cs.serialise 20150116

some serialisation functions

I use these functions to serialise and de-serialise non-negative integers of arbitrary size and run length encoded block data.

The integers are encoded as octets in big-endian order, with the high bit indicating that more octets follow.

• get_bs(bs, offset=0): collect an integer from the bytes bs at the specified offset

• get_bsdata(bs, offset=0): collect a run length encoded data block from the bytes bs at the specified offset

• get_bsfp(fp): collect an integer from the binary file fp

• put_bs(n): return the bytes encoding of the supplied integer n

• put_bsdata(data): return the bytes run length encoding of the supplied data block