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Add cow_http:parse_{status_line,headers}/1
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Imported from Cowboy and then optimized.
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@essen
essen committed Feb 27, 2014
1 parent acf2c13 commit cdb6c13
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178 changes: 178 additions & 0 deletions src/cow_http.erl
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Original file line number Diff line number Diff line change
Expand Up @@ -14,12 +14,189 @@

-module(cow_http).

%% @todo parse_request_line
-export([parse_status_line/1]).
-export([parse_headers/1]).

-export([parse_fullhost/1]).
-export([parse_fullpath/1]).
-export([parse_version/1]).

-type version() :: 'HTTP/1.0' | 'HTTP/1.1'.
-type status() :: 100..999.
-type headers() :: [{binary(), binary()}].

-include("cow_inline.hrl").

%% @doc Parse the status line.

-spec parse_status_line(binary()) -> {version(), status(), binary(), binary()}.
parse_status_line(<< "HTTP/1.1 200 OK\r\n", Rest/bits >>) ->
{'HTTP/1.1', 200, <<"OK">>, Rest};
parse_status_line(<< "HTTP/1.1 404 Not Found\r\n", Rest/bits >>) ->
{'HTTP/1.1', 404, <<"Not Found">>, Rest};
parse_status_line(<< "HTTP/1.1 500 Internal Server Error\r\n", Rest/bits >>) ->
{'HTTP/1.1', 500, <<"Internal Server Error">>, Rest};
parse_status_line(<< "HTTP/1.1 ", Status/bits >>) ->
parse_status_line(Status, 'HTTP/1.1');
parse_status_line(<< "HTTP/1.0 ", Status/bits >>) ->
parse_status_line(Status, 'HTTP/1.0').

parse_status_line(<< H, T, U, " ", Rest/bits >>, Version)
when $0 =< H, H =< $9, $0 =< T, T =< $9, $0 =< U, U =< $9 ->
Status = (H - $0) * 100 + (T - $0) * 10 + (U - $0),
{Pos, _} = binary:match(Rest, <<"\r">>),
<< StatusStr:Pos/binary, "\r\n", Rest2/bits >> = Rest,
{Version, Status, StatusStr, Rest2}.

-ifdef(TEST).
parse_status_line_test_() ->
Tests = [
{<<"HTTP/1.1 200 OK\r\nRest">>,
{'HTTP/1.1', 200, <<"OK">>, <<"Rest">>}},
{<<"HTTP/1.0 404 Not Found\r\nRest">>,
{'HTTP/1.0', 404, <<"Not Found">>, <<"Rest">>}},
{<<"HTTP/1.1 500 Something very funny here\r\nRest">>,
{'HTTP/1.1', 500, <<"Something very funny here">>, <<"Rest">>}},
{<<"HTTP/1.1 200 \r\nRest">>,
{'HTTP/1.1', 200, <<>>, <<"Rest">>}}
],
[{V, fun() -> R = parse_status_line(V) end}
|| {V, R} <- Tests].

parse_status_line_error_test_() ->
Tests = [
<<>>,
<<"HTTP/1.1">>,
<<"HTTP/1.1 200\r\n">>,
<<"HTTP/1.1 200 OK">>,
<<"HTTP/1.1 200 OK\r">>,
<<"HTTP/1.1 200 OK\n">>,
<<"HTTP/0.9 200 OK\r\n">>,
<<"HTTP/1.1 42 Answer\r\n">>,
<<"HTTP/1.1 999999999 More than OK\r\n">>,
<<"content-type: text/plain\r\n">>,
<<0:80, "\r\n">>
],
[{V, fun() -> {'EXIT', _} = (catch parse_status_line(V)) end}
|| V <- Tests].
-endif.

-ifdef(PERF).
horse_parse_status_line_200() ->
horse:repeat(200000,
parse_status_line(<<"HTTP/1.1 200 OK\r\n">>)
).

horse_parse_status_line_404() ->
horse:repeat(200000,
parse_status_line(<<"HTTP/1.1 404 Not Found\r\n">>)
).

horse_parse_status_line_500() ->
horse:repeat(200000,
parse_status_line(<<"HTTP/1.1 500 Internal Server Error\r\n">>)
).

horse_parse_status_line_other() ->
horse:repeat(200000,
parse_status_line(<<"HTTP/1.1 416 Requested range not satisfiable\r\n">>)
).
-endif.

%% @doc Parse the list of headers.

-spec parse_headers(binary()) -> {headers(), binary()}.
parse_headers(Data) ->
parse_header(Data, []).

parse_header(<< $\r, $\n, Rest/bits >>, Acc) ->
{lists:reverse(Acc), Rest};
parse_header(Data, Acc) ->
parse_hd_name(Data, Acc, <<>>).

parse_hd_name(<< C, Rest/bits >>, Acc, SoFar) ->
case C of
$: -> parse_hd_before_value(Rest, Acc, SoFar);
$\s -> parse_hd_name_ws(Rest, Acc, SoFar);
$\t -> parse_hd_name_ws(Rest, Acc, SoFar);
?INLINE_LOWERCASE(parse_hd_name, Rest, Acc, SoFar)
end.

parse_hd_name_ws(<< C, Rest/bits >>, Acc, Name) ->
case C of
$: -> parse_hd_before_value(Rest, Acc, Name);
$\s -> parse_hd_name_ws(Rest, Acc, Name);
$\t -> parse_hd_name_ws(Rest, Acc, Name)
end.

parse_hd_before_value(<< $\s, Rest/bits >>, Acc, Name) ->
parse_hd_before_value(Rest, Acc, Name);
parse_hd_before_value(<< $\t, Rest/bits >>, Acc, Name) ->
parse_hd_before_value(Rest, Acc, Name);
parse_hd_before_value(Data, Acc, Name) ->
parse_hd_value(Data, Acc, Name, <<>>).

parse_hd_value(<< $\r, Rest/bits >>, Acc, Name, SoFar) ->
case Rest of
<< $\n, C, Rest2/bits >> when C =:= $\s; C =:= $\t ->
parse_hd_value(Rest2, Acc, Name, << SoFar/binary, C >>);
<< $\n, Rest2/bits >> ->
parse_header(Rest2, [{Name, SoFar}|Acc])
end;
parse_hd_value(<< C, Rest/bits >>, Acc, Name, SoFar) ->
parse_hd_value(Rest, Acc, Name, << SoFar/binary, C >>).

-ifdef(TEST).
parse_headers_test_() ->
Tests = [
{<<"\r\nRest">>,
{[], <<"Rest">>}},
{<<"Server: Erlang/R17\r\n"
"Date: Sun, 23 Feb 2014 09:30:39 GMT\r\n"
"Multiline-Header: why hello!\r\n"
" I didn't see you all the way over there!\r\n"
"Content-Length: 12\r\n"
"Content-Type: text/plain\r\n"
"\r\nRest">>,
{[{<<"server">>, <<"Erlang/R17">>},
{<<"date">>, <<"Sun, 23 Feb 2014 09:30:39 GMT">>},
{<<"multiline-header">>,
<<"why hello! I didn't see you all the way over there!">>},
{<<"content-length">>, <<"12">>},
{<<"content-type">>, <<"text/plain">>}],
<<"Rest">>}}
],
[{V, fun() -> R = parse_headers(V) end}
|| {V, R} <- Tests].

parse_headers_error_test_() ->
Tests = [
<<>>,
<<"\r">>,
<<"Malformed\r\n\r\n">>,
<<"content-type: text/plain\r\nMalformed\r\n\r\n">>,
<<"HTTP/1.1 200 OK\r\n\r\n">>,
<<0:80, "\r\n\r\n">>,
<<"content-type: text/plain\r\ncontent-length: 12\r\n">>
],
[{V, fun() -> {'EXIT', _} = (catch parse_headers(V)) end}
|| V <- Tests].
-endif.

-ifdef(PERF).
horse_parse_headers() ->
horse:repeat(50000,
parse_headers(<<"Server: Erlang/R17\r\n"
"Date: Sun, 23 Feb 2014 09:30:39 GMT\r\n"
"Multiline-Header: why hello!\r\n"
" I didn't see you all the way over there!\r\n"
"Content-Length: 12\r\n"
"Content-Type: text/plain\r\n"
"\r\nRest">>)
).
-endif.

%% @doc Extract host and port from a binary.
%%
%% Because the hostname is case insensitive it is converted
Expand All @@ -33,6 +210,7 @@ parse_fullhost(<< $[, Rest/bits >>, false, <<>>) ->
parse_fullhost(Rest, true, << $[ >>);
parse_fullhost(<<>>, false, Acc) ->
{Acc, undefined};
%% @todo Optimize.
parse_fullhost(<< $:, Rest/bits >>, false, Acc) ->
{Acc, list_to_integer(binary_to_list(Rest))};
parse_fullhost(<< $], Rest/bits >>, true, Acc) ->
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