Class: Gem::Resolver
- Inherits:
-
Object
- Object
- Gem::Resolver
- Defined in:
- lib/rubygems/resolver.rb
Overview
Given a set of Gem::Dependency objects as needed
and a way to query the set of available specs via set
, calculates a set of ActivationRequest objects which indicate all the specs that should be activated to meet the all the requirements.
Defined Under Namespace
Classes: APISet, APISpecification, ActivationRequest, BestSet, ComposedSet, Conflict, CurrentSet, DependencyRequest, GitSet, GitSpecification, IndexSet, IndexSpecification, InstalledSpecification, InstallerSet, LocalSpecification, LockSet, LockSpecification, RequirementList, Set, SpecSpecification, Specification, State, Stats, VendorSet, VendorSpecification
Constant Summary collapse
- DEBUG_RESOLVER =
If the DEBUG_RESOLVER environment variable is set then debugging mode is enabled for the resolver. This will display information about the state of the resolver while a set of dependencies is being resolved.
!ENV['DEBUG_RESOLVER'].nil?
- DependencyConflict =
TODO: Remove in RubyGems 3
Gem::Resolver::Conflict
Instance Attribute Summary collapse
-
#conflicts ⇒ Object
readonly
Contains all the conflicts encountered while doing resolution.
-
#development ⇒ Object
Set to true if development dependencies should be considered.
-
#ignore_dependencies ⇒ Object
When true, no dependencies are looked up for requested gems.
-
#missing ⇒ Object
readonly
List of dependencies that could not be found in the configured sources.
-
#soft_missing ⇒ Object
When a missing dependency, don’t stop.
-
#stats ⇒ Object
readonly
Returns the value of attribute stats.
Class Method Summary collapse
-
.compose_sets(*sets) ⇒ Object
Combines
sets
into a ComposedSet that allows specification lookup in a uniform manner. -
.for_current_gems(needed) ⇒ Object
Creates a Resolver that queries only against the already installed gems for the
needed
dependencies.
Instance Method Summary collapse
-
#activation_request(dep, possible) ⇒ Object
Creates an ActivationRequest for the given
dep
and the lastpossible
specification. -
#explain(stage, *data) ⇒ Object
:nodoc:.
-
#explain_list(stage, data) ⇒ Object
:nodoc:.
-
#find_possible(dependency) ⇒ Object
Extracts the specifications that may be able to fulfill
dependency
and returns those that match the local platform and all those that match. -
#handle_conflict(dep, existing) ⇒ Object
:nodoc:.
-
#initialize(needed, set = nil) ⇒ Resolver
constructor
Create Resolver object which will resolve the tree starting with
needed
Dependency objects. -
#requests(s, act, reqs = nil) ⇒ Object
:nodoc:.
-
#resolve ⇒ Object
Proceed with resolution! Returns an array of ActivationRequest objects.
-
#resolve_for(needed, specs) ⇒ Object
The meat of the algorithm.
-
#resolve_for_conflict(needed, specs, state) ⇒ Object
Rewinds
needed
andspecs
to a previous state instate
for a conflict betweendep
andexisting
. -
#resolve_for_multiple(needed, specs, states, dep, possible) ⇒ Object
There are multiple
possible
specifications for thisdep
. -
#resolve_for_single(needed, specs, dep, possible) ⇒ Object
Add the spec from the
possible
list tospecs
and process the spec’s dependencies by adding them toneeded
. -
#resolve_for_zero(dep, platform_mismatch) ⇒ Object
When there are no possible specifications for
dep
our work is done. -
#select_local_platforms(specs) ⇒ Object
Returns the gems in
specs
that match the local platform.
Constructor Details
#initialize(needed, set = nil) ⇒ Resolver
Create Resolver object which will resolve the tree starting with needed
Dependency objects.
set
is an object that provides where to look for specifications to satisfy the Dependencies. This defaults to IndexSet, which will query rubygems.org.
97 98 99 100 101 102 103 104 105 106 107 |
# File 'lib/rubygems/resolver.rb', line 97 def initialize needed, set = nil @set = set || Gem::Resolver::IndexSet.new @needed = needed @conflicts = [] @development = false @ignore_dependencies = false @missing = [] @soft_missing = false @stats = Gem::Resolver::Stats.new end |
Instance Attribute Details
#conflicts ⇒ Object (readonly)
Contains all the conflicts encountered while doing resolution
27 28 29 |
# File 'lib/rubygems/resolver.rb', line 27 def conflicts @conflicts end |
#development ⇒ Object
Set to true if development dependencies should be considered.
32 33 34 |
# File 'lib/rubygems/resolver.rb', line 32 def development @development end |
#ignore_dependencies ⇒ Object
When true, no dependencies are looked up for requested gems.
37 38 39 |
# File 'lib/rubygems/resolver.rb', line 37 def ignore_dependencies @ignore_dependencies end |
#missing ⇒ Object (readonly)
List of dependencies that could not be found in the configured sources.
42 43 44 |
# File 'lib/rubygems/resolver.rb', line 42 def missing @missing end |
#soft_missing ⇒ Object
When a missing dependency, don’t stop. Just go on and record what was missing.
50 51 52 |
# File 'lib/rubygems/resolver.rb', line 50 def soft_missing @soft_missing end |
#stats ⇒ Object (readonly)
Returns the value of attribute stats.
44 45 46 |
# File 'lib/rubygems/resolver.rb', line 44 def stats @stats end |
Class Method Details
.compose_sets(*sets) ⇒ Object
Combines sets
into a ComposedSet that allows specification lookup in a uniform manner. If one of the sets
is itself a ComposedSet its sets are flattened into the result ComposedSet.
57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 |
# File 'lib/rubygems/resolver.rb', line 57 def self.compose_sets *sets sets.compact! sets = sets.map do |set| case set when Gem::Resolver::BestSet then set when Gem::Resolver::ComposedSet then set.sets else set end end.flatten case sets.length when 0 then raise ArgumentError, 'one set in the composition must be non-nil' when 1 then sets.first else Gem::Resolver::ComposedSet.new(*sets) end end |
.for_current_gems(needed) ⇒ Object
Creates a Resolver that queries only against the already installed gems for the needed
dependencies.
85 86 87 |
# File 'lib/rubygems/resolver.rb', line 85 def self.for_current_gems needed new needed, Gem::Resolver::CurrentSet.new end |
Instance Method Details
#activation_request(dep, possible) ⇒ Object
Creates an ActivationRequest for the given dep
and the last possible
specification.
Returns the Specification and the ActivationRequest
131 132 133 134 135 136 137 138 139 140 |
# File 'lib/rubygems/resolver.rb', line 131 def activation_request dep, possible # :nodoc: spec = possible.pop explain :activate, [spec.full_name, possible.size] activation_request = Gem::Resolver::ActivationRequest.new spec, dep, possible return spec, activation_request end |
#explain(stage, *data) ⇒ Object
:nodoc:
109 110 111 112 113 114 |
# File 'lib/rubygems/resolver.rb', line 109 def explain stage, *data # :nodoc: if DEBUG_RESOLVER d = data.map { |x| x.inspect }.join(", ") STDOUT.printf "%20s %s\n", stage.to_s.upcase, d end end |
#explain_list(stage, data) ⇒ Object
:nodoc:
116 117 118 119 120 121 122 123 |
# File 'lib/rubygems/resolver.rb', line 116 def explain_list stage, data # :nodoc: if DEBUG_RESOLVER STDOUT.printf "%20s (%d entries)\n", stage.to_s.upcase, data.size data.each do |d| STDOUT.printf "%20s %s\n", "", d end end end |
#find_possible(dependency) ⇒ Object
Extracts the specifications that may be able to fulfill dependency
and returns those that match the local platform and all those that match.
187 188 189 190 191 192 |
# File 'lib/rubygems/resolver.rb', line 187 def find_possible dependency # :nodoc: all = @set.find_all dependency matching_platform = select_local_platforms all return matching_platform, all end |
#handle_conflict(dep, existing) ⇒ Object
:nodoc:
194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 |
# File 'lib/rubygems/resolver.rb', line 194 def handle_conflict(dep, existing) # :nodoc: # There is a conflict! We return the conflict object which will be seen by # the caller and be handled at the right level. # If the existing activation indicates that there are other possibles for # it, then issue the conflict on the dependency for the activation itself. # Otherwise, if there was a requester, issue it on the requester's # request itself. # Finally, if the existing request has no requester (toplevel) unwind to # it anyway. if existing.others_possible? conflict = Gem::Resolver::Conflict.new dep, existing elsif dep.requester depreq = dep.requester.request conflict = Gem::Resolver::Conflict.new depreq, existing, dep elsif existing.request.requester.nil? conflict = Gem::Resolver::Conflict.new dep, existing else raise Gem::DependencyError, "Unable to figure out how to unwind conflict" end @conflicts << conflict unless @conflicts.include? conflict return conflict end |
#requests(s, act, reqs = nil) ⇒ Object
:nodoc:
142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 |
# File 'lib/rubygems/resolver.rb', line 142 def requests s, act, reqs=nil # :nodoc: return reqs if @ignore_dependencies s.dependencies.reverse_each do |d| next if d.type == :development and not @development reqs.add Gem::Resolver::DependencyRequest.new(d, act) @stats.requirement! end @set.prefetch reqs @stats.record_requirements reqs reqs end |
#resolve ⇒ Object
Proceed with resolution! Returns an array of ActivationRequest objects.
161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 |
# File 'lib/rubygems/resolver.rb', line 161 def resolve @conflicts = [] needed = Gem::Resolver::RequirementList.new @needed.reverse_each do |n| request = Gem::Resolver::DependencyRequest.new n, nil needed.add request @stats.requirement! end @stats.record_requirements needed res = resolve_for needed, nil raise Gem::DependencyResolutionError, res if res.kind_of? Gem::Resolver::Conflict res.to_a end |
#resolve_for(needed, specs) ⇒ Object
The meat of the algorithm. Given needed
DependencyRequest objects and specs
being a list to ActivationRequest, calculate a new list of ActivationRequest objects.
264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 |
# File 'lib/rubygems/resolver.rb', line 264 def resolve_for needed, specs # :nodoc: # The State objects that are used to attempt the activation tree. states = [] while !needed.empty? @stats.iteration! dep = needed.remove explain :try, [dep, dep.requester ? dep.requester.request : :toplevel] explain_list :next5, needed.next5 explain_list :specs, Array(specs).map { |x| x.full_name }.sort # If there is already a spec activated for the requested name... if specs && existing = specs.find { |s| dep.name == s.name } # then we're done since this new dep matches the existing spec. next if dep.matches_spec? existing conflict = handle_conflict dep, existing return conflict unless dep.requester explain :conflict, dep, :existing, existing.full_name depreq = dep.requester.request state = nil until states.empty? x = states.pop i = existing.request.requester explain :consider, x.spec.full_name, [depreq.name, dep.name, i ? i.name : :top] if x.spec.name == depreq.name or x.spec.name == dep.name or (i && (i.name == x.spec.name)) explain :found, x.spec.full_name state = x break end end return conflict unless state @stats.backtracking! needed, specs = resolve_for_conflict needed, specs, state states << state unless state.possibles.empty? next end matching, all = find_possible dep case matching.size when 0 resolve_for_zero dep, all when 1 needed, specs = resolve_for_single needed, specs, dep, matching else needed, specs = resolve_for_multiple needed, specs, states, dep, matching end end specs end |
#resolve_for_conflict(needed, specs, state) ⇒ Object
Rewinds needed
and specs
to a previous state in state
for a conflict between dep
and existing
.
337 338 339 340 341 342 343 344 345 346 347 348 349 350 |
# File 'lib/rubygems/resolver.rb', line 337 def resolve_for_conflict needed, specs, state # :nodoc: # We exhausted the possibles so it's definitely not going to work out, # bail out. raise Gem::ImpossibleDependenciesError.new state.dep, state.conflicts if state.possibles.empty? # Retry resolution with this spec and add it's dependencies spec, act = activation_request state.dep, state.possibles needed = requests spec, act, state.needed.dup specs = Gem::List.prepend state.specs, act return needed, specs end |
#resolve_for_multiple(needed, specs, states, dep, possible) ⇒ Object
There are multiple possible
specifications for this dep
. Updates needed
, specs
and states
for further resolution of the possible
choices.
357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 |
# File 'lib/rubygems/resolver.rb', line 357 def resolve_for_multiple needed, specs, states, dep, possible # :nodoc: # Sort them so that we try the highest versions first. possible = possible.sort_by do |s| [s.source, s.version, s.platform == Gem::Platform::RUBY ? -1 : 1] end spec, act = activation_request dep, possible # We may need to try all of +possible+, so we setup state to unwind back # to current +needed+ and +specs+ so we can try another. This is code is # what makes conflict resolution possible. states << State.new(needed.dup, specs, dep, spec, possible, []) @stats.record_depth states explain :states, states.map { |s| s.dep } needed = requests spec, act, needed specs = Gem::List.prepend specs, act return needed, specs end |
#resolve_for_single(needed, specs, dep, possible) ⇒ Object
Add the spec from the possible
list to specs
and process the spec’s dependencies by adding them to needed
.
384 385 386 387 388 389 390 391 392 393 394 395 396 397 |
# File 'lib/rubygems/resolver.rb', line 384 def resolve_for_single needed, specs, dep, possible # :nodoc: spec, act = activation_request dep, possible specs = Gem::List.prepend specs, act # Put the deps for at the beginning of needed # rather than the end to match the depth first # searching done by the multiple case code below. # # This keeps the error messages consistent. needed = requests spec, act, needed return needed, specs end |
#resolve_for_zero(dep, platform_mismatch) ⇒ Object
When there are no possible specifications for dep
our work is done.
402 403 404 405 406 407 408 |
# File 'lib/rubygems/resolver.rb', line 402 def resolve_for_zero dep, platform_mismatch # :nodoc: @missing << dep unless @soft_missing raise Gem::UnsatisfiableDependencyError.new(dep, platform_mismatch) end end |
#select_local_platforms(specs) ⇒ Object
Returns the gems in specs
that match the local platform.
413 414 415 416 417 |
# File 'lib/rubygems/resolver.rb', line 413 def select_local_platforms specs # :nodoc: specs.select do |spec| Gem::Platform.installable? spec end end |