1 files changed, 182 insertions, 0 deletions
diff --git a/lib/rubygems/request_set.rb b/lib/rubygems/request_set.rb
new file mode 100644
index 0000000000..6c52b90c40
--- /dev/null
+++ b/lib/rubygems/request_set.rb
@@ -0,0 +1,182 @@
+require 'rubygems'
+require 'rubygems/dependency'
+require 'rubygems/dependency_resolver'
+require 'rubygems/dependency_list'
+require 'rubygems/installer'
+require 'tsort'
+
+module Gem
+  class RequestSet
+
+    include TSort
+
+    def initialize(*deps)
+      @dependencies = deps
+
+      yield self if block_given?
+    end
+
+    attr_reader :dependencies
+
+    # Declare that a gem of name +name+ with +reqs+ requirements
+    # is needed.
+    #
+    def gem(name, *reqs)
+      @dependencies << Gem::Dependency.new(name, reqs)
+    end
+
+    # Add +deps+ Gem::Depedency objects to the set.
+    #
+    def import(deps)
+      @dependencies += deps
+    end
+
+    # Resolve the requested dependencies and return an Array of
+    # Specification objects to be activated.
+    #
+    def resolve(set=nil)
+      r = Gem::DependencyResolver.new(@dependencies, set)
+      @requests = r.resolve
+    end
+
+    # Resolve the requested dependencies against the gems
+    # available via Gem.path and return an Array of Specification
+    # objects to be activated.
+    #
+    def resolve_current
+      resolve DependencyResolver::CurrentSet.new
+    end
+
+    # Load a dependency management file.
+    #
+    def load_gemdeps(path)
+      gf = GemDepedencyAPI.new(self, path)
+      gf.load
+    end
+
+    def specs
+      @specs ||= @requests.map { |r| r.full_spec }
+    end
+
+    def tsort_each_node(&block)
+      @requests.each(&block)
+    end
+
+    def tsort_each_child(node)
+      node.spec.dependencies.each do |dep|
+        next if dep.type == :development
+
+        match = @requests.find { |r| dep.match? r.spec.name, r.spec.version }
+        if match
+          begin
+            yield match
+          rescue TSort::Cyclic
+          end
+        else
+          raise Gem::DependencyError, "Unresolved depedency found during sorting - #{dep}"
+        end
+      end
+    end
+
+    def sorted_requests
+      @sorted ||= strongly_connected_components.flatten
+    end
+
+    def specs_in(dir)
+      Dir["#{dir}/specifications/*.gemspec"].map do |g|
+        Gem::Specification.load g
+      end
+    end
+
+    def install_into(dir, force=true, &b)
+      existing = force ? [] : specs_in(dir)
+
+      dir = File.expand_path dir
+
+      installed = []
+
+      sorted_requests.each do |req|
+        if existing.find { |s| s.full_name == req.spec.full_name }
+          b.call req, nil if b
+          next
+        end
+
+        path = req.download(dir)
+
+        inst = Gem::Installer.new path, :install_dir => dir,
+                                        :only_install_dir => true
+
+        b.call req, inst if b
+
+        inst.install
+
+        installed << req
+      end
+
+      installed
+    end
+
+    def install(options, &b)
+      if dir = options[:install_dir]
+        return install_into(dir, false, &b)
+      end
+
+      cache_dir = options[:cache_dir] || Gem.dir
+
+      specs = []
+
+      sorted_requests.each do |req|
+        if req.installed?
+          b.call req, nil if b
+          next
+        end
+
+        path = req.download cache_dir
+
+        inst = Gem::Installer.new path, options
+
+        b.call req, inst if b
+
+        specs << inst.install
+      end
+
+      specs
+    end
+
+    # A semi-compatible DSL for Bundler's Gemfile format
+    #
+    class GemDepedencyAPI
+      def initialize(set, path)
+        @set = set
+        @path = path
+      end
+
+      def load
+        instance_eval File.read(@path).untaint, @path, 1
+      end
+
+      # DSL
+
+      def source(url)
+      end
+
+      def gem(name, *reqs)
+        # Ignore the opts for now.
+        reqs.pop if reqs.last.kind_of?(Hash)
+
+        @set.gem name, *reqs
+      end
+
+      def platform(what)
+        if what == :ruby
+          yield
+        end
+      end
+
+      alias_method :platforms, :platform
+
+      def group(*what)
+      end
+    end
+  end
+end