class Gem::Resolver

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.

Constants

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.

Attributes

development[RW]

Set to true if all development dependencies should be considered.

development_shallow[RW]

Set to true if immediate development dependencies should be considered.

ignore_dependencies[RW]

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

missing[R]

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

skip_gems[RW]

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

soft_missing[RW]

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

stats[R]

Public Class Methods

compose_sets(*sets) click to toggle source

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.

# File lib/rubygems/resolver.rb, line 65
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) click to toggle source

Creates a Resolver that queries only against the already installed gems for the needed dependencies.

# File lib/rubygems/resolver.rb, line 93
def self.for_current_gems needed
  new needed, Gem::Resolver::CurrentSet.new
end

new(needed, set = nil) click to toggle source

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.

# File lib/rubygems/resolver.rb, line 105
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

Public Instance Methods

allow_missing?(dependency) click to toggle source

# File lib/rubygems/resolver.rb, line 254
def allow_missing?(dependency)
  @missing << dependency
  @soft_missing
end

debug?() click to toggle source

# File lib/rubygems/resolver.rb, line 180
def debug?
  DEBUG_RESOLVER
end

dependencies_for(specification) click to toggle source

# File lib/rubygems/resolver.rb, line 240
def dependencies_for(specification)
  return [] if @ignore_dependencies
  spec = specification.spec
  requests(spec, specification)
end

name_for(dependency) click to toggle source

# File lib/rubygems/resolver.rb, line 250
def name_for(dependency)
  dependency.name
end

output() click to toggle source

# File lib/rubygems/resolver.rb, line 176
def output
  @output ||= debug? ? $stdout : File.open(Gem::Util::NULL_DEVICE, 'w')
end

requirement_satisfied_by?(requirement, activated, spec) click to toggle source

# File lib/rubygems/resolver.rb, line 246
def requirement_satisfied_by?(requirement, activated, spec)
  requirement.matches_spec? spec
end

resolve() click to toggle source

Proceed with resolution! Returns an array of ActivationRequest objects.

# File lib/rubygems/resolver.rb, line 189
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 @output and !debug?
end

search_for(dependency) click to toggle source

# File lib/rubygems/resolver.rb, line 228
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
  possibles.sort_by { |s| [s.source, s.version, s.platform.to_s == Gem::Platform.local.to_s ? 1 : 0] }.
    map { |s| ActivationRequest.new s, dependency, [] }
end