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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 34

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 16

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 71

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 78

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 29

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)
  new_pos
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 50

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 43

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 57

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 87

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 102

def getc
  check_closed

  return nil if @read >= @header.size

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

  ret
end

#length

Alias for #size.

[ GitHub ]

  
# File 'lib/rubygems/package/tar_reader/entry.rb', line 155

alias length size

#read(len = nil)

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

[ GitHub ]

  
# File 'lib/rubygems/package/tar_reader/entry.rb', line 161

def read(len = nil)
  check_closed

  len ||= @header.size - @read

  return nil if len > 0 && @read >= @header.size

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

  ret = @io.read max_read
  @read += ret.size

  ret
end

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

Raises:

  • (EOFError)
[ GitHub ]

  
# File 'lib/rubygems/package/tar_reader/entry.rb', line 176

def readpartial(maxlen = nil, outbuf = "".b)
  check_closed

  maxlen ||= @header.size - @read

  raise EOFError if maxlen > 0 && @read >= @header.size

  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 245

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 195

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

  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 UnexpectedEOF if @io.eof?
    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 151

def size
  @header.size
end