The Builder class processes RubyGem specification files to produce a .gem file.

Methods
B
N
S
W
Included Modules
Class Public methods
new(spec)

Constructs a builder instance for the provided specification

spec
Gem::Specification

The specification instance

Source: show | on GitHub 

# File ../ruby/lib/rubygems/builder.rb, line 27
def initialize(spec)
  @spec = spec
end
Instance Public methods
build(skip_validation=false)

Builds the gem from the specification. Returns the name of the file written.

Source: show | on GitHub 

# File ../ruby/lib/rubygems/builder.rb, line 35
def build(skip_validation=false)
  @spec.mark_version
  @spec.validate unless skip_validation
  @signer = sign
  write_package
  say success if Gem.configuration.verbose
  File.basename @spec.cache_file
end
success()

Source: show | on GitHub 

# File ../ruby/lib/rubygems/builder.rb, line 44
  def success
    <<-EOM
  Successfully built RubyGem
  Name: #{@spec.name}
  Version: #{@spec.version}
  File: #{File.basename @spec.cache_file}
EOM
  end
Instance Private methods
sign()

If the signing key was specified, then load the file, and swap to the public key (TODO: we should probably just omit the signing key in favor of the signing certificate, but that's for the future, also the signature algorithm should be configurable)

Source: show | on GitHub 

# File ../ruby/lib/rubygems/builder.rb, line 61
def sign
  signer = nil

  if @spec.respond_to?(:signing_key) and @spec.signing_key then
    require 'rubygems/security'

    signer = Gem::Security::Signer.new @spec.signing_key, @spec.cert_chain
    @spec.signing_key = nil
    @spec.cert_chain = signer.cert_chain.map { |cert| cert.to_s }
  end

  signer
end
write_package()

Source: show | on GitHub 

# File ../ruby/lib/rubygems/builder.rb, line 75
def write_package
  file_name = File.basename @spec.cache_file
  open file_name, 'wb' do |gem_io|
    Gem::Package.open gem_io, 'w', @signer do |pkg|
      yaml = @spec.to_yaml
      pkg.metadata = yaml

      @spec.files.each do |file|
        next if File.directory?(file)
        next if file == file_name # Don't add gem onto itself

        stat = File.stat(file)
        mode = stat.mode & 0777
        size = stat.size

        pkg.add_file_simple file, mode, size do |tar_io|
          tar_io.write open(file, "rb") { |f| f.read }
        end
      end
    end
  end
end