Module: Swiff::Compression

Included in:
Swiff
Defined in:
lib/swiff/compression.rb

Instance Method Summary collapse

Instance Method Details

#compress ⇒ Object 



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# File 'lib/swiff/compression.rb', line 16

def compress
  compressor = Zlib::Deflate.new
  data = compressor.deflate(strip_header(decompressed_bytes), Zlib::FINISH)
  data = bytes[0,8] + data
  data[0] = ?C
  data
end

#decompress ⇒ Object 



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# File 'lib/swiff/compression.rb', line 24

def decompress
  decompressor = Zlib::Inflate.new
  swf = decompressor.inflate(strip_header)
  swf = bytes[0,8] + swf
  swf[0] = ?F
  swf
end

#is_compressed? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/swiff/compression.rb', line 45

def is_compressed?
  bytes[0] == ?C
end

#read_file(file, to) ⇒ Object

Raises:

  • (RuntimeError.new) 


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# File 'lib/swiff/compression.rb', line 5

def read_file(file,to)
  buff = File.open(file,"rb") do |fin|
    fin.read
  end
  raise RuntimeError.new,"The file have already been compressed",caller if is_compressed?(buff[0])
  result = compress(buff)
  File.open(to,"wb") do |fout|
    fout.write(result)
  end
end

#read_full_size ⇒ Object 



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# File 'lib/swiff/compression.rb', line 32

def read_full_size
  buff = File.open(@path,"rb") do |f|
    f.seek(4,IO::SEEK_CUR)
    f.read 4
  end
  buff.unpack("L")[0]
end

#strip_header(buffer = nil) ⇒ Object 



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# File 'lib/swiff/compression.rb', line 40

def strip_header(buffer = nil)
  buffer ||= bytes
  buffer[8,bytes.size-8]
end