7 @@ class DirectedGraph(object):
         return other
 
     def add(self, key):
-        """Add a new vertex to the graph.
+        """Add a new vertex to the graph."""
-        """
         if key in self._vertices:
             raise ValueError("vertex exists")
         self._vertices.add(key)
@@ -35,8 +35,7 @@ class DirectedGraph(object):
         self._backwards[key] = set()
 
     def remove(self, key):
-        """Remove a vertex from the graph, disconnecting all edges from/to it.
+        """Remove a vertex from the graph, disconnecting all edges from/to it."""
-        """
         self._vertices.remove(key)
         for f in self._forwards.pop(key):
             self._backwards[f].remove(key)
@@ -66,3 +65,79 @@ class DirectedGraph(object):
 
     def iter_parents(self, key):
         return iter(self._backwards[key])
+
+
+class _FactoryIterableView(object):
+    """Wrap an iterator factory returned by `find_matches()`.
+
+    Calling `iter()` on this class would invoke the underlying iterator
+    factory, making it a "collection with ordering" that can be iterated
+    through multiple times, but lacks random access methods presented in
+    built-in Python sequence types.
+    """
+
+    def __init__(self, factory):
+        self._factory = factory
+
+    def __bool__(self):
+        try:
+            next(self._factory())
+        except StopIteration:
+            return False
+        return True
+
+    __nonzero__ = __bool__  # XXX: Python 2.
+
+    def __iter__(self):
+        return self._factory()
+
+    def for_preference(self):
+        """Provide an candidate iterable for `get_preference()`"""
+        return self._factory()
+
+    def excluding(self, candidate):
+        """Create a new `Candidates` instance excluding `candidate`."""
+
+        def factory():
+            return (c for c in self._factory() if c != candidate)
+
+        return type(self)(factory)
+
+
+class _SequenceIterableView(object):
+    """Wrap an iterable returned by find_matches().
+
+    This is essentially just a proxy to the underlying sequence that provides
+    the same interface as `_FactoryIterableView`.
+    """
+
+    def __init__(self, sequence):
+        self._sequence = sequence
+
+    def __bool__(self):
+        return bool(self._sequence)
+
+    __nonzero__ = __bool__  # XXX: Python 2.
+
+    def __iter__(self):
+        return iter(self._sequence)
+
+    def __len__(self):
+        return len(self._sequence)
+
+    def for_preference(self):
+        """Provide an candidate iterable for `get_preference()`"""
+        return self._sequence
+
+    def excluding(self, candidate):
+        """Create a new instance excluding `candidate`."""
+        return type(self)([c for c in self._sequence if c != candidate])
+
+
+def build_iter_view(matches):
+    """Build an iterable view from the value returned by `find_matches()`."""
+    if callable(matches):
+        return _FactoryIterableView(matches)
+    if not isinstance(matches, collections_abc.Sequence):
+        matches = list(matches)
+    return _SequenceIterableView(matches)

src/pip/_vendor/vendor.txt

@@ -16,7 +16,7 @@ requests==2.25.0
     chardet==3.0.4
     idna==2.10
     urllib3==1.26.2
-resolvelib==0.4.0
+resolvelib==0.5.2
 retrying==1.3.3
 setuptools==44.0.0
 six==1.15.0