class Gem::Package::TarWriter

Allows writing of tar files

Public Class Methods

new (io) { |writer| ... }

Creates a new TarWriter, yielding it if a block is given

Calls superclass method BasicObject::new 
# File lib/rubygems/package/tar_writer.rb, line 75
def self.new(io)
  writer = super

  return writer unless block_given?

  begin
    yield writer
  ensure
    writer.close
  end

  nil
end
new (io)

Creates a new TarWriter that will write to io

# File lib/rubygems/package/tar_writer.rb, line 92
def initialize(io)
  @io = io
  @closed = false
end

Public Instance Methods

add_file (name, mode) { |io| ... }

Adds file name with permissions mode, and yields an IO for writing the file to

# File lib/rubygems/package/tar_writer.rb, line 101
def add_file(name, mode) # :yields: io
  check_closed

  name, prefix = split_name name

  init_pos = @io.pos
  @io.write Gem::Package::TarHeader::EMPTY_HEADER # placeholder for the header

  yield RestrictedStream.new(@io) if block_given?

  size = @io.pos - init_pos - 512

  remainder = (512 - (size % 512)) % 512
  @io.write "\0" * remainder

  final_pos = @io.pos
  @io.pos = init_pos

  header = Gem::Package::TarHeader.new name: name, mode: mode,
                                       size: size, prefix: prefix,
                                       mtime: Gem.source_date_epoch

  @io.write header
  @io.pos = final_pos

  self
end
add_file_digest (name, mode, digest_algorithms) { |io| ... }

Adds name with permissions mode to the tar, yielding io for writing the file. The digest_algorithm is written to a read-only name.sum file following the given file contents containing the digest name and hexdigest separated by a tab.

The created digest object is returned.

# File lib/rubygems/package/tar_writer.rb, line 137
def add_file_digest(name, mode, digest_algorithms) # :yields: io
  digests = digest_algorithms.map do |digest_algorithm|
    digest = digest_algorithm.new
    digest_name =
      if digest.respond_to? :name
        digest.name
      else
        digest_algorithm.class.name[/::([^:]+)\z/, 1]
      end

    [digest_name, digest]
  end

  digests = Hash[*digests.flatten]

  add_file name, mode do |io|
    Gem::Package::DigestIO.wrap io, digests do |digest_io|
      yield digest_io
    end
  end

  digests
end
add_file_signed (name, mode, signer) { |io| ... }

Adds name with permissions mode to the tar, yielding io for writing the file. The signer is used to add a digest file using its digest_algorithm per add_file_digest and a cryptographic signature in name.sig. If the signer has no key only the checksum file is added.

Returns the digest.

# File lib/rubygems/package/tar_writer.rb, line 169
def add_file_signed(name, mode, signer)
  digest_algorithms = [
    signer.digest_algorithm,
    Gem::Security.create_digest("SHA512"),
  ].compact.uniq

  digests = add_file_digest name, mode, digest_algorithms do |io|
    yield io
  end

  signature_digest = digests.values.compact.find do |digest|
    digest_name =
      if digest.respond_to? :name
        digest.name
      else
        digest.class.name[/::([^:]+)\z/, 1]
      end

    digest_name == signer.digest_name
  end

  raise "no #{signer.digest_name} in #{digests.values.compact}" unless signature_digest

  if signer.key
    signature = signer.sign signature_digest.digest

    add_file_simple "#{name}.sig", 0o444, signature.length do |io|
      io.write signature
    end
  end

  digests
end
add_file_simple (name, mode, size) { |io| ... }

Add file name with permissions mode size bytes long. Yields an IO to write the file to.

# File lib/rubygems/package/tar_writer.rb, line 207
def add_file_simple(name, mode, size) # :yields: io
  check_closed

  name, prefix = split_name name

  header = Gem::Package::TarHeader.new(name: name, mode: mode,
                                       size: size, prefix: prefix,
                                       mtime: Gem.source_date_epoch).to_s

  @io.write header
  os = BoundedStream.new @io, size

  yield os if block_given?

  min_padding = size - os.written
  @io.write("\0" * min_padding)

  remainder = (512 - (size % 512)) % 512
  @io.write("\0" * remainder)

  self
end
add_symlink (name, target, mode)

Adds symlink name with permissions mode, linking to target.

check_closed ()

Raises IOError if the TarWriter is closed

# File lib/rubygems/package/tar_writer.rb, line 252
def check_closed
  raise IOError, "closed #{self.class}" if closed?
end
close ()

Closes the TarWriter

# File lib/rubygems/package/tar_writer.rb, line 259
def close
  check_closed

  @io.write "\0" * 1024
  flush

  @closed = true
end
closed? ()

Is the TarWriter closed?

# File lib/rubygems/package/tar_writer.rb, line 271
def closed?
  @closed
end
flush ()

Flushes the TarWriter’s IO

# File lib/rubygems/package/tar_writer.rb, line 278
def flush
  check_closed

  @io.flush if @io.respond_to? :flush
end
mkdir (name, mode)

Creates a new directory in the tar file name with mode

# File lib/rubygems/package/tar_writer.rb, line 287
def mkdir(name, mode)
  check_closed

  name, prefix = split_name(name)

  header = Gem::Package::TarHeader.new name: name, mode: mode,
                                       typeflag: "5", size: 0,
                                       prefix: prefix,
                                       mtime: Gem.source_date_epoch

  @io.write header

  self
end