1 files changed, 152 insertions, 0 deletions
diff --git a/lib/rubygems/resolver/installer_set.rb b/lib/rubygems/resolver/installer_set.rb
new file mode 100644
index 0000000000..73d9e39651
--- /dev/null
+++ b/lib/rubygems/resolver/installer_set.rb
@@ -0,0 +1,152 @@
+##
+# A set of gems for installation sourced from remote sources and local .gem
+# files
+
+class Gem::Resolver::InstallerSet < Gem::Resolver::Set
+
+  ##
+  # List of Gem::Specification objects that must always be installed.
+
+  attr_reader :always_install # :nodoc:
+
+  ##
+  # Only install gems in the always_install list
+
+  attr_accessor :ignore_dependencies # :nodoc:
+
+  ##
+  # Do not look in the installed set when finding specifications.  This is
+  # used by the --install-dir option to `gem install`
+
+  attr_accessor :ignore_installed # :nodoc:
+
+  def initialize domain
+    @domain = domain
+
+    @f = Gem::SpecFetcher.fetcher
+
+    @all = Hash.new { |h,k| h[k] = [] }
+    @always_install      = []
+    @ignore_dependencies = false
+    @ignore_installed    = false
+    @loaded_remote_specs = []
+    @specs               = {}
+  end
+
+  ##
+  # Should local gems should be considered?
+
+  def consider_local? # :nodoc:
+    @domain == :both or @domain == :local
+  end
+
+  ##
+  # Should remote gems should be considered?
+
+  def consider_remote? # :nodoc:
+    @domain == :both or @domain == :remote
+  end
+
+  ##
+  # Returns an array of IndexSpecification objects matching DependencyRequest
+  # +req+.
+
+  def find_all req
+    res = []
+
+    dep  = req.dependency
+
+    return res if @ignore_dependencies and
+              @always_install.none? { |spec| dep.matches_spec? spec }
+
+    name = dep.name
+
+    dep.matching_specs.each do |gemspec|
+      next if @always_install.include? gemspec
+
+      res << Gem::Resolver::InstalledSpecification.new(self, gemspec)
+    end unless @ignore_installed
+
+    if consider_local? then
+      local_source = Gem::Source::Local.new
+
+      if spec = local_source.find_gem(name, dep.requirement) then
+        res << Gem::Resolver::IndexSpecification.new(
+          self, spec.name, spec.version, local_source, spec.platform)
+      end
+    end
+
+    if consider_remote? then
+      load_remote_specs dep
+
+      @all[name].each do |remote_source, n|
+        if dep.match? n then
+          res << Gem::Resolver::IndexSpecification.new(
+            self, n.name, n.version, remote_source, n.platform)
+        end
+      end
+    end
+
+    res
+  end
+
+  def inspect # :nodoc:
+    always_install = @always_install.map { |s| s.full_name }
+
+    '#<%s domain: %s specs: %p always install: %p>' % [
+      self.class, @domain, @specs.keys, always_install,
+    ]
+  end
+
+  ##
+  # Loads remote prerelease specs if +dep+ is a prerelease dependency
+
+  def load_remote_specs dep # :nodoc:
+    types = [:released]
+    types << :prerelease if dep.prerelease?
+
+    types.each do |type|
+      next if @loaded_remote_specs.include? type
+      @loaded_remote_specs << type
+
+      list, = @f.available_specs type
+
+      list.each do |uri, specs|
+        specs.each do |n|
+          @all[n.name] << [uri, n]
+        end
+      end
+    end
+  end
+
+  ##
+  # Called from IndexSpecification to get a true Specification
+  # object.
+
+  def load_spec name, ver, platform, source # :nodoc:
+    key = "#{name}-#{ver}-#{platform}"
+
+    @specs.fetch key do
+      tuple = Gem::NameTuple.new name, ver, platform
+
+      @specs[key] = source.fetch_spec tuple
+    end
+  end
+
+  def pretty_print q # :nodoc:
+    q.group 2, '[InstallerSet', ']' do
+      q.breakable
+      q.text "domain: #{@domain}"
+
+      q.breakable
+      q.text 'specs: '
+      q.pp @specs.keys
+
+      q.breakable
+      q.text 'always install: '
+      q.pp @always_install
+    end
+  end
+
+end
+