From: "theosib@..." <theosib@...>
Date: 2007-03-09T10:30:05+09:00
Subject: Efficient processing of binary data streams in Ruby?

I'm writing a Ruby program that has to process binary data from files
and sockets.  Data items are in bytes, 16-bit words, or 32-bit words,
and I cannot predict in advance whether the data will be msb-first or
lsb-first, so I end up writing things like this:

    def unpack_16(x)
        @msb_first ? ((x[0]<<8)|x[1]) : ((x[1]<<8)|x[0])
    end

    def pack_16(x)
        y = "xx"
        if (@msb_first)
            y[0] = x>>8
            y[1] = x&255
        else
            y[0] = x&255
            y[1] = x>>8
        end
    end

I expect, however, that this will be painfully slow, and I can't
imagine that this hasn't been though of before.  Is there a better way
to do this that will result in much better performance?

Thanks!