Class: Gem::Resolver

Inherits:
Object
  • Object
show all
Includes:
Molinillo::SpecificationProvider, Molinillo::UI
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

Modules: Molinillo Classes: APISet, APISpecification, ActivationRequest, BestSet, ComposedSet, Conflict, CurrentSet, DependencyRequest, GitSet, GitSpecification, IndexSet, IndexSpecification, InstalledSpecification, InstallerSet, LocalSpecification, LockSet, LockSpecification, RequirementList, Set, SourceSet, SpecSpecification, Specification, 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

Class Method Summary collapse

Instance Method Summary collapse

Methods included from Molinillo::SpecificationProvider

#name_for_explicit_dependency_source, #name_for_locking_dependency_source

Methods included from Molinillo::UI

#after_resolution, #before_resolution, #debug, #indicate_progress, #progress_rate

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.


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# File 'lib/rubygems/resolver.rb', line 102

def initialize needed, set = nil
  @set = set || Gem::Resolver::IndexSet.new
  @needed = needed

  @development         = false
  @development_shallow = false
  @ignore_dependencies = false
  @missing             = []
  @skip_gems           = {}
  @soft_missing        = false
  @stats               = Gem::Resolver::Stats.new
end

Instance Attribute Details

#developmentObject

Set to true if all development dependencies should be considered.


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# File 'lib/rubygems/resolver.rb', line 26

def development
  @development
end

#development_shallowObject

Set to true if immediate development dependencies should be considered.


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# File 'lib/rubygems/resolver.rb', line 31

def development_shallow
  @development_shallow
end

#ignore_dependenciesObject

When true, no dependencies are looked up for requested gems.


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# File 'lib/rubygems/resolver.rb', line 36

def ignore_dependencies
  @ignore_dependencies
end

#missingObject (readonly)

List of dependencies that could not be found in the configured sources.


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# File 'lib/rubygems/resolver.rb', line 41

def missing
  @missing
end

#skip_gemsObject

Hash of gems to skip resolution. Keyed by gem name, with arrays of gem specifications as values.


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# File 'lib/rubygems/resolver.rb', line 49

def skip_gems
  @skip_gems
end

#soft_missingObject

When a missing dependency, don't stop. Just go on and record what was missing.


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# File 'lib/rubygems/resolver.rb', line 55

def soft_missing
  @soft_missing
end

#statsObject (readonly)

Returns the value of attribute stats


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# File 'lib/rubygems/resolver.rb', line 43

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.


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# File 'lib/rubygems/resolver.rb', line 62

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.


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# File 'lib/rubygems/resolver.rb', line 90

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


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# File 'lib/rubygems/resolver.rb', line 136

def activation_request dep, possible # :nodoc:
  spec = possible.pop

  explain :activate, [spec.full_name, possible.size]
  explain :possible, possible

  activation_request =
    Gem::Resolver::ActivationRequest.new spec, dep, possible

  return spec, activation_request
end

#allow_missing?(dependency) ⇒ Boolean


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# File 'lib/rubygems/resolver.rb', line 271

def allow_missing?(dependency)
  @missing << dependency
  @soft_missing
end

#debug?Boolean


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# File 'lib/rubygems/resolver.rb', line 177

def debug?
  DEBUG_RESOLVER
end

#dependencies_for(specification) ⇒ Object


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# File 'lib/rubygems/resolver.rb', line 257

def dependencies_for(specification)
  return [] if @ignore_dependencies
  spec = specification.spec
  requests(spec, specification)
end

#explain(stage, *data) ⇒ Object

:nodoc:


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# File 'lib/rubygems/resolver.rb', line 115

def explain stage, *data # :nodoc:
  return unless DEBUG_RESOLVER

  d = data.map { |x| x.pretty_inspect }.join(", ")
  $stderr.printf "%10s %s\n", stage.to_s.upcase, d
end

#explain_list(stage) ⇒ Object

:nodoc:


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# File 'lib/rubygems/resolver.rb', line 122

def explain_list stage # :nodoc:
  return unless DEBUG_RESOLVER

  data = yield
  $stderr.printf "%10s (%d entries)\n", stage.to_s.upcase, data.size
  PP.pp data, $stderr unless data.empty?
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.


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# File 'lib/rubygems/resolver.rb', line 200

def find_possible dependency # :nodoc:
  all = @set.find_all dependency

  if (skip_dep_gems = skip_gems[dependency.name]) && !skip_dep_gems.empty?
    matching = all.select do |api_spec|
      skip_dep_gems.any? { |s| api_spec.version == s.version }
    end

    all = matching unless matching.empty?
  end

  matching_platform = select_local_platforms all

  return matching_platform, all
end

#name_for(dependency) ⇒ Object


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# File 'lib/rubygems/resolver.rb', line 267

def name_for(dependency)
  dependency.name
end

#outputObject


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# File 'lib/rubygems/resolver.rb', line 173

def output
  @output ||= debug? ? $stdout : File.open(IO::NULL, 'w')
end

#requests(s, act, reqs = []) ⇒ Object

:nodoc:


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# File 'lib/rubygems/resolver.rb', line 148

def requests s, act, reqs=[] # :nodoc:
  return reqs if @ignore_dependencies

  s.fetch_development_dependencies if @development

  s.dependencies.reverse_each do |d|
    next if d.type == :development and not @development
    next if d.type == :development and @development_shallow and
            act.development?
    next if d.type == :development and @development_shallow and
            act.parent

    reqs << Gem::Resolver::DependencyRequest.new(d, act)
    @stats.requirement!
  end

  @set.prefetch reqs

  @stats.record_requirements reqs

  reqs
end

#requirement_satisfied_by?(requirement, activated, spec) ⇒ Boolean


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# File 'lib/rubygems/resolver.rb', line 263

def requirement_satisfied_by?(requirement, activated, spec)
  requirement.matches_spec? spec
end

#resolveObject

Proceed with resolution! Returns an array of ActivationRequest objects.


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# File 'lib/rubygems/resolver.rb', line 186

def resolve
  locking_dg = Molinillo::DependencyGraph.new
  Molinillo::Resolver.new(self, self).resolve(@needed.map { |d| DependencyRequest.new d, nil }, locking_dg).tsort.map(&:payload).compact
rescue Molinillo::VersionConflict => e
  conflict = e.conflicts.values.first
  raise Gem::DependencyResolutionError, Conflict.new(conflict.requirement_trees.first.first, conflict.existing, conflict.requirement)
ensure
  @output.close if defined?(@output) and !debug?
end

#search_for(dependency) ⇒ Object


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# File 'lib/rubygems/resolver.rb', line 225

def search_for(dependency)
  possibles, all = find_possible(dependency)
  if !@soft_missing && possibles.empty?
    @missing << dependency
    exc = Gem::UnsatisfiableDependencyError.new dependency, all
    exc.errors = @set.errors
    raise exc
  end

  sources = []

  groups = Hash.new { |hash, key| hash[key] = [] }

  # create groups & sources in the same loop
  sources = possibles.map { |spec|
    source = spec.source
    groups[source] << spec
    source
  }.uniq.reverse

  activation_requests = []

  sources.each do |source|
    groups[source].
      sort_by { |spec| [spec.version, Gem::Platform.local =~ spec.platform ? 1 : 0] }.
      map { |spec| ActivationRequest.new spec, dependency, [] }.
      each { |activation_request| activation_requests << activation_request }
  end

  activation_requests
end

#select_local_platforms(specs) ⇒ Object

Returns the gems in specs that match the local platform.


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# File 'lib/rubygems/resolver.rb', line 219

def select_local_platforms specs # :nodoc:
  specs.select do |spec|
    Gem::Platform.installable? spec
  end
end

#sort_dependencies(dependencies, activated, conflicts) ⇒ Object


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# File 'lib/rubygems/resolver.rb', line 276

def sort_dependencies(dependencies, activated, conflicts)
  dependencies.sort_by.with_index do |dependency, i|
    name = name_for(dependency)
    [
      activated.vertex_named(name).payload ? 0 : 1,
      amount_constrained(dependency),
      conflicts[name] ? 0 : 1,
      activated.vertex_named(name).payload ? 0 : search_for(dependency).count,
      i # for stable sort
    ]
  end
end