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Optimize Connection header parsing

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Still optimizing the critical path.

Removes cowboy_http:connection_to_atom/1.
This commit is contained in:
Loïc Hoguin 2012-09-27 01:31:19 +02:00
parent 681a216a24
commit cd7f37d346
2 changed files with 88 additions and 37 deletions
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100
src/cowboy_req.erl
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@ -170,6 +170,9 @@
%%
%% This function takes care of setting the owner's pid to self().
%% @private
%%
%% Since we always need to parse the Connection header, we do it
%% in an optimized way and add the parsed value to p_headers' cache.
-spec new(inet:socket(), module(), binary(), binary(), binary(), binary(),
cowboy_http:version(), cowboy_http:headers(), binary(),
inet:port_number() | undefined, binary(), boolean(),
@ -187,16 +190,16 @@ new(Socket, Transport, Method, Path, Query, Fragment,
false ->
Req#http_req{connection=close};
true ->
case lists:keymember(<<"connection">>, 1, Headers) of
case lists:keyfind(<<"connection">>, 1, Headers) of
false when Version =:= {1, 1} ->
Req; %% keepalive
false ->
Req#http_req{connection=close};
true ->
{ok, Tokens, Req2} = parse_header(<<"connection">>, Req),
%% @todo Might want to bring this function into cowboy_req.
Connection = cowboy_http:connection_to_atom(Tokens),
Req2#http_req{connection=Connection}
{_, ConnectionHeader} ->
Tokens = parse_connection_before(ConnectionHeader, []),
Connection = connection_to_atom(Tokens),
Req#http_req{connection=Connection,
p_headers=[{<<"connection">>, Tokens}]}
end
end.
@ -432,11 +435,6 @@ parse_header(Name, Req, Default) when Name =:= <<"accept-language">> ->
fun (Value) ->
cowboy_http:nonempty_list(Value, fun cowboy_http:language_range/2)
end);
parse_header(Name, Req, Default) when Name =:= <<"connection">> ->
parse_header(Name, Req, Default,
fun (Value) ->
cowboy_http:nonempty_list(Value, fun cowboy_http:token_ci/2)
end);
parse_header(Name, Req, Default) when Name =:= <<"content-length">> ->
parse_header(Name, Req, Default,
fun (Value) ->
@ -1099,7 +1097,7 @@ response_connection([{Name, Value}|Tail], Connection) ->
-spec response_connection_parse(binary()) -> keepalive | close.
response_connection_parse(ReplyConn) ->
Tokens = cowboy_http:nonempty_list(ReplyConn, fun cowboy_http:token/2),
cowboy_http:connection_to_atom(Tokens).
connection_to_atom(Tokens).
-spec response_merge_headers(cowboy_http:headers(), cowboy_http:headers(),
cowboy_http:headers()) -> cowboy_http:headers().
@ -1127,6 +1125,74 @@ atom_to_connection(keepalive) ->
atom_to_connection(close) ->
<<"close">>.
%% Optimized parsing functions for the Connection header.
parse_connection_before(<<>>, Acc) ->
lists:reverse(Acc);
parse_connection_before(<< C, Rest/bits >>, Acc)
when C =:= $,; C =:= $\s; C =:= $\t ->
parse_connection_before(Rest, Acc);
parse_connection_before(Buffer, Acc) ->
parse_connection(Buffer, Acc, <<>>).
%% An evil block of code appeared!
parse_connection(<<>>, Acc, <<>>) ->
lists:reverse(Acc);
parse_connection(<<>>, Acc, Token) ->
lists:reverse([Token|Acc]);
parse_connection(<< C, Rest/bits >>, Acc, Token)
when C =:= $,; C =:= $\s; C =:= $\t ->
parse_connection_after(Rest, [Token|Acc]);
parse_connection(<< C, Rest/bits >>, Acc, Token) ->
case C of
$A -> parse_connection(Rest, Acc, << Token/binary, $a >>);
$B -> parse_connection(Rest, Acc, << Token/binary, $b >>);
$C -> parse_connection(Rest, Acc, << Token/binary, $c >>);
$D -> parse_connection(Rest, Acc, << Token/binary, $d >>);
$E -> parse_connection(Rest, Acc, << Token/binary, $e >>);
$F -> parse_connection(Rest, Acc, << Token/binary, $f >>);
$G -> parse_connection(Rest, Acc, << Token/binary, $g >>);
$H -> parse_connection(Rest, Acc, << Token/binary, $h >>);
$I -> parse_connection(Rest, Acc, << Token/binary, $i >>);
$J -> parse_connection(Rest, Acc, << Token/binary, $j >>);
$K -> parse_connection(Rest, Acc, << Token/binary, $k >>);
$L -> parse_connection(Rest, Acc, << Token/binary, $l >>);
$M -> parse_connection(Rest, Acc, << Token/binary, $m >>);
$N -> parse_connection(Rest, Acc, << Token/binary, $n >>);
$O -> parse_connection(Rest, Acc, << Token/binary, $o >>);
$P -> parse_connection(Rest, Acc, << Token/binary, $p >>);
$Q -> parse_connection(Rest, Acc, << Token/binary, $q >>);
$R -> parse_connection(Rest, Acc, << Token/binary, $r >>);
$S -> parse_connection(Rest, Acc, << Token/binary, $s >>);
$T -> parse_connection(Rest, Acc, << Token/binary, $t >>);
$U -> parse_connection(Rest, Acc, << Token/binary, $u >>);
$V -> parse_connection(Rest, Acc, << Token/binary, $v >>);
$W -> parse_connection(Rest, Acc, << Token/binary, $w >>);
$X -> parse_connection(Rest, Acc, << Token/binary, $x >>);
$Y -> parse_connection(Rest, Acc, << Token/binary, $y >>);
$Z -> parse_connection(Rest, Acc, << Token/binary, $z >>);
C -> parse_connection(Rest, Acc, << Token/binary, C >>)
end.
parse_connection_after(<<>>, Acc) ->
lists:reverse(Acc);
parse_connection_after(<< $,, Rest/bits >>, Acc) ->
parse_connection_before(Rest, Acc);
parse_connection_after(<< C, Rest/bits >>, Acc)
when C =:= $\s; C =:= $\t ->
parse_connection_after(Rest, Acc).
%% @doc Walk through a tokens list and return whether
%% the connection is keepalive or closed.
%%
%% We don't match on <<"keep-alive">> since it is the default value.
-spec connection_to_atom([binary()]) -> keepalive | close.
connection_to_atom([]) ->
keepalive;
connection_to_atom([<<"close">>|_]) ->
close;
connection_to_atom([_|Tail]) ->
connection_to_atom(Tail).
-spec status(cowboy_http:status()) -> binary().
status(100) -> <<"100 Continue">>;
status(101) -> <<"101 Switching Protocols">>;
@ -1225,4 +1291,14 @@ url_test() ->
pid=self()}),
ok.
connection_to_atom_test_() ->
%% {Tokens, Result}
Tests = [
{[<<"close">>], close},
{[<<"keep-alive">>], keepalive},
{[<<"keep-alive">>, <<"upgrade">>], keepalive}
],
[{lists:flatten(io_lib:format("~p", [T])),
fun() -> R = connection_to_atom(T) end} || {T, R} <- Tests].
-endif.