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/src/mochiweb_headers.erl

http://github.com/basho/mochiweb
Erlang | 438 lines | 302 code | 38 blank | 98 comment | 0 complexity | a206affe8b911da4d1b26cd7f54fd091 MD5 | raw file
  1%% @author Bob Ippolito <bob@mochimedia.com>
  2%% @copyright 2007 Mochi Media, Inc.
  3%%
  4%% Permission is hereby granted, free of charge, to any person obtaining a
  5%% copy of this software and associated documentation files (the "Software"),
  6%% to deal in the Software without restriction, including without limitation
  7%% the rights to use, copy, modify, merge, publish, distribute, sublicense,
  8%% and/or sell copies of the Software, and to permit persons to whom the
  9%% Software is furnished to do so, subject to the following conditions:
 10%%
 11%% The above copyright notice and this permission notice shall be included in
 12%% all copies or substantial portions of the Software.
 13%%
 14%% THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 15%% IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 16%% FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
 17%% THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 18%% LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 19%% FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 20%% DEALINGS IN THE SOFTWARE.
 21
 22%% @doc Case preserving (but case insensitive) HTTP Header dictionary.
 23
 24-module(mochiweb_headers).
 25-author('bob@mochimedia.com').
 26-export([empty/0, from_list/1, insert/3, enter/3, get_value/2, lookup/2]).
 27-export([delete_any/2, get_primary_value/2, get_combined_value/2]).
 28-export([default/3, enter_from_list/2, default_from_list/2]).
 29-export([to_list/1, make/1]).
 30-export([from_binary/1]).
 31
 32%% @type headers().
 33%% @type key() = atom() | binary() | string().
 34%% @type value() = atom() | binary() | string() | integer().
 35
 36%% @spec empty() -> headers()
 37%% @doc Create an empty headers structure.
 38empty() ->
 39    gb_trees:empty().
 40
 41%% @spec make(headers() | [{key(), value()}]) -> headers()
 42%% @doc Construct a headers() from the given list.
 43make(L) when is_list(L) ->
 44    from_list(L);
 45%% assume a non-list is already mochiweb_headers.
 46make(T) ->
 47    T.
 48
 49%% @spec from_binary(iolist()) -> headers()
 50%% @doc Transforms a raw HTTP header into a mochiweb headers structure.
 51%%
 52%%      The given raw HTTP header can be one of the following:
 53%%
 54%%      1) A string or a binary representing a full HTTP header ending with
 55%%         double CRLF.
 56%%         Examples:
 57%%         ```
 58%%         "Content-Length: 47\r\nContent-Type: text/plain\r\n\r\n"
 59%%         <<"Content-Length: 47\r\nContent-Type: text/plain\r\n\r\n">>'''
 60%%
 61%%      2) A list of binaries or strings where each element represents a raw
 62%%         HTTP header line ending with a single CRLF.
 63%%         Examples:
 64%%         ```
 65%%         [<<"Content-Length: 47\r\n">>, <<"Content-Type: text/plain\r\n">>]
 66%%         ["Content-Length: 47\r\n", "Content-Type: text/plain\r\n"]
 67%%         ["Content-Length: 47\r\n", <<"Content-Type: text/plain\r\n">>]'''
 68%%
 69from_binary(RawHttpHeader) when is_binary(RawHttpHeader) ->
 70    from_binary(RawHttpHeader, []);
 71from_binary(RawHttpHeaderList) ->
 72    from_binary(list_to_binary([RawHttpHeaderList, "\r\n"])).
 73
 74from_binary(RawHttpHeader, Acc) ->
 75    case erlang:decode_packet(httph, RawHttpHeader, []) of
 76        {ok, {http_header, _, H, _, V}, Rest} ->
 77            from_binary(Rest, [{H, V} | Acc]);
 78        _ ->
 79            make(Acc)
 80    end.
 81
 82%% @spec from_list([{key(), value()}]) -> headers()
 83%% @doc Construct a headers() from the given list.
 84from_list(List) ->
 85    lists:foldl(fun ({K, V}, T) -> insert(K, V, T) end, empty(), List).
 86
 87%% @spec enter_from_list([{key(), value()}], headers()) -> headers()
 88%% @doc Insert pairs into the headers, replace any values for existing keys.
 89enter_from_list(List, T) ->
 90    lists:foldl(fun ({K, V}, T1) -> enter(K, V, T1) end, T, List).
 91
 92%% @spec default_from_list([{key(), value()}], headers()) -> headers()
 93%% @doc Insert pairs into the headers for keys that do not already exist.
 94default_from_list(List, T) ->
 95    lists:foldl(fun ({K, V}, T1) -> default(K, V, T1) end, T, List).
 96
 97%% @spec to_list(headers()) -> [{key(), string()}]
 98%% @doc Return the contents of the headers. The keys will be the exact key
 99%%      that was first inserted (e.g. may be an atom or binary, case is
100%%      preserved).
101to_list(T) ->
102    F = fun ({K, {array, L}}, Acc) ->
103                L1 = lists:reverse(L),
104                lists:foldl(fun (V, Acc1) -> [{K, V} | Acc1] end, Acc, L1);
105            (Pair, Acc) ->
106                [Pair | Acc]
107        end,
108    lists:reverse(lists:foldl(F, [], gb_trees:values(T))).
109
110%% @spec get_value(key(), headers()) -> string() | undefined
111%% @doc Return the value of the given header using a case insensitive search.
112%%      undefined will be returned for keys that are not present.
113get_value(K, T) ->
114    case lookup(K, T) of
115        {value, {_, V}} ->
116            expand(V);
117        none ->
118            undefined
119    end.
120
121%% @spec get_primary_value(key(), headers()) -> string() | undefined
122%% @doc Return the value of the given header up to the first semicolon using
123%%      a case insensitive search. undefined will be returned for keys
124%%      that are not present.
125get_primary_value(K, T) ->
126    case get_value(K, T) of
127        undefined ->
128            undefined;
129        V ->
130            lists:takewhile(fun (C) -> C =/= $; end, V)
131    end.
132
133%% @spec get_combined_value(key(), headers()) -> string() | undefined
134%% @doc Return the value from the given header using a case insensitive search.
135%%      If the value of the header is a comma-separated list where holds values
136%%      are all identical, the identical value will be returned.
137%%      undefined will be returned for keys that are not present or the
138%%      values in the list are not the same.
139%%
140%%      NOTE: The process isn't designed for a general purpose. If you need
141%%            to access all values in the combined header, please refer to
142%%            '''tokenize_header_value/1'''.
143%%
144%%      Section 4.2 of the RFC 2616 (HTTP 1.1) describes multiple message-header
145%%      fields with the same field-name may be present in a message if and only
146%%      if the entire field-value for that header field is defined as a
147%%      comma-separated list [i.e., #(values)].
148get_combined_value(K, T) ->
149    case get_value(K, T) of
150        undefined ->
151            undefined;
152        V ->
153            case sets:to_list(sets:from_list(tokenize_header_value(V))) of
154                [Val] ->
155                    Val;
156                _ ->
157                    undefined
158            end
159    end.
160
161%% @spec lookup(key(), headers()) -> {value, {key(), string()}} | none
162%% @doc Return the case preserved key and value for the given header using
163%%      a case insensitive search. none will be returned for keys that are
164%%      not present.
165lookup(K, T) ->
166    case gb_trees:lookup(normalize(K), T) of
167        {value, {K0, V}} ->
168            {value, {K0, expand(V)}};
169        none ->
170            none
171    end.
172
173%% @spec default(key(), value(), headers()) -> headers()
174%% @doc Insert the pair into the headers if it does not already exist.
175default(K, V, T) ->
176    K1 = normalize(K),
177    V1 = any_to_list(V),
178    try gb_trees:insert(K1, {K, V1}, T)
179    catch
180        error:{key_exists, _} ->
181            T
182    end.
183
184%% @spec enter(key(), value(), headers()) -> headers()
185%% @doc Insert the pair into the headers, replacing any pre-existing key.
186enter(K, V, T) ->
187    K1 = normalize(K),
188    V1 = any_to_list(V),
189    gb_trees:enter(K1, {K, V1}, T).
190
191%% @spec insert(key(), value(), headers()) -> headers()
192%% @doc Insert the pair into the headers, merging with any pre-existing key.
193%%      A merge is done with Value = V0 ++ ", " ++ V1.
194insert(K, V, T) ->
195    K1 = normalize(K),
196    V1 = any_to_list(V),
197    try gb_trees:insert(K1, {K, V1}, T)
198    catch
199        error:{key_exists, _} ->
200            {K0, V0} = gb_trees:get(K1, T),
201            V2 = merge(K1, V1, V0),
202            gb_trees:update(K1, {K0, V2}, T)
203    end.
204
205%% @spec delete_any(key(), headers()) -> headers()
206%% @doc Delete the header corresponding to key if it is present.
207delete_any(K, T) ->
208    K1 = normalize(K),
209    gb_trees:delete_any(K1, T).
210
211%% Internal API
212
213tokenize_header_value(undefined) ->
214    undefined;
215tokenize_header_value(V) ->
216    reversed_tokens(trim_and_reverse(V, false), [], []).
217
218trim_and_reverse([S | Rest], Reversed) when S=:=$ ; S=:=$\n; S=:=$\t ->
219    trim_and_reverse(Rest, Reversed);
220trim_and_reverse(V, false) ->
221    trim_and_reverse(lists:reverse(V), true);
222trim_and_reverse(V, true) ->
223    V.
224
225reversed_tokens([], [], Acc) ->
226    Acc;
227reversed_tokens([], Token, Acc) ->
228    [Token | Acc];
229reversed_tokens("\"" ++ Rest, [], Acc) ->
230    case extract_quoted_string(Rest, []) of
231        {String, NewRest} ->
232            reversed_tokens(NewRest, [], [String | Acc]);
233        undefined ->
234            undefined
235    end;
236reversed_tokens("\"" ++ _Rest, _Token, _Acc) ->
237    undefined;
238reversed_tokens([C | Rest], [], Acc) when C=:=$ ;C=:=$\n;C=:=$\t;C=:=$, ->
239    reversed_tokens(Rest, [], Acc);
240reversed_tokens([C | Rest], Token, Acc) when C=:=$ ;C=:=$\n;C=:=$\t;C=:=$, ->
241    reversed_tokens(Rest, [], [Token | Acc]);
242reversed_tokens([C | Rest], Token, Acc) ->
243    reversed_tokens(Rest, [C | Token], Acc);
244reversed_tokens(_, _, _) ->
245    undefeined.
246
247extract_quoted_string([], _Acc) ->
248    undefined;
249extract_quoted_string("\"\\" ++ Rest, Acc) ->
250    extract_quoted_string(Rest, "\"" ++ Acc);
251extract_quoted_string("\"" ++ Rest, Acc) ->
252    {Acc, Rest};
253extract_quoted_string([C | Rest], Acc) ->
254    extract_quoted_string(Rest, [C | Acc]).
255
256expand({array, L}) ->
257    mochiweb_util:join(lists:reverse(L), ", ");
258expand(V) ->
259    V.
260
261merge("set-cookie", V1, {array, L}) ->
262    {array, [V1 | L]};
263merge("set-cookie", V1, V0) ->
264    {array, [V1, V0]};
265merge(_, V1, V0) ->
266    V0 ++ ", " ++ V1.
267
268normalize(K) when is_list(K) ->
269    string:to_lower(K);
270normalize(K) when is_atom(K) ->
271    normalize(atom_to_list(K));
272normalize(K) when is_binary(K) ->
273    normalize(binary_to_list(K)).
274
275any_to_list(V) when is_list(V) ->
276    V;
277any_to_list(V) when is_atom(V) ->
278    atom_to_list(V);
279any_to_list(V) when is_binary(V) ->
280    binary_to_list(V);
281any_to_list(V) when is_integer(V) ->
282    integer_to_list(V).
283
284%%
285%% Tests.
286%%
287-ifdef(TEST).
288-include_lib("eunit/include/eunit.hrl").
289
290make_test() ->
291    Identity = make([{hdr, foo}]),
292    ?assertEqual(
293       Identity,
294       make(Identity)).
295
296enter_from_list_test() ->
297    H = make([{hdr, foo}]),
298    ?assertEqual(
299       [{baz, "wibble"}, {hdr, "foo"}],
300       to_list(enter_from_list([{baz, wibble}], H))),
301    ?assertEqual(
302       [{hdr, "bar"}],
303       to_list(enter_from_list([{hdr, bar}], H))),
304    ok.
305
306default_from_list_test() ->
307    H = make([{hdr, foo}]),
308    ?assertEqual(
309       [{baz, "wibble"}, {hdr, "foo"}],
310       to_list(default_from_list([{baz, wibble}], H))),
311    ?assertEqual(
312       [{hdr, "foo"}],
313       to_list(default_from_list([{hdr, bar}], H))),
314    ok.
315
316get_primary_value_test() ->
317    H = make([{hdr, foo}, {baz, <<"wibble;taco">>}]),
318    ?assertEqual(
319       "foo",
320       get_primary_value(hdr, H)),
321    ?assertEqual(
322       undefined,
323       get_primary_value(bar, H)),
324    ?assertEqual(
325       "wibble",
326       get_primary_value(<<"baz">>, H)),
327    ok.
328
329get_combined_value_test() ->
330    H = make([{hdr, foo}, {baz, <<"wibble,taco">>}, {content_length, "123, 123"},
331              {test, " 123,  123,     123  , 123,123 "},
332              {test2, "456,  123,     123  , 123"},
333              {test3, "123"}, {test4, " 123, "}]),
334    ?assertEqual(
335       "foo",
336       get_combined_value(hdr, H)),
337    ?assertEqual(
338       undefined,
339       get_combined_value(bar, H)),
340    ?assertEqual(
341       undefined,
342       get_combined_value(<<"baz">>, H)),
343    ?assertEqual(
344       "123",
345       get_combined_value(<<"content_length">>, H)),
346    ?assertEqual(
347       "123",
348       get_combined_value(<<"test">>, H)),
349    ?assertEqual(
350       undefined,
351       get_combined_value(<<"test2">>, H)),
352    ?assertEqual(
353       "123",
354       get_combined_value(<<"test3">>, H)),
355    ?assertEqual(
356       "123",
357       get_combined_value(<<"test4">>, H)),
358    ok.
359
360set_cookie_test() ->
361    H = make([{"set-cookie", foo}, {"set-cookie", bar}, {"set-cookie", baz}]),
362    ?assertEqual(
363       [{"set-cookie", "foo"}, {"set-cookie", "bar"}, {"set-cookie", "baz"}],
364       to_list(H)),
365    ok.
366
367headers_test() ->
368    H = ?MODULE:make([{hdr, foo}, {"Hdr", "bar"}, {'Hdr', 2}]),
369    [{hdr, "foo, bar, 2"}] = ?MODULE:to_list(H),
370    H1 = ?MODULE:insert(taco, grande, H),
371    [{hdr, "foo, bar, 2"}, {taco, "grande"}] = ?MODULE:to_list(H1),
372    H2 = ?MODULE:make([{"Set-Cookie", "foo"}]),
373    [{"Set-Cookie", "foo"}] = ?MODULE:to_list(H2),
374    H3 = ?MODULE:insert("Set-Cookie", "bar", H2),
375    [{"Set-Cookie", "foo"}, {"Set-Cookie", "bar"}] = ?MODULE:to_list(H3),
376    "foo, bar" = ?MODULE:get_value("set-cookie", H3),
377    {value, {"Set-Cookie", "foo, bar"}} = ?MODULE:lookup("set-cookie", H3),
378    undefined = ?MODULE:get_value("shibby", H3),
379    none = ?MODULE:lookup("shibby", H3),
380    H4 = ?MODULE:insert("content-type",
381                        "application/x-www-form-urlencoded; charset=utf8",
382                        H3),
383    "application/x-www-form-urlencoded" = ?MODULE:get_primary_value(
384                                             "content-type", H4),
385    H4 = ?MODULE:delete_any("nonexistent-header", H4),
386    H3 = ?MODULE:delete_any("content-type", H4),
387    HB = <<"Content-Length: 47\r\nContent-Type: text/plain\r\n\r\n">>,
388    H_HB = ?MODULE:from_binary(HB),
389    H_HB = ?MODULE:from_binary(binary_to_list(HB)),
390    "47" = ?MODULE:get_value("Content-Length", H_HB),
391    "text/plain" = ?MODULE:get_value("Content-Type", H_HB),
392    L_H_HB = ?MODULE:to_list(H_HB),
393    2 = length(L_H_HB),
394    true = lists:member({'Content-Length', "47"}, L_H_HB),
395    true = lists:member({'Content-Type', "text/plain"}, L_H_HB),
396    HL = [ <<"Content-Length: 47\r\n">>, <<"Content-Type: text/plain\r\n">> ],
397    HL2 = [ "Content-Length: 47\r\n", <<"Content-Type: text/plain\r\n">> ],
398    HL3 = [ <<"Content-Length: 47\r\n">>, "Content-Type: text/plain\r\n" ],
399    H_HL = ?MODULE:from_binary(HL),
400    H_HL = ?MODULE:from_binary(HL2),
401    H_HL = ?MODULE:from_binary(HL3),
402    "47" = ?MODULE:get_value("Content-Length", H_HL),
403    "text/plain" = ?MODULE:get_value("Content-Type", H_HL),
404    L_H_HL = ?MODULE:to_list(H_HL),
405    2 = length(L_H_HL),
406    true = lists:member({'Content-Length', "47"}, L_H_HL),
407    true = lists:member({'Content-Type', "text/plain"}, L_H_HL),
408    [] = ?MODULE:to_list(?MODULE:from_binary(<<>>)),
409    [] = ?MODULE:to_list(?MODULE:from_binary(<<"">>)),
410    [] = ?MODULE:to_list(?MODULE:from_binary(<<"\r\n">>)),
411    [] = ?MODULE:to_list(?MODULE:from_binary(<<"\r\n\r\n">>)),
412    [] = ?MODULE:to_list(?MODULE:from_binary("")),
413    [] = ?MODULE:to_list(?MODULE:from_binary([<<>>])),
414    [] = ?MODULE:to_list(?MODULE:from_binary([<<"">>])),
415    [] = ?MODULE:to_list(?MODULE:from_binary([<<"\r\n">>])),
416    [] = ?MODULE:to_list(?MODULE:from_binary([<<"\r\n\r\n">>])),
417    ok.
418
419tokenize_header_value_test() ->
420    ?assertEqual(["a quote in a \"quote\"."],
421                 tokenize_header_value("\"a quote in a \\\"quote\\\".\"")),
422    ?assertEqual(["abc"], tokenize_header_value("abc")),
423    ?assertEqual(["abc", "def"], tokenize_header_value("abc def")),
424    ?assertEqual(["abc", "def"], tokenize_header_value("abc , def")),
425    ?assertEqual(["abc", "def"], tokenize_header_value(",abc ,, def,,")),
426    ?assertEqual(["abc def"], tokenize_header_value("\"abc def\"      ")),
427    ?assertEqual(["abc, def"], tokenize_header_value("\"abc, def\"")),
428    ?assertEqual(["\\a\\$"], tokenize_header_value("\"\\a\\$\"")),
429    ?assertEqual(["abc def", "foo, bar", "12345", ""],
430                 tokenize_header_value("\"abc def\" \"foo, bar\" , 12345, \"\"")),
431    ?assertEqual(undefined,
432                 tokenize_header_value(undefined)),
433    ?assertEqual(undefined,
434                 tokenize_header_value("umatched quote\"")),
435    ?assertEqual(undefined,
436                 tokenize_header_value("\"unmatched quote")).
437
438-endif.