diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/cowboy_http_rest.erl | 31 | ||||
| -rw-r--r-- | src/cowboy_http_static.erl | 34 |
2 files changed, 37 insertions, 28 deletions
diff --git a/src/cowboy_http_rest.erl b/src/cowboy_http_rest.erl index ee67b36..8bce1d4 100644 --- a/src/cowboy_http_rest.erl +++ b/src/cowboy_http_rest.erl @@ -41,7 +41,7 @@ charset_a :: undefined | binary(), %% Cached resource calls. - etag :: undefined | no_call | binary(), + etag :: undefined | no_call | {strong | weak, binary()}, last_modified :: undefined | no_call | calendar:datetime(), expires :: undefined | no_call | calendar:datetime() }). @@ -487,14 +487,10 @@ if_match_exists(Req, State) -> if_match(Req, State, EtagsList) -> {Etag, Req2, State2} = generate_etag(Req, State), - case Etag of - no_call -> - precondition_failed(Req2, State2); - Etag -> - case lists:member(Etag, EtagsList) of - true -> if_unmodified_since_exists(Req2, State2); - false -> precondition_failed(Req2, State2) - end + case lists:member(Etag, EtagsList) of + true -> if_unmodified_since_exists(Req2, State2); + %% Etag may be `undefined' which cannot be a member. + false -> precondition_failed(Req2, State2) end. if_match_musnt_exist(Req, State) -> @@ -534,7 +530,7 @@ if_none_match_exists(Req, State) -> if_none_match(Req, State, EtagsList) -> {Etag, Req2, State2} = generate_etag(Req, State), case Etag of - no_call -> + undefined -> precondition_failed(Req2, State2); Etag -> case lists:member(Etag, EtagsList) of @@ -810,10 +806,14 @@ set_resp_etag(Req, State) -> {Req2, State2}; Etag -> {ok, Req3} = cowboy_http_req:set_resp_header( - <<"Etag">>, Etag, Req2), + <<"ETag">>, encode_etag(Etag), Req2), {Req3, State2} end. +-spec encode_etag({strong | weak, binary()}) -> iolist(). +encode_etag({strong, Etag}) -> [$",Etag,$"]; +encode_etag({weak, Etag}) -> ["W/\"",Etag,$"]. + set_resp_expires(Req, State) -> {Expires, Req2, State2} = expires(Req, State), case Expires of @@ -834,6 +834,15 @@ generate_etag(Req, State=#state{etag=undefined}) -> case call(Req, State, generate_etag) of no_call -> {undefined, Req, State#state{etag=no_call}}; + %% Previously the return value from the generate_etag/2 callback was set + %% as the value of the ETag header in the response. Therefore the only + %% valid return type was `binary()'. If a handler returns a `binary()' + %% it must be mapped to the expected type or it'll always fail to + %% compare equal to any entity tags present in the request headers. + %% @todo Remove support for binary return values after 0.6. + {Etag, Req2, HandlerState} when is_binary(Etag) -> + [Etag2] = cowboy_http:entity_tag_match(Etag), + {Etag2, Req2, State#state{handler_state=HandlerState, etag=Etag2}}; {Etag, Req2, HandlerState} -> {Etag, Req2, State#state{handler_state=HandlerState, etag=Etag}} end; diff --git a/src/cowboy_http_static.erl b/src/cowboy_http_static.erl index 0ee996a..007cd16 100644 --- a/src/cowboy_http_static.erl +++ b/src/cowboy_http_static.erl @@ -96,15 +96,16 @@ %% %% The default behaviour can be overridden to generate an ETag header based on %% a combination of the file path, file size, inode and mtime values. If the -%% option value is a list of attribute names tagged with `attributes' a hex -%% encoded CRC32 checksum of the attribute values are used as the ETag header -%% value. +%% option value is a non-empty list of attribute names tagged with `attributes' +%% a hex encoded checksum of each attribute specified is included in the value +%% of the the ETag header. If the list of attribute names is empty no ETag +%% header is generated. %% %% If a strong ETag is required a user defined function for generating the %% header value can be supplied. The function must accept a proplist of the %% file attributes as the first argument and a second argument containing any -%% additional data that the function requires. The function must return a -%% `binary()' or `undefined'. +%% additional data that the function requires. The function must return a term +%% of the type `{weak | strong, binary()}' or `undefined'. %% %% ==== Examples ==== %% ``` @@ -130,7 +131,7 @@ %% {_, _Modified} = lists:keyfind(mtime, 1, Arguments), %% ChecksumCommand = lists:flatten(io_lib:format("sha1sum ~s", [Filepath])), %% [Checksum|_] = string:tokens(os:cmd(ChecksumCommand), " "), -%% iolist_to_binary(Checksum). +%% {strong, iolist_to_binary(Checksum)}. %% ''' -module(cowboy_http_static). @@ -161,7 +162,8 @@ filepath :: binary() | error, fileinfo :: {ok, #file_info{}} | {error, _} | error, mimetypes :: {fun((binary(), T) -> [mimedef()]), T} | undefined, - etag_fun :: {fun(([etagarg()], T) -> undefined | binary()), T}}). + etag_fun :: {fun(([etagarg()], T) -> + undefined | {strong | weak, binary()}), T}}). %% @private Upgrade from HTTP handler to REST handler. @@ -183,8 +185,9 @@ rest_init(Req, Opts) -> ETagFunction = case proplists:get_value(etag, Opts) of default -> {fun no_etag_function/2, undefined}; undefined -> {fun no_etag_function/2, undefined}; + {attributes, []} -> {fun no_etag_function/2, undefined}; {attributes, Attrs} -> {fun attr_etag_function/2, Attrs}; - {_, _}=EtagFunction1 -> EtagFunction1 + {_, _}=ETagFunction1 -> ETagFunction1 end, {Filepath, Req1} = cowboy_http_req:path_info(Req), State = case check_path(Filepath) of @@ -411,16 +414,13 @@ no_etag_function(_Args, undefined) -> %% @private A simple alternative is to send an ETag based on file attributes. -type fileattr() :: filepath | filesize | mtime | inode. --spec attr_etag_function([etagarg()], [fileattr()]) -> binary(). +-spec attr_etag_function([etagarg()], [fileattr()]) -> {strong, binary()}. attr_etag_function(Args, Attrs) -> - attr_etag_function(Args, Attrs, []). - --spec attr_etag_function([etagarg()], [fileattr()], [binary()]) -> binary(). -attr_etag_function(_Args, [], Acc) -> - list_to_binary(integer_to_list(erlang:crc32(Acc), 16)); -attr_etag_function(Args, [H|T], Acc) -> - {_, Value} = lists:keyfind(H, 1, Args), - attr_etag_function(Args, T, [term_to_binary(Value)|Acc]). + [[_|H]|T] = [begin + {_,Pair} = {_,{_,_}} = {Attr,lists:keyfind(Attr, 1, Args)}, + [$-|integer_to_list(erlang:phash2(Pair, 1 bsl 32), 16)] + end || Attr <- Attrs], + {strong, list_to_binary([H|T])}. -ifdef(TEST). |