require 'rubygems' require 'rubygems/dependency' require 'rubygems/exceptions' require 'rubygems/util/list' require 'uri' require 'net/http' ## # 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. class Gem::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. DEBUG_RESOLVER = !ENV['DEBUG_RESOLVER'].nil? ## # Contains all the conflicts encountered while doing resolution attr_reader :conflicts ## # Set to true if development dependencies should be considered. attr_accessor :development ## # When true, no dependencies are looked up for requested gems. attr_accessor :ignore_dependencies ## # List of dependencies that could not be found in the configured sources. attr_reader :missing attr_reader :stats ## # When a missing dependency, don't stop. Just go on and record what was # missing. attr_accessor :soft_missing ## # 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. 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 ## # Creates a Resolver that queries only against the already installed gems # for the +needed+ dependencies. def self.for_current_gems needed new needed, Gem::Resolver::CurrentSet.new end ## # 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. 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 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 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 ## # Creates an ActivationRequest for the given +dep+ and the last +possible+ # specification. # # Returns the Specification and the ActivationRequest 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 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 ## # Proceed with resolution! Returns an array of ActivationRequest objects. 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 ## # Extracts the specifications that may be able to fulfill +dependency+ and # returns those that match the local platform and all those that match. def find_possible dependency # :nodoc: all = @set.find_all dependency matching_platform = select_local_platforms all return matching_platform, all end 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 # Contains the state for attempting activation of a set of possible specs. # +needed+ is a Gem::List of DependencyRequest objects that, well, need # to be satisfied. # +specs+ is the List of ActivationRequest that are being tested. # +dep+ is the DependencyRequest that was used to generate this state. # +spec+ is the Specification for this state. # +possible+ is List of DependencyRequest objects that can be tried to # find a complete set. # +conflicts+ is a [DependencyRequest, Conflict] hit tried to # activate the state. # State = Struct.new(:needed, :specs, :dep, :spec, :possibles, :conflicts) do def summary # :nodoc: nd = needed.map { |s| s.to_s }.sort if nd if specs then ss = specs.map { |s| s.full_name }.sort ss.unshift ss.length end d = dep.to_s d << " from #{dep.requester.full_name}" if dep.requester ps = possibles.map { |p| p.full_name }.sort ps.unshift ps.length cs = conflicts.map do |(s, c)| [s.full_name, c.conflicting_dependencies.map { |cd| cd.to_s }] end { :needed => nd, :specs => ss, :dep => d, :spec => spec.full_name, :possibles => ps, :conflicts => cs } end end ## # The meat of the algorithm. Given +needed+ DependencyRequest objects and # +specs+ being a list to ActivationRequest, calculate a new list of # ActivationRequest objects. 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 ## # Rewinds +needed+ and +specs+ to a previous state in +state+ for a conflict # between +dep+ and +existing+. 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 ## # There are multiple +possible+ specifications for this +dep+. Updates # +needed+, +specs+ and +states+ for further resolution of the +possible+ # choices. 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 ## # Add the spec from the +possible+ list to +specs+ and process the spec's # dependencies by adding them to +needed+. 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 ## # When there are no possible specifications for +dep+ our work is done. def resolve_for_zero dep, platform_mismatch # :nodoc: @missing << dep unless @soft_missing raise Gem::UnsatisfiableDependencyError.new(dep, platform_mismatch) end end ## # Returns the gems in +specs+ that match the local platform. def select_local_platforms specs # :nodoc: specs.select do |spec| Gem::Platform.installable? spec end end end ## # TODO remove in RubyGems 3 Gem::DependencyResolver = Gem::Resolver # :nodoc: require 'rubygems/resolver/activation_request' require 'rubygems/resolver/conflict' require 'rubygems/resolver/dependency_request' require 'rubygems/resolver/requirement_list' require 'rubygems/resolver/stats' require 'rubygems/resolver/set' require 'rubygems/resolver/api_set' require 'rubygems/resolver/composed_set' require 'rubygems/resolver/best_set' require 'rubygems/resolver/current_set' require 'rubygems/resolver/git_set' require 'rubygems/resolver/index_set' require 'rubygems/resolver/installer_set' require 'rubygems/resolver/lock_set' require 'rubygems/resolver/vendor_set' require 'rubygems/resolver/specification' require 'rubygems/resolver/spec_specification' require 'rubygems/resolver/api_specification' require 'rubygems/resolver/git_specification' require 'rubygems/resolver/index_specification' require 'rubygems/resolver/installed_specification' require 'rubygems/resolver/local_specification' require 'rubygems/resolver/lock_specification' require 'rubygems/resolver/vendor_specification'