/src/server_gateways/ewgi_mochiweb.erl
Erlang | 421 lines | 300 code | 56 blank | 65 comment | 0 complexity | 4dcd6d9b4ba1849b2bb0a158d2b97c65 MD5 | raw file
1%%%------------------------------------------------------------------- 2%%% File : ewgi_mochiweb.erl 3%%% Authors : Filippo Pacini <filippo.pacini@gmail.com> 4%%% Hunter Morris <huntermorris@gmail.com> 5%%% License : 6%%% The contents of this file are subject to the Mozilla Public 7%%% License Version 1.1 (the "License"); you may not use this file 8%%% except in compliance with the License. You may obtain a copy of 9%%% the License at http://www.mozilla.org/MPL/ 10%%% 11%%% Software distributed under the License is distributed on an "AS IS" 12%%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See 13%%% the License for the specific language governing rights and 14%%% limitations under the License. 15%%% The Initial Developer of the Original Code is S.G. Consulting 16%%% srl. Portions created by S.G. Consulting s.r.l. are Copyright (C) 17%%% 2007 S.G. Consulting srl. All Rights Reserved. 18%%% 19%%% @doc 20%%% <p>Reference implementation of a MochiWeb EWGI server gateway.</p> 21%%% 22%%% @end 23%%% 24%%% Created : 12 Oct 2007 by Filippo Pacini <filippo.pacini@gmail.com> 25%%%------------------------------------------------------------------- 26-module(ewgi_mochiweb). 27 28%% ewgi callbacks 29-export([run/2]). 30-export([ 31 stream_process_deliver/2, 32 stream_process_deliver_chunk/2, 33 stream_process_deliver_final_chunk/2, 34 stream_process_end/2 35 ]). 36 37-include_lib("ewgi.hrl"). 38 39-define(EWGI2MOCHI(Err, Hdrs), {element(1, Err), Hdrs, element(2, Err)}). 40 41%%==================================================================== 42%% ewgi_server callbacks 43%%==================================================================== 44run(Appl, MochiReq) -> 45 try parse_arg(MochiReq) of 46 Req when ?IS_EWGI_REQUEST(Req) -> 47 try process_application(Appl, ewgi_api:context(Req, ewgi_api:empty_response())) of 48 not_found -> 49 MochiReq:not_found(); 50 Ctx when ?IS_EWGI_CONTEXT(Ctx) -> 51 handle_result(?INSPECT_EWGI_RESPONSE(Ctx), MochiReq) 52 catch 53 _:Reason -> 54 error_logger:error_report(Reason), 55 MochiReq:respond({500, [], "Internal server error"}) 56 end 57 catch 58 _:Reason -> 59 error_logger:error_report(Reason), 60 MochiReq:respond({400, [], "Bad request"}) 61 end. 62 63%% Chunked response if a nullary function is returned 64handle_result(Ctx, Req) -> 65 case ewgi_api:response_message_body(Ctx) of 66 {push_stream, GeneratorPid, Timeout} when is_pid(GeneratorPid) -> 67 handle_push_stream(Ctx, Req, GeneratorPid, Timeout); 68 Body -> 69 {Code, _} = ewgi_api:response_status(Ctx), 70 Headers = ewgi_api:response_headers(Ctx), 71 handle_result1(Code, Headers, Body, Req) 72 end. 73 74handle_result1(Code, Headers, F, Req) when is_function(F, 0) -> 75 MochiResp = Req:respond({Code, Headers, chunked}), 76 %handle_stream_result(MochiResp, (catch F())); 77 handle_stream(MochiResp, F); 78handle_result1(Code, Headers, L, Req) -> 79 Req:respond({Code, Headers, L}). 80 81handle_push_stream(Ctx, Req, GeneratorPid, Timeout) -> 82 Socket = Req:get(socket), 83 GeneratorPid ! {push_stream_init, ?MODULE, self(), Socket}, 84 receive 85 {push_stream_init, GeneratorPid, Code, Headers, TransferEncoding} -> 86 case TransferEncoding of 87 chunked -> 88 Req:respond({Code, Headers, chunked}), 89 GeneratorPid ! {ok, self()} 90 ;_ -> 91 %% mochiweb_request:respond/1 expects the full body in order to 92 %% count the content-length but we already have that. What we're 93 %% missing is the [to-be-sent] body. 94 HResponse = mochiweb_headers:make(Headers), 95 Req:start_response({Code, HResponse}), 96 %% WARNING: we're depending on the original ewgi_context here!!!! 97 case ewgi_api:request_method(Ctx) of 98 'HEAD' -> 99 GeneratorPid ! {discard, self()}; 100 _ -> 101 GeneratorPid ! {ok, self()} 102 end 103 end, 104 wait_for_streamcontent_pid(Socket, GeneratorPid) 105 after Timeout -> 106 Req:respond({504, [], <<"Gateway Timeout">>}) 107 end. 108 109%% Treat a stream with chunked transfer encoding 110handle_stream(R, Generator) when is_function(Generator, 0) -> 111 case (catch Generator()) of 112 {H, T} when is_function(T, 0) -> 113 %% Prevent finishing the chunked response 114 case H of 115 <<>> -> ok; 116 [] -> ok; 117 _ -> 118 R:write_chunk(H) 119 end, 120 handle_stream(R, T); 121 {} -> 122 R:write_chunk([]); 123 Error -> 124 error_logger:error_report(io_lib:format("Unexpected stream ouput (~p): ~p~n", [Generator, Error])), 125 R:write_chunk([]) 126 end; 127handle_stream(R, Generator) -> 128 error_logger:error_report(io_lib:format("Invalid stream generator: ~p~n", [Generator])), 129 R:write_chunk([]). 130 131%% Copied/adapted from yaws_server 132wait_for_streamcontent_pid(CliSock, ContentPid) -> 133 Ref = erlang:monitor(process, ContentPid), 134 gen_tcp:controlling_process(CliSock, ContentPid), 135 ContentPid ! {ok, self()}, 136 receive 137 endofstreamcontent -> 138 ok = gen_tcp:close(CliSock), 139 erlang:demonitor(Ref), 140 %% should just use demonitor [flush] option instead? 141 receive 142 {'DOWN', Ref, _, _, _} -> 143 ok 144 after 0 -> 145 ok 146 end; 147 {'DOWN', Ref, _, _, _} -> 148 ok 149 end, 150 done. 151 152%%-------------------------------------------------------------------- 153%% Push Streams API - copied from yaws_api 154%% We could use mochiweb's write_chunk function but that 155%% would require that we copy MochiResp around instead of 156%% just copying the socket. 157%%-------------------------------------------------------------------- 158 159%% This won't work for SSL for now 160stream_process_deliver(Sock, IoList) -> 161 gen_tcp:send(Sock, IoList). 162 163%% This won't work for SSL for now either 164stream_process_deliver_chunk(Sock, IoList) -> 165 Chunk = case erlang:iolist_size(IoList) of 166 0 -> 167 stream_process_deliver_final_chunk(Sock, IoList); 168 S -> 169 [mochihex:to_hex(S), "\r\n", IoList, "\r\n"] 170 end, 171 gen_tcp:send(Sock, Chunk). 172stream_process_deliver_final_chunk(Sock, IoList) -> 173 Chunk = case erlang:iolist_size(IoList) of 174 0 -> 175 <<"0\r\n\r\n">>; 176 S -> 177 [mochihex:to_hex(S), "\r\n", IoList, "\r\n0\r\n\r\n"] 178 end, 179 gen_tcp:send(Sock, Chunk). 180 181stream_process_end(Sock, ServerPid) -> 182 gen_tcp:controlling_process(Sock, ServerPid), 183 ServerPid ! endofstreamcontent. 184 185%%-------------------------------------------------------------------- 186 187process_application(Appl, Ctx) when is_list(Appl) -> 188 Path = ewgi_api:path_info(Ctx), 189 process_mount_application(Ctx, Path, find_mount(Appl, Path)); 190process_application(Appl, Ctx) -> 191 ewgi_application:run(Appl, Ctx). 192 193process_mount_application(_, _, {not_found, _}) -> 194 not_found; 195process_mount_application(Ctx0, Path0, {MountPoint, Application}) -> 196 Path = case Path0 of 197 "*" -> "*"; 198 _ -> string:substr(Path0, length(MountPoint) + 1) 199 end, 200 Ctx = ewgi_api:path_info(Path, ewgi_api:script_name(MountPoint, Ctx0)), 201 ewgi_application:run(Application, Ctx). 202 203find_mount([], _) -> 204 {not_found, fun (_, _) -> not_found end}; 205find_mount(Mounts, "*") -> 206 lists:last(Mounts); 207find_mount([{Path, _}=M|_], Path) -> 208 M; 209find_mount([{Point, _}=M|T], Path) -> 210 case string:str(Path, Point ++ "/") of 211 1 -> 212 M; 213 _ -> 214 find_mount(T, Path) 215 end. 216 217%%-------------------------------------------------------------------- 218%%% Internal functions 219%%-------------------------------------------------------------------- 220 221parse_arg(Req) -> 222 ewgi_api:server_request_foldl(Req, fun parse_element/2, fun parse_ewgi_element/2, fun parse_http_header_element/2). 223 224parse_element(auth_type, _Req) -> 225 undefined; 226 227parse_element(content_length, Req) -> 228 case Req:get_header_value("content-length") of 229 undefined -> undefined; 230 Length when is_integer(Length) -> 231 Length; 232 Length when is_list(Length) -> 233 list_to_integer(Length) 234 end; 235 236parse_element(content_type, Req) -> 237 Req:get_header_value("content-type"); 238 239parse_element(gateway_interface, _Req) -> 240 "EWGI/1.0"; 241 242parse_element(path_info, Req) -> 243 RawPath = Req:get(raw_path), 244 case RawPath of 245 RawPath when RawPath =:= '*' -> 246 "*"; 247 RawPath -> 248 {_, _, Path, _, _} = mochiweb_util:urlsplit(RawPath), 249 ewgi_api:unquote_path(Path) 250 end; 251 252%% Used to be: 253%% filename:dirname(filename:dirname(code:which(Appl)))++Req:get(path); The 254%% problem here is that the application only has a function which acts as the 255%% entry point to the application. 256parse_element(path_translated, _Req) -> 257 undefined; 258 259parse_element(query_string, Req) -> 260 RawPath = Req:get(raw_path), 261 case RawPath of 262 RawPath when RawPath =:= '*' -> 263 undefined; 264 RawPath -> 265 {_, _, _, QueryString, _} = mochiweb_util:urlsplit(RawPath), 266 QueryString 267 end; 268 269parse_element(remote_addr, Req) -> 270 Req:get(peer); 271 272parse_element(remote_host, _Req) -> 273 undefined; 274 275parse_element(remote_ident, _Req) -> 276 undefined; 277 278parse_element(remote_user, _Req) -> 279 undefined; 280 281parse_element(request_method, Req) -> 282 Req:get(method); 283 284%% Default value is empty string. If mount points are used, SCRIPT_NAME 285%% becomes the mount point. 286parse_element(script_name, _Req) -> 287 []; 288 289parse_element(server_name, Req) -> 290 HostPort = Req:get_header_value(host), 291 case HostPort of 292 HostPort when is_list(HostPort) -> 293 hd(string:tokens(HostPort, ":")); 294 HostPort -> HostPort 295 end; 296 297parse_element(server_port, Req) -> 298 HostPort0 = Req:get_header_value(host), 299 case HostPort0 of 300 HostPort0 when is_list(HostPort0) -> 301 HostPort = string:tokens(HostPort0, ":"), 302 case length(HostPort) of 303 2 -> lists:nth(2, HostPort); 304 _ -> undefined 305 end; 306 _ -> 307 undefined 308 end; 309 310parse_element(server_protocol, Req) -> 311 {Maj, Min} = Req:get(version), 312 lists:flatten(io_lib:format("HTTP/~b.~b", [Maj, Min])); 313 314parse_element(server_software, _Req) -> 315 "MochiWeb"; 316 317%% All other elements are undefined 318parse_element(_, _) -> 319 undefined. 320 321parse_ewgi_element(read_input, Req) -> 322 F = fun(Callback, Length) -> 323 case Req:get_header_value("expect") of 324 "100-continue" -> 325 Req:start_raw_response({100, gb_trees:empty()}); 326 _Else -> 327 ok 328 end, 329 read_input(Callback, Length, Req) 330 end, 331 F; 332 333parse_ewgi_element(write_error, Req) -> 334 F = fun(Msg) -> 335 write_error(Msg, Req) 336 end, 337 F; 338 339%% https? 340parse_ewgi_element(url_scheme, _Req) -> 341 "http"; 342 343parse_ewgi_element(version, _Req) -> 344 {1, 0}; 345 346parse_ewgi_element(data, _Req) -> 347 gb_trees:empty(); 348 349%% Ignore others 350parse_ewgi_element(_, _) -> 351 undefined. 352 353parse_http_header_element(http_accept, Req) -> 354 Req:get_header_value("accept"); 355 356parse_http_header_element(http_cookie, Req) -> 357 Req:get_header_value("cookie"); 358 359parse_http_header_element(http_host, Req) -> 360 Req:get_header_value("host"); 361 362parse_http_header_element(http_if_modified_since, Req) -> 363 Req:get_header_value("if-modified-since"); 364 365parse_http_header_element(http_user_agent, Req) -> 366 Req:get_header_value("user-agent"); 367 368parse_http_header_element(http_x_http_method_override, Req) -> 369 Req:get_header_value("x-http-method-override"); 370 371parse_http_header_element(other, Req) -> 372 lists:foldl(fun({K0, _}=Pair, Acc) -> 373 {K, V} = ewgi_api:normalize_header(Pair), 374 case K of 375 K when K =:= "content-length" 376 ; K =:= "content-type" 377 ; K =:= "accept" 378 ; K =:= "cookie" 379 ; K =:= "host" 380 ; K =:= "if-modified-since" 381 ; K =:= "user-agent" 382 ; K =:= "x-http-method-override" -> 383 Acc; 384 _ -> 385 Ex = case gb_trees:lookup(K, Acc) of 386 {value, L} -> 387 L; 388 none -> 389 [] 390 end, 391 gb_trees:insert(K, [{K0, V}|Ex], Acc) 392 end 393 end, gb_trees:empty(), mochiweb_headers:to_list(Req:get(headers))); 394 395parse_http_header_element(_, _) -> 396 undefined. 397 398%% No chunk size specified, so use default 399read_input(Callback, Length, Req) when is_integer(Length) -> 400 read_input(Callback, {Length, ?DEFAULT_CHUNKSIZE}, Req); 401 402%% Final callback after entire input has been read 403read_input(Callback, {Length, _ChunkSz}, _Req) when is_function(Callback), Length =< 0 -> 404 Callback(eof); 405 406%% Continue reading and calling back with each chunk of data 407read_input(Callback, {Length, ChunkSz}, Req) when is_function(Callback) -> 408 Bin = recv_input(Req, Length, ChunkSz), 409 Rem = Length - size(Bin), 410 NewCallback = Callback({data, Bin}), 411 read_input(NewCallback, {Rem, ChunkSz}, Req). 412 413%% Read either Length bytes or ChunkSz, whichever is smaller 414recv_input(Req, Length, ChunkSz) when Length > 0, Length < ChunkSz -> 415 Req:recv(Length); 416recv_input(Req, _, ChunkSz) -> 417 Req:recv(ChunkSz). 418 419%% Write errors to error_logger 420write_error(Msg, Req) -> 421 error_logger:error_report([{message, Msg}, {request, Req}]).