1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
|
%%% -*- erlang-indent-level: 2 -*-
%%%-------------------------------------------------------------------
%%% File : bs_match.erl
%%% Author : Per Gustafsson <[email protected]>
%%% Purpose : Performs simple matching and construction of binaries
%%% TODO : Add binary and float tests
%%% Created : 20 Feb 2004
%%%-------------------------------------------------------------------
-module(bs_match).
-export([test/0]).
test() ->
Funs = [fun test_aligned/0, fun test_unaligned/0,
fun test_zero_tail/0, fun test_integer_matching/0,
fun test_writable_bin/0],
lists:foreach(fun (F) -> ok = F() end, Funs).
%%-------------------------------------------------------------------
%% Test aligned accesses
test_aligned() ->
10 = aligned_skip_bits_all(1, <<10,11,12>>),
ok = aligned().
aligned_skip_bits_all(N, Bin) ->
<<X:N/integer-unit:8, _/binary>> = Bin,
X.
aligned() ->
Tail1 = mkbin([]),
{258, Tail1} = al_get_tail_used(mkbin([1,2])),
Tail2 = mkbin(lists:seq(1, 127)),
{35091, Tail2} = al_get_tail_used(mkbin([137,19|Tail2])),
64896 = al_get_tail_unused(mkbin([253,128])),
64895 = al_get_tail_unused(mkbin([253,127|lists:seq(42, 255)])),
Tail3 = mkbin(lists:seq(0, 19)),
{0, Tail1} = get_dyn_tail_used(Tail1, 0),
{0, Tail3} = get_dyn_tail_used(mkbin([Tail3]), 0),
{73, Tail3} = get_dyn_tail_used(mkbin([73|Tail3]), 8),
0 = get_dyn_tail_unused(mkbin([]), 0),
233 = get_dyn_tail_unused(mkbin([233]), 8),
23 = get_dyn_tail_unused(mkbin([23,22,2]), 8),
ok.
mkbin(L) when is_list(L) -> list_to_binary(L).
al_get_tail_used(<<A:16,T/binary>>) -> {A, T}.
al_get_tail_unused(<<A:16,_/binary>>) -> A.
%%-------------------------------------------------------------------
%% Test unaligned accesses
test_unaligned() ->
10 = unaligned_skip_bits_all(8, <<10,11,12>>),
ok = unaligned().
unaligned_skip_bits_all(N, Bin) ->
<<X:N, _/binary>> = Bin,
X.
unaligned() ->
{'EXIT', {function_clause,_}} = (catch get_tail_used(mkbin([42]))),
{'EXIT', {{badmatch,_},_}} = (catch get_dyn_tail_used(mkbin([137]), 3)),
{'EXIT', {function_clause,_}} = (catch get_tail_unused(mkbin([42,33]))),
{'EXIT', {{badmatch,_},_}} = (catch get_dyn_tail_unused(mkbin([44]), 7)),
ok.
get_tail_used(<<A:1, T/binary>>) -> {A, T}.
get_tail_unused(<<A:15, _/binary>>) -> A.
get_dyn_tail_used(Bin, Sz) ->
<<A:Sz, T/binary>> = Bin,
{A,T}.
get_dyn_tail_unused(Bin, Sz) ->
<<A:Sz, _T/binary>> = Bin,
A.
%%-------------------------------------------------------------------
%% Test zero tail
test_zero_tail() ->
42 = zt8(mkbin([42])),
{'EXIT', {function_clause, _}} = (catch zt8(mkbin([1,2]))),
{'EXIT', {function_clause, _}} = (catch zt44(mkbin([1,2]))),
ok.
zt8(<<A:8>>) -> A.
zt44(<<_:4,_:4>>) -> ok.
%%-------------------------------------------------------------------
%% Test integer matching
test_integer_matching() ->
ok = test_static_integer_matching_1(),
ok = test_static_integer_matching_2(),
ok = test_static_integer_matching_3(),
ok = test_static_integer_matching_4(),
DynFun = fun (N) -> ok = test_dynamic_integer_matching(N) end,
lists:foreach(DynFun, [28, 27, 9, 17, 25, 8, 16, 24, 32]).
test_static_integer_matching_1() ->
<<0:6, -25:28/integer-signed, 0:6>> = s11(),
<<0:6, -25:28/integer-little-signed, 0:6>> = s12(),
<<0:6, 25:28/integer-little, 0:6>> = s13(),
<<0:6, 25:28, 0:6>> = s14(),
ok.
s11() ->
<<0:6, -25:28/integer-signed, 0:6>>.
s12() ->
<<0:6, -25:28/integer-little-signed, 0:6>>.
s13() ->
<<0:6, 25:28/integer-little, 0:6>>.
s14() ->
<<0:6, 25:28, 0:6>>.
test_static_integer_matching_2() ->
<<0:6, -25:20/integer-signed, 0:6>> = s21(),
<<0:6, -25:20/integer-little-signed, 0:6>> = s22(),
<<0:6, 25:20/integer-little, 0:6>> = s23(),
<<0:6, 25:20, 0:6>> = s24(),
ok.
s21() ->
<<0:6, -25:20/integer-signed, 0:6>>.
s22() ->
<<0:6, -25:20/integer-little-signed, 0:6>>.
s23() ->
<<0:6, 25:20/integer-little, 0:6>>.
s24() ->
<<0:6, 25:20, 0:6>>.
test_static_integer_matching_3() ->
<<0:6, -25:12/integer-signed, 0:6>> = s31(),
<<0:6, -25:12/integer-little-signed, 0:6>> = s32(),
<<0:6, 25:12/integer-little, 0:6>> = s33(),
<<0:6, 25:12, 0:6>> = s34(),
ok.
s31() ->
<<0:6, -25:12/integer-signed, 0:6>>.
s32() ->
<<0:6, -25:12/integer-little-signed, 0:6>>.
s33() ->
<<0:6, 25:12/integer-little, 0:6>>.
s34() ->
<<0:6, 25:12, 0:6>>.
test_static_integer_matching_4() ->
<<0:6, -3:4/integer-signed, 0:6>> = s41(),
<<0:6, -3:4/integer-little-signed, 0:6>> = s42(),
<<0:6, 7:4/integer-little, 0:6>> = s43(),
<<0:6, 7:4, 0:6>> = s44(),
ok.
s41() ->
<<0:6, -3:4/integer-signed, 0:6>>.
s42() ->
<<0:6, -3:4/integer-little-signed, 0:6>>.
s43() ->
<<0:6, 7:4/integer-little, 0:6>>.
s44() ->
<<0:6, 7:4, 0:6>>.
test_dynamic_integer_matching(N) ->
S = 32 - N,
<<-12:N/integer-signed, 0:S>> = <<-12:N/integer-signed, 0:S>>,
<<-12:N/integer-little-signed, 0:S>> = <<-12:N/integer-little-signed, 0:S>>,
<<12:N/integer, 0:S>> = <<12:N/integer, 0:S>>,
<<12:N/integer-little, 0:S>> = <<12:N/integer-little, 0:S>>,
ok.
test_writable_bin() ->
test_writable_bin(<<>>, 0),
ok.
test_writable_bin(Bin, 128) ->
Bin;
test_writable_bin(Bin0, N) when N < 128 ->
Bin1 = <<Bin0/binary, N>>,
<<_/utf8, _/binary>> = Bin1,
test_writable_bin(Bin1, N+1).
|
