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Class: Gem::Package::TarReader::Entry

Relationships & Source Files
Inherits: Object
Defined in: lib/rubygems/package/tar_reader/entry.rb

Overview

Class for reading entries out of a tar file

Class Method Summary

Instance Attribute Summary

Instance Method Summary

Constructor Details

.new(header, io) ⇒ Entry

Creates a new tar entry for #header that will be read from io

[ GitHub ] 

  


# File 'lib/rubygems/package/tar_reader/entry.rb', line 36



def initialize(header, io)
  @closed = false
  @header = header
  @io = io
  @orig_pos = @io.pos
  @end_pos = @orig_pos + @header.size
  @read = 0
end


  







Class Method Details



  

    .open(header, io, &block)  
  



  

    

Creates a new tar entry for #header that will be read from io If a block is given, the entry is yielded and then closed.


  



  [ GitHub ]


  

  


# File 'lib/rubygems/package/tar_reader/entry.rb', line 18



def self.open(header, io, &block)
  entry = new header, io
  return entry unless block_given?
  begin
    yield entry
  ensure
    entry.close
  end
end


  







Instance Attribute Details



  

    #closed?  ⇒ Boolean  (readonly)
  



  

    

Is the tar entry closed?


  





  


  [ GitHub ]


  

  


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



def closed?
  @closed
end


  








  

    #directory?  ⇒ Boolean  (readonly)
  



  

    

Is this tar entry a directory?


  





  


  [ GitHub ]


  

  


# File 'lib/rubygems/package/tar_reader/entry.rb', line 116



def directory?
  @header.typeflag == "5"
end


  








  

    #eof?  ⇒ Boolean  (readonly)
  



  

    

Are we at the end of the tar entry?


  





  


  [ GitHub ]


  

  


# File 'lib/rubygems/package/tar_reader/entry.rb', line 80



def eof?
  check_closed

  @read >= @header.size
end


  








  

    #file?  ⇒ Boolean  (readonly)
  



  

    

Is this tar entry a file?


  





  


  [ GitHub ]


  

  


# File 'lib/rubygems/package/tar_reader/entry.rb', line 123



def file?
  @header.typeflag == "0"
end


  








  

    #header   (readonly)
  



  

    

Header for this tar entry


  



  [ GitHub ]


  

  


# File 'lib/rubygems/package/tar_reader/entry.rb', line 31



attr_reader :header


  








  

    #pos   (rw)
  



  

    

The position in the tar entry


  



  [ GitHub ]


  

  


# File 'lib/rubygems/package/tar_reader/entry.rb', line 137



def pos
  check_closed

  bytes_read
end


  








  

    #pos=(new_pos)   (rw)
  



  

    

Seek to the position in the tar entry


  



  [ GitHub ]


  

  


# File 'lib/rubygems/package/tar_reader/entry.rb', line 146



def pos=(new_pos)
  seek(new_pos, IO::SEEK_SET)
end


  








  

    #symlink?  ⇒ Boolean  (readonly)
  



  

    

Is this tar entry a symlink?


  





  


  [ GitHub ]


  

  


# File 'lib/rubygems/package/tar_reader/entry.rb', line 130



def symlink?
  @header.typeflag == "2"
end


  







Instance Method Details



  

    #bytes_read  
  



  

    

Number of bytes read out of the tar entry


  



  [ GitHub ]


  

  


# File 'lib/rubygems/package/tar_reader/entry.rb', line 52



def bytes_read
  @read
end


  








  

    #check_closed  
  

  

    This method is for internal use only.
  



  

    
  





  
Raises:


    
  
  • 
    (IOError)
  
    • 





  [ GitHub ]


  

  


# File 'lib/rubygems/package/tar_reader/entry.rb', line 45



def check_closed # :nodoc:
  raise IOError, "closed #{self.class}" if closed?
end


  








  

    #close  
  



  

    

Closes the tar entry


  



  [ GitHub ]


  

  


# File 'lib/rubygems/package/tar_reader/entry.rb', line 59



def close
  return if closed?
  # Seek to the end of the entry if it wasn't fully read
  seek(0, IO::SEEK_END)
  # discard trailing zeros
  skip = (512 - (@header.size % 512)) % 512
  @io.read(skip)
  @closed = true
  nil
end


  








  

    #full_name  
  



  

    

Full name of the tar entry


  



  [ GitHub ]


  

  


# File 'lib/rubygems/package/tar_reader/entry.rb', line 89



def full_name
  if @header.prefix != ""
    File.join @header.prefix, @header.name
  else
    @header.name
  end
rescue ArgumentError => e
  raise unless e.message == "string contains null byte"
  raise Gem::Package::TarInvalidError,
        "tar is corrupt, name contains null byte"
end


  








  

    #getc  
  



  

    

Read one byte from the tar entry


  



  [ GitHub ]


  

  


# File 'lib/rubygems/package/tar_reader/entry.rb', line 104



def getc
  return nil if eof?

  ret = @io.getc
  @read += 1 if ret

  ret
end


  








  

    #length  
  



  

    

Alias for #size.


  



  [ GitHub ]


  

  


# File 'lib/rubygems/package/tar_reader/entry.rb', line 154



alias_method :length, :size


  








  

    #read(maxlen = nil)  
  



  

    

Reads maxlen bytes from the tar file entry, or the rest of the entry if nil


  



  [ GitHub ]


  

  


# File 'lib/rubygems/package/tar_reader/entry.rb', line 159



def read(maxlen = nil)
  if eof?
    return maxlen.to_i.zero? ? "" : nil
  end

  max_read = [maxlen, @header.size - @read].compact.min

  ret = @io.read max_read
  if ret.nil?
    return maxlen ? nil : "" # IO.read returns nil on EOF with len argument
  end
  @read += ret.size

  ret
end


  








  

    #readpartial(maxlen, outbuf = "".b)  
  

  [ GitHub ]


  

  


# File 'lib/rubygems/package/tar_reader/entry.rb', line 175



def readpartial(maxlen, outbuf = "".b)
  if eof? && maxlen > 0
    raise EOFError, "end of file reached"
  end

  max_read = [maxlen, @header.size - @read].min

  @io.readpartial(max_read, outbuf)
  @read += outbuf.size

  outbuf
end


  








  

    #rewind  
  



  

    

Rewinds to the beginning of the tar file entry


  



  [ GitHub ]


  

  


# File 'lib/rubygems/package/tar_reader/entry.rb', line 244



def rewind
  check_closed
  seek(0, IO::SEEK_SET)
end


  








  

    #seek(offset, whence = IO::SEEK_SET)  
  



  

    

Seeks to offset bytes into the tar file entry whence can be IO::SEEK_SET, IO::SEEK_CUR, or IO::SEEK_END


  



  [ GitHub ]


  

  


# File 'lib/rubygems/package/tar_reader/entry.rb', line 192



def seek(offset, whence = IO::SEEK_SET)
  check_closed

  new_pos =
    case whence
    when IO::SEEK_SET then @orig_pos + offset
    when IO::SEEK_CUR then @io.pos + offset
    when IO::SEEK_END then @end_pos + offset
    else
      raise ArgumentError, "invalid whence"
    end

  if new_pos < @orig_pos
    new_pos = @orig_pos
  elsif new_pos > @end_pos
    new_pos = @end_pos
  end

  pending = new_pos - @io.pos

  return 0 if pending == 0

  if @io.respond_to?(:seek)
    begin
      # avoid reading if the @io supports seeking
      @io.seek new_pos, IO::SEEK_SET
      pending = 0
    rescue Errno::EINVAL
    end
  end

  # if seeking isn't supported or failed
  # negative seek requires that we rewind and read
  if pending < 0
    @io.rewind
    pending = new_pos
  end

  while pending > 0 do
    size_read = @io.read([pending, 4096].min)&.size
    raise(EOFError, "end of file reached") if size_read.nil?
    pending -= size_read
  end

  @read = @io.pos - @orig_pos

  0
end


  








  

    #size  
    Also known as: #length
  

  [ GitHub ]


  

  


# File 'lib/rubygems/package/tar_reader/entry.rb', line 150



def size
  @header.size
end