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authorLoïc Hoguin <[email protected]>2014-12-13 11:13:05 +0200
committerLoïc Hoguin <[email protected]>2014-12-13 13:10:22 +0200
commit20ada930c3996945fe2771518da05b5e7ae9b904 (patch)
tree8433054c9cdee4aa1ced11f992ee9dcf247f2cf6 /src
parent63f2e99b39c98354077f96015370506e5745a109 (diff)
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Add cow_http_hd:parse_accept/1
From RFC7231. This code is more than twice faster as the current Cowboy code, while filtering out more bad cases.
Diffstat (limited to 'src')
-rw-r--r--src/cow_http_hd.erl202
1 files changed, 202 insertions, 0 deletions
diff --git a/src/cow_http_hd.erl b/src/cow_http_hd.erl
index 9a920a9..a6624a8 100644
--- a/src/cow_http_hd.erl
+++ b/src/cow_http_hd.erl
@@ -14,14 +14,216 @@
-module(cow_http_hd).
+-export([parse_accept/1]).
-export([parse_connection/1]).
-export([parse_content_length/1]).
-export([parse_expect/1]).
-export([parse_max_forwards/1]).
-export([parse_transfer_encoding/1]).
+-type qvalue() :: 0..1000.
+-export_type([qvalue/0]).
+
-include("cow_inline.hrl").
+%% @doc Parse the Accept header.
+
+-spec parse_accept(binary()) -> [{{binary(), binary(), [{binary(), binary()}]}, qvalue(), [binary() | {binary(), binary()}]}].
+parse_accept(<<"*/*">>) ->
+ [{{<<"*">>, <<"*">>, []}, 1000, []}];
+parse_accept(Accept) ->
+ nonempty(media_range_list(Accept, [])).
+
+media_range_list(<<>>, Acc) -> lists:reverse(Acc);
+media_range_list(<< $\s, R/bits >>, Acc) -> media_range_list(R, Acc);
+media_range_list(<< $\t, R/bits >>, Acc) -> media_range_list(R, Acc);
+media_range_list(<< $,, R/bits >>, Acc) -> media_range_list(R, Acc);
+media_range_list(<< C, R/bits >>, Acc) when ?IS_TOKEN(C) ->
+ case C of
+ ?INLINE_LOWERCASE(media_range_type, R, Acc, <<>>)
+ end.
+
+media_range_type(<< $/, R/bits >>, Acc, T) -> media_range_subtype(R, Acc, T, <<>>);
+%% Special clause for badly behaving user agents that send * instead of */*.
+media_range_type(<< _, R/bits >>, Acc, <<"*">>) -> media_range_before_param(R, Acc, <<"*">>, <<"*">>, []);
+media_range_type(<< C, R/bits >>, Acc, T) when ?IS_TOKEN(C) ->
+ case C of
+ ?INLINE_LOWERCASE(media_range_type, R, Acc, T)
+ end.
+
+media_range_subtype(<<>>, Acc, T, S) when S =/= <<>> -> lists:reverse([{{T, S, []}, 1000, []}|Acc]);
+media_range_subtype(<< $,, R/bits >>, Acc, T, S) when S =/= <<>> -> media_range_list(R, [{{T, S, []}, 1000, []}|Acc]);
+media_range_subtype(<< $;, R/bits >>, Acc, T, S) when S =/= <<>> -> media_range_before_param(R, Acc, T, S, []);
+media_range_subtype(<< $\s, R/bits >>, Acc, T, S) when S =/= <<>> -> media_range_before_semicolon(R, Acc, T, S, []);
+media_range_subtype(<< $\t, R/bits >>, Acc, T, S) when S =/= <<>> -> media_range_before_semicolon(R, Acc, T, S, []);
+media_range_subtype(<< C, R/bits >>, Acc, T, S) when ?IS_TOKEN(C) ->
+ case C of
+ ?INLINE_LOWERCASE(media_range_subtype, R, Acc, T, S)
+ end.
+
+media_range_before_semicolon(<<>>, Acc, T, S, P) -> lists:reverse([{{T, S, lists:reverse(P)}, 1000, []}|Acc]);
+media_range_before_semicolon(<< $,, R/bits >>, Acc, T, S, P) -> media_range_list(R, [{{T, S, lists:reverse(P)}, 1000, []}|Acc]);
+media_range_before_semicolon(<< $;, R/bits >>, Acc, T, S, P) -> media_range_before_param(R, Acc, T, S, P);
+media_range_before_semicolon(<< $\s, R/bits >>, Acc, T, S, P) -> media_range_before_semicolon(R, Acc, T, S, P);
+media_range_before_semicolon(<< $\t, R/bits >>, Acc, T, S, P) -> media_range_before_semicolon(R, Acc, T, S, P).
+
+media_range_before_param(<< $\s, R/bits >>, Acc, T, S, P) -> media_range_before_param(R, Acc, T, S, P);
+media_range_before_param(<< $\t, R/bits >>, Acc, T, S, P) -> media_range_before_param(R, Acc, T, S, P);
+%% Special clause for badly behaving user agents that send .123 instead of 0.123.
+media_range_before_param(<< $q, $=, $., R/bits >>, Acc, T, S, P) -> media_range_broken_weight(R, Acc, T, S, P);
+media_range_before_param(<< $q, $=, R/bits >>, Acc, T, S, P) -> media_range_weight(R, Acc, T, S, P);
+media_range_before_param(<< C, R/bits >>, Acc, T, S, P) when ?IS_TOKEN(C) ->
+ case C of
+ ?INLINE_LOWERCASE(media_range_param, R, Acc, T, S, P, <<>>)
+ end.
+
+media_range_param(<< $=, $", R/bits >>, Acc, T, S, P, K) -> media_range_quoted(R, Acc, T, S, P, K, <<>>);
+media_range_param(<< $=, R/bits >>, Acc, T, S, P, K) -> media_range_value(R, Acc, T, S, P, K, <<>>);
+media_range_param(<< C, R/bits >>, Acc, T, S, P, K) when ?IS_TOKEN(C) ->
+ case C of
+ ?INLINE_LOWERCASE(media_range_param, R, Acc, T, S, P, K)
+ end.
+
+media_range_quoted(<< $", R/bits >>, Acc, T, S, P, K, V) -> media_range_before_semicolon(R, Acc, T, S, [{K, V}|P]);
+media_range_quoted(<< $\\, C, R/bits >>, Acc, T, S, P, K, V) when ?IS_VCHAR(C) -> media_range_quoted(R, Acc, T, S, P, K, << V/binary, C >>);
+media_range_quoted(<< C, R/bits >>, Acc, T, S, P, K, V) when ?IS_VCHAR(C) -> media_range_quoted(R, Acc, T, S, P, K, << V/binary, C >>).
+
+media_range_value(<<>>, Acc, T, S, P, K, V) -> lists:reverse([{{T, S, lists:reverse([{K, V}|P])}, 1000, []}|Acc]);
+media_range_value(<< $,, R/bits >>, Acc, T, S, P, K, V) -> media_range_list(R, [{{T, S, lists:reverse([{K, V}|P])}, 1000, []}|Acc]);
+media_range_value(<< $;, R/bits >>, Acc, T, S, P, K, V) -> media_range_before_param(R, Acc, T, S, [{K, V}|P]);
+media_range_value(<< $\s, R/bits >>, Acc, T, S, P, K, V) -> media_range_before_semicolon(R, Acc, T, S, [{K, V}|P]);
+media_range_value(<< $\t, R/bits >>, Acc, T, S, P, K, V) -> media_range_before_semicolon(R, Acc, T, S, [{K, V}|P]);
+media_range_value(<< C, R/bits >>, Acc, T, S, P, K, V) when ?IS_TOKEN(C) -> media_range_value(R, Acc, T, S, P, K, << V/binary, C >>).
+
+%% Special function for badly behaving user agents that send .123 instead of 0.123.
+media_range_broken_weight(<< A, B, C, R/bits >>, Acc, T, S, P)
+ when ?IS_DIGIT(A), ?IS_DIGIT(B), ?IS_DIGIT(C) ->
+ accept_before_semicolon(R, Acc, T, S, P, (A - $0) * 100 + (B - $0) * 10 + (C - $0), []);
+media_range_broken_weight(<< A, B, R/bits >>, Acc, T, S, P)
+ when ?IS_DIGIT(A), ?IS_DIGIT(B) ->
+ accept_before_semicolon(R, Acc, T, S, P, (A - $0) * 100 + (B - $0) * 10, []);
+media_range_broken_weight(<< A, R/bits >>, Acc, T, S, P)
+ when ?IS_DIGIT(A) ->
+ accept_before_semicolon(R, Acc, T, S, P, (A - $0) * 100, []).
+
+media_range_weight(<< "1.000", R/bits >>, Acc, T, S, P) -> accept_before_semicolon(R, Acc, T, S, P, 1000, []);
+media_range_weight(<< "1.00", R/bits >>, Acc, T, S, P) -> accept_before_semicolon(R, Acc, T, S, P, 1000, []);
+media_range_weight(<< "1.0", R/bits >>, Acc, T, S, P) -> accept_before_semicolon(R, Acc, T, S, P, 1000, []);
+media_range_weight(<< "1.", R/bits >>, Acc, T, S, P) -> accept_before_semicolon(R, Acc, T, S, P, 1000, []);
+media_range_weight(<< "1", R/bits >>, Acc, T, S, P) -> accept_before_semicolon(R, Acc, T, S, P, 1000, []);
+media_range_weight(<< "0.", A, B, C, R/bits >>, Acc, T, S, P)
+ when ?IS_DIGIT(A), ?IS_DIGIT(B), ?IS_DIGIT(C) ->
+ accept_before_semicolon(R, Acc, T, S, P, (A - $0) * 100 + (B - $0) * 10 + (C - $0), []);
+media_range_weight(<< "0.", A, B, R/bits >>, Acc, T, S, P)
+ when ?IS_DIGIT(A), ?IS_DIGIT(B) ->
+ accept_before_semicolon(R, Acc, T, S, P, (A - $0) * 100 + (B - $0) * 10, []);
+media_range_weight(<< "0.", A, R/bits >>, Acc, T, S, P)
+ when ?IS_DIGIT(A) ->
+ accept_before_semicolon(R, Acc, T, S, P, (A - $0) * 100, []);
+media_range_weight(<< "0.", R/bits >>, Acc, T, S, P) -> accept_before_semicolon(R, Acc, T, S, P, 0, []);
+media_range_weight(<< "0", R/bits >>, Acc, T, S, P) -> accept_before_semicolon(R, Acc, T, S, P, 0, []).
+
+accept_before_semicolon(<<>>, Acc, T, S, P, Q, E) -> lists:reverse([{{T, S, lists:reverse(P)}, Q, lists:reverse(E)}|Acc]);
+accept_before_semicolon(<< $,, R/bits >>, Acc, T, S, P, Q, E) -> media_range_list(R, [{{T, S, lists:reverse(P)}, Q, lists:reverse(E)}|Acc]);
+accept_before_semicolon(<< $;, R/bits >>, Acc, T, S, P, Q, E) -> accept_before_ext(R, Acc, T, S, P, Q, E);
+accept_before_semicolon(<< $\s, R/bits >>, Acc, T, S, P, Q, E) -> accept_before_semicolon(R, Acc, T, S, P, Q, E);
+accept_before_semicolon(<< $\t, R/bits >>, Acc, T, S, P, Q, E) -> accept_before_semicolon(R, Acc, T, S, P, Q, E).
+
+accept_before_ext(<< $\s, R/bits >>, Acc, T, S, P, Q, E) -> accept_before_ext(R, Acc, T, S, P, Q, E);
+accept_before_ext(<< $\t, R/bits >>, Acc, T, S, P, Q, E) -> accept_before_ext(R, Acc, T, S, P, Q, E);
+accept_before_ext(<< C, R/bits >>, Acc, T, S, P, Q, E) when ?IS_TOKEN(C) ->
+ case C of
+ ?INLINE_LOWERCASE(accept_ext, R, Acc, T, S, P, Q, E, <<>>)
+ end.
+
+accept_ext(<<>>, Acc, T, S, P, Q, E, K) -> lists:reverse([{{T, S, lists:reverse(P)}, Q, lists:reverse([K|E])}|Acc]);
+accept_ext(<< $,, R/bits >>, Acc, T, S, P, Q, E, K) -> media_range_list(R, [{{T, S, lists:reverse(P)}, Q, lists:reverse([K|E])}|Acc]);
+accept_ext(<< $;, R/bits >>, Acc, T, S, P, Q, E, K) -> accept_before_ext(R, Acc, T, S, P, Q, [K|E]);
+accept_ext(<< $\s, R/bits >>, Acc, T, S, P, Q, E, K) -> accept_before_semicolon(R, Acc, T, S, P, Q, [K|E]);
+accept_ext(<< $\t, R/bits >>, Acc, T, S, P, Q, E, K) -> accept_before_semicolon(R, Acc, T, S, P, Q, [K|E]);
+accept_ext(<< $=, $", R/bits >>, Acc, T, S, P, Q, E, K) -> accept_quoted(R, Acc, T, S, P, Q, E, K, <<>>);
+accept_ext(<< $=, R/bits >>, Acc, T, S, P, Q, E, K) -> accept_value(R, Acc, T, S, P, Q, E, K, <<>>);
+accept_ext(<< C, R/bits >>, Acc, T, S, P, Q, E, K) when ?IS_TOKEN(C) ->
+ case C of
+ ?INLINE_LOWERCASE(accept_ext, R, Acc, T, S, P, Q, E, K)
+ end.
+
+accept_quoted(<< $", R/bits >>, Acc, T, S, P, Q, E, K, V) -> accept_before_semicolon(R, Acc, T, S, P, Q, [{K, V}|E]);
+accept_quoted(<< $\\, C, R/bits >>, Acc, T, S, P, Q, E, K, V) when ?IS_VCHAR(C) -> accept_quoted(R, Acc, T, S, P, Q, E, K, << V/binary, C >>);
+accept_quoted(<< C, R/bits >>, Acc, T, S, P, Q, E, K, V) when ?IS_VCHAR(C) -> accept_quoted(R, Acc, T, S, P, Q, E, K, << V/binary, C >>).
+
+accept_value(<<>>, Acc, T, S, P, Q, E, K, V) -> lists:reverse([{{T, S, lists:reverse(P)}, Q, lists:reverse([{K, V}|E])}|Acc]);
+accept_value(<< $,, R/bits >>, Acc, T, S, P, Q, E, K, V) -> media_range_list(R, [{{T, S, lists:reverse(P)}, Q, lists:reverse([{K, V}|E])}|Acc]);
+accept_value(<< $;, R/bits >>, Acc, T, S, P, Q, E, K, V) -> accept_before_semicolon(R, Acc, T, S, P, Q, [{K, V}|E]);
+accept_value(<< $\s, R/bits >>, Acc, T, S, P, Q, E, K, V) -> accept_before_semicolon(R, Acc, T, S, P, Q, [{K, V}|E]);
+accept_value(<< $\t, R/bits >>, Acc, T, S, P, Q, E, K, V) -> accept_before_semicolon(R, Acc, T, S, P, Q, [{K, V}|E]);
+accept_value(<< C, R/bits >>, Acc, T, S, P, Q, E, K, V) when ?IS_TOKEN(C) -> accept_value(R, Acc, T, S, P, Q, E, K, << V/binary, C >>).
+
+-ifdef(TEST).
+parse_accept_test_() ->
+ Tests = [
+ {<<"audio/*; q=0.2, audio/basic">>, [
+ {{<<"audio">>, <<"*">>, []}, 200, []},
+ {{<<"audio">>, <<"basic">>, []}, 1000, []}
+ ]},
+ {<<"text/plain; q=0.5, text/html, "
+ "text/x-dvi; q=0.8, text/x-c">>, [
+ {{<<"text">>, <<"plain">>, []}, 500, []},
+ {{<<"text">>, <<"html">>, []}, 1000, []},
+ {{<<"text">>, <<"x-dvi">>, []}, 800, []},
+ {{<<"text">>, <<"x-c">>, []}, 1000, []}
+ ]},
+ {<<"text/*, text/html, text/html;level=1, */*">>, [
+ {{<<"text">>, <<"*">>, []}, 1000, []},
+ {{<<"text">>, <<"html">>, []}, 1000, []},
+ {{<<"text">>, <<"html">>, [{<<"level">>, <<"1">>}]}, 1000, []},
+ {{<<"*">>, <<"*">>, []}, 1000, []}
+ ]},
+ {<<"text/*;q=0.3, text/html;q=0.7, text/html;level=1, "
+ "text/html;level=2;q=0.4, */*;q=0.5">>, [
+ {{<<"text">>, <<"*">>, []}, 300, []},
+ {{<<"text">>, <<"html">>, []}, 700, []},
+ {{<<"text">>, <<"html">>, [{<<"level">>, <<"1">>}]}, 1000, []},
+ {{<<"text">>, <<"html">>, [{<<"level">>, <<"2">>}]}, 400, []},
+ {{<<"*">>, <<"*">>, []}, 500, []}
+ ]},
+ {<<"text/html;level=1;quoted=\"hi hi hi\";"
+ "q=0.123;standalone;complex=gits, text/plain">>, [
+ {{<<"text">>, <<"html">>,
+ [{<<"level">>, <<"1">>}, {<<"quoted">>, <<"hi hi hi">>}]}, 123,
+ [<<"standalone">>, {<<"complex">>, <<"gits">>}]},
+ {{<<"text">>, <<"plain">>, []}, 1000, []}
+ ]},
+ {<<"text/html, image/gif, image/jpeg, *; q=.2, */*; q=.2">>, [
+ {{<<"text">>, <<"html">>, []}, 1000, []},
+ {{<<"image">>, <<"gif">>, []}, 1000, []},
+ {{<<"image">>, <<"jpeg">>, []}, 1000, []},
+ {{<<"*">>, <<"*">>, []}, 200, []},
+ {{<<"*">>, <<"*">>, []}, 200, []}
+ ]}
+ ],
+ [{V, fun() -> R = parse_accept(V) end} || {V, R} <- Tests].
+
+parse_accept_error_test_() ->
+ Tests = [
+ <<>>,
+ <<" ">>,
+ <<"audio/basic, */;q=0.5">>,
+ <<"audio/, audio/basic">>,
+ <<"aud\tio/basic">>,
+ <<"audio/basic;t=\"zero \\", 0, " woo\"">>
+ ],
+ [{V, fun() -> {'EXIT', _} = (catch parse_accept(V)) end} || V <- Tests].
+-endif.
+
+-ifdef(PERF).
+horse_parse_accept() ->
+ horse:repeat(20000,
+ parse_accept(<<"text/*;q=0.3, text/html;q=0.7, text/html;level=1, "
+ "text/html;level=2;q=0.4, */*;q=0.5">>)
+ ).
+-endif.
+
%% @doc Parse the Connection header.
-spec parse_connection(binary()) -> [binary()].