1 files changed, 81 insertions, 0 deletions
diff --git a/lib/rubygems/resolver/lock_set.rb b/lib/rubygems/resolver/lock_set.rb
new file mode 100644
index 0000000000..e5ee32a9a6
--- /dev/null
+++ b/lib/rubygems/resolver/lock_set.rb
@@ -0,0 +1,81 @@
+# frozen_string_literal: true
+
+##
+# A set of gems from a gem dependencies lockfile.
+
+class Gem::Resolver::LockSet < Gem::Resolver::Set
+  attr_reader :specs # :nodoc:
+
+  ##
+  # Creates a new LockSet from the given +sources+
+
+  def initialize(sources)
+    super()
+
+    @sources = sources.map do |source|
+      Gem::Source::Lock.new source
+    end
+
+    @specs = []
+  end
+
+  ##
+  # Creates a new IndexSpecification in this set using the given +name+,
+  # +version+ and +platform+.
+  #
+  # The specification's set will be the current set, and the source will be
+  # the current set's source.
+
+  def add(name, version, platform) # :nodoc:
+    version = Gem::Version.new version
+    specs = [
+      Gem::Resolver::LockSpecification.new(self, name, version, @sources, platform),
+    ]
+
+    @specs.concat specs
+
+    specs
+  end
+
+  ##
+  # Returns an Array of IndexSpecification objects matching the
+  # DependencyRequest +req+.
+
+  def find_all(req)
+    @specs.select do |spec|
+      req.match? spec
+    end
+  end
+
+  ##
+  # Loads a Gem::Specification with the given +name+, +version+ and
+  # +platform+.  +source+ is ignored.
+
+  def load_spec(name, version, platform, source) # :nodoc:
+    dep = Gem::Dependency.new name, version
+
+    found = @specs.find do |spec|
+      dep.matches_spec?(spec) && spec.platform == platform
+    end
+
+    tuple = Gem::NameTuple.new found.name, found.version, found.platform
+
+    found.source.fetch_spec tuple
+  end
+
+  def pretty_print(q) # :nodoc:
+    q.group 2, "[LockSet", "]" do
+      q.breakable
+      q.text "source:"
+
+      q.breakable
+      q.pp @source
+
+      q.breakable
+      q.text "specs:"
+
+      q.breakable
+      q.pp @specs.map(&:full_name)
+    end
+  end
+end