1 files changed, 130 insertions, 0 deletions
diff --git a/lib/rubygems/dependency_resolver/installer_set.rb b/lib/rubygems/dependency_resolver/installer_set.rb
new file mode 100644
index 0000000000..7de052df77
--- /dev/null
+++ b/lib/rubygems/dependency_resolver/installer_set.rb
@@ -0,0 +1,130 @@
+class Gem::DependencyResolver::InstallerSet
+
+  ##
+  # List of Gem::Specification objects that must always be installed.
+
+  attr_reader :always_install
+
+  ##
+  # Only install gems in the always_install list
+
+  attr_accessor :ignore_dependencies
+
+  ##
+  # 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
+
+  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?
+    @domain == :both or @domain == :local
+  end
+
+  ##
+  # Should remote gems should be considered?
+
+  def consider_remote?
+    @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::DependencyResolver::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::DependencyResolver::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::DependencyResolver::IndexSpecification.new(
+            self, n.name, n.version, remote_source, n.platform)
+        end
+      end
+    end
+
+    res
+  end
+
+  def inspect # :nodoc:
+    '#<%s domain: %s specs: %p>' % [ self.class, @domain, @specs.keys ]
+  end
+
+  ##
+  # Loads remote prerelease specs if +dep+ is a prerelease dependency
+
+  def load_remote_specs dep
+    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, source
+    key = "#{name}-#{ver}"
+    @specs[key] ||= source.fetch_spec Gem::NameTuple.new name, ver
+  end
+
+  ##
+  # No prefetching needed since we load the whole index in initially.
+
+  def prefetch(reqs)
+  end
+
+end
+