Class: Gem::Package::TarReader

Inherits:
Object
  • Object
show all
Includes:
Enumerable
Defined in:
lib/rubygems/package/tar_reader.rb

Overview

TarReader reads tar files and allows iteration over their items

Defined Under Namespace

Classes: Entry

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(io) ⇒ TarReader

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



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# File 'lib/rubygems/package/tar_reader.rb', line 35

def initialize(io)
  @io = io
  @init_pos = io.pos
end

Class Method Details

.new(io) ⇒ Object

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



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# File 'lib/rubygems/package/tar_reader.rb', line 17

def self.new(io)
  reader = super

  return reader unless block_given?

  begin
    yield reader
  ensure
    reader.close
  end

  nil
end

Instance Method Details

#close ⇒ Object

Close the tar file



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# File 'lib/rubygems/package/tar_reader.rb', line 43

def close
end

#each ⇒ Object Also known as: each_entry

Iterates over files in the tarball yielding each entry



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# File 'lib/rubygems/package/tar_reader.rb', line 49

def each
  return enum_for __method__ unless block_given?

  until @io.eof? do
    begin
      header = Gem::Package::TarHeader.from @io
    rescue ArgumentError => e
      # Specialize only exceptions from Gem::Package::TarHeader.strict_oct
      raise e unless e.message.match?(/ is not an octal string$/)
      raise Gem::Package::TarInvalidError, e.message
    end

    return if header.empty?
    entry = Gem::Package::TarReader::Entry.new header, @io
    yield entry
    entry.close
  end
end

#rewind ⇒ Object

NOTE: Do not call #rewind during #each



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# File 'lib/rubygems/package/tar_reader.rb', line 73

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

#seek(name) ⇒ Object

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.



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# File 'lib/rubygems/package/tar_reader.rb', line 86

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

  return unless found

  yield found
ensure
  rewind
end