##
# A Lock source wraps an installed gem's source and sorts before other sources
# during dependency resolution.  This allows RubyGems to prefer gems from
# dependency lock files.

class Gem::Source::Lock < Gem::Source

  ##
  # The wrapped Gem::Source

  attr_reader :wrapped

  ##
  # Creates a new Lock source that wraps +source+ and moves it earlier in the
  # sort list.

  def initialize source
    @wrapped = source
  end

  def <=> other # :nodoc:
    case other
    when Gem::Source::Lock then
      @wrapped <=> other.wrapped
    when Gem::Source then
      1
    else
      nil
    end
  end

  def == other # :nodoc:
    0 == (self <=> other)
  end

  ##
  # Delegates to the wrapped source's fetch_spec method.

  def fetch_spec name_tuple
    @wrapped.fetch_spec name_tuple
  end

  def uri # :nodoc:
    @wrapped.uri
  end

end