class Gem::RequestSet

# File lib/rubygems/request_set.rb, line 94
def initialize(*deps)
  @dependencies = deps

  @always_install      = []
  @conservative        = false
  @dependency_names    = {}
  @development         = false
  @development_shallow = false
  @errors              = []
  @git_set             = nil
  @ignore_dependencies = false
  @install_dir         = Gem.dir
  @prerelease          = false
  @remote              = true
  @requests            = []
  @sets                = []
  @soft_missing        = false
  @sorted              = nil
  @specs               = nil
  @vendor_set          = nil
  @source_set          = nil

  yield self if block_given?
end

# File lib/rubygems/request_set.rb, line 122
def gem(name, *reqs)
  if dep = @dependency_names[name]
    dep.requirement.concat reqs
  else
    dep = Gem::Dependency.new name, *reqs
    @dependency_names[name] = dep
    @dependencies << dep
  end
end

# File lib/rubygems/request_set.rb, line 135
def import(deps)
  @dependencies.concat deps
end

# File lib/rubygems/request_set.rb, line 146
def install(options, &block) # :yields: request, installer
  if dir = options[:install_dir]
    requests = install_into dir, false, options, &block
    return requests
  end

  @prerelease = options[:prerelease]

  requests = []
  download_queue = Queue.new

  # Create a thread-safe list of gems to download
  sorted_requests.each do |req|
    download_queue << req
  end

  # Create N threads in a pool, have them download all the gems
  threads = Gem.configuration.concurrent_downloads.times.map do
    # When a thread pops this item, it knows to stop running. The symbol
    # is queued here so that there will be one symbol per thread.
    download_queue << :stop

    Thread.new do
      # The pop method will block waiting for items, so the only way
      # to stop a thread from running is to provide a final item that
      # means the thread should stop.
      while req = download_queue.pop
        break if req == :stop
        req.spec.download options unless req.installed?
      end
    end
  end

  # Wait for all the downloads to finish before continuing
  threads.each(&:value)

  # Install requested gems after they have been downloaded
  sorted_requests.each do |req|
    if req.installed?
      req.spec.spec.build_extensions

      if @always_install.none? { |spec| spec == req.spec.spec }
        yield req, nil if block_given?
        next
      end
    end

    spec =
      begin
        req.spec.install options do |installer|
          yield req, installer if block_given?
        end
      rescue Gem::RuntimeRequirementNotMetError => e
        recent_match = req.spec.set.find_all(req.request).sort_by(&:version).reverse_each.find do |s|
          s = s.spec
          s.required_ruby_version.satisfied_by?(Gem.ruby_version) &&
            s.required_rubygems_version.satisfied_by?(Gem.rubygems_version) &&
            Gem::Platform.installable?(s)
        end
        if recent_match
          suggestion = "The last version of #{req.request} to support your Ruby & RubyGems was #{recent_match.version}. Try installing it with `gem install #{recent_match.name} -v #{recent_match.version}`"
          suggestion += " and then running the current command again" unless @always_install.include?(req.spec.spec)
        else
          suggestion = "There are no versions of #{req.request} compatible with your Ruby & RubyGems"
          suggestion += ". Maybe try installing an older version of the gem you're looking for?" unless @always_install.include?(req.spec.spec)
        end
        e.suggestion = suggestion
        raise
      end

    requests << spec
  end

  return requests if options[:gemdeps]

  install_hooks requests, options

  requests
end

# File lib/rubygems/request_set.rb, line 233
def install_from_gemdeps(options, &block)
  gemdeps = options[:gemdeps]

  @install_dir = options[:install_dir] || Gem.dir
  @prerelease  = options[:prerelease]
  @remote      = options[:domain] != :local
  @conservative = true if options[:conservative]

  gem_deps_api = load_gemdeps gemdeps, options[:without_groups], true

  resolve

  if options[:explain]
    puts "Gems to install:"

    sorted_requests.each do |spec|
      puts "  #{spec.full_name}"
    end

    if Gem.configuration.really_verbose
      @resolver.stats.display
    end
  else
    installed = install options, &block

    if options.fetch :lock, true
      lockfile =
        Gem::RequestSet::Lockfile.build self, gemdeps, gem_deps_api.dependencies
      lockfile.write
    end

    installed
  end
end

# File lib/rubygems/request_set.rb, line 308
def install_hooks(requests, options)
  specs = requests.map do |request|
    case request
    when Gem::Resolver::ActivationRequest then
      request.spec.spec
    else
      request
    end
  end

  require "rubygems/dependency_installer"
  inst = Gem::DependencyInstaller.new options
  inst.installed_gems.replace specs

  Gem.done_installing_hooks.each do |hook|
    hook.call inst, specs
  end unless Gem.done_installing_hooks.empty?
end

# File lib/rubygems/request_set.rb, line 268
def install_into(dir, force = true, options = {})
  gem_home, ENV['GEM_HOME'] = ENV['GEM_HOME'], dir

  existing = force ? [] : specs_in(dir)
  existing.delete_if { |s| @always_install.include? s }

  dir = File.expand_path dir

  installed = []

  options[:development] = false
  options[:install_dir] = dir
  options[:only_install_dir] = true
  @prerelease = options[:prerelease]

  sorted_requests.each do |request|
    spec = request.spec

    if existing.find { |s| s.full_name == spec.full_name }
      yield request, nil if block_given?
      next
    end

    spec.install options do |installer|
      yield request, installer if block_given?
    end

    installed << request
  end

  install_hooks installed, options

  installed
ensure
  ENV['GEM_HOME'] = gem_home
end

# File lib/rubygems/request_set.rb, line 330
def load_gemdeps(path, without_groups = [], installing = false)
  @git_set    = Gem::Resolver::GitSet.new
  @vendor_set = Gem::Resolver::VendorSet.new
  @source_set = Gem::Resolver::SourceSet.new

  @git_set.root_dir = @install_dir

  lock_file = "#{File.expand_path(path)}.lock".dup.tap(&Gem::UNTAINT)
  begin
    tokenizer = Gem::RequestSet::Lockfile::Tokenizer.from_file lock_file
    parser = tokenizer.make_parser self, []
    parser.parse
  rescue Errno::ENOENT
  end

  gf = Gem::RequestSet::GemDependencyAPI.new self, path
  gf.installing = installing
  gf.without_groups = without_groups if without_groups
  gf.load
end

# File lib/rubygems/request_set.rb, line 397
def resolve(set = Gem::Resolver::BestSet.new)
  @sets << set
  @sets << @git_set
  @sets << @vendor_set
  @sets << @source_set

  set = Gem::Resolver.compose_sets(*@sets)
  set.remote = @remote
  set.prerelease = @prerelease

  resolver = Gem::Resolver.new @dependencies, set
  resolver.development         = @development
  resolver.development_shallow = @development_shallow
  resolver.ignore_dependencies = @ignore_dependencies
  resolver.soft_missing        = @soft_missing

  if @conservative
    installed_gems = {}
    Gem::Specification.find_all do |spec|
      (installed_gems[spec.name] ||= []) << spec
    end
    resolver.skip_gems = installed_gems
  end

  @resolver = resolver

  @requests = resolver.resolve

  @errors = set.errors

  @requests
end

# File lib/rubygems/request_set.rb, line 434
def resolve_current
  resolve Gem::Resolver::CurrentSet.new
end

# File lib/rubygems/request_set.rb, line 438
def sorted_requests
  @sorted ||= strongly_connected_components.flatten
end

# File lib/rubygems/request_set.rb, line 442
def specs
  @specs ||= @requests.map { |r| r.full_spec }
end

# File lib/rubygems/request_set.rb, line 446
def specs_in(dir)
  Gem::Util.glob_files_in_dir("*.gemspec", File.join(dir, "specifications")).map do |g|
    Gem::Specification.load g
  end
end