1 files changed, 144 insertions, 0 deletions
diff --git a/lib/rubygems/source.rb b/lib/rubygems/source.rb
new file mode 100644
index 0000000000..c85a2cf660
--- /dev/null
+++ b/lib/rubygems/source.rb
@@ -0,0 +1,144 @@
+require 'uri'
+require 'fileutils'
+
+class Gem::Source
+  FILES = {
+    :released   => 'specs',
+    :latest     => 'latest_specs',
+    :prerelease => 'prerelease_specs',
+  }
+
+  def initialize(uri)
+    unless uri.kind_of? URI
+      uri = URI.parse(uri.to_s)
+    end
+
+    @uri = uri
+    @api_uri = nil
+  end
+
+  attr_reader :uri
+
+  def api_uri
+    require 'rubygems/remote_fetcher'
+    @api_uri ||= Gem::RemoteFetcher.fetcher.api_endpoint uri
+  end
+
+  def <=>(other)
+    if !@uri
+      return 0 unless other.uri
+      return -1
+    end
+
+    return 1 if !other.uri
+
+    @uri.to_s <=> other.uri.to_s
+  end
+
+  include Comparable
+
+  def ==(other)
+    case other
+    when self.class
+      @uri == other.uri
+    else
+      false
+    end
+  end
+
+  alias_method :eql?, :==
+
+  def hash
+    @uri.hash
+  end
+
+  ##
+  # Returns the local directory to write +uri+ to.
+
+  def cache_dir(uri)
+    # Correct for windows paths
+    escaped_path = uri.path.sub(/^\/([a-z]):\//i, '/\\1-/')
+    root = File.join Gem.user_home, '.gem', 'specs'
+    File.join root, "#{uri.host}%#{uri.port}", File.dirname(escaped_path)
+  end
+
+  def update_cache?
+    @update_cache ||= File.stat(Gem.user_home).uid == Process.uid
+  end
+
+  def fetch_spec(name)
+    fetcher = Gem::RemoteFetcher.fetcher
+
+    spec_file_name = name.spec_name
+
+    uri = @uri + "#{Gem::MARSHAL_SPEC_DIR}#{spec_file_name}"
+
+    cache_dir = cache_dir uri
+
+    local_spec = File.join cache_dir, spec_file_name
+
+    if File.exist? local_spec then
+      spec = Gem.read_binary local_spec
+      spec = Marshal.load(spec) rescue nil
+      return spec if spec
+    end
+
+    uri.path << '.rz'
+
+    spec = fetcher.fetch_path uri
+    spec = Gem.inflate spec
+
+    if update_cache? then
+      FileUtils.mkdir_p cache_dir
+
+      open local_spec, 'wb' do |io|
+        io.write spec
+      end
+    end
+
+    # TODO: Investigate setting Gem::Specification#loaded_from to a URI
+    Marshal.load spec
+  end
+
+  ##
+  # Loads +type+ kind of specs fetching from +@uri+ if the on-disk cache is
+  # out of date.
+  #
+  # +type+ is one of the following:
+  #
+  # :released   => Return the list of all released specs
+  # :latest     => Return the list of only the highest version of each gem
+  # :prerelease => Return the list of all prerelease only specs
+  #
+
+  def load_specs(type)
+    file       = FILES[type]
+    fetcher    = Gem::RemoteFetcher.fetcher
+    file_name  = "#{file}.#{Gem.marshal_version}"
+    spec_path  = @uri + "#{file_name}.gz"
+    cache_dir  = cache_dir spec_path
+    local_file = File.join(cache_dir, file_name)
+    retried    = false
+
+    FileUtils.mkdir_p cache_dir if update_cache?
+
+    spec_dump = fetcher.cache_update_path(spec_path, local_file)
+
+    begin
+      Gem::NameTuple.from_list Marshal.load(spec_dump)
+    rescue ArgumentError
+      if update_cache? && !retried
+        FileUtils.rm local_file
+        retried = true
+        retry
+      else
+        raise Gem::Exception.new("Invalid spec cache file in #{local_file}")
+      end
+    end
+  end
+
+  def download(spec, dir=Dir.pwd)
+    fetcher = Gem::RemoteFetcher.fetcher
+    fetcher.download spec, @uri.to_s, dir
+  end
+end