def _resolve_dependencies_to_remove(self,
packages: list[str]) -> list[str]:
"""Perform a BFS to find all unneeded dependencies"""
result: set[str] = set()
to_resolve = list(packages)
ws = WorkingSet()
graph = build_dependency_graph(ws)
while to_resolve:
temp: list[Package] = []
for name in to_resolve:
key = normalize_name(name)
if key in ws:
result.add(key)
package = Package(key, "0.0.0", {})
if package not in graph:
continue
for dep in graph.iter_children(package):
temp.append(dep)
graph.remove(package)
to_resolve.clear()
for dep in temp:
if not any(graph.iter_parents(dep)) and dep.name != "pdm":
to_resolve.append(dep.name)
return sorted(result)
def build_dependency_graph(working_set: WorkingSet) -> DirectedGraph:
"""Build a dependency graph from locked result."""
graph: DirectedGraph[Package | None] = DirectedGraph()
graph.add(None) # sentinel parent of top nodes.
node_with_extras = set()
def add_package(key: str, dist: Distribution) -> Package:
name, extras = strip_extras(key)
extras = extras or ()
reqs: dict[str, Requirement] = {}
if dist:
requirements = (
Requirement.from_pkg_requirement(r)
for r in dist.requires(extras) # type: ignore
)
for req in requirements:
reqs[req.identify()] = req
version = dist.version
else:
version = None
node = Package(key, version, reqs)
if node not in graph:
if extras:
node_with_extras.add(name)
graph.add(node)
for k in reqs:
child = add_package(
k, cast(Distribution, working_set.get(strip_extras(k)[0])))
graph.connect(node, child)
return node
for k, dist in working_set.items():
add_package(k, dist)
for node in list(graph):
if node is not None and not list(graph.iter_parents(node)):
# Top requirements
if node.name in node_with_extras:
# Already included in package[extra], no need to keep the top level
# non-extra package.
graph.remove(node)
else:
graph.connect(None, node)
return graph