blob: 4c4b8ca8444b93b4ad90cf63d47e9557b9d57cb2 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
|
require_relative 'assignment'
module Bundler::PubGrub
class PartialSolution
attr_reader :assignments, :decisions
attr_reader :attempted_solutions
def initialize
reset!
@attempted_solutions = 1
@backtracking = false
end
def decision_level
@decisions.length
end
def relation(term)
package = term.package
return :overlap if !@terms.key?(package)
@relation_cache[package][term] ||=
@terms[package].relation(term)
end
def satisfies?(term)
relation(term) == :subset
end
def derive(term, cause)
add_assignment(Assignment.new(term, cause, decision_level, assignments.length))
end
def satisfier(term)
assignment =
@assignments_by[term.package].bsearch do |assignment_by|
@cumulative_assignments[assignment_by].satisfies?(term)
end
assignment || raise("#{term} unsatisfied")
end
# A list of unsatisfied terms
def unsatisfied
@required.keys.reject do |package|
@decisions.key?(package)
end.map do |package|
@terms[package]
end
end
def decide(package, version)
@attempted_solutions += 1 if @backtracking
@backtracking = false;
decisions[package] = version
assignment = Assignment.decision(package, version, decision_level, assignments.length)
add_assignment(assignment)
end
def backtrack(previous_level)
@backtracking = true
new_assignments = assignments.select do |assignment|
assignment.decision_level <= previous_level
end
new_decisions = Hash[decisions.first(previous_level)]
reset!
@decisions = new_decisions
new_assignments.each do |assignment|
add_assignment(assignment)
end
end
private
def reset!
# { Array<Assignment> }
@assignments = []
# { Package => Array<Assignment> }
@assignments_by = Hash.new { |h,k| h[k] = [] }
@cumulative_assignments = {}.compare_by_identity
# { Package => Package::Version }
@decisions = {}
# { Package => Term }
@terms = {}
@relation_cache = Hash.new { |h,k| h[k] = {} }
# { Package => Boolean }
@required = {}
end
def add_assignment(assignment)
term = assignment.term
package = term.package
@assignments << assignment
@assignments_by[package] << assignment
@required[package] = true if term.positive?
if @terms.key?(package)
old_term = @terms[package]
@terms[package] = old_term.intersect(term)
else
@terms[package] = term
end
@relation_cache[package].clear
@cumulative_assignments[assignment] = @terms[package]
end
end
end
|
