%%% -*- erlang-indent-level: 2 -*-
%%%-------------------------------------------------------------------
%%% File : bs_bits.erl
%%% Author : Per Gustafsson <[email protected]>
%%% Purpose : Tests for bit stream operations including matching,
%%% construction, binary_to_list and list_to_binary
%%% Created : 6 Sep 2006
%%%-------------------------------------------------------------------
-module(bs_bits).
-export([test/0]).
test() ->
<<1:100>> = <<1:100>>,
ok = match(7),
ok = match(9),
ok = match1(15),
ok = match1(31),
ok = horrid_match(),
ok = test_bitstr(),
ok = test_is_bitstr(<<1:1>>,<<8>>),
ok = test_is_binary(<<1:1>>,<<8>>),
ok = test_bitsize(),
ok = asymmetric_tests(),
ok = big_asymmetric_tests(),
ok = bitstr_to_and_from_list(),
ok = big_bitstr_to_and_from_list(),
ok = send_and_receive(),
ok = send_and_receive_alot(),
ok.
match(N) ->
<<0:N>> = <<0:N>>,
ok.
match1(N) ->
<<42:N/little>> = <<42:N/little>>,
ok.
test_is_bitstr(Bitstr, Binary) ->
true = is_bitstring(Bitstr),
true = is_bitstring(Binary),
ok = if is_bitstring(Bitstr) -> ok end,
ok = if is_bitstring(Binary) -> ok end.
test_is_binary(Bitstr, Binary) ->
false = is_binary(Bitstr),
true = is_binary(Binary),
ok = if is_binary(Bitstr) -> not_ok; true -> ok end,
ok = if is_binary(Binary) -> ok end.
test_bitsize() ->
101 = erlang:bit_size(<<1:101>>),
1001 = erlang:bit_size(<<1:1001>>),
80 = erlang:bit_size(<<1:80>>),
800 = erlang:bit_size(<<1:800>>),
Bin = <<0:16#1000000>>,
BigBin = list_to_bitstring([Bin||_ <- lists:seq(1,16#10)]++[<<1:1>>]),
16#10000001 = bit_size(BigBin),
%% Only run these on computers with lots of memory
%% HugeBin = list_to_bitstring([BigBin||_ <- lists:seq(1,16#10)]++[<<1:1>>]),
%% 16#100000011 = bit_size(HugeBin),
0 = erlang:bit_size(<<>>),
ok.
horrid_match() ->
<<1:4,B:24/bitstring>> = <<1:4,42:24/little>>,
<<42:24/little>> = B,
ok.
test_bitstr() ->
<<1:7,B/bitstring>> = <<1:7,<<1:1,6>>/bitstring>>,
<<1:1,6>> = B,
B = <<1:1,6>>,
ok.
asymmetric_tests() ->
<<1:12>> = <<0,1:4>>,
<<0,1:4>> = <<1:12>>,
<<1:1,X/bitstring>> = <<128,255,0,0:2>>,
<<1,254,0,0:1>> = X,
X = <<1,254,0,0:1>>,
<<1:1,X1:25/bitstring>> = <<128,255,0,0:2>>,
<<1,254,0,0:1>> = X1,
X1 = <<1,254,0,0:1>>,
ok.
big_asymmetric_tests() ->
<<1:875,1:12>> = <<1:875,0,1:4>>,
<<1:875,0,1:4>> = <<1:875,1:12>>,
<<1:1,X/bitstring>> = <<128,255,0,0:2,1:875>>,
<<1,254,0,0:1,1:875>> = X,
X = <<1,254,0,0:1,1:875>>,
<<1:1,X1:900/bitstring>> = <<128,255,0,0:2,1:875>>,
<<1,254,0,0:1,1:875>> = X1,
X1 = <<1,254,0,0:1,1:875>>,
ok.
bitstr_to_and_from_list() ->
<<1:7>> = list_to_bitstring(bitstring_to_list(<<1:7>>)),
<<1,2,3,4,1:1>> = list_to_bitstring(bitstring_to_list(<<1,2,3,4,1:1>>)),
[1,2,3,4,<<1:1>>] = bitstring_to_list(<<1,2,3,4,1:1>>),
<<1:1,1,2,3,4>> = list_to_bitstring([<<1:1>>,1,2,3,4]),
[128,129,1,130,<<0:1>>] = bitstring_to_list(<<1:1,1,2,3,4>>),
ok.
big_bitstr_to_and_from_list() ->
<<1:800,2,3,4,1:1>> = list_to_bitstring(bitstring_to_list(<<1:800,2,3,4,1:1>>)),
[1,2,3,4|_Rest1] = bitstring_to_list(<<1,2,3,4,1:800,1:1>>),
<<1:801,1,2,3,4>> = list_to_bitstring([<<1:801>>,1,2,3,4]),
ok.
send_and_receive() ->
Bin = <<1,2:7>>,
Pid = spawn(fun() -> receiver(Bin) end),
Pid ! {self(),<<1:7,8:5,Bin/bitstring>>},
receive
ok ->
ok
end.
receiver(Bin) ->
receive
{Pid,<<1:7,8:5,Bin/bitstring>>} ->
Pid ! ok
end.
send_and_receive_alot() ->
Bin = <<1:1000001>>,
Pid = spawn(fun() -> receiver_alot(Bin) end),
send_alot(100,Bin,Pid).
send_alot(N,Bin,Pid) when N > 0 ->
Pid ! {self(),<<1:7,8:5,Bin/bitstring>>},
receive
ok ->
ok
end,
send_alot(N-1,Bin,Pid);
send_alot(0,_Bin,Pid) ->
Pid ! no_more,
ok.
receiver_alot(Bin) ->
receive
{Pid,<<1:7,8:5,Bin/bitstring>>} ->
Pid ! ok;
no_more -> ok
end,
receiver_alot(Bin).
