# class Gem::Source

A Source knows how to list and fetch gems from a RubyGems marshal index.

There are other Source subclasses for installed gems, local gems, the bundler dependency API and so-forth.

### Attributes

uri[R]

The URI this source will fetch gems from.

### Public Class Methods

new(uri) click to toggle source

Creates a new Source which will use the index located at `uri`.

    # File lib/rubygems/source.rb, line 28
    def initialize(uri)
      begin
        unless uri.kind_of? URI
          uri = URI.parse(uri.to_s)
        end
      rescue URI::InvalidURIError
        raise if Gem::Source == self.class
      end

      @uri = uri
      @api_uri = nil
    end

### Public Instance Methods

<=>(other) click to toggle source

Sources are ordered by installation preference.

    # File lib/rubygems/source.rb, line 52
    def <=>(other)
      case other
      when Gem::Source::Installed,
           Gem::Source::Local,
           Gem::Source::Lock,
           Gem::Source::SpecificFile,
           Gem::Source::Git,
           Gem::Source::Vendor then
        -1
      when Gem::Source then
        if !@uri
          return 0 unless other.uri
          return 1
        end

        return -1 if !other.uri

        # Returning 1 here ensures that when sorting a list of sources, the
        # original ordering of sources supplied by the user is preserved.
        return 1 unless @uri.to_s == other.uri.to_s

        0
      else
        nil
      end
    end

cache_dir(uri) click to toggle source

Returns the local directory to write `uri` to.

    # File lib/rubygems/source.rb, line 114
    def cache_dir(uri)
      # Correct for windows paths
      escaped_path = uri.path.sub(/^\/([a-z]):\//i, '/\\1-/')
      escaped_path.untaint

      File.join Gem.spec_cache_dir, "#{uri.host}%#{uri.port}", File.dirname(escaped_path)
    end

download(spec, dir=Dir.pwd) click to toggle source

Downloads `spec` and writes it to `dir`. See also Gem::RemoteFetcher#download.

    # File lib/rubygems/source.rb, line 212
    def download(spec, dir=Dir.pwd)
      fetcher = Gem::RemoteFetcher.fetcher
      fetcher.download spec, api_uri.to_s, dir
    end

fetch_spec(name_tuple) click to toggle source

Fetches a specification for the given `name_tuple`.

    # File lib/rubygems/source.rb, line 137
    def fetch_spec name_tuple
      fetcher = Gem::RemoteFetcher.fetcher

      spec_file_name = name_tuple.spec_name

      uri = api_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

        File.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

load_specs(type) click to toggle source

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

    # File lib/rubygems/source.rb, line 182
    def load_specs(type)
      file       = FILES[type]
      fetcher    = Gem::RemoteFetcher.fetcher
      file_name  = "#{file}.#{Gem.marshal_version}"
      spec_path  = api_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, update_cache?

      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

update_cache?() click to toggle source

Returns true when it is possible and safe to update the cache directory.

    # File lib/rubygems/source.rb, line 125
    def update_cache?
      @update_cache ||=
        begin
          File.stat(Gem.user_home).uid == Process.uid
        rescue Errno::ENOENT
          false
        end
    end