Question

def deflate(string, level)
  z = Zlib::Deflate.new(level)
  dst = z.deflate(string, Zlib::NO_FLUSH)
  z.close
  return dst
end

def inflate(string)
  zstream = Zlib::Inflate.new
  buf = zstream.inflate(string)
  zstream.finish
  zstream.close
  return buf
end

a = deflate("asasasas",6)
p a
p inflate(a)

Gives me a buffer error on line

  zstream.finish

Why is that? Ruby 1.8.7 I believe.

Answer 1

The documentation on deflate says:

Normally the parameter flush is set to Z_NO_FLUSH, which allows
deflate to decide how much data to accumulate before producing output,
in order to maximize compression.

By using Zlib::NO_FLUSH the returned value is not the entire deflated stream. Use Zlib::FINISH instead.

The functions you’ve written are the ones provided in the Zlib::Deflate / Zlib::Inflate documentation. You could replace all the code you’ve written with:

a = Zlib::Deflate.deflate("asasasas", 6)
p a
p Zlib::Inflate.inflate(a)