1 files changed, 165 insertions, 0 deletions
diff --git a/lib/rubygems/available_set.rb b/lib/rubygems/available_set.rb
new file mode 100644
index 0000000000..0af80cc3db
--- /dev/null
+++ b/lib/rubygems/available_set.rb
@@ -0,0 +1,165 @@
+# frozen_string_literal: true
+
+class Gem::AvailableSet
+  include Enumerable
+
+  Tuple = Struct.new(:spec, :source)
+
+  attr_accessor :remote # :nodoc:
+
+  def initialize
+    @set = []
+    @sorted = nil
+    @remote = true
+  end
+
+  attr_reader :set
+
+  def add(spec, source)
+    @set << Tuple.new(spec, source)
+    @sorted = nil
+    self
+  end
+
+  def <<(o)
+    case o
+    when Gem::AvailableSet
+      s = o.set
+    when Array
+      s = o.map do |sp,so|
+        if !sp.is_a?(Gem::Specification) || !so.is_a?(Gem::Source)
+          raise TypeError, "Array must be in [[spec, source], ...] form"
+        end
+
+        Tuple.new(sp,so)
+      end
+    else
+      raise TypeError, "must be a Gem::AvailableSet"
+    end
+
+    @set += s
+    @sorted = nil
+
+    self
+  end
+
+  ##
+  # Yields each Tuple in this AvailableSet
+
+  def each
+    return enum_for __method__ unless block_given?
+
+    @set.each do |tuple|
+      yield tuple
+    end
+  end
+
+  ##
+  # Yields the Gem::Specification for each Tuple in this AvailableSet
+
+  def each_spec
+    return enum_for __method__ unless block_given?
+
+    each do |tuple|
+      yield tuple.spec
+    end
+  end
+
+  def empty?
+    @set.empty?
+  end
+
+  def all_specs
+    @set.map(&:spec)
+  end
+
+  def match_platform!
+    @set.reject! {|t| !Gem::Platform.match_spec?(t.spec) }
+    @sorted = nil
+    self
+  end
+
+  def sorted
+    @sorted ||= @set.sort do |a,b|
+      i = b.spec <=> a.spec
+      i != 0 ? i : (a.source <=> b.source)
+    end
+  end
+
+  def size
+    @set.size
+  end
+
+  def source_for(spec)
+    f = @set.find {|t| t.spec == spec }
+    f.source
+  end
+
+  ##
+  # Converts this AvailableSet into a RequestSet that can be used to install
+  # gems.
+  #
+  # If +development+ is :none then no development dependencies are installed.
+  # Other options are :shallow for only direct development dependencies of the
+  # gems in this set or :all for all development dependencies.
+
+  def to_request_set(development = :none)
+    request_set = Gem::RequestSet.new
+    request_set.development = development == :all
+
+    each_spec do |spec|
+      request_set.always_install << spec
+
+      request_set.gem spec.name, spec.version
+      request_set.import spec.development_dependencies if
+        development == :shallow
+    end
+
+    request_set
+  end
+
+  ##
+  #
+  # Used by the Resolver, the protocol to use a AvailableSet as a
+  # search Set.
+
+  def find_all(req)
+    dep = req.dependency
+
+    match = @set.find_all do |t|
+      dep.match? t.spec
+    end
+
+    match.map do |t|
+      Gem::Resolver::LocalSpecification.new(self, t.spec, t.source)
+    end
+  end
+
+  def prefetch(reqs)
+  end
+
+  def pick_best!
+    return self if empty?
+
+    @set = [sorted.first]
+    @sorted = nil
+    self
+  end
+
+  def remove_installed!(dep)
+    @set.reject! do |_t|
+      # already locally installed
+      Gem::Specification.any? do |installed_spec|
+        dep.name == installed_spec.name &&
+          dep.requirement.satisfied_by?(installed_spec.version)
+      end
+    end
+
+    @sorted = nil
+    self
+  end
+
+  def inject_into_list(dep_list)
+    @set.each {|t| dep_list.add t.spec }
+  end
+end