in amplify/backend/function/MAPSMediaInfoLambdaLayer/opt/python/lib/python3.7/site-packages/pkg_resources/__init__.py [0:0]
def resolve(self, requirements, env=None, installer=None,
replace_conflicting=False, extras=None):
"""List all distributions needed to (recursively) meet `requirements`
`requirements` must be a sequence of ``Requirement`` objects. `env`,
if supplied, should be an ``Environment`` instance. If
not supplied, it defaults to all distributions available within any
entry or distribution in the working set. `installer`, if supplied,
will be invoked with each requirement that cannot be met by an
already-installed distribution; it should return a ``Distribution`` or
``None``.
Unless `replace_conflicting=True`, raises a VersionConflict exception
if
any requirements are found on the path that have the correct name but
the wrong version. Otherwise, if an `installer` is supplied it will be
invoked to obtain the correct version of the requirement and activate
it.
`extras` is a list of the extras to be used with these requirements.
This is important because extra requirements may look like `my_req;
extra = "my_extra"`, which would otherwise be interpreted as a purely
optional requirement. Instead, we want to be able to assert that these
requirements are truly required.
"""
# set up the stack
requirements = list(requirements)[::-1]
# set of processed requirements
processed = {}
# key -> dist
best = {}
to_activate = []
req_extras = _ReqExtras()
# Mapping of requirement to set of distributions that required it;
# useful for reporting info about conflicts.
required_by = collections.defaultdict(set)
while requirements:
# process dependencies breadth-first
req = requirements.pop(0)
if req in processed:
# Ignore cyclic or redundant dependencies
continue
if not req_extras.markers_pass(req, extras):
continue
dist = best.get(req.key)
if dist is None:
# Find the best distribution and add it to the map
dist = self.by_key.get(req.key)
if dist is None or (dist not in req and replace_conflicting):
ws = self
if env is None:
if dist is None:
env = Environment(self.entries)
else:
# Use an empty environment and workingset to avoid
# any further conflicts with the conflicting
# distribution
env = Environment([])
ws = WorkingSet([])
dist = best[req.key] = env.best_match(
req, ws, installer,
replace_conflicting=replace_conflicting
)
if dist is None:
requirers = required_by.get(req, None)
raise DistributionNotFound(req, requirers)
to_activate.append(dist)
if dist not in req:
# Oops, the "best" so far conflicts with a dependency
dependent_req = required_by[req]
raise VersionConflict(dist, req).with_context(dependent_req)
# push the new requirements onto the stack
new_requirements = dist.requires(req.extras)[::-1]
requirements.extend(new_requirements)
# Register the new requirements needed by req
for new_requirement in new_requirements:
required_by[new_requirement].add(req.project_name)
req_extras[new_requirement] = req.extras
processed[req] = True
# return list of distros to activate
return to_activate