class Gem::Package::TarReader

TarReader reads tar files and allows iteration over their items

Public Class Methods

new(io) { |reader| ... } click to toggle source

Creates a new TarReader on io and yields it to the block, if given.

Calls superclass method BasicObject.new
# File lib/rubygems/package/tar_reader.rb, line 22
def self.new(io)
  reader = super

  return reader unless block_given?

  begin
    yield reader
  ensure
    reader.close
  end

  nil
end
new(io) click to toggle source

Creates a new tar file reader on io which needs to respond to pos, eof?, read, getc and pos=

# File lib/rubygems/package/tar_reader.rb, line 40
def initialize(io)
  @io = io
  @init_pos = io.pos
end

Public Instance Methods

close() click to toggle source

Close the tar file

# File lib/rubygems/package/tar_reader.rb, line 48
def close
end
each() { |entry| ... } click to toggle source

Iterates over files in the tarball yielding each entry

# File lib/rubygems/package/tar_reader.rb, line 54
  def each
    return enum_for __method__ unless block_given?

    until @io.eof? do
      header = Gem::Package::TarHeader.from @io
      return if header.empty?

      entry = Gem::Package::TarReader::Entry.new header, @io
      size = entry.header.size

      yield entry

      skip = (512 - (size % 512)) % 512
      pending = size - entry.bytes_read

      begin
        # avoid reading...
        @io.seek pending, IO::SEEK_CUR
        pending = 0
      rescue Errno::EINVAL, NameError
        while pending > 0 do
          bytes_read = @io.read([pending, 4096].min).size
          raise UnexpectedEOF if @io.eof?
          pending -= bytes_read
        end
      end

      @io.read skip # discard trailing zeros

      # make sure nobody can use #read, #getc or #rewind anymore
      entry.close
    end
  end

  alias each_entry each

  ##
  # NOTE: Do not call #rewind during #each

  def rewind
    if @init_pos == 0
      @io.rewind
    else
      @io.pos = @init_pos
    end
  end

  ##
  # Seeks through the tar file until it finds the +entry+ with +name+ and
  # yields it.  Rewinds the tar file to the beginning when the block
  # terminates.

  def seek(name) # :yields: entry
    found = find do |entry|
      entry.full_name == name
    end

    return unless found

    return yield found
  ensure
    rewind
  end

end

require
rewind() click to toggle source

NOTE: Do not call rewind during each

# File lib/rubygems/package/tar_reader.rb, line 93
def rewind
  if @init_pos == 0
    @io.rewind
  else
    @io.pos = @init_pos
  end
end
seek(name) { |entry| ... } click to toggle source

Seeks through the tar file until it finds the entry with name and yields it. Rewinds the tar file to the beginning when the block terminates.

# File lib/rubygems/package/tar_reader.rb, line 106
  def seek(name) # :yields: entry
    found = find do |entry|
      entry.full_name == name
    end

    return unless found

    return yield found
  ensure
    rewind
  end

end