Class: RHC::Vendor::Zlib::GzipReader

Inherits:
GzipFile show all
Defined in:
lib/rhc/vendor/zliby.rb

Constant Summary collapse

OSES = 
['FAT filesystem', 
'Amiga', 
'VMS (or OpenVMS)', 
'Unix', 
'VM/CMS', 
'Atari TOS', 
'HPFS fileystem (OS/2, NT)', 
'Macintosh', 
'Z-System',
'CP/M',
'TOPS-20',
'NTFS filesystem (NT)',
'QDOS',
'Acorn RISCOS',
'unknown']

Class Method Summary collapse

Instance Method Summary collapse

Methods inherited from GzipFile

#close

Constructor Details

#initialize(io) ⇒ GzipReader

Returns a new instance of GzipReader.



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# File 'lib/rhc/vendor/zliby.rb', line 528

def initialize io
  
  #Add a helper method to check bits
  ::Fixnum.module_eval do
    def isbitset? bit_to_check
    if self & (2 ** bit_to_check)  == (2 ** bit_to_check) then true else false end
  end
  end

  super()
  @io = io
  io.read.each_byte {|b| @input_buffer << b}
  if @input_buffer[@in_pos+=1] != 0x1f || @input_buffer[@in_pos+=1] != 0x8b then raise Zlib::GzipFile::Error.new("not in gzip format") end
  if @input_buffer[@in_pos+=1] != 0x08 then raise Zlib::GzipFile::Error.new("unknown compression method") end
  flg = @input_buffer[@in_pos+=1]
  @ftext = flg.isbitset? 0
  @fhcrc = flg.isbitset? 1
  @fextra = flg.isbitset? 2
  @fname = flg.isbitset? 3
  @fcomment = flg.isbitset? 4
  @mtime = Time.at(@input_buffer[@in_pos+=1] | (@input_buffer[@in_pos+=1] << 8) | (@input_buffer[@in_pos+=1] << 16) | (@input_buffer[@in_pos+=1] << 24))
  @xfl = @input_buffer[@in_pos+=1]
  @os = OSES[@input_buffer[@in_pos+=1]]
  if @fextra then 
    @xlen = (@input_buffer[@in_pos+=1] | (@input_buffer[@in_pos+=1] << 8)) 
    @xtra_field = []
    @xlen.times {@xtra_field << @input_buffer[@in_pos+=1]}
  end
  if @fname then
    @original_name = ""
    until @original_name["\0"].nil? == false
      @original_name.concat(@input_buffer[@in_pos+=1])
    end
    @original_name.chop!
  end
  if @fcomment then
    @comment = ""
    until @comment["\0"].nil? == false
      @comment.concat(@input_buffer[@in_pos+=1])
    end
    @comment.chop!
  end
  if @fhcrc then
    @header_crc = @input_buffer[@in_pos+=1] | (@input_buffer[@in_pos+=1] << 8)
  end  
  @contents = ""
  until @in_pos == @input_buffer.length-1
    @contents.concat(@input_buffer[@in_pos+=1])
  end

  #we do raw deflate, no headers
  @zstream = Zlib::Inflate.new -MAX_WBITS
  @inflated = StringIO.new(@zstream.inflate @contents)
   
end

Class Method Details

.open(filename) ⇒ Object 



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# File 'lib/rhc/vendor/zliby.rb', line 603

def open filename
  io = File.open filename, 'rb'
  gz = self.new io
  if block_given? then yield gz else gz end
end

Instance Method Details

#eof? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/rhc/vendor/zliby.rb', line 588

def eof?
  @inflated.eof?
end

#pos ⇒ Object 



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# File 'lib/rhc/vendor/zliby.rb', line 592

def pos
  @inflated.pos
end

#read(length = nil) ⇒ Object 



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# File 'lib/rhc/vendor/zliby.rb', line 584

def read length=nil
  @inflated.read length
end

#rewind ⇒ Object 



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# File 'lib/rhc/vendor/zliby.rb', line 596

def rewind
  @inflated.rewind
  @io.seek 0, IO::SEEK_SET
end