[erlang-questions] Fast binary reverse
Ward Bekker
ward@REDACTED
Thu Oct 27 10:12:54 CEST 2011
Hi,
I want to reverse the bytes of a bitstring as fast as possible. There is not a erlang BIF that does this, so I googled some possible solutions:
Fun1 = fun(B) -> S = size(B)*8,<<X:S/integer-little>>=B, <<X:S/integer-big>> end.
Fun2 = fun(B) -> binary:list_to_bin(lists:reverse(binary:bin_to_list(B))) end.
Fun1 = ~37 microseconds when executing Fun1(<"terribly">).
Fun2 = ~16 microseconds when executing Fun2(<"terribly">)
But a simple reverse of a list of integers is much, much faster:
timer:tc(lists, reverse, ["terribly"]) = ~1 microseconds.
Are there other options or do I need to write a new BIF function?
Regards,
Ward Bekker
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