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%% Copyright (c) Loïc Hoguin <[email protected]>
%%
%% Permission to use, copy, modify, and/or distribute this software for any
%% purpose with or without fee is hereby granted, provided that the above
%% copyright notice and this permission notice appear in all copies.
%%
%% THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
%% WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
%% MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
%% ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
%% WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
%% ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
%% OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
-module(cow_uri).
-dialyzer(no_improper_lists).
-export([urldecode/1]).
-export([urlencode/1]).
-include("cow_inline.hrl").
-define(IS_PLAIN(C), (
(C =:= $!) orelse (C =:= $$) orelse (C =:= $&) orelse (C =:= $') orelse
(C =:= $() orelse (C =:= $)) orelse (C =:= $*) orelse (C =:= $+) orelse
(C =:= $,) orelse (C =:= $-) orelse (C =:= $.) orelse (C =:= $0) orelse
(C =:= $1) orelse (C =:= $2) orelse (C =:= $3) orelse (C =:= $4) orelse
(C =:= $5) orelse (C =:= $6) orelse (C =:= $7) orelse (C =:= $8) orelse
(C =:= $9) orelse (C =:= $:) orelse (C =:= $;) orelse (C =:= $=) orelse
(C =:= $@) orelse (C =:= $A) orelse (C =:= $B) orelse (C =:= $C) orelse
(C =:= $D) orelse (C =:= $E) orelse (C =:= $F) orelse (C =:= $G) orelse
(C =:= $H) orelse (C =:= $I) orelse (C =:= $J) orelse (C =:= $K) orelse
(C =:= $L) orelse (C =:= $M) orelse (C =:= $N) orelse (C =:= $O) orelse
(C =:= $P) orelse (C =:= $Q) orelse (C =:= $R) orelse (C =:= $S) orelse
(C =:= $T) orelse (C =:= $U) orelse (C =:= $V) orelse (C =:= $W) orelse
(C =:= $X) orelse (C =:= $Y) orelse (C =:= $Z) orelse (C =:= $_) orelse
(C =:= $a) orelse (C =:= $b) orelse (C =:= $c) orelse (C =:= $d) orelse
(C =:= $e) orelse (C =:= $f) orelse (C =:= $g) orelse (C =:= $h) orelse
(C =:= $i) orelse (C =:= $j) orelse (C =:= $k) orelse (C =:= $l) orelse
(C =:= $m) orelse (C =:= $n) orelse (C =:= $o) orelse (C =:= $p) orelse
(C =:= $q) orelse (C =:= $r) orelse (C =:= $s) orelse (C =:= $t) orelse
(C =:= $u) orelse (C =:= $v) orelse (C =:= $w) orelse (C =:= $x) orelse
(C =:= $y) orelse (C =:= $z) orelse (C =:= $~)
)).
%% Decode a percent encoded string. (RFC3986 2.1)
%%
%% Inspiration for some of the optimisations done here come
%% from the new `json` module as it was in mid-2024.
%%
%% Possible input includes:
%%
%% * nothing encoded (no % character):
%% We want to return the binary as-is to avoid an allocation.
%%
%% * small number of encoded characters:
%% We can "skip" words of text.
%%
%% * mostly encoded characters (non-ascii languages)
%% We can decode characters in bulk.
-spec urldecode(binary()) -> binary().
urldecode(Binary) ->
skip_dec(Binary, Binary, 0).
%% This functions helps avoid a binary allocation when
%% there is nothing to decode.
skip_dec(Binary, Orig, Len) ->
case Binary of
<<C1, C2, C3, C4, Rest/bits>>
when ?IS_PLAIN(C1) andalso ?IS_PLAIN(C2)
andalso ?IS_PLAIN(C3) andalso ?IS_PLAIN(C4) ->
skip_dec(Rest, Orig, Len + 4);
_ ->
dec(Binary, [], Orig, 0, Len)
end.
%% This clause helps speed up decoding of highly encoded values.
dec(<<$%, H1, L1, $%, H2, L2, $%, H3, L3, $%, H4, L4, Rest/bits>>, Acc, Orig, Skip, Len) ->
C1 = ?UNHEX(H1, L1),
C2 = ?UNHEX(H2, L2),
C3 = ?UNHEX(H3, L3),
C4 = ?UNHEX(H4, L4),
case Len of
0 ->
dec(Rest, [Acc|<<C1, C2, C3, C4>>], Orig, Skip + 12, 0);
_ ->
Part = binary_part(Orig, Skip, Len),
dec(Rest, [Acc, Part|<<C1, C2, C3, C4>>], Orig, Skip + Len + 12, 0)
end;
dec(<<$%, H, L, Rest/bits>>, Acc, Orig, Skip, Len) ->
C = ?UNHEX(H, L),
case Len of
0 ->
dec(Rest, [Acc|<<C>>], Orig, Skip + 3, 0);
_ ->
Part = binary_part(Orig, Skip, Len),
dec(Rest, [Acc, Part|<<C>>], Orig, Skip + Len + 3, 0)
end;
%% This clause helps speed up decoding of barely encoded values.
dec(<<C1, C2, C3, C4, Rest/bits>>, Acc, Orig, Skip, Len)
when ?IS_PLAIN(C1) andalso ?IS_PLAIN(C2)
andalso ?IS_PLAIN(C3) andalso ?IS_PLAIN(C4) ->
dec(Rest, Acc, Orig, Skip, Len + 4);
dec(<<C, Rest/bits>>, Acc, Orig, Skip, Len)
when ?IS_PLAIN(C) ->
dec(Rest, Acc, Orig, Skip, Len + 1);
dec(<<>>, _, Orig, 0, _) ->
Orig;
dec(<<>>, Acc, _, _, 0) ->
iolist_to_binary(Acc);
dec(<<>>, Acc, Orig, Skip, Len) ->
Part = binary_part(Orig, Skip, Len),
iolist_to_binary([Acc|Part]);
dec(_, _, Orig, Skip, Len) ->
error({invalid_byte, binary:at(Orig, Skip + Len)}).
-ifdef(TEST).
urldecode_test_() ->
Tests = [
{<<"%20">>, <<" ">>},
{<<"+">>, <<"+">>},
{<<"%00">>, <<0>>},
{<<"%fF">>, <<255>>},
{<<"123">>, <<"123">>},
{<<"%i5">>, error},
{<<"%5">>, error}
],
[{Qs, fun() ->
E = try urldecode(Qs) of
R -> R
catch _:_ ->
error
end
end} || {Qs, E} <- Tests].
urldecode_identity_test_() ->
Tests = [
<<"%20">>,
<<"+">>,
<<"nothingnothingnothingnothing">>,
<<"Small+fast+modular+HTTP+server">>,
<<"Small%20fast%20modular%20HTTP%20server">>,
<<"Small%2F+fast%2F+modular+HTTP+server.">>,
<<"%E3%83%84%E3%82%A4%E3%83%B3%E3%82%BD%E3%82%A6%E3%83"
"%AB%E3%80%9C%E8%BC%AA%E5%BB%BB%E3%81%99%E3%82%8B%E6%97%8B%E5"
"%BE%8B%E3%80%9C">>
],
[{V, fun() -> V = urlencode(urldecode(V)) end} || V <- Tests].
horse_urldecode() ->
horse:repeat(100000,
urldecode(<<"nothingnothingnothingnothing">>)
).
horse_urldecode_hex() ->
horse:repeat(100000,
urldecode(<<"Small%2C%20fast%2C%20modular%20HTTP%20server.">>)
).
horse_urldecode_jp_hex() ->
horse:repeat(100000,
urldecode(<<"%E3%83%84%E3%82%A4%E3%83%B3%E3%82%BD%E3%82%A6%E3%83"
"%AB%E3%80%9C%E8%BC%AA%E5%BB%BB%E3%81%99%E3%82%8B%E6%97%8B%E5"
"%BE%8B%E3%80%9C">>)
).
horse_urldecode_jp_mixed_hex() ->
horse:repeat(100000,
urldecode(<<"%E3%83%84%E3%82%A4%E3%83%B3%E3%82%BD%E3123%82%A6%E3%83"
"%AB%E3%80%9C%E8%BC%AA%E5%BB%BB%E3%81%99%E3%82%8B%E6%97%8B%E5"
"%BE%8B%E3%80%9C">>)
).
horse_urldecode_worst_case_hex() ->
horse:repeat(100000,
urldecode(<<"%e3%83123%84%e3123%82%a4123%e3%83123%b3%e3123%82%bd123">>)
).
-endif.
%% Percent encode a string. (RFC3986 2.1)
%%
%% This function is meant to be used for path components.
-spec urlencode(binary()) -> binary().
urlencode(Binary) ->
skip_enc(Binary, Binary, 0).
skip_enc(Binary, Orig, Len) ->
case Binary of
<<C1, C2, C3, C4, Rest/bits>>
when ?IS_PLAIN(C1) andalso ?IS_PLAIN(C2)
andalso ?IS_PLAIN(C3) andalso ?IS_PLAIN(C4) ->
skip_enc(Rest, Orig, Len + 4);
_ ->
enc(Binary, [], Orig, 0, Len)
end.
enc(<<C1, C2, C3, C4, Rest/bits>>, Acc, Orig, Skip, Len)
when ?IS_PLAIN(C1) andalso ?IS_PLAIN(C2)
andalso ?IS_PLAIN(C3) andalso ?IS_PLAIN(C4) ->
enc(Rest, Acc, Orig, Skip, Len + 4);
enc(<<C, Rest/bits>>, Acc, Orig, Skip, Len)
when ?IS_PLAIN(C) ->
enc(Rest, Acc, Orig, Skip, Len + 1);
enc(<<C1, C2, C3, C4, Rest/bits>>, Acc, Orig, Skip, Len)
when (not ?IS_PLAIN(C2)) andalso (not ?IS_PLAIN(C3))
andalso (not ?IS_PLAIN(C4)) ->
Enc = <<$%, ?HEX(C1), $%, ?HEX(C2), $%, ?HEX(C3), $%, ?HEX(C4)>>,
case Len of
0 ->
enc(Rest, [Acc|Enc], Orig, Skip + 4, 0);
_ ->
Part = binary_part(Orig, Skip, Len),
enc(Rest, [Acc, Part|Enc], Orig, Skip + Len + 4, 0)
end;
enc(<<C, Rest/bits>>, Acc, Orig, Skip, Len) ->
Enc = <<$%, ?HEX(C)>>,
case Len of
0 ->
enc(Rest, [Acc|Enc], Orig, Skip + 1, 0);
_ ->
Part = binary_part(Orig, Skip, Len),
enc(Rest, [Acc, Part|Enc], Orig, Skip + Len + 1, 0)
end;
enc(<<>>, _, Orig, 0, _) ->
Orig;
enc(<<>>, Acc, _, _, 0) ->
iolist_to_binary(Acc);
enc(<<>>, Acc, Orig, Skip, Len) ->
Part = binary_part(Orig, Skip, Len),
iolist_to_binary([Acc|Part]);
enc(_, _, Orig, Skip, Len) ->
error({invalid_byte, binary:at(Orig, Skip + Len)}).
-ifdef(TEST).
urlencode_test_() ->
Tests = [
{<<255, 0>>, <<"%FF%00">>},
{<<255, " ">>, <<"%FF%20">>},
{<<"+">>, <<"+">>},
{<<"aBc123">>, <<"aBc123">>},
{<<"!$&'()*+,:;=@-._~">>, <<"!$&'()*+,:;=@-._~">>}
],
[{V, fun() -> E = urlencode(V) end} || {V, E} <- Tests].
urlencode_identity_test_() ->
Tests = [
<<"+">>,
<<"nothingnothingnothingnothing">>,
<<"Small fast modular HTTP server">>,
<<"Small, fast, modular HTTP server.">>,
<<227,131,132,227,130,164,227,131,179,227,130,189,227,
130,166,227,131,171,227,128,156,232,188,170,229,187,187,227,
129,153,227,130,139,230,151,139,229,190,139,227,128,156>>
],
[{V, fun() -> V = urldecode(urlencode(V)) end} || V <- Tests].
horse_urlencode() ->
horse:repeat(100000,
urlencode(<<"nothingnothingnothingnothing">>)
).
horse_urlencode_spaces() ->
horse:repeat(100000,
urlencode(<<"Small fast modular HTTP server">>)
).
horse_urlencode_jp() ->
horse:repeat(100000,
urlencode(<<227,131,132,227,130,164,227,131,179,227,130,189,227,
130,166,227,131,171,227,128,156,232,188,170,229,187,187,227,
129,153,227,130,139,230,151,139,229,190,139,227,128,156>>)
).
horse_urlencode_jp_mixed() ->
horse:repeat(100000,
urlencode(<<227,131,132,227,130,164,227,131,179,227,130,189,227,
$1, $2, $3,
130,166,227,131,171,227,128,156,232,188,170,229,187,187,227,
129,153,227,130,139,230,151,139,229,190,139,227,128,156>>)
).
horse_urlencode_mix() ->
horse:repeat(100000,
urlencode(<<"Small, fast, modular HTTP server.">>)
).
-endif.
|
