Coverage for britney2/installability/universe.py: 96%
42 statements
« prev ^ index » next coverage.py v6.5.0, created at 2025-03-23 07:34 +0000
1# -*- coding: utf-8 -*-
3# Copyright (C) 2012 Niels Thykier <niels@thykier.net>
5# This program is free software; you can redistribute it and/or modify
6# it under the terms of the GNU General Public License as published by
7# the Free Software Foundation; either version 2 of the License, or
8# (at your option) any later version.
10# This program is distributed in the hope that it will be useful,
11# but WITHOUT ANY WARRANTY; without even the implied warranty of
12# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13# GNU General Public License for more details.
15from typing import TYPE_CHECKING
16from collections.abc import Iterator
18if TYPE_CHECKING: 18 ↛ 19line 18 didn't jump to line 19, because the condition on line 18 was never true
19 from .. import BinaryPackageId
22class BinaryPackageRelation(object):
23 """All relations of a given binary package"""
25 __slots__ = [
26 "pkg_ids",
27 "dependencies",
28 "negative_dependencies",
29 "reverse_dependencies",
30 ]
32 def __init__(
33 self,
34 pkg_ids: frozenset["BinaryPackageId"],
35 dependencies: frozenset[frozenset["BinaryPackageId"]],
36 negative_dependencies: frozenset["BinaryPackageId"],
37 reverse_dependencies: set["BinaryPackageId"],
38 ) -> None:
39 self.pkg_ids = pkg_ids
40 self.dependencies = dependencies
41 self.negative_dependencies = negative_dependencies
42 self.reverse_dependencies = reverse_dependencies
45class BinaryPackageUniverse(object):
46 """A "universe" of all binary packages and their relations
48 The package universe is a read-only ("immutable") data structure
49 that knows of all binary packages and their internal relations.
50 The relations are either in Conjunctive Normal Form (CNF) represented
51 via sets of sets of the package ids or simply sets of package ids.
53 Being immutable, the universe does *not* track stateful data such
54 as "which package is in what suite?" nor "is this package installable
55 in that suite?".
57 The universe also includes some packages that are considered "broken".
58 These packages have been identified to always be uninstallability
59 regardless of the selection of package available (e.g. the depend
60 on a non-existent package or has a relation that is impossible to
61 satisfy).
63 For these packages, the universe only tracks that they
64 exist and that they are broken. This implies that their relations
65 have been nulled into empty sets and they have been removed from
66 the relations of other packages. This optimizes analysis of the
67 universe on packages that is/can be installable at the expense
68 of a "minor" lie about the "broken" packages.
69 """
71 def __init__(
72 self,
73 relations: dict["BinaryPackageId", BinaryPackageRelation],
74 essential_packages: frozenset["BinaryPackageId"],
75 broken_packages: frozenset["BinaryPackageId"],
76 equivalent_packages: frozenset["BinaryPackageId"],
77 ) -> None:
78 self._relations = relations
79 self._essential_packages = essential_packages
80 self._broken_packages = broken_packages
81 self._equivalent_packages = equivalent_packages
83 def dependencies_of(
84 self, pkg_id: "BinaryPackageId"
85 ) -> frozenset[frozenset["BinaryPackageId"]]:
86 """Returns the set of dependencies of a given package
88 :return: A set containing the package ids all of the dependencies
89 of the input package in CNF.
90 """
91 return self._relations[pkg_id].dependencies
93 def negative_dependencies_of(
94 self, pkg_id: "BinaryPackageId"
95 ) -> frozenset["BinaryPackageId"]:
96 """Returns the set of negative dependencies of a given package
98 Note that there is no "reverse_negative_dependencies_of" method,
99 since negative dependencies have no "direction" unlike positive
100 dependencies.
102 :return: A set containing the package ids all of the negative
103 dependencies of the input package.
104 """
105 return self._relations[pkg_id].negative_dependencies
107 def reverse_dependencies_of(
108 self, pkg_id: "BinaryPackageId"
109 ) -> set["BinaryPackageId"]:
110 """Returns the set of reverse dependencies of a given package
112 Note that a package is considered a reverse dependency of the
113 given package as long as at least one of its dependency relations
114 *could* be satisfied by the given package.
116 :return: A set containing the package ids all of the reverse
117 dependencies of the input package.
118 """
119 return self._relations[pkg_id].reverse_dependencies
121 def are_equivalent(
122 self, pkg_id1: "BinaryPackageId", pkg_id2: "BinaryPackageId"
123 ) -> bool:
124 """Test if pkg_id1 and pkg_id2 are equivalent
126 :param pkg_id1: The id of the first package
127 :param pkg_id2: The id of the second package
128 :return: True if pkg_id1 and pkg_id2 have the same "signature" in
129 the package dependency graph (i.e. relations can not tell
130 them apart semantically except for their name). Otherwise False.
132 Note that this can return True even if pkg_id1 and pkg_id2 can
133 tell each other apart.
134 """
135 return pkg_id2 in self.packages_equivalent_to(pkg_id1)
137 def packages_equivalent_to(
138 self, pkg_id: "BinaryPackageId"
139 ) -> frozenset["BinaryPackageId"]:
140 """Determine which packages are equivalent to a given package
142 :return: A frozenset of all package ids that are equivalent to the
143 input package.
144 """
145 return self._relations[pkg_id].pkg_ids
147 def relations_of(self, pkg_id: "BinaryPackageId") -> BinaryPackageRelation:
148 """Get the direct relations of a given package
150 :param pkg_id: The BinaryPackageId of a binary package.
151 :return: A BinaryPackageRelation describing all known direct
152 relations for the package.
153 """
154 return self._relations[pkg_id]
156 @property
157 def essential_packages(self) -> frozenset["BinaryPackageId"]:
158 """A frozenset of all "Essential: yes" binaries in the universe
160 :return: All of the binaries that are marked as essential.
161 """
162 return self._essential_packages
164 @property
165 def broken_packages(self) -> frozenset["BinaryPackageId"]:
166 """A frozenset of all broken binaries in the universe
168 :return: All binaries that are considered "broken" and had their relations nulled.
169 """
170 return self._broken_packages
172 @property
173 def equivalent_packages(self) -> frozenset["BinaryPackageId"]:
174 """A frozenset of all binary packages that are equivalent to at least one other package
176 The binary packages in this set has the property that "universe.packages_equivalent_to(pkg_id)"
177 will return a set of at least 2 or more elements for each of them.
179 :return: All packages that are equivalent to other packages.
180 """
181 return self._equivalent_packages
183 def __contains__(self, pkg_id: "BinaryPackageId") -> bool:
184 return pkg_id in self._relations
186 def __iter__(self) -> Iterator["BinaryPackageId"]:
187 yield from self._relations