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?

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 103

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 27

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 32

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 37

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 42

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 50

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 56

def soft_missing
  @soft_missing
end

#statsObject (readonly)

Returns the value of attribute stats


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# 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.


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# File 'lib/rubygems/resolver.rb', line 63

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 91

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 140

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

Returns:

  • (Boolean)

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# File 'lib/rubygems/resolver.rb', line 273

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

#debug?Boolean

Returns:

  • (Boolean)

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# File 'lib/rubygems/resolver.rb', line 181

def debug?
  DEBUG_RESOLVER
end

#dependencies_for(specification) ⇒ Object


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# File 'lib/rubygems/resolver.rb', line 259

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 116

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 123

def explain_list(stage) # :nodoc:
  return unless DEBUG_RESOLVER

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


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# File 'lib/rubygems/resolver.rb', line 204

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 269

def name_for(dependency)
  dependency.name
end

#outputObject


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

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 152

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

Returns:

  • (Boolean)

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# File 'lib/rubygems/resolver.rb', line 265

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 190

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 229

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

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

  # create groups & sources in the same loop
  sources = possibles.map do |spec|
    source = spec.source
    groups[source] << spec
    source
  end.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 223

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 278

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