diff options
Diffstat (limited to 'lib/hipe/test/bs_SUITE_data/bs_split.erl')
-rw-r--r-- | lib/hipe/test/bs_SUITE_data/bs_split.erl | 105 |
1 files changed, 105 insertions, 0 deletions
diff --git a/lib/hipe/test/bs_SUITE_data/bs_split.erl b/lib/hipe/test/bs_SUITE_data/bs_split.erl new file mode 100644 index 0000000000..2e52308a77 --- /dev/null +++ b/lib/hipe/test/bs_SUITE_data/bs_split.erl @@ -0,0 +1,105 @@ +%% -*- erlang-indent-level: 2 -*- +%%-------------------------------------------------------------------- + +-module(bs_split). + +-export([test/0]). + +test() -> + Funs = [fun byte_split_binary/0, fun bit_split_binary/0, fun z_split/0], + lists:foreach(fun (F) -> ok = F() end, Funs). + +%%-------------------------------------------------------------------- + +byte_split_binary() -> + L = lists:seq(0, 57), + B = mkbin(L), + byte_split(L, B, byte_size(B)). + +byte_split(L, B, Pos) when Pos >= 0 -> + Sz1 = Pos, + Sz2 = byte_size(B) - Pos, + bs1(L, B, Pos, Sz1, Sz2); +byte_split(_, _, _) -> ok. + +bs1(L, B, Pos, Sz1, Sz2) -> + <<B1:Sz1/binary, B2:Sz2/binary>> = B, + bs2(L, B, Pos, B1, B2). + +bs2(L, B, Pos, B1, B2)-> + B1 = list_to_binary(lists:sublist(L, 1, Pos)), + bs3(L, B, Pos, B2). + +bs3(L, B, Pos, B2) -> + B2 = list_to_binary(lists:nthtail(Pos, L)), + byte_split(L, B, Pos-1). + +%%-------------------------------------------------------------------- + +bit_split_binary() -> + Fun = fun(Bin, List, SkipBef, N) -> + SkipAft = bit_size(Bin) - N - SkipBef, + %% io:format("~p, ~p, ~p", [SkipBef,N,SkipAft]), + <<_I1:SkipBef,OutBin:N/binary-unit:1,_I2:SkipAft>> = Bin, + OutBin = make_bin_from_list(List, N) + end, + bit_split_binary1(Fun, erlang:md5(<<1,2,3>>)). + +bit_split_binary1(Action, Bin) -> + BitList = bits_to_list(binary_to_list(Bin), 16#80), + bit_split_binary2(Action, Bin, BitList, 0). + +bit_split_binary2(Action, Bin, [_|T]=List, Bef) -> + bit_split_binary3(Action, Bin, List, Bef, bit_size(Bin)), + bit_split_binary2(Action, Bin, T, Bef+1); +bit_split_binary2(_Action, _Bin, [], _Bef) -> ok. + +bit_split_binary3(Action, Bin, List, Bef, Aft) when Bef =< Aft -> + Action(Bin, List, Bef, (Aft-Bef) div 8 * 8), + bit_split_binary3(Action, Bin, List, Bef, Aft-8); +bit_split_binary3(_, _, _, _, _) -> ok. + +make_bin_from_list(_List, 0) -> + mkbin([]); +make_bin_from_list(List, N) -> + list_to_binary([make_int(List, 8, 0), + make_bin_from_list(lists:nthtail(8, List), N-8)]). + +make_int(_List, 0, Acc) -> Acc; +make_int([H|T], N, Acc) -> make_int(T, N-1, Acc bsl 1 bor H). + +bits_to_list([_|T], 0) -> bits_to_list(T, 16#80); +bits_to_list([H|_]=List, Mask) -> + [case H band Mask of + 0 -> 0; + _ -> 1 + end|bits_to_list(List, Mask bsr 1)]; +bits_to_list([], _) -> []. + +mkbin(L) when is_list(L) -> list_to_binary(L). + +%%-------------------------------------------------------------------- +%% Splits a series of null terminated segments of a binary without +%% creating any new sub-binaries until the zero is found. + +z_split() -> + [<<61,62,63>>] = z_split(<<61,62,63>>), + [<<61,62,63>>, <<>>] = z_split(<<61,62,63,0>>), + [<<61,62,63>>, <<64>>] = z_split(<<61,62,63,0,64>>), + [<<61,62,63>>, <<64,65,66>>] = z_split(<<61,62,63,0,64,65,66>>), + [<<61,62>>, <<64>>, <<>>, <<65,66>>] = z_split(<<61,62,0,64,0,0,65,66>>), + ok. + +z_split(B) when is_binary(B) -> + z_split(B, 0). + +z_split(B, N) -> + case B of + <<_B1:N/binary,0,_B2/binary>> -> % use skip_bits for B1, B2 + <<B1:N/binary,_,B2/binary>> = B, % and postpone the matching + [B1 | z_split(B2)]; + <<_:N/binary>> -> + [B]; + _ -> + z_split(B, N+1) + end. |